Understanding the relationship between earthquake rupture dynamics and fault structure is fundamental to earthquake physics. The 2025 Mw7.8 Myanmar earthquake is a valuable case to advance this understanding. Here we show that the Mw7.8 Myanmar earthquake produced the longest inland rupture of near 500 km along the Sagaing fault passing through the seismic gap between Mandalay and Naypyidaw,...
This keynote is devoted to the strongest Kamchatka earthquake since 1952 (July 29, 2025, Mw = 8.8). This earthquake ranks among the top ten strongest events of the instrumental era. Preliminary results from processing regional data recorded by the Kamchatka Regional Seismological Observation System are presented. The seismic history of the region, tectonic setting, aftershock process,...
The influence of anisotropic wind velocity and temperature inhomogeneities on the attenuation of infrasound field intensity with increasing distance from a point source and its altitude distribution is studied. The field is calculated as a function of receiver height and horizontal distance from the source using method of the pseudo-differential parabolic equation for the atmosphere with model...
Pisces (https://lanl-seismoacoustics.github.io/pisces/) is a python-based data management library designed to facilitate interaction with seismological databases utilizing CSS3.0-like schemas. Pisces leverages existing free and open source technologies maintained by the wider seismological community to incorporate information from these databases into python workflows. Recent additions to...
This paper explores how gamification can enhance youth engagement in CTBT advocacy and verification. By bridging barriers, gamification fosters participation in test ban monitoring at the intersection of technology, policy and advocacy. CTBTO’s mission depends on global awareness, technical expertise and diplomatic engagement — yet youth involvement remains limited due to technical complexity...
Radionuclides from underground nuclear explosions can migrate through soil and rock, eventually reaching the surface and entering the atmosphere. Once airborne, they can be carried by winds to detectors located downwind. The detectability of these radionuclides is affected by the geographical and geological features of the test site, particularly in remote areas with complex terrain, which can...
Global seismic monitoring allows for robust real-time analysis to provide useful information about seismic events to assist in earthquake emergency response and for international monitoring efforts of underground nuclear explosions (UNE) and nuisance events. Seismic explosion data is limited but is useful ground truth information for characterization studies and has been shown to be useful...
Early stage identification of seismic station equipment problems can save unnecessary maintenance on healthy equipment, while prompting necessary maintenance on equipment at risk of failure. Performing maintenance before equipment fails can ensure data quality and avoid outages. In a previous study, we proposed an unsupervised deep autoencoder model to detect ambient data anomalies, indicating...
Understanding the structure and dynamics of the Earth’s inner core is the key to understanding the history and evolution of the Earth’s magnetic field. However, knowledge about the inner core remains limited. Fine-scale (1–10 km) structures within the inner core scatter high-frequency seismic waves (ICS), providing critical insights, although detecting these signals is challenging. Using the...
During any on-site inspection programme of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), field geophysics applications used after results from the initial inspection period indicate the need for further investigation. Ground Penetration Radar, resonance seismometry, active seismic survey, electrical resistivity surveys, gravitational and magnetic mapping are the main geophysical methods...
This research aims to create realistic earthquake scenarios for the expected Main Marmara Fault Earthquake and develop Peak Ground Velocity (PGV) maps using physics-based approaches to protect ~20 million inhabitants in the Istanbul Metropolitan and its surroundings. In this study, a new 3-D dynamic simulation scenario for the expected M≥7.0 earthquake in the Sea of Marmara, incorporates...
Focal depth is a critical parameter in earthquake monitoring, offering insights into seismic processes and tectonic behavior. This study employs the Depth Scanning Algorithm (DSA) to determine the focal depths of 3388 seismic events recorded between 19 December 2022 and 26 August 2024, in the Mogod fault area, Mongolia. As part of an international collaboration with KIGAM, 10 temporary seismic...
Earthquake source parameters are valuable for seismology, including monitoring the Comprehensive Nuclear-Test-Ban Treaty. One needs to determine the hypocentre location, seismic moment, radiated energy, event size, and released stress drop. A stress-strain pattern of the crust is inferred from a statistical analysis of focal mechanisms. It provides information on geometry and kinematics of...
This study aims to identify the variety of NORM (Naturally Occurring Radioactive Material) radionuclides in the Nuclear Energy Research Organization, National Research and Innovation Agency, Pasar Jumat, South Jakarta, Indonesia, along with the concentration levels received by workers and to see the influence of radionuclides from countries outside Indonesia during 2023. Air sampling using the...
Noble gas monitoring systems are used in the International Monitoring System (IMS) for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). They monitor the atmosphere for traces of radioxenon released by clandestine nuclear weapon tests. Radioargon is used as a complementary tracer during on-site inspections to look for underground tests. Efficient collection and purification...
Seismic observation at Syowa Station (69.0°S, 39.6°E; SYO), Antarctica started since 1959 associated with the International Geophysical Year (IGY; 1957-1958) campaign. Since the establishment of the INTELSAT telecommunication link, digital waveform data have been transmitted to the National Institute of Polar Research (NIPR) for the utilization of phase identification more clearly....
The explosive fragmentation of large meteoroids is one of the most significant sources of infrasonic waves. In the absence of atmospheric nuclear tests since 1980, bolide explosions have become key infrasound sources for calibrating and testing the instrument sensitivity of the International Monitoring System (IMS). Moreover, detecting meteoroid explosions with infrasound arrays is crucial for...
The development of equipment for measuring of low levels of argon-37 activity in atmospheric and soil air samples remains a priority task for improving nuclear test monitoring technologies during on-site inspections (OSI), as well as a promising direction for the International Monitoring System (IMS).
In recent years, under a contract with the CTBTO, the Khlopin Radium Institute has been...
The INL Noble Gas Laboratory provides intercomparison samples for the noble gas analysis laboratories as part of the International Monitoring System. Xe-133m is one of the four relevant radionuclides in nuclear explosion monitoring. Without commercially available Xe-133m calibration standards laboratories must create and improve calibration methods. Improvements in calibration methods at the...
This paper presents a detailed analysis of 12 global megatrends — including technological advancements, climate change and sustainability, energy transition, demographic shifts, migration flows, the circular economy, smart cities and urbanization, economic restructuring, cybersecurity threats, health and wellness advancements, changes in consumer behavior, and geopolitical and strategic shifts...
Resonance seismometry (RES) and active seismic surveys (ACT) can be used during a continuation period of a CTBT on-site inspection (OSI). Given the time-restricted nature of an OSI, semi-automated workflows have been developed for quick understanding of the ACT and RES imaging potential, compatible with the standardized georeferenced data outputs of the current ACT equipment operated by the...
In 2011, the Fukushima nuclear disaster was a big accident and the approximate cause is the Tohoku earthquake and tsunami. In the days after the accident, radiation was released into the atmosphere and water, and caesium was detected at IMS particulate stations. Caesium (Cs) is a chemical element in the periodic table with atomic number 55 and 40 known isotopes. This study presents the...
Accurate seismic event detection is crucial for understanding seismic activity and ensuring compliance with the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The National Data Center (NDC) of Israel uses data from local and regional stations, as well as the International Monitoring System (IMS) of the CTBTO. With increasing seismic stations and available data, administrators have...
The aim of this research is to explore seismic activity in the North Sulawesi Indonesia, which lies within the Pacific Ring of Fire and is highly susceptible to significant earthquakes and tsunamis. The study involved calculating and mapping the distribution of b-values and z-values, as well as identifying the recurrence times of earthquake events. The earthquake data used were sourced from...
The northeast monsoon (NEM) is an annual natural phenomenon in Malaysia, typically occurring from October to March. During this period, strong winds driven by two significant surges — the easterly surge and the meridional surge — bring heavy rainfall, often leading to severe flooding that can result in property damage and casualties. This study utilizes eight years of data (2011–2018) from...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT), established to prohibit all nuclear test explosions, stands as a pivotal framework in the global disarmament and non-proliferation regime. However, while the treaty has earned considerable support internationally, this three Signatory Non-Annex 2 States have yet to ratify it, raising questions about the underlying reasons for this delay. In...
In 2024, Cambodia experienced several seismic events, primarily originating from neighboring regions, notably Viet Nam. These earthquakes were felt in various parts of Cambodia, including Ratanakiri province. Notable Earthquakes Near Cambodia in 2024: 28 July 2024: A magnitude 5.1 earthquake occurred near Ratanakiri province. The tremors were felt in the area, marking a significant seismic...
Time-space variations of infrasound source locations for three years, 2019-2021, were studied by using a combination of two local arrays in the Lützow-Holm Bay (LHB), Antarctica. The local arrays deployed at two coastal outcrops detected temporal variations in signal frequency content as well as propagating directions during these years. A large number of infrasound sources were detected with...
The earthquake catalog is a crucial component in seismic hazard assessment. However, it can be affected by non-natural earthquake sources. Hence, this study aims to differentiate between natural and non-natural earthquakes through machine learning techniques. We propose a convolutional neural network based on spectrograms for waveform classification, applied to the contexte of Madagascar. Our...
Electromagnetic signatures from the Low Yield Nuclear Monitoring PE1 Shot A conducted in October 2023 at the Nevada Nuclear Security Site have been analyzed. The data show signals from the hot, expanding plasma in the Earth's natural magnetic field and from seismo-electric mechanisms. However, the polarization signatures of the prompt signal do not match predictions from a simple "magnetic...
The primary method the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO PrepCom) uses in monitoring for underground nuclear explosions is a seismic network of 50 primary stations and 120 auxiliary stations. Currently the primary network's detection capability has been calculated using theoretical methods. But now that a majority of the network has been...
Since 2004, a unique underground geophysical laboratory has been equipped at the Baksan Neutrino Observatory (BNO) at a distance of about 4 km from the mouth of the tunnel. A complex of scientific equipment was installed in the laboratory, which allows continuous studies of fluid activity, deformation processes, weak seismicity, as well as studying temperature anomalies within the Elbrus...
In 2021, PTS presented the first comprehensive draft list of equipment for use during OSI, which is another milestone for the further development of the OSI verification regime. Multispectral imaging plays a vital role for the identification of potential OSI related anomalies and observables like abnormal heat sources, surface disturbances of vegetation and soil. In this work, further study of...
Geothermal energy exploration has been going on in Kenya for the last five decades for green energy exploitation. Between the month of April and August 2024, 20 seismometers were installed throughout the Menengai geothermal field/Caldera and its surrounding at a radius of 15 km using. The stations were installed with IGU-BD3C-5 Smart solo seismometer, a low-frequency, three-component sensor...
Accurate seismic event location is essential not only for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification but also for national data centers in order to advice national governments. Following the 22nd June 2024 M. 4.4 earthquake locating in Kenya we improve the location of CTBTO at 2.228° S and 39.18444° E with Mb 4.1. The event is also reported by the USGS to be located at...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operates five seismic monitoring stations in Indonesia. To ensure the traceability of measurement units for these seismometers, in situ calibration is essential. This study presents a calibration methodology based on the ISO 17025 standard, employing a comparative method where the seismometer to be calibrated is placed side-by-side...
The classification of infrasound signals has important application value in the fields of nuclear test monitoring, earthquake and other natural disaster warning. However, traditional infrasound signals classification methods are difficult to effectively extract the significant features that quantify event differences. To address this issue, this paper proposes an end-to-end infrasound signal...
A series of multi-physics experiments, referred to as Physics Experiment 1 (PE1), is underway at Aqueduct Mesa within the United States’ Nevada National Security Site (NNSS). The PE1 series includes detonation of underground chemical explosions that will provide key observations relevant to source discrimination models and algorithms. An important aspect in understanding the signals generated...
Some strong indications were identified to confirm nuclear research reactors (NRRs) as a possible source of radioxenon emission generated by neutron activation from stable xenon. This source type is of high relevance to nuclear explosion monitoring for two reasons. First, the isotopic activity ratios may be confused with nuclear explosion signals. Second, neutron activation generates other...
During infrasound propagation in the atmosphere, shadow zones can be induced by the temperature and/or wind speed gradients, the ground surface or the source geometry. Although commonly used to simulate the atmospheric infrasound propagation at large scales and three-dimensional domains, acoustic rays method is not able to simulate the propagation where the geometrical approximation is not...
For the most practical cases, the inspection team should be self-sufficient in the inspection area. From the energy requirement perspective, the inspectors need energy for their daily accommodation support. There are different categories of on-site inspection (OSI) equipment, more than 100 tonnes, which need electricity supply for normal functionality. This work provided a photovoltaic energy...
Accurate seismic event location is essential for Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification. This study presents the relocation of a seismic event detected on 22 June 2024, using data from a temporary local network of 20 stations in Nakuru, Kenya, combined with approximately 8 regional stations. The event, initially reported at 2.2896° S, 39.1603° E by IRIS/USGS, varied...
Sensor data from radionuclide systems within the International Monitoring System (IMS) provides critical information about the operating status of a given station. Typically, station operators monitor sensors for significant deviations from normal operation to signify a potential problem and take some action. Detecting subtle changes over long periods of time always presents a challenge, but...
The development of space reactors represents a crucial advancement in exploration, providing sustainable energy for extended missions and emergency scenarios. This study focuses on the radiological impacts of a hypothetical space reactor accident during atmospheric re-entry at an altitude of 70 km, where aerodynamic and thermal stresses increase the risk of structural disintegration and...
Effective emergency preparedness in nuclear accidents requires understanding the observed radionuclide background, which the African continent is rarely studied for this purpose. This has made it necessary to evaluate the regional radiological baseline data that could be used for radiation impact assessment. The study fills this gap by cataloguing and monitoring radionuclides as detected by...
This research explores the application of the YOLOv8 object detection framework for real time earthquake detection using spectrogram images derived from seismic data. The proposed method is a promising candidate for real time event detection, with the potential to improve detection accuracy and reduce the risk of human error. By leveraging the strengths of YOLOv8, known for its speed and...
Base of operations (BOO), as the accommodation and working base of an inspection team, would be a very important facility for an OSI mission. As the OSI would be based on the heavy culture of nuclear, the radiation safety of BOO has its special significance. In the practical case, continued monitoring of the radiation level and the identification of the radioactive sources at BOO, would have...
During the rainy season in Costa Rica there are problems with satellite communications. This is due to the large amount of rain and bad weather conditions. It is analysed as follows: the frequencies used in a VSAT with the International Data Centre (IDC) are between 4.172GHz to 4.174GHz and between 6.397 and 6.399GHz. Using the formula, we can find that the
wavelength of these frequencies are...
This paper elaborates on the history, achievements and impact of the Science and Technology Conferences (SnT) in bolstering the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The paper tracks the evolution from the inaugural Synergies with Science Conference in 2006, the shift to the International Scientific Studies Conference in 2009 and the rebranding to SnT in 2011. These conferences have...
Sudan is classified as an area of moderate seismic activity. The main objective is to study the seismic activity and estimate the morphometric aspect of the North locality. A unified Mw earthquake data for the period between 1906 to 2016 was used to construct the seismicity map. The areal distribution of the earthquake illustrated the concentration of the earthquakes in the eastern part, A Pie...
The Shkodër-Pejë zone is an internal transverse fault zone with active normal faults stretching east-west, primarily along the boundary of the Mirdita ophiolitic zone. This fault divides the geological structure of the Albanides into two parts: the northern part, which continues with the Dinarides, and the southern part, which continues with the Hellenides. The region has been historically...
With the projected increase in world nuclear capacity comes the hurdle of spent nuclear fuel. Pyroprocessing is one method to process irradiated fuel by using high temperatures and electrochemical steps to separate radioactive components of interest. High temperatures, high radiation levels and equipment confined to a heavily shielded hot cell are a few of the challenges introduced regarding...
In 2012, the National Research Council concluded that earthquake signals cannot effectively mask those produced by explosions. We test that conclusion with multi-channel correlation detectors (correlators) that use records of ground motion (templates) sourced by explosions to detect smaller signals from similar, collocated sources. Our test applies these detectors against thousands of signals...
Albania, situated on the Adriatic microplate boundary, experiences high seismicity. The Gutenberg-Richter relationship, characterized by the a and b values, is crucial for understanding seismicity and forms the foundation for seismic hazard assessment. Using ZMAP7, we analysed seismicity in Albania (18.5–21.5° longitude, 38.0–43.0° latitude) from 2015 to 2024. The declustered seismic catalog,...
The exhibition "¡Habla Tierra! Venezuela, País Sísmico" aims to enhance public awareness and understanding of seismic activities in Venezuela. This article presents the successful implementation of these initiatives and discusses the integration of International Monitoring System (IMS) technologies into the exhibition as a tool to complement the Capacity Building and Training program,...
Nearly three decades since the establishment of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), rapid developments in artificial intelligence (AI), autonomous systems, and global communication and data networks are radically changing the technological landscape in which the CTBTO operates. Concurrently, geopolitical conflicts have impacted states’ trust in international institutions and...
We performed a comprehensive analysis of the seismic activity in the Valley of Mexico using the records of the nearby seismic stations. We determine the focal mechanisms of earthquakes (M > 2.5) in the Mexico Basin from 2010 to 2024. Events were chosen with a high signal to noise ratio, i.e., raw P and S arrivals clear enough to be distinguished. Focal mechanisms were inverted using the ISOLA...
The various microplates collided and resulted in Sulawesi Island. Compression stress became the main force at the beginning of tectonic episodes. Nowadays, two subductions still exist. However, it is still an open question whether those two subductions significantly contribute to seismic wave arrival times. The global 1-D and 3-D velocity models are used to identify the residual patterns in...
The Idaho National Laboratory (INL), located in Eastern Idaho in the United States, has a history of operating nuclear test reactors and is currently designated as a Reactor Innovation Center. The seismic monitoring network began as a single seismic station in 1973 and has grown to include over 100 instruments for the purpose of monitoring geophysical phenomena. As the network has evolved over...
Global Climate Governance is an emerging arena of policy-making with the primary objective of formulating practical alternatives to deal with the adverse consequences of climate change along with creating an agile mechanism that is adequate from a scientific perspective and also encourages universal participation. Countries are experiencing frequent natural disasters due to climate change,...
Seismic data from the International Monitoring System (IMS) captures both natural and environmental noise, along with signals from seismic events such as earthquakes or potential explosions. While most of these stations are surface-based, a few instruments are deployed at depths ranging from tens to 100 meters. Although previous studies suggest that deeper instrument deployment may improve...
This work presents the results obtained from the use of geological and geophysical techniques for the identification of large unstable regions, and can be used in on-site inspections within the framework of cooperation and knowledge exchange of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Deep-seated gravitational slope deformations are slow and of great volume. The analyzed case is a...
Traditional moment tensor inversions are a common tool used to characterize events of interest for nonproliferation monitoring. Many inversions assume a known source time function and solve for the moment tensor of a seismic source. However, this requires a source time function to be assumed, which could result in inaccurate results if, for example, an explosion source time function is used...
Seismicity of Africa is moderate by global standards, primarily due to limited recorded earthquakes. However, moment-magnitude Mw larger than 6.0 events frequently occur along poorly understood fault lines, posing significant risks, such as the Mw 6.9 Moroccan earthquake on 8 September 2023. This underscores the urgent need to improve earthquake forecasting on the continent.
Epidemic-Type...
The field of geophysics is seeing rapid development of new technologies, including Distributed Acoustic Sensing (DAS). This innovative technique attracts scientists and researchers for its ability to monitor and analyze geological and structural changes with high spatial resolution over large distances. Unlike traditional methods based on the use of stationary instruments, DAS allows to make...
Xenon International has recently tested a new quality control (QC) source for the nuclear detectors which uses an acrylic housing for a $^{137}$Cs source. The original source holder used in acceptance testing was $^{137}$Cs housed in a stainless-steel pellet. The high Z of the stainless steel attenuated low energy X-rays. The new QC source allows for the lower energy (~30 keV) emissions from...
Confidence in the quality of infrasound measurements is at the heart of the operational requirements linked to the detection and assessment of geophysical and industrial events. The entire measurement process, from laboratory calibration to the field, must be considered to estimate the confidence level of the measurement through the associated uncertainty. As part of the European Infra-AUV...
Research using acoustic recordings to estimate animal population sizes is being applied increasingly frequently to both marine and terrestrial species. Here, data from the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) International Monitoring System (IMS) hydroacoustic stations have been used to monitor baleen whales. For example, several baleen whale species have been recorded at...
With the majority of the Comprehensive Nuclear-Test-Ban (CTBT) International Monitoring System (IMS) network now fully operational, management of the network is undergoing a significant transition from establishing capability towards sustainment. The challenge is not limited to maintaining these capabilities, but extends to optimising the IMS network performance and providing the best possible...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is uniquely positioned at the intersection of science and diplomacy. To sustain the talent needed to achieve a world without nuclear tests, the CTBTO continues to invest in cultivating the next generation of leaders in STEM, and nuclear disarmament and non-proliferation, from across the world.
This panel will bring together some...
After the Sumatra-Andaman earthquake, leading to a tsunami devastating Thailand's west coast, concerns were raised about the effects on infrastructure and human life. This study aims to model Tsunami Arrival Times and Wave Heights along the Andaman Sea Coast of Thailand using the TOAST (Tsunami Observation and Simulation Terminal) module integrated into the SeisComP software. The default...
Confidence in the quality of infrasound measurements is essential for meeting operational requirements in the detection and assessment of geophysical events. This confidence is partly established through accurate calibration of the instrumentation, encompassing the entire measurement process, from laboratory calibration to field deployment and calibration. In this process, transfer standards...
The International Monitoring System (IMS) infrasound network’s ability to detect atmospheric nuclear detonations is limited by a combination of wind-noise, anthropogenic sources, and the microbarom, the constant and globally ubiquitous infrasonic noise driven by oceanic waves. The presence of seasonal weather conditions may increase the strength of the microbarom, further increasing background...
Traceable calibration of broadband weak-motion seismometers is an ongoing challenge. In a specialized laboratory, verification of the response up to the upper corner frequency is achievable, but at a typical lower corner period accuracy is limited by parasitic tilts. Since such primary calibrations are not practical in the field, it has been proposed instead to use lab-calibrated reference...
Explosive volcanic eruptions produce large amount of infrasound (<20 Hz), which can propagate over hundreds to thousands of kilometers in the atmosphere. These eruptions also inject large amounts of ash in the atmosphere, posing a direct threat to commercial flights and the population under the ash plume trajectory.
The Volcanic Information System (VIS) was developed within the Atmospheric...
Predicting and responding to changing environmental conditions is an essential part of making optimal decisions about movement. Over small spatial scales such decisions may be guided by short-range cues, but it can be unclear what cues underlie movement at scales exceeding 1000s of km. Infrasound could form such a cue. In marine habitats, infrasound is largely generated by non-linear wave...
The essential role played by observation networks for improving the performance of Numerical Weather Prediction (NWP) and atmospheric composition forecasts systems is illustrated in this presentation by the ECMWF experience. The European Center on Medium range Weather Forecasts is both a research institute and a 24/7 operational service, producing global numerical weather predictions for its...
Creare has developed an electrostatic precipitator (ESP) for high volume atmospheric aerosol collection. Previously, we demonstrated a laboratory-based ESP system with limited flow rates. With this work, we have demonstrated well over 80% collection efficiencies of 0.2–0.3 µm particles at significantly higher flow rates and lower pressure drop than the current RASA system. The particles are...
We present a novel approach to the detection and parameter estimation of infrasonic signals: the Multi-Channel Maximum-Likelihood (MCML) method [https://doi.org/10.1093/gji/ggac377]. MCML is based on the likelihood function derived from a multi-sensor stochastic model expressed in different frequency bands. Using the likelihood function, we determine, for the detection problem, the Generalized...
An effort is underway to update the Radionuclide Aerosol Sampler Analyzer that is currently deployed by the International Monitoring System with one of the objectives being to increase the frequency of sample collection while maintaining or improving detection sensitivity. Detection efficiency will be increased using a pair of high purity germanium detectors, which will surround the sample...
Accurate phase picking detection is crucial in seismic analysis, particularly in detecting underground nuclear explosions. Due to the overlapping wave characteristics, differentiation between seismic events caused by nuclear detonations and natural earthquakes is challenging. This study focuses on developing and applying advanced phase-picking techniques to identify and analyze nuclear...
Distributed Acoustic Sensing (DAS) technology using fibre optic cables presents a promising tool for detecting, locating and characterizing seismic events, including explosions. This study, based on a real experiment, assesses DAS’s capability to enhance nuclear-test-ban monitoring, aligning with CTBT goals. With its ability to transform fibre optic infrastructure into extensive arrays of...
This study presents a 4πβ (plastic scintillator)–γ coincidence detection system developed with the integration of machine learning to optimize the absolute activity measurement of radionuclides. A hardware setup utilizing a CAEN N5751 digitizer employed a pulse shape discrimination procedure to process signals from the detectors and generate binary list-mode files representing the measurement...
This panel will broaden the understanding of extreme environment effects on the CTBT's operations and the potential for CTBTO to contribute to environmental resilience through data sharing and adaptive practices. The panel aims at sparking discussion on how CTBTO’s data can be leveraged to enhance the understanding about our planet and support global risk mitigation. By bringing together...
Deep learning (DL) has shown to be a powerful method for seismic phase detection for single three-component station. Here, we explore the application of DL to enhance automatic array processing pipelines for seismic event detection. Our work focuses on three key tasks where DL could complement or potentially replace traditional methods: (1) seismic phase detection, (2) seismic phase...
Laboratory measurements of air samples can be used as a complement to measurements at the IMS station. Such measurements are performed today on a regular basis for the particulate stations within the IMS. Laboratory re-measurements of radioxenon samples, however, are not yet fully implemented in the verification regime. To study the benefits and restrictions for re-measurements of radioxenon...
FRL08 operates a system for very low-level measurement of fission products, named Gamma3. In addition to classical gamma spectrometry, it can operate in coincidence mode. The low probability of coincidence events is compensated by high signal-to-noise ratio and much lower detection limits, facilitating the qualitative and quantitative characterizations of samples with a large number of fission...
Here, we use coda measurements and apply the waveform envelope spectral ratio method to obtain the measurements necessary for source discrimination and to determine absolute yield and depth of burial at globally distributed test sites. Studies of high‐frequency (>~1 Hz) source processes are crucial for both event discrimination and yield/magnitude determination of smaller seismic events....
The International Monitoring System (IMS) of CTBTO includes sixteen radionuclide laboratories, one of them is the Brazilian Laboratory (BRL04) at the Institute of Radiation Protection and Dosimetry in Rio de Janeiro, which is not certified to analyze IMS station filters but has consistently performed well in proficiency test exercises organized by the Provisional Technical Secretariat....
Monitoring techniques based on infrasound arrays have contributed to the detection, location, characterisation and quantification of volcanic and seismic activity at local as well as regional distances. Currently, the Azores infrasound network comprises an International Monitoring System (IMS) station IS42 on Graciosa Island and two low-cost arrays (SJ1 and TER), located on São Jorge and...
The presence of radioactive particles and their nuclide mixture in the air is measured by gamma ray spectra through International Monitoring System radionuclide stations to help detect nuclear explosions. These gamma ray spectra are reported to the International Data Centre by each radionuclide station. We use supervised machine learning to show that the radionuclides present in each sample...
The sustainment of hydroacoustic stations is crucial for global monitoring and the verification of nuclear test-ban compliance. These stations, operating in harsh marine environments, require advanced materials to ensure their longevity/reliability. Recent developments in superhydrophobic coatings have shown great promise in enhancing the durability and sustainability of these stations....
Effective maintenance strategies and quality assurance are critical for sustaining the performance of seismic networks. The optimal mass position of seismic sensors directly impacts the quality of seismic signals, yet the diverse interfaces provided by various digitizer manufacturers complicate consistent monitoring and state of health evaluations. In Indonesia’s extensive seismic network,...
Between late November and early December 2022, large amounts of radioxenon were detected by multiple IMS stations and by the Swedish Radioxenon array, which at the time consisted of four SAUNA Q$_B$ detectors. In total, there were over 100 detections of Xe-133, with Xe-133m concurrently found in approximately a dozen samples. The continuous and complex nature of these detections, along with...
In the analysis of radioxenon sampling data from three SAUNA QB systems sited in the North of England, a variety of different approaches have been used to identify the likely source(s) of over 300 detections of Treaty-relevant isotopes of radioxenon. This work utilises stack monitoring data from both European radionuclide emitters and local sources, forward atmospheric transport & dispersion...
Hydroacoustic hydrophone stations of the International Monitoring System (IMS) network continuously monitor the global oceans for nuclear test explosions. The stations are equipped with hydrophones in triplet configurations placed in the SOFAR channel, where the speed of sound reaches its minimum, to detect acoustic events. Acoustic signals detected by the hydrophones are conveyed to the...
Since 2011, Bangladesh has been hosting an International Monitoring System (IMS) auxiliary seismic station, AS7 (BRDH), in Bariadhala, Chattogram. The station is located atop a hill. Erosion of the sediments and subsidence occurred on the flanks of the hills around the seismic vault and the building. As a consequence, the floor of the building began to subside as well, fractures and cracks...
Artificial Intelligence has an increasingly important role in medicine. It is used to guide treatment decisions, and to enable the development of novel therapies based on the integration of complex multi-modal data. This talk will give an overview of how AI is used in medical imaging and connected modalities to predict disease course or treatment response, or the onset of future disease for...
This event will explore recent advances in metrology for SHI technologies and their application within the CTBTO verification regime. It will focus on the transfer of laboratory calibration methods to the field, address key technical challenges, and highlight the importance of strengthening calibration traceability to ensure reliable IMS data.
Session Objectives:
- Review the most recent...
Artificial intelligence (AI) methods have had recently significant impacts in science and technology, on redefining operations and overall, on innovation and efficiency. These methods for generating models from datasets or logic-based algorithms that emulate aspects of human performance can similarly accelerate all aspects of the work of CTBTO and other international organizations. For CTBTO,...
Overview
Artificial intelligence (AI) is no longer a futuristic concept; it's a transformative force reshaping every aspect of the industrial landscape. From station operations to global workflows, AI is moving beyond simple automation to create intelligent, predictive, and collaborative systems. This event provides a deep dive into the practical applications and strategic implications of...
Radionuclide monitoring for nuclear explosions requires sufficient information and an adequate understanding of existing radioxenon sources which are frequently observed as background in atmospheric noble gas samples. In the absence of measured discharge data from nuclear installations, one can only revert to rough approximations of discharges based on publicly available information. In many...
Zaporizhya Nuclear Power Plant is facing the risk of unexpected accidents. If it is damaged, lots of radioactive materials will be released into the air. The atmospheric dispersion model named LADAS (Lagrangian Atmospheric Dose Assessment System) was applied to evaluate the behaviour of radioactive material released into the air for the hypothetical nuclear accident at Zaporizhya. The global...
A central challenge of radioxenon monitoring for the CTBT remains to classify radioactive xenon isotopes originating from reactor sources. This was also crucial for the interpretation of radioxenon detections in the aftermath of the announced North Korean nuclear test explosions. Due to its geo-location, the IMS noble gas system at RN38 played a crucial role for that. At RN38, Takasaki,...
Radiation Protection Centre has launched a network of three SAUNA QB and one SAUNA III atmospheric radioxenon measuring stations in Lithuania. Measurements are performed regularly since the end of 2024 and the number of episodes with the elevated radioxenon (mostly 133Xe) concentrations were detected. The backward atmospheric transport modeling using HYSPLIT computer code allowed us to...
We present our work on the CHIMERE Assisting Radioactive Analysis Toolkit (CARATk), a new toolkit for the CHIMERE chemistry transport model. This toolkit will permit simulation of transport, chemistry and physical processes of radionuclides in the atmosphere.
Our poster will focus on two main points in our development of CARATk.
Firstly, we validate the eulerian transport CHIMERE by...
Xenon radionuclides atmospheric monitoring is part of the International Monitoring System, including multiple measurement stations, that were developed in the context of the Comprehensive Nuclear-Test-Ban Treaty. However, civil infrastructures, mainly nuclear power plants and medical isotope factories, constantly generate these radionuclides, creating a global atmospheric...
Development of nuclear devices tends to take place in secrecy, without sharing specification of technical details. Tests are generally performed underground and unannounced. Seismics will announce a detonation and give an approximate location and time. One of the challenges of CTBTO is the reverse engineering of the specs of the nuclear device itself. After some containment time, noble gases...
Radionuclide monitoring is one of the CTBT verification technologies that measures radioactive particles and noble gases generated by nuclear explosions. Detecting underground nuclear explosions (UNEs) is challenging as these events are unlikely to release radioactive particles into the atmosphere. To address this, monitoring noble gases more likely to escape into the atmosphere has been...
In case of an underground nuclear explosion (UNE), the waveform component of the International Monitoring System (IMS) that is being established by the Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty allows for the determination of the location and timing of the event. To confirm the nuclear character of any UNE, the radionuclide component of the IMS searches for traces of...
This study is about radioxenon Xe-133 background in the Southern and Northern hemispheres and to discuss the influence of this context on nuclear test identification.
The study was carried out in four CTBTO stations in Northern and Southern hemispheres. They were chosen taking into account NPPs and medical facilities close the stations. Data was extracted from Review Radionuclide Report (RRR)...
The relative abundances of radioxenon isotopes in underground nuclear explosions depend on the direct production by fission and the β-decay of their radioactive precursors. Since the precursors are moderately volatile elements that can condense into the magma within the nuclear cavity as the system cools off, the radioxenon budget available for subsequent migration to the atmosphere, as well...
Knowing the time pattern of radioxenon releases is crucial for expert analysis in nuclear explosion monitoring. The standard assumption, which uses a constant discharge rate based on the average of the annual total, is overly simplistic. The noble gas measurement systems are not typically sensitive to continuous emissions and instead usually observe puff emissions. The measurement data from...
The nuclear nature of any explosion occurrence under the CTBT can be determined/established using the detections of any relevant radionuclides at IMS stations. This plays an essential role in the compliance monitoring of the Treaty. During an explosion, Radionuclide materials, specifically radioxenon gases, can be carried in the atmosphere or vented from underground or underwater source. Since...
The knowledge of the natural background of xenon radioisotopes in the ground is required to be able to distinguish it from any signals due to a potential underground nuclear explosion, as would be the case during an on-site inspection (OSI). The natural background of xenon isotopes from spontaneous fission in the soil has been studied during several measurement campaigns in Sweden. In most of...
The turbulent diffusion coefficient is the rate at which turbulent motion disperses radionuclides. It controls the rate of spread of their concentrations into the atmosphere, thus influencing their behaviour. The turbulent diffusion coefficient is an essential parameter in the study of atmospheric transport, and the accurate determination of its value in the atmosphere is crucial. This study...
A numerical study of conjugate flow, heat and mass transfer by natural convection of noble gases within an underground cavity partially filled with molten rock is presented. The molten rock is initially considered at rest at an initial temperature and concentration. The molten rock is viscous and possesses strength that is temperature and crystal fraction dependent. Under natural conditions,...
The estimation of a source in the CTBT context is an ill-posed problem that is highly sensitive to small variations in data, whether meteorological information or radionuclide concentration values. The current version of the Web-Grape software includes three methods for identifying possible source regions. The first two methods rely on the correlation between measured concentration values and...
Estimation of Xe133 emissions associated with nuclear tests is a challenging task for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) due to noble gas background emissions from nuclear power plants, research reactors, and medical isotope production facilities. These background emissions make data interpretation from the International Monitoring System (IMS) a complex issue since...
Underground nuclear explosions produce radioxenon, which may be transported through the geology and subsequently collected and measured locally in an On-Site Inspection or regionally via the International Monitoring System. Predicting how much radioxenon may be available for collection and measurement requires development of geology-specific subsurface gas transport models to estimate timing...
Since March 2021, the Pacific Northwest National Laboratory (PNNL), in cooperation with Radiation Protection Center in Lithuania, has been supporting a radionuclide background measurement campaign in Pabrade, Lithuania. This measurement campaign aims to provide a better understanding of background detections in a previously unobserved region. Lithuania is a complex region for measuring...
Understanding and accurately modelling Xe-133 is fundamental for the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty. Therefore, the potential of nudging techniques within FLEXPART-LCM, the Linear Chemistry Module of FLEXPART 11, to improve global Xe-133 background concentration...
Standard atmospheric transport modelling can be of great help for categorizing specific radioxenon observations but will not prevail on average when it comes to screening out nuclear explosion signals that are mixed into the global industrial background. The challenge pertains to both poorly characterized emissions and uncertainties in the modelled dispersion. Improved screening can be...
Previous studies on the trajectories of air masses from nuclear power plants in the Florida peninsula showed that they contribute to the radioxenon background in the northern Caribbean Sea when the center of the migrating anticyclone was in the Gulf of Mexico and Lousiana, North America.
The objective of this work is to determine whether the Turkey Point and Saint Lucie NPP discharges...
The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operates a global network of stations designed to detect potential violations of the CTBT. As a critical part of this system, the noble gas (NG) network plays a major role for the monitoring of radioxenon isotopes. Recently, extended episodes of elevated concentrations of radioxenon were...
Xenon isotopes are relevant to the monitoring regime of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). We report radioxenon measurements data taken directly at source, deriving emission inventories for International Monitoring System (IMS)-relevant isotopes and isotopic ratios used to discriminate nuclear explosions from civil emissions. Time series activity plots have been produced from...
We present ocean modelling work aimed at detecting the debris from nuclear detonations in the ocean. By following the dispersion of near-surface warm pools of radionuclides from specific starting positions, we assess their likely spreading rates and pathways for some months after the explosions, enabling on-site monitoring or sample collection to take place with the best chance of detection....
Radioxenon emissions originating from a variety of nuclear facilities (e.g. nuclear power plants) induce a variable and observable background that poses a challenge for the global monitoring of nuclear explosions since it may conceal signals resulting from a nuclear test explosion. More precision is required to accurately model civilian facilities so that noble gas detections can be screened...
Whenever 135Xe is observed, it must originate from a fresh release due to its short half-life (9.2 hours). An activity ratio of 135Xe to 133Xe above 5 is an indicator for a possible nuclear test release. Therefore, it is important to fully understand observation of very high activity ratios of 135Xe to 133Xe in atmospheric air and even 135Xe without simultaneous observation of 133Xe as they...
The International Monitoring System stations may occasionally detect radionuclides relevant to the CTBTO. Such is the case of station MXP44, which is located in Guerrero, in the Mexican state of Baja California. Cesium-137 was detected three times in the year 2024 with a level 4 categorization. The objective of this work is to estimate the possible source origin of the cesium-137 detections....
Atmospheric transport and dispersion models (ATDM) are routinely used in the simulation of the global radioxenon background as well as in the localisation and characterisation of unknown radioxenon emitters. However, ATDMs contain uncertainties due to the assumptions made in the model setup as well as the chaotic nature of the atmosphere. Currently, quantification of these uncertainties and an...
Each anthropogenic emission possesses a unique radionuclide composition, serving as a 'fingerprint' that enables the identification of radionuclide contamination sources. This report presents a cutting-edge and rapid technique for radionuclide detection and source identification, focusing on ultra-trace concentration levels critical for detecting small-scale nuclear tests. Radionuclide...
Atmospheric transport modelling requires the rapid estimation of a radionuclide source term (including radioxenon) potentially released to the atmosphere from an underground nuclear cavity. A versatile model must include venting to the atmosphere and seepage into the host rock, allowing for barometric pumping. The nuclear cavity is connected to the ground surface by two interacting media,...
Air pollution, including radiological pollution, is one of the most harmful consequences of industrialization because of its strong influence on both human health quality and climate in general. Often a need appears to identify one single strong source of air pollution. Such a source may be the result of accident or routine release from nuclear industry. We propose a new algorithm for a single...
Isotopic activity ratios of 135Xe to 133Xe above 5 are considered as an indicator for a possible nuclear test release. High activity ratios of 135Xe to 133Xe in atmospheric air and even 135Xe without simultaneous observation of 133Xe are occasionally observed at IMS noble gas systems. Whenever 135Xe is observed, it must come from a fresh release because its half-life is just 9.2 hours. Despite...
The RN43 station, located in Nouakchott, Mauritania, is a key component of the International Monitoring System (IMS) under the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). Established in 2006, the station plays a crucial role in detecting and analyzing airborne radionuclides, contributing to global atmospheric transport models and radiological risk assessments. Due to its...
In September 2024, anthropogenic radionuclides observed from RN64 station located in Tanzania. This incident triggered us to make a review of data analyses from CDC from January 2010 up October 2024. Key finding includes the detection of both natural and anthropogenic radionuclides (fission and activation products). However, the interest was on anthropogenic radionuclides (fission and...
The detection of underground nuclear explosions by means of the radioactive gases generated during the explosion requires a sufficient fraction of radionuclides to be emitted to the atmosphere. In the case of late seepage observed after a few days to a few weeks, this fraction is very small and results from the transport of gases under the combined effects of thermal gradient and barometric...
Understanding the propagation of the waveform and radionuclide signals is an important component of the International Monitoring System. On October 18th, 2023 we executed a 16.3 T chemical explosive experiment with stable radioxenon and tritium tracers to understand pressure-driven transport through the subsurface. The initial chemical explosion and subsequent gas migration were monitored with...
The development and validation of noble gas transport models through field collected data is critical in the improvement of nuclear explosion monitoring techniques. Complex surface terrain in the area of release can drastically impact the transport of the resulting plume and the subsurface geology can alter material flow to the surface, resulting in large discrepancies in release times,...
The Source Term Analysis of Xenon (STAX) project is an international technical collaboration that has been installing stack monitors in partnering nuclear facilities and sharing stack effluent data with National Data Centers for use in better understanding Xe background sources detected by the International Monitoring System (IMS). The STAX project is now in its 7th year and during the course...
Radioxenon discharges from nuclear power reactors (NPPs) are frequently detected by the noble gas monitoring systems of the International Monitoring System. However, the standard assumption of continuous releases is not realistic. It has been demonstrated that ramping power down and up during operations are occasions of elevated discharges, which are most likely to be observed. Despite this,...
The detection of xenon isotopes in the atmosphere plays a critical role in monitoring nuclear explosions under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Understanding the temporal and geographical distribution of CTBT-relevant xenon isotopes, such as 131mXe, 133Xe, 133mXe, and 135Xe is essential for distinguishing between natural, medical, and anthropogenic sources and potential...
Many Arab countries in the Middle East face negative impacts from dust fallout, which includes both natural and human-made radionuclides. This study thoroughly analyses long-term atmospheric radionuclide levels in Kuwait. Over ten years (2013–2022), daily measurements of natural and anthropogenic radionuclides—specifically 137Cs, 7Be and 40K—were collected using the RN40 station. The average...
The ability to detect and localize radiation sources and special nuclear materials is key for many fields including nuclear security, safeguarding and nuclear materials nonproliferation. A fundamental aspect in in-field detection or imaging is the availability of an accurate natural background radiation map in the area of interest. In general, countries map background radiation levels for many...
A background analysis of xenon in Nigeria would enhance the understanding of its release and dispersion from reactors and natural sources. Although Nigeria lacks a nuclear power plant, it operates a research reactor in Zaria (11.1512° N, 7.6546° E) and is planning a 2GW multipurpose research reactor in Sheda (8.8569° N, 7.0434° E). Nigeria’s strategic location between IMS stations in Niger...
The measurement of radionuclides is continually performed by International Monitoring System (IMS) operated by the Comprehensive Nuclear-Test-Ban Treaty Organization Preparatory Commission (CTBTO PrepCom). The detection of radionuclides plays an important role in confirming if an explosion is nuclear or chemical. As radioactive gases are transported through the subsurface environment, there is...
In 2017, the Government of Japan has decided to make a voluntary contribution to further strengthen the capabilities of the CTBTO verification regime. As part of that initiative, two transportable noble gas measurement systems were deployed in Japan, in Horonobe and Mutsu. They started operations in January 2018 and March 2018, respectively. In January 2025, a third transportable measurement...
Bundesamt für Strahlenschutz (BfS) has been operating a network with weekly sample collection at 6-8 locations in Germany with sampling starting in 1977. Since 2024, this network is complemented by the automatic Xenon system Sauna Qb with a sampling period of 12h followed by automatic radioxenon analysis. The shorter sampling periods of the Sauna Qb promise a much better ability to...
The automated particulate and HPGe noble gas analysis engine, Autosaint, has been in use at the IDC for over a decade. This code is one of the last remaining radionuclide processing algorithms written in C, with all other key applications either developed in or ported to Python 3. For long term maintainability and consistency, the functions performed by this module will be redeveloped and...
Bundesamt für Strahlenschutz (BfS) has been operating a network with weekly air sample collection at up to 26 locations in Germany and worldwide, with sampling going back to 1973. The samples are analyzed for Kr-85 at the BfS Noble Gas laboratory in Freiburg which is accredited according to DIN EN ISO/IEC 17025. Large quantities of the radioactive noble gas Kr-85 are released into the...
Various human-made phenomena such as medical isotope facilities and power plants have complicated the understanding of radioxenon measurements. Argon-37 could be added to increase confidence in observations. However, the atmospheric background of argon-37 is not as well understood as the radioxenons. Pacific Northwest National Laboratory has developed a new continuous and automatic benchtop...
Existing radionuclide aerosol collection systems within the CTBT’s International Monitoring System operate near the noise floor of the gamma spectrometer measurement. Increasing the flow rate of radionuclide aerosol systems while meeting the CTBT’s specified collection efficiencies will increase particle collection and, potentially, decrease sample interval. Creare developed a detailed model...
The Swedish Xenon Array is a first-of-its-kind measurement system, consisting of five SAUNA QB units placed around Sweden with an inter-distance around one order of magnitude smaller than the IMS. Here, we present a comprehensive analysis of the first two years of data (2021-2022), where xenon background sources relevant to Sweden and northern Europe are characterized, and a comparison of the...
The SAUNA QUBE, developed by the Swedish Defence Research Agency and manufactured by Scienta Envinet, represents a major advancement in atmospheric radioxenon monitoring. It offers high performance at significantly lower costs than its predecessors, allowing the creation of dense monitoring arrays that improve detection probability, data availability, and source localization precision. To...
In early September 2024, the particulate radionuclide IMS station in Stockholm, Sweden, observed several anomalous measurements of caesium-137. Similarly unusual detections were simultaneously being observed on national monitoring networks across Europe, and preliminary investigations suggested that the source of the fission products was somewhere in Eastern Europe. In time, it became apparent...
The Sahel is that band of Africa laying between 12°N and 20°N with a semi-arid region separating the Sahara desert from the Sudanian tropical savanna. The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans any testing of nuclear explosive devices which is carried out underground, in the atmosphere and underwater. Two main technologies, radionuclide and seismo-acoustic monitoring, are deployed...
Monitoring atmospheric radioxenon concentration is crucial for verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and may confirm the nuclear nature of an underground explosion. The International Monitoring System (IMS) collects and analyzes air samples to determine the activity concentrations of four radioxenon nuclides (131mXe, 133mXe, 133Xe, 135Xe). Multiple civil...
Usually, a volume of IMS Xe sample is not exceeding a few cc of pure Xe and volume of OSI sample is significant less. Proposed technology increased Xe volume for more than 100 times and provide high sensitivity spectrometric measurement (MDC for Xe133, Xe135, Xe133m and Xe135 always during the measurement were less than 10-5 Bq/m3). MDC for 4 Xe are by several orders less than MDC of existing...
Xenon-127 is a neutron-deficient radionuclide produced from neutron activation rather than fission, for example via radiative capture on stable xenon-126. It is not an isotope actively monitored as a signature of a nuclear test; however, its longer half-life (36 d), measurable nuclear decay emissions and lack of environmental background signal make it an ideal tracer radionuclide for...
Modern radioxenon detection systems exhibit a low memory effect. For example, the MIKS plastic detector cell has a memory effect coefficient of less than 5%. However, even low levels of memory effect can affect measurement results. To account for this, the gas background is measured separately and incorporated into the calculation of sample activity.
Accurate accounting for the gas...
The International Monitoring System (IMS) is a global network that when complete will consist of 16 laboratories and 321 monitoring stations providing real time data delivering insights to the nuclear explosion monitoring community. A thorough comparison of results produced by these monitoring systems and labs has been conducted utilising data from multiple years of Radionuclide Laboratory...
Pacific Northwest National Laboratory (PNNL) is developing a comprehensive database of over 100,000 analyzed gamma-ray spectra from an archive from decades of radiometric analysis of a diverse range of radionuclide samples by trained gamma spectroscopists. This dataset will be leveraged to embed domain expert interpretation and analysis of gamma-ray spectra into trained semi-supervised...
One of the aims of using Atmospheric Transport Modelling (ATM) in National Data Centres (NDC) is to locate the geographical areas likely to contain the source at the origin of a set of measurements at International Monitoring System (IMS) stations, and to provide an estimate of the associated release quantity. One of the main challenges lies in uncertainty quantification. For this purpose,...
In the Comprehensive Nuclear-Test-Ban Treaty (CTBT), radionuclide monitoring is a key to provide evidence of an explosion being nuclear in nature. In this respect, the gamma-ray coincidence spectrometry has emerged as a powerful technique to suppress background from naturally occurring radioactivity while maintaining good efficiency for coincident gamma-ray emitters of interest. Although this...
The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) includes 80 radionuclide stations performing continuous radionuclide particulate monitoring, supported by a network of 16 radionuclide laboratories which undertake verification and reanalysis of samples. The current analysis technique employed across the IMS uses high-resolution gamma spectroscopy to...
Many countries around the world use high volume samplers to sample air for radioactive particulate measurements. For many years, the Dutch National Institute for Public Health and the Environment (RIVM) performs the sampling and measurements in the Netherlands for environmental monitoring purposes. Since 2011 a Snow White air sampler from manufacturer Senya Oy is used, which is the same air...
In the scope of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the detection of radioactive xenon by the stations of the International Monitoring System (IMS) is a crucial challenge for the detection and the qualification of nuclear tests. This task is made difficult because of the low activity of these elements present in trace amounts in the atmosphere.
The laboratory is therefore...
IMS nuclear explosion monitoring systems rely primarily on the radioxenon to detect illicit nuclear events. However, these systems require prompt event detection since the main isotopes of interest (131mXe, 133+133mXe and 135Xe) have half-lives between 11.9 days and 9.14 hours. Here, we present a complimentary tool for detecting fission events utilizing...
High resolution gamma spectrometry allows least-squares-based net area calculation in radioactive xenon detections. The least-squares-based calculation accounts for X-ray deconvolution and gamma peak area quantification. The International Data Centre (IDC) has been seeking a new approach to enhance the capability of gamma area quantification by taking advantage of X-ray counts. In a previous...
Under a collaboration known as Xenon and Environmental Radionuclide Analysis at Hartlepool (XENAH), an advanced gas-cooled nuclear reactor based in the UK has granted access to real time monitoring data of the gaseous CO2 primary coolant. These data, partly intended to inform station operators as to the state of health of the core, represent a vast repository that may be further explored for...
Modern systems for detecting radioactive noble gas isotopes require high sensitivity, reliability and durability. One of the critical challenges is minimizing the memory effect, which manifests itself as residual activity on the surface of the detectors. Previously, VNIIA developed a barrier coating technology for scintillation cells using poly-chloro-para-xylylene, known for its high gas...
The first commercially available unit of the Xenon International system was installed at the General Dynamics Mission Systems’ Engineering Test Bed (Chantilly, Virginia, USA) in May of 2024. In preparation for deployment into the IMS, General Dynamics has operated the system in the same manner as a certified system and has been working in conjunction with the Provisional Technical Secretariat...
Cadmium Zinc Telluride (CZT) based FirstLook detector systems can provide a near-real time look at the collection of aerosolized radionuclides on the filter media in particulate collecting systems. In cases where high levels or radionuclides are present in air masses, FirstLook detectors could provide station operators the ability to tune the collection of the system to prevent contamination...
The CTBTO’s International Data Centre (IDC) collects, processes and analyses data originating from the facilities of the CTBTO’s International Monitoring System (IMS), which uses four complementary verification methods (including radionuclide) to detect nuclear explosions. Radionuclide technique is the last step to validate whether a nuclear explosion has been carried out. Data from the 73...
A newly commissioned STAX series monitor, developed by INVAP, has successfully completed factory acceptance tests and demonstrated reliable data transmission in accordance with STAX project requirements. This monitor is scheduled for installation at the La Reina RECH-1 Research Reactor facility in Santiago, Chile, during the first half of 2025. This unit represents an upgraded version of the...
This study investigates the long term variations in radioxenon efficiency calibrations by conducting nearly monthly calibration experiments over an extended period on a single system. Historically, radioxenon detection systems are calibrated infrequently, often only once or very rarely, raising concerns about the long term accuracy and reliability of the detectors. Accurate and consistent...
This talk aims to explore the potential transformative impact of machine learning, deep learning, and high-performance computing on enhancing the operational capabilities of CTBTO in global monitoring and verification. Advanced AI techniques and scalable computational resources open up an opportunity for CTBTO to improve the detection, localization, and analysis of nuclear test signatures...
The measurement of low-levels of radioxenon is an important part of the International Monitoring System (IMS) operated by the Comprehensive Nuclear-Test-Ban Treaty Organization Preparatory Commission (CTBTO PrepCom). These stations are continually measuring the radioxenon in air samples to monitor for nuclear explosions. The IMS also includes laboratories capable of measuring radioxenon...
With the establishment of radioxenon detector networks, such as the IMS, a long-standing challenge has been to accurately correlate individually detected samples that share a common source. Traditional methods, relying on classifications by human operators or simplistic time-based connections, can be time-consuming and prone to biases and oversimplifications. To address these issues, we...
Lessons learned from more than 20+ years of aerosol sampling have better informed the International Monitoring System community of heightened needs for an updated aerosol monitoring capability. Increased efficiency contributing to delivering lower minimum detectable concentrations, system resilience, system agility and better timely access to data are just some of the heightened performance...
This work is devoted to the study of sorption materials for use in the sample processing device of the MIKS monitoring system of xenon isotopes. The aim of the work was to select new materials with improved sorption characteristics with respect to xenon to ensure stable xenon extraction and reduce the minimum detectable concentration (MDC) for the Xe-133 isotope. To determine the sorption...
In response to the demand for high-sensitivity monitoring atmospheric radioactive xenon isotopes, this study investigates an intelligent dynamic sampling method based on online mass spectrometry technology. Traditional atmospheric xenon sampling processes rely on time-fixed control modes and stable xenon measurement techniques using thermal conductivity detectors, which suffer from issues such...
National Data Centres (NDCs) participated in 2024 Experiment by performing Automated and Interactive analysis of Radionuclide Spectral Data and produced both the Automated Radionuclide Reports (ARR) and the Reviewed Radionuclide Reports (RRR) for a selection of particulate and noble gas sample spectra. The NDC reports are used to produce the baseline reports for comparison with the IDC...
The International Monitoring System (IMS) network of radionuclide monitoring stations is supported by the PTS certified radionuclide laboratories through the analysis of particulate and noble gas samples from these stations.
The purposes of the laboratory analysis are to corroborate the results of the routine analysis of a sample from an IMS station, to provide more accurate and precise...
Since its certification by CTBTO into the IMS network, a total of eight SAUNA III systems and one SAUNA III laboratory have been installed in the field and several additional upgrades are on the way. Four of the installed systems are in the IMS network and the others are independent customers in Europe and the Middle East. On this poster we report on the lessons learned from the first years of...
Radioxenon detection is one of the key methods used in the International Monitoring System (IMS) of CTBTO for detecting a nuclear explosion event. However, since there are numerous civilian sources of radioxenon, such as isotope production facilities and nuclear power plants, any detection of radioxenon must be carefully analysed in order to determine if the source could be a nuclear...
The Comprehensive Nuclear Test-Ban Treaty (CTBT) International Monitoring System (IMS) is designed to provide a network of 80 Radionuclide detection systems, strategically positioned around the globe to detect particulate radionuclide emissions from nuclear explosions. This paper describes progress on the implementation of ultra-sensitive monitoring systems to the IMS, including the...
The calibration procedure used for SAUNA-type noble gas systems has been revisited. Input data to the calibration procedure was resampled using a bootstrapping method, this showed that uncertainties in detection efficiencies and interference correction ratios estimated by earlier procedures were too large. For this reason, the curve fitting method and its uncertainty evaluation was revised....
How can emerging technologies (e.g. machine learning, deep learning, artificial intelligence, cloud computing, etc.) support our core business / mission / verification sciences? The session will draw the connection between CTBTO tasks (data verification related activities) and ML/DL opportunities, identify infrastructure support for ML/DL-related activities, and discuss how to integrate ML/DL...
Underground nuclear explosions create cavities and zones of fractured rock, which can be detected using seismic reflection and inversion techniques. This study focuses on using seismic methods in accordance with the Comprehensive Nuclear Test-Ban Treaty (CTBT) protocols to improve the accuracy of cavity detection. Simulations of wave propagation using the Spectral Element Method (SEM) through...
Gravitational field mapping (GRV) is permitted by paragraph 69 of the CTBT treaty (1996; UN A/50/1027) for deployment during the continuation period of an on-site inspection (OSI) to look for features relevant to underground nuclear explosions (UNEs), including tunnels used for horizontal emplacements, underground voids and collapse features. Whilst the technique offers one of the best...
The inspected State Party (ISP) is a key role for on-site inspection (OSI) integrated exercises as it represents the sovereign rights of the inspected State, and thus keeps the integrated exercise play realistic, while providing a view of what may be experienced by an inspected State and what they may be required to provide in the case of hosting an actual on-site inspection. We will discuss...
Resonance Seismometry is one of the allowed techniques of CTBT that the Inspection team may apply during the continuation period of an on-site inspection (OSI). The intent is to analyse seismic signals (earthquakes, active sources and noise) to detect wavefield disturbances indicative of a cavity or rubble zone caused by an underground nuclear explosion (UNE). However, the technique is only...
On-site inspection (OSI) is a verification mechanism that would strengthen the confidence among States in the Comprehensive Nuclear-Test-Ban Treaty, especially the confidence between IT and ISP during the real OSI. To achieve this goal, a culture of anti-counterfeiting for OSI would be essential for building confidence in OSI activities. Quantum Stealth Code is based on a kind of special ink...
2-D radial electrical resistivity imaging profiles established around ground zero of the 18:45 GMT January 17, 2024 Ibadan, Nigeria explosion was adopted as an on-site inspection geophysical approach to establish the subsurface explosion disturbance pattern and delineate the lateral and depth extents. The blast was reported to have resulted from poor handling of mining explosives causing loss...
An Integrated Field Exercise (IFE) is the most advanced training procedure that simulates an on-site inspection (OSI) and is designed to train inspectors, providing hands-on experience of a potential OSI. Once the Treaty enters into force (EIF), conduct of an OSI on a request of an ambiguous event may become a reality and the OSI inspectorate shall have adequate training to deliver the...
On-site inspections (OSI) serve as the ultimate verification measure under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The Geospatial Information Management for OSI (GIMO) system is critical in these inspections, facilitating mission planning and decision making through advanced geospatial and analytical tools. While GIMO represents a technological leap in inspection methodology, its...
Verification of compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) requires highly accurate analysis methods. Based on the fission products analysis, it is proposed to increase inspections efficiency by using machine learning.
As part of research conducted by students from the National Research Nuclear University MEPhI, a system is currently being developed that automates...
Gravitational field mapping (GRV) is one of the techniques that an inspection team can use during a Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) on-site inspection (OSI). High precision microgravity surveys may be able to detect the gravitational anomalies created by subsurface observables related to an underground nuclear explosion, namely the presence of a cavity around the...
On-site inspections (OSIs) under the Comprehensive Nuclear-Test-Ban Treaty (CTBT) require inspectors to operate in complex environments where radiological concerns may arise. While their primary objective is technical verification, inspectors may need to address stakeholder uncertainties regarding radiation risks. Drawing on lessons learned from the aftermath of the Chernobyl and Fukushima...
On-Site Inspections (OSIs) are critical to the Comprehensive Nuclear-Test-Ban Treaty Organization’s (CTBTO) mission of verifying compliance with the Treaty. The complexity of an OSI necessitates continuous and effective training for surrogate inspectors of the non-standing inspectorate. The computer-based and online training programme is designed to prepare surrogate inspectors for in-person...
In preparation of the next Integrated Field Exercise, and in line with the capabilities developed with past field exercises, action plan project and expert meetings, the section Equipment and Instrumentalization of On-site Inspection division of the PTS has entered into a new stage of development of its telemetry solution. In 2022, the existing data transmission system had been subject to a...
The ENEA Laboratory has been working since many years on difficult-to-measure radionuclides and low level activity isotopes. To achieve low level measurement, dedicated equipment is required as well as specific protocols for the analytical plan. During an OSI, a field laboratory will be run to measure relevant OSI radionuclides, in samples collected in the inspected area. The field laboratory...
A method for assessing the reduction in effectiveness of on-site inspections, taking into account the frequency and duration of potential illnesses among inspection team members, as well as recommendations for reducing the likelihood of these illnesses, has been developed. The models used account for the geographical and climatic characteristics of the regions, as well as the season during...
To improve on-site inspection detection techniques, it is proposed to investigate the area based on changes in the local electromagnetic field of the Earth in the vicinity of the explosion site for residual magnetization.
As part of the research conducted by MEPhI students, approaches aimed at analyzing changes in the electromagnetic characteristics of the environment are being developed....
In the practical scenarios, On-Site Inspection (OSI) could be conducted in any place that is in an environment with radiation hazards. Traditional radiation shielding materials are mainly made of lead-containing rubber materials. Although lead is a good radiation shielding material, its high toxicity, overweight and unstable shielding efficiency also cause irreversible damage to the human body...
This work presents the methodological framework for MAM Microtremor Array Measurements (MAM) and Multichannel Analysis of Surface Waves (MASW) techniques applied for a test site in Magurele, near the headquarters of the National Institute for Earth Physics. MAM provides information about deeper subsurface layers using low-frequency seismic waves, while MASW utilizes high-frequency surface...
The report presents a description and results of ongoing research at VNIIA on the following areas related to CTBT:
- research in the field of a scientific and methodological support and hardware and software for the CTBT on-site inspection activities, provides a comprehensive assessment and analysis of efficiency of controls and data information content published by the International Data...
This paper discusses ways to verify the integrity of information transmitted from tablets of on-site inspectors to a server for inspection data collection. Ensuring the integrity of incoming information is critical in on-site inspection work, as the slightest distortion of data, loss or addition of file, distortion of time and date of information collection, substitution or imitation of...
For verification purposes, it is crucial to obtain comprehensive information time-efficiently. Alongside gamma measurement results, neutron data plays a key role in the evaluation. A promising approach is the simultaneous detection of gamma and neutron radiation using a combined detector, such as the NaIL detector. It is based on sodium iodide (NaI). The NaI is doped with 6Li,...
Once the Treaty enters into force (EIF), the on-site inspection (OSI) team could be in a position to conduct an OSI almost in any environment. The main training process of the OSI Inspectorate, Integrated Field Exercise (IFE), could not practically be performed in demanding and different environments with all possible scenarios. Hence, building up plausible alternatives could be an added asset...
In preparation for the Integrated Field Exercise (IFE) and based on lessons learned from the past field exercises, the Equipment and Implementation section of the On-site Inspection (OSI) Division of the Provisional Technical Secretariat has redesigned the technology infrastructure of the OSI field laboratory for full compatibility of computing platforms, internal data transmission and data...
Measurements of radioactive noble gases, i.e. isotopes of xenon and argon, are an important part for an on-site inspection (OSI) in detecting an underground nuclear explosion. The first integrated field exercise where the capacity to collect and analyse noble gases exercised was in Jordan in 2014 (IFE14). Since then, the development of methods and systems has improved the capacity for xenon...
During on-site inspection (OSI) training or small exercises focused on specific techniques, decontamination control procedures were typically the subject of discussion between IT leadership due to the fictitious scenario, human resources, equipment deployed and limited time. The goal of this presentation is to show and discuss a new approach to establishing a decontamination line,...
The phrase “On-Site Inspections (OSIs) in challenging environments” has been extensively used in reference to OSI exercise environments. For example, the OSI build-up exercise 2024 (BUE2024) was held in somewhat mountainous/rugged terrain and the next Integrated Field Exercise (IFE) is anticipated to be held in a tropical rainforest environment. These are just a few among many other OSI...
The IGU-16HR3C, a cutting-edge wireless seismic sensor developed by SmartSolo, offers transformative potential for geophysical applications, particularly in enhancing the International Monitoring System (IMS) seismic stations, improving on-site inspections (OSIs) and adapting for explosion detection. For IMS stations, part of the Comprehensive Nuclear-Test-Ban Treaty’s global network, the...
The initial overflight (IOF) and the additional overflight (AOF) multispectral (MSIR) configurations for use during an on-site inspection (OSI) have been reengineered to simplify installation, enhance ease-of-use, maximise capabilities as well as streamlining downstream data processing. These changes have been undertaken in compliance with the specifications listed in the First Comprehensive...
On-Site Inspection (OSI) Build-Up Exercise 2024 (BUE24) was a medium scale exercise focusing on the continuation period of an OSI, conducted in Hungary and involving over 150 participants from 37 States Signatories over three weeks in June-July 2024. Considerable work has been undertaken by the OSI Division and wider Provisional Technical Secretariat to develop OSI capabilities since the last...
The On-Site Inspection (OSI) Communications System is an advanced framework enabling seamless and secure communication during inspections under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Designed for rapid deployment, potentially anywhere in the world within six days, it supports real time coordination among inspection team members and between field teams and the Operations Support...
The On-Site Inspection (OSI) Directed Exercises in 2023 were the first field exercises conducted under the framework of the OSI exercise programme for 2022-2025 and the first field exercises conducted since the Integrated Field Exercise in 2014 (IFE14). The Directed Exercises aimed to demonstrate and evaluate progress made in the development of selected OSI technical and operational...
A robust health, safety, and security management system is foundational to ensuring that on-site inspection (OSI) activities under the Comprehensive Nuclear-Test-Ban Treaty are conducted safely, efficiently, and effectively while maintaining the trust and cooperation of all parties involved. A build-up exercise and prior training highlighted three vectors which are integral to instilling a...
The On-Site Inspection (OSI) Exercise Programme for 2022-2025 is envisaged to culminate with the conduct of an Integrated Field Exercise (IFE): the largest and most complex multinational exercises in the field of chemical, biological, radiological, and nuclear non-proliferation and arms control. The primary aim is to test and demonstrate the capability of the Comprehensive Nuclear-Test-Ban...
This paper presents a draft development plan for Radionuclide Techniques in on-site inspections (OSI) for the years 2025-2027. It outlines key areas of focus, including improvements in subsoil gas sampling methods, the integration of meteorological data into analysis and advancements in software for data processing. The plan emphasizes the need for enhanced usability of sampling equipment,...
In preparation for the Integrated Field Exercise (IFE) and in line with the capabilities developed with past field exercises and expert meetings, the On-site Inspection (OSI) Division of the Provisional Technical Secretariat has entered into a new stage of development. Among radionuclides techniques in use at OSI, systems which are operational for gamma radiation monitoring and low resolution...
Particulate and Noble gas data collected during the OSI need to be assessed and integrated with the other OSI techniques in order to create a comprehensive report. While the spectra are analyzed jointly with ISP in the OSI Field laboratory on individual sample level, the results of their analysis shall be integrated over the entire Inspection Area and provide the basis for further refinement...
A nuclear weapon explosion emitted radioactive contamination into the environment. The Comprehensive Nuclear-Test-Ban Treaty (CTBTO) in paragraph 69 of the protocol on “Inspection Activities and Techniques” refers to the tests that must be collected as evidence to prove the origin of the explosion. These samples are collected in a radiologically contaminated area with a risk to inspectors’...
Large scale on-site inspection (OSI) exercises – especially with limited resources directly available on site – require robust support infrastructure well beyond the standard support requirements of an inspection team. Additional exercise participants and teams (such as personnel playing notional “inspected State Party” roles, exercise control team, external evaluation team, management team,...
In 2022 and 2023, the PTS conducted field tests for the development of seismic and non-seismic geophysical techniques for deep on-site inspection (OSI) applications. The 2022 Field Test took place in the Austrian Alps over a cave system in limestone with karst voids 5-15 m in diameter at depths of 40-350 m. Non-seismic methods were deployed over two profiles: electrical resistivity tomography...
In 2022 and 2023, the PTS conducted two field tests for the development of seismic and non-seismic geophysical techniques for deep on-site inspection (OSI) applications. The 2022 Field Test took place in the Austrian Alps over a cave system embedded in limestone with karst voids 5-15 m in diameter at depths of 40-350 m. Active seismic surveys (ACT) and resonance seismometry (RES) were...
The advancement of geophysical acquisition technology is currently growing. One of the technologies that we have begun to develop and apply is the Aero-magnetic and Aero-GPR methods that utilize Drone vehicles. We apply this aero GPR acquisition method to coal mining areas and have succeeded in identifying micro fractures, coal thickness to sedimentation in water reservoirs in exploitation...
The Build-Up Exercise 2024 (BUE24) in Hungary was the first large scale on-site inspection (OSI) exercise to involve a working tunnel complex, opening up new possibilities for the Scenario Task Force designing the exercise scenario. A scenario was developed that involved both radioparticulate detections at the tunnel entrance and radioxenon detections from shallow sub-surface samples taken in...
Ground Penetrating Radar (GPR) is a crucial geophysical technique used by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) during On-Site Inspections (OSI) to detect and investigate subsurface anomalies potentially associated with underground nuclear tests. This paper explores the application of the open source software “GPRmax” to simulate GPR scenarios relevant to OSI missions....
The zero-yield standard prohibits explosive experiments involving a supercritical fission chain reaction while permitting subcritical experiments. The latter are still conducted by certain nuclear weapon states today to ensure the performance and safety of their nuclear arsenals. However, there have been growing tensions between these states as they suspect each other of violating the...
Contrary to expectations based on simulations of neutron irradiation, the discharges from medical isotope production facilities (MIPFs) differ from the radioxenon isotopic activity ratios typically associated with decay chain ingrowth following a nuclear explosion whenever 131mXe is present. This discrepancy is explained in this presentation through fundamental physical principles and...
The invention of quantum mechanics is this year a century old, and you would have thought that most its applications would have been discovered. Nothing could be further from the truth. This field of research is more active than ever before with most of the attention going to quantum computing: a new form of computing based on the principles of quantum mechanics and is predicted to outperform...
Noble gas tracers play a crucial role in environmental transport experiments, offering valuable insights into gas movement and interactions in both the subsurface and atmosphere which can be used to enhance noble gas sampling strategies for On-Site Inspections (OSI) and inform noble gas source terms for the International Monitoring System (IMS). The selection of appropriate noble gas tracers...
Global scale infrasound observations confirm that the detection capability of the International Monitoring System (IMS) infrasound network deployed to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is the most variable among the three waveform technologies. The time- and space-dependent dynamics of the different atmospheric layers explain the typical diurnal and...
This study examines the efficiency of off-gas systems in Molten Salt Reactors (MSRs) and their influence on radioxenon release trajectories, with implications for the International Monitoring System (IMS) under the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). Expanding on previous work analyzing radioxenon dispersion from the TMSR-LF1 reactor in China (Retnoasih, 2023), this...
The auxiliary seismic station AS40 in Lembang, part of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) network, is also registered as a seismic monitoring station in Indonesia under the code IA LEM. In addition to its primary role in monitoring nuclear events, this station is used for earthquake location determination. This study relocated earthquake hypocenters using the HypoDD...
Technology refreshment is an important part of CTBTO’s mission. The IMS was designed in the 1990s, often using equipment and technology that was mature at that time. As technology advances, the possibility arises that sensing technologies that were not available at the beginning of the IMS may be capable of improving its performance, robustness and sustainability. The panel will discuss...
The SAUNA III and three SAUNA QB networks in Lithuania for radioxenon detection in the atmosphere have been successfully launched at the end of 2024. The SAUNA QB modules have been installed on the border of Lithuania: SAUNA QB in Kackonys, on the eastern border, two others SAUNA QB modules on the western and southwestern border of Lithuania at Šventoji and Kybartai towns respectively, and...
Recent advancements in commercial satellite technology have emerged as powerful tools to support Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification efforts. This presentation explores the potential of high resolution satellite imagery to enhance monitoring and verification capabilities. It delves into recent analyses of activities at both current and former nuclear test sites, as well...
Many source-term estimation algorithms for atmospheric releases assume there is no influence from nuisance sources. However, industrial sources result in a world-wide background of xenon isotopes (Miley and Eslinger 2023) that are also useful for detecting nuclear explosions. A large synthetic data set of atmospheric samples was developed for 384 release events with varying levels of 133Xe...
During an on-site inspection (OSI), the collection and analysis of environmental samples in the inspected area is allowed by the Treaty and its Protocol. The procedures for the selection of the samples and their collection are described in the draft Operational Manual and in the related OSI documentation. A field mission must be carefully planned and, based on its objectives, the inspectors...
ALGE is a 3-D aqueous model capable of simulating thermal and contaminant transport, including the fate of dissolved and particulate materials, along with suspended sediment. The model has been applied to quantifying cooling dissipation and providing consequence assessment for accidental releases of chemicals and radionuclides in complex ecosystems. The ALGE model is currently prepopulated for...
Today, the second quantum revolution is unfolding across the globe, driving the development of disruptive quantum technologies with the potential to reshape science, industry, and society. These technologies promise to open new commercial frontiers, address pressing global challenges, enhance strategic security capabilities, and enable future applications that are currently beyond...
An on-site inspection (OSI) foresees the use of multi-geophysical methods to investigate the presence of possible underground nuclear explosion (UNE)-relevant observables at a given site to assist in identifying any possible violator of the Comprehensive Nuclear-Test-Ban Treaty. We present the results of numerical simulations obtained by means of Python functions based on the Simpeg libraries,...
Ground based observing networks (e.g. CTBTO/IMS, FDSN) usually have static metadata. Some observing systems have rapidly changing metadata (e.g., moving stations) difficult to include in existing formats. The RCM project enables standardized methods to include rapidly changing metadata, improving FAIRness (Findability, Accessibility, Interoperability, and Reusability) of data. Project RCM’s...
We present a framework for developing Large Language Model (LLM) applications that integrate with various data sources and systems, enabling advanced AI-driven capabilities. Our approach focuses on automating time-consuming/repetitive tasks that require knowledge work through incremental deployment of LLM applications, which can process unstructured information in a common sense manner. We...
The inspection team functionality (ITF) is the conceptual framework that guides the inspection team during a Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) on-site inspection (OSI). ITF provides a structured thinking space, which limits the impact of cognitive bias and noise on the decisions taken by the inspection team. With that purpose, ITF acts as a regulatory system that slows...
Innovation is playing an important role today and will even play a more critical role in the years to come. This also applies to the RN technology / equipment currently in use in the IMS network and OSI. The panel will discuss topics such as: the impact of cutting-edge technologies and novel materials in radionuclide detectors design and sensitivity, including AI and ML; understanding whether...
On 17 August 2024, an mb6.0 earthquake at a depth of 29 km occurred approximately 102 km southeast of Petropavlovsk-Kamchatsky, Russian Federation. The earthquake triggered the eruption of the Shiveluch volcano the following day, producing a 9000-meter ash plume. Using his Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) National Data Centre NDC training from 5 to 16 August 2024 in...
The Afar Region, located in East Africa, is characterized by significant geological dynamism due to its distinctive tectonic setting. This complexity presents both challenges and opportunities for scientific research and sustainable development. A deep understanding of the region's tectonic processes is crucial for mitigating hazards and maximizing its potential. The primary goal of this study...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) recently installed a capacity building system (CBS) at the National Data Centre (NDC) in Bangladesh. The CBS is designed to help technical staff use the CTBTO International Monitoring System (IMS) data and International Data Centre (IDC) products more efficiently and accurately. Through this new CBS that comes with some analysis...
Madagascar is located on the African Plate and is not intersected by any plate boundaries. Despite this, the East African Rift (EAR) extends into the island, suggesting potential tectonic influences. Given Madagascar's position within the African Plate, it would theoretically be expected to exhibit low seismic activity and relative tectonic stability. However, contrary to this assumption, the...
Regional seismic travel time (RSTT) is a global model (Myers et al. 2010, Begnaud et al. 2021) that rapidly predicts travel times of regional seismic phases (Pn, Sn, Pg and Lg), while accounting for key effects of the three-dimensional crustal and upper mantle structures. RSTT is currently used by the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization for...
The international community, mindful of the severe impact of nuclear test explosions, agreed to positive measures to reduce and prevent the further use of these weapons of mass destruction. Hence, the adoption of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) by the United Nations General Assembly in 1996 was an essential step in the field of nuclear disarmament and non-proliferation for...
Malaysia signed the Comprehensive Nuclear-Test-Ban Treaty (CTBT) in 1998 and ratified it in 2008. To demonstrate its commitment, Malaysia established the National Data Centre (My-NDC) to maximize its CTBT membership. Initially, with only three analysts, My-NDC has grown to 20 analysts from diverse backgrounds. A key challenge is the effective training of these analysts to ensure optimal...
Crustal thickness beneath Mongolia was determined using the teleseismic receiver function H-k stacking method, which employed waveform data from broadband seismic stations in Mongolia. The findings reveal that the crust of Mongolia thickens from east to west, with the thickness reaching 63 km in western Mongolia and 35.9 km in eastern Mongolia. In the central part of Mongolia, the average...
Earthquake monitoring in Namibia dates back since 1900s. In 2010,Namibia's Seismological Network only had six permanent seismic stations with aging equipment that were continuously failing, making it difficult to accurately monitor earthquake activities. In 2014, a National Seismological Network expansion project commenced to completely overhaul the Network. With advent use of social media,...
Jamaica is located in a seismically active zone in the northern Caribbean where historical events including the 1692 Port Royal and 1907 Kingston earthquakes resulted in significant loss. The 2023 magnitude 5.6 earthquake and 2024 magnitude 5.2 earthquake highlighted the continued risk from significant ground shaking and the propagation of seismic hazards. Over the last two years, the...
The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) comprises 170 seismic, 60 infrasound, 11 hydroacoustic and 80 radionuclide stations, along with 16 radionuclide laboratories, distributed across 89 countries worldwide. Deployment of the network began in 1996, when the Treaty was opened for signature. The initial focus was on the...
Panel on the technological and logistical challenges of ensuring the long-term sustainability of the IMS network into the future. The outcomes of the panel will be to learn from the various strategies and discussions proposed in order to constantly improve the IMS sustainment strategy, and this will be obtained through: encouraging network managers/operators to share their experiences and...
FOLDS is a system being developed enabling seismological data centres with legacy data collections to create, curate and distribute standardized metadata and image files related to analog seismic records. The system will promote data reuse, following FAIR principles, leveraging a new suite of International Federation of Digital Seismograph Networks (FDSN) web services similar in capability to...
The isotopic ratio of radioxenon is crucial for distinguishing between civilian sources and nuclear explosions. This study focuses on using the Xe-135/Xe-133 ratio to precisely determine the origin time of detected radioxenon. Due to the shorter half-life of Xe-135 compared to Xe-133, this ratio decreases over time, serving as a reliable indicator for estimating the sample's age.
At the...
Bolides, or exceptionally bright meteors resulting from the atmospheric entry of asteroids or meteoroids typically over 10 cm in diameter, provide significant infrasound sources for global monitoring efforts. Originating from cometary or asteroidal fragments, these objects enter Earth's atmosphere at hypervelocity, generating shockwaves that decay into low-frequency (<20 Hz) sound or...
Continued sustainment of the International Monitoring System (IMS) network is of critical importance to the longer term viability of the Comprehensive Nuclear-Test-Ban Treaty. Increasing global costs and budget constraints may limit the level of future investment in the maintenance and operational costs of the IMS. To mitigate this financial restriction, individual sub-systems of radionuclide...
Localization and characterization of nuclear detonations can be accomplished using various observation techniques, including seismic and infrasound data. In both cases, accurate knowledge of the propagation medium - specifically, Earth's subsurface and atmospheric properties - is essential for reliable inversion results. This study introduces a joint inference framework designed to localize...
Although more than 90% of the International Monitoring System (IMS), operated by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has been installed, over the next decade, a large proportion of IMS stations will reach the milestone of 20+ years post-certification with continuous operation. Thus, in order to develop a strategy for the long term sustainment of the IMS, the expected...
The Central and Eastern European Infrasound Network (CEEIN) was established in 2018 as a cooperative initiative among research institutions in Czechia, Austria, Hungary and Romania, with Ukraine joining in 2019. Currently, CEEIN consists of 10 infrasound arrays, making this a dense network with great monitoring capabilities. This study presents the biannual CEEIN bulletin for 2023 and 2024,...
Characterizing seismic sources is critical to accurately constraining important seismic source features of interest. Many factors affect seismic far-field waveforms (FFWFs) used for source characterization, including physical characteristics near the source, such as emplacement or ground material properties. How near-source characteristics and the methods with which we estimate source features...
Urban environments present unique challenges for seismic event monitoring and discrimination. Persistent anthropogenic noise can reduce the signal-to-noise ratios of seismic events and impulsive man-made events can falsely trigger detection algorithms. One approach to improving our monitoring algorithms—to accommodate diverse detection environments—is to incorporate more dynamic anthropogenic...
Collaborating with station operators and representatives from National Data Centres has been an important part in developing a sustainment strategy for the International Monitoring System (IMS), operated by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). A questionnaire was distributed to all station operators and representatives from National Data Centres. The questionnaire...
The discovery and vectorization of legacy seismic data are two of the barriers to the (re)use of seismic data recorded on physical media. Challenges to use include imaging the large numbers of records, metadata discovery and curation, and the creation of time series accessible to modern processing methods. Here we describe and demonstrate progress on the development of an open source...
This study provides comprehensive documentation and detailed information on Funvisis' extensive experience in managing AS117 and AS118 for over two decades, as part of Venezuela's commitment to the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). This article presents a robust methodology based on thorough records of both preventive and corrective maintenance carried out at these...
The 'Waveforms From Nuclear Explosions (WFNE)' repository includes detailed information (origin, bulletin, other geophysical data) on all the 2,157 atmospheric, underground and underwater nuclear explosions detonated in the world between 1945 and 2017. Over 146,600 waveforms recorded at 343 stations in 78 countries are associated to 1,109 of the nuclear explosions, ranging from digitized...
Understanding the propagation of long-range acoustic waves is a cornerstone of infrasound research, yet solving the wave equation remains a computationally intensive challenge. This complexity is further exacerbated by the need for recalculations whenever the sound speed structure or source characteristics change. In this study, we present an innovative application of the Fourier Neural...
Given the existing radioxenon and radioaerosol backgrounds encountered by the IMS, detections of multiple isotopes are useful for screening purposes. We examined this issue by using six UNE release scenarios, including fractionated ones based on the literature, and subsequent atmospheric transport to IMS stations. The study identifies those radioisotopes (radioxenon and particulate) that are...
The establishment of the Comprehensive Nuclear-Test-Ban (CTBT) International Monitoring System (IMS) network has progressed at an impressive pace in the last 25 years: to date, 90% of the network has been built and is operational. While major efforts are made by the Provisional Technical Secretariat (PTS) to complete the establishment of the network, the challenge of sustaining the IMS...
A large number of records of nuclear tests conducted at various test sites and different environments around the world remain in the archives of historical analog seismograms in the Seismological Agencies of Central Asian countries. At the same time, not enough attention has been paid to the study of the features of the wave pattern of atmospheric nuclear explosions in comparison with...
The Nuclear Explosion Legacy Data (NELD) Repository was designed and built to store analog scanned and digitized data in a format consistent with the CTBTO PrepCom database. It follows and extends the CSS/IMS formats for the time series data and station metadata. NELD repository includes over 2,000 scanned seismic recordings but can be easily extended to a digital waveform repository. Scanned...
Various nuclear test monitoring techniques require numerous waveforms and expect good spatial coverage of seismic source. The examples, inter alia, are master-event based location and event discrimination, needing data augmentation due to class imbalance and synthetic seismogram simulation can make a job. Generative Networks (GN) are a novel way of producing realistic, high-quality synthetic...
Recently, the detection of two small seismic events that have occurred close to sites where North Korea carried out underground nuclear weapons tests was reported in the literature. A seismic event, considered to be a small earthquake of magnitude 1.5, occurred on 12 May 2010 close to the site of the 25 May 2009 underground nuclear test (UNT) in North Korea. Another seismic event of magnitude...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) plays a pivotal role in global nuclear non-proliferation efforts through its extensive monitoring systems designed to detect natural phenomena and also nuclear explosions. The ongoing progress of upgrading CTBTO seismic sensors in Indonesia highlights the nation's commitment to supporting the International Monitoring System (IMS)...
Rocket launches and reentries are powerful atmospheric noise sources detectable at infrasound arrays in thousands of kilometers distance. Recorded signatures originate from the ignition, launch, supersonic movement, stage separation and reentry of rockets within the first about 100 kilometers of altitude of the atmosphere. We use IMS infrasound data to localize and characterize these events...
The Timisoara Seismological Observatory has a history of over 120 years and contributions to the early stages of seismic monitoring in Europe. It hosts a well-preserved collection of seismograms dating from the early 1950 until the late 2000. During the process of sorting and indexing chronologically the seismogram collection, recordings of nuclear tests on different types of instruments were...
Characterisation of seismic sources, including earthquakes and explosions, is of interest to the nuclear-test-ban verification community. At local to near-regional distances (≤300km) signals from quarrying, mining and controlled explosions are commonly observed in addition to earthquake seismicity. We investigate the ratio of P- to S- wave amplitudes as a seismic source discriminant for...
The re-entry of NASA’s OSIRIS-REx Sample Return Capsule (SRC) into Earth’s atmosphere in 2023 provided a unique opportunity to detect and analyze infrasound generated by a controlled atmospheric entry. As the SRC traversed denser atmospheric layers at hypervelocity, it produced shock waves that decayed into acoustic signals. The strategic placement of ground-based and airborne sensors along...
With the certification of the hydroacoustic hydrophone station HA4 Crozet in 2017, the International Monitoring System (IMS) hydroacoustic network became the first component of the IMS to be completely certified. Six of the 11 IMS hydroacoustic stations are cabled hydrophone stations with triplets of hydrophones suspended by risers in the deep sound channel; the remaining five are T-stations...
A transfer learning approach was adopted, using a VGG16 neural network model to classify earthquakes from non-earthquake events in North-East China, close to the North Korean test site. Magnitudes below 4 are considered for classification of tectonic events (earthquakes) from explosions. Because of the scarcity of observed explosion data, synthetic seismograms were generated using SW4 to...
On 28 May 1998, Pakistan detonated its first nuclear explosion. The teleseismic P-waves from this seismic disturbance are complex compared to those typically observed from underground explosions. We observe a spatial correlation between waveform simplicity and take-off angle; with the most simple seismograms being recorded at small take-off angles at the source (${\Delta}$ < 15$^\circ$) and at...
The need for a clear and transparent approach for sustaining the International Monitoring System (IMS) network has grown since the early days of the Provisional Technical Secretariat (PTS), when activities primarily focused on the installation and certification of IMS facilities. Today, as much of the network is ageing, efforts have shifted towards modelling and anticipating future needs for...
The global verification system under the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is designed to detect all nuclear explosions on Earth, with seismic monitoring relying on the International Monitoring System (IMS) to identify explosion signals. This study applies Moment Tensor (MT) inversion analysis to assist States Parties through expert technical analysis (ETA) of IMS and additional...
The three-dimensional (3D) spatial analysis of radioxenon isotopic activity ratios is a powerful approach for the determination of the time of a nuclear event. In contrast to the 2D planar analysis, this method requires at least a triple detection from the same sample among the four CTBT-relevant radioxenon isotopes, which are 131mXe, 133mXe, 133Xe, and 135Xe. One method of the 3D spatial...
Between 1965 and 1987, 39 peaceful underground nuclear explosions were conducted by the USSR on the territory of Kazakhstan, 17 of them at the Azgir Test Site, located in Western Kazakhstan. The Test Site is located on the Bolshoi Azgir salt-dome uplift, on the western part of the Pre-Caspian saline province located north of the Caspian Sea. At the Azgir Test Site, for research purposes, in...
For the past several years, Sandia National Laboratories (SNL) has been working to digitize, recover, and calibrate seismic data from its archive of hundreds of analog magnetic tapes. These tapes are original archives from the historical nuclear testing era, some dating more than 60 years old, and contain analog waveforms of regional seismic data of historical U.S. underground nuclear tests...
Seismic moment tensors are a fundamental tool used to characterize events of interest to the nonproliferation community. Understanding and quantifying the uncertainty in moment tensor solutions are key to that characterization task. There are many sources of uncertainty confounding the accurate recovery of moment tensors, including imperfect knowledge of Earth structure between the source...
The historic nuclear test sites of the world provide a key resource in legacy seismic measurements. Many of the seismic recording stations in place for historic tests have been abandoned as new locations have been established. We deployed sensors equivalent to those installed in the 1980s with modern equivalents at historic seismic station locations to compare measurement and site...
PS02/WRA, the Warramunga Seismic Array in Australia’s Northern Territory, operates in one of the most challenging environments within the International Monitoring System (IMS). Certified since December 2000, the station has been critical to the IMS global monitoring network. Recent engineering activities have focused on enhancing its resilience to environmental hazards, including flooding,...
The IASPEI Reference Events List, referred to as the “Ground Truth” (GT) event list, is a database of earthquakes and explosions where the epicentral location is known to a confidence of within 10 km. GT events support nuclear test monitoring and the mission of the Comprehensive Nuclear-Test-Ban Treaty by aiding NDCs in improving event location accuracy. We will present a new Preliminary GT...
Six underground nuclear explosions (UNEs) were conducted at the DPRK nuclear test site in 2006-2017. Magnitudes of these events varied from 4.3 to 6.3. We analyzed seismograms of UNEs and near earthquakes, obtained by stations MDJ and VLA at distances of ~270-450 km to investigate characteristics of the attenuation field. We studied the ratios of maximum amplitudes of Lg and Pg waves (Lg/Pg...
The International Monitoring System network, the national networks of different countries, consists of various facilities and a variety of equipment and designs deployed in different parts of the globe. The operation and maintenance (O&M) of these facilities in order to achieve the required level of data availability and quality is very challenging and requires resource mobilization, planning,...
The National Preparedness Exercises (NPE) are held regularly to practise analysis and test procedures within the NDCs and in exchange with the IDC. The German NDC has been organising the NPE series since 2007. The NPE 2024 was announced by the fictitious NDC Andlantis in the NDC Forum. Key elements of the information released included:
- National seismic data in a rather unusual format...
During the SnT2023, Mulwa and Dindi (2023) presented case examples of systematic seismic events discrimination methods at KE-NDC. The results were subsequently published in Pure and Applied geophysics journal (see Mulwa, 2024 in PAGEOPH, https://doi.org/10.1007/s00024-024-03458-4). The NPE2024 entailed a request by the State of “Andlantis” for Expert Technical Analysis (ETA) of potentially...
At the KMBO 3C primary seismic station, International Monitoring System and Global Communications Infrastructure (GCI) equipment are powered by 240 VAC mains power. A power stabilizer is installed, which regulates the input AC mains power voltage between 180V and 260V. Station visits for routine operation and maintenance are performed once every calendar month. Before 2021, the seismic station...
Kandilli Observatory and Earthquake Research Institute (KOERI) was established in the 1800s during the Ottoman Empire as the Imperial Observatory and has conducted observations in meteorology, astronomy and seismology for over a century. KOERI expanded its seismic network and ability to determine earthquake parameters, evolving with advancements in seismology. Over time, it built a rich...
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A new method to invert regional seismograms had recently been presented to extract the yield and depth of explosions which are accompanied by contributions from both double couple (DC) and a strong compensated linear vector dipole (CLVD) source (presented in this conference by Saikia). In this paper, we are applying this approach to investigate the reliability of the yield and depth of the...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) relies on a global network of experts in science, technology, policy, and operations. Building the next generation of specialists to carry this mission forward is central to the work of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).
This panel offers insights into career pathways within the CTBTO and the wider field of nuclear...
The Global Volcanism Program (GVP) includes comprehensive list of the 1281 Earth's active volcanoes and their eruptions over the last 12,000 years. In this work, we used the web-based GVP database of the Smithsonian Institute to correlate detections from the International Monitoring System (IMS) infrasound network in the period 2011-2020. According to GVP data, 360 eruptions (or confirmed...
The Standard Screened Event Bulletin (SSEB) from the IDC Product of the CTBTO provides a detailed and accurate record of global seismic activity, serving as a key tool for analyzing tectonic patterns and studying significant events. This study focuses on global seismicity recorded during the year 2024, ***emphasizing the identification of events with a magnitude greater than Mw: 4,...
In this study, we present the assessment of the hypocenter location and the dissemination information in the Indonesia Tsunamy Early Warning system (INATEWS), Indonesia. The determination of accurate hypocentral parameters is crucial in seismic monitoring and early warning. In this study, we present the earthquake parameters computed by SeiscomP from the January 2020 to December 2024 scale for...
The CTBTO maintains a global network of monitoring stations with air filtering equipment to detect radionucleotide signatures. These air filters also pick up plant, animal and microbial DNA that has been scattered on the wind. This environmental DNA (eDNA) can be profiled to catalogue species, providing the opportunity to monitor ecosystem changes and track biodiversity at an unprecedented...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) relies on a global network of monitoring stations, including auxiliary seismic stations, to detect and verify seismic events. Ensuring the reliability and quality of data from these stations is critical for maintaining the integrity of the CTBT verification regime. However, noise, signal contamination and equipment anomalies can compromise data...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) faces evolving challenges in its mission to monitor and verify nuclear-test-ban compliance due to the intensifying effects of climate change and the increasing frequency of severe natural disasters. The CTBTO's International Monitoring System (IMS) must now contend with heightened environmental noise, data anomalies and system...
The oceans are filled with acoustic waves, which are trapped in a low-velocity layer at about 1 km water depth. The sound speed of these waves strongly depends on the temperature. An increase in temperature will lead to an increase in the sound speed and hence shorter travel times. IMS hydro-acoustic stations measure these waves continuously and travel times can be obtained through the cross...
As part of its commitment to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the Philippines started the operation of its radionuclide station RN52 at Tanay in 2005 under the International Monitoring System (IMS). The station can detect not only anthropogenic radionuclides which may indicate existence of nuclear explosions, but also natural radionuclides such as Lead-212. Lead-212 is...
This study focuses on the importance of data integrating Jordanian national stations with the International Monitoring System (IMS) network of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) in enhancing earthquake and explosion detection capabilities in Jordan. It includes analytical comparison of local and regional events between results that were obtained from the seismic...
The International Monitoring System (IMS) is deployed at locations around the world, allowing for potential linkages to other data streams. One example of this is the correlation between radionuclide data and climate phenomena (e.g. monsoons). Due to the varying climate conditions, the IMS is well positioned to investigate potential signatures for climate change indicators through the...
The method of tsunami splitting is applied to analyse tsunami hazards along the eastern Indian coastal regions, specifically the states of West Bengal, Odisha, Andhra Pradesh, Tamil Nadu, the Andaman and Nicobar Islands, as well as Sri Lanka. This approach involves segmenting the tsunami event into distinct phases—deformation, propagation, and inundation—and simulating each phase using Finite...
Climate change is a matter of both geopolitical and regional concern. In order to address it comprehensively, Global Climate governance is a crucial issue that requires both scientific and practical attention. Climate change governance is an emerging domain that has a complex relationship with public and state administrative structures. In recent times the Comprehensive Nuclear-Test-Ban Treaty...
How can Artificial Intelligence (AI) enhance the CTBT’s verification regime and contribute to confidence-building among States Parties, while promoting science diplomacy to achieve universalization and entry into force? This paper explores the potential of Artificial Intelligence to revolutionize the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime and foster international...
Eruptions at continental basaltic volcanoes, the dominant mode of volcanism on Earth, can take and combine various forms, including lava lake, lava flows and fountaining, explosions or structural collapses. Aside from a few well-instrumented cases, accurately reconstructing their precise processes and chronology is hampered by the lack of detailed visual observations in space and time....
The National Nuclear and Radiological Emergency Plan (NNREP) outlines Nigeria’s strategy for a coordinated and timely response to radiation emergencies, integrating local, national and international efforts to protect public and worker safety. The CTBTO’s International Monitoring System (IMS) and International Data Centre (IDC) provide advanced technologies and data for detecting nuclear...
The Plurinational State of Bolivia has been striving to establish a seismic building code for over 12 years. While some building guidelines on 'how to build' were previously developed, they did not comprehensively address critical aspects related to seismic hazard. Although Bolivia experiences moderate seismic activity, destructive earthquakes have occurred with recurrence intervals of...
On 25 August 2024, around 6h50 UT, Bolide impacted the Earth atmosphere over South Africa. This event was recorded at some IMS infrasound arrays in Southern Africa. Data analysis were performed using GTK-PMCC software (CTBTO) based on PMCC method (Y. Cansi 1995). A pass-band frequency between 0.1 Hz and 4 Hz is applied to detect the source. As results from infrasound station I47ZA, azimuth is...
The Chemical Weapons Convention and the Comprehensive Nuclear-Test-Ban Treaty were both adopted in the early to mid-1990’s, a time of renewed hope for global disarmament and non-proliferation efforts. In the decades since, both implementing organizations for these instruments – the Organisation for the Prohibition of Chemical Weapons (OPCW) and the Preparatory Commission for the Comprehensive...
At KNDC, data from Makanchi's PS23 array revealed a large number of similar events with sources in the area of large glaciers in Tien-Shan. All events are in the 185-190 back-azimuth range at a distance of 550 km south of the station. The size of the epicentre area were about 90x90 km. Daily and seasonal variations in the number of events recorded were revealed, and their energy and magnitude...
A software framework - Nuclear Event Monitoring Simulator (NEMOS) - has been developed to simulate the response of sensor networks, which are intended to detect, identify and locate nuclear explosions and other nuclear events. NEMOS simulates the response from seismic sensors, infrasound detection sensors and several types of radioactivity instruments (GM - tubes, NaI- sensors; either...
Nuclear explosions have enormous environmental impacts on the planet and its systems, which intersect with climate change in a variety of ways. Analogous to climate change, these impacts and their social repercussions are unequally distributed. The importance of education, effective science communication and an intersectional social understanding are paramount to building public...
Earthquake is one of the foremost disasters which cause severe disruption of life and property. In Bangladesh, earthquake is considered as hidden disaster as the country is tectonically located at the junction of three tectonic plates (Eurasian, Burma and Indian plate). To understand the potential risks of the deadly catastrophe in Bangladesh, an earthquake distribution map was prepared using...
The International Monitoring System (IMS) offers a vast amount of data that can advance scientific research beyond treaty verification. Here, observations of beryllium-7 (Be-7) that are made by particulate radionuclide IMS stations are considered to study atmospheric processes. Be-7 is a cosmogenic radionuclide that is produced mainly in the upper troposphere and lower stratosphere....
Seismic events in South Africa are recorded by the national seismograph network and located with the SeisComp software. Seismic events include earthquakes, mining-related events associated with deep gold and platinum mining, and explosions that occur in opencast mines. Suspected explosions are identified through their geographical association with opencast mines and the time-of-day. From April...
RSMC Beijing became one of the world’s eight Regional Environmental Emergency Response Centers by the end of 1996. Since 1997, it has provided nuclear incident response exercises for the IAEA under the WMO framework and has offered source reconstruction services for CTBTO’s IMS monitoring stations since 2003. The center’s current environmental emergency response system is based on China’s...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) processes data from the International Monitoring System (IMS), which, though primarily used for nuclear explosion detection, also has valuable applications in scientific and civil domains. As the effects of climate change become more evident each day, it is crucial to keep the topic alive and continue exploring ways IMS data can...
This study examines the evolution of radionuclide detections over time at eight stations within the CTBTO IMS network: SEP63 and SEX63 (Stockholm, Sweden), RUP61 and RUX61 (Dubna, Russian Federation), DEP33 and DEX33 (Schauinsland, Germany), and NOP49 and NOX49 (Spitsbergen, Norway). Data covering the period of 2021 to 2024 were analysed and compared using the RNToolkit software. The...
This study presents a real time technology for detecting and classifying geophysical events using acoustic signals. Initially developed for tsunami monitoring, the system integrates advanced computational models and machine learning algorithms to process acoustic data and extract event characteristics, including location, magnitude and fault dynamics [1]. The methodology facilitates real time...
The European-Mediterranean Seismological Centre (EMSC) monitors earthquakes on a global scale by merging the parametric data shared in real time by 113 networks; this represents almost 9 500 seismic stations, 5 million arrival times and 114 000 earthquakes (median location time: 15 minutes). The presence of the main global networks (e.g. NEIC, GEOFON, etc.) and numerous national networks among...
According to the scarce journalistic records, scientific reports and the testimony of some inhabitants in Paraguayan territory, volcanic activity in the Andes Mountain Range has had repercussions in Paraguayan territory. This refers to the dispersion of tephra originating from different volcanic conduits of the subduction zone type in the Pacific Ring of Fire located in the Chilean Andean...
A study examined seismic hazard in Thailand's central plain, characterized by a thick quaternary basin. Unconsolidated sediments may amplify seismic ground shaking, potentially increasing structural damage. The research resulted in a fundamental frequency map derived from HVSR analyses at 149 microtremor sites. A Vs30 map was subsequently generated using HVSR inversion methods, alongside a...
Jordan's seismicity is heavily influenced by the Dead Sea Transform Fault (DST), a significant tectonic boundary between the Arabian and African plates, posing the highest seismic risk to the region. Historical earthquakes, including those in 749 AD and 1033 AD, highlight this threat. Other regional sources, such as the Zagros Fold and Thrust Belt in Iran, the Red Sea Rift and the Cyprus Arc,...
Indonesia, located at the intersection of major subduction zones and active fault systems, such as the Sunda Trench, Lembang and Cimandiri Faults, is vulnerable to seismic hazards that pose risks to critical infrastructure, including nuclear research reactors.
This study evaluates seismic risks at three reactor sites — Kartini (Yogyakarta), Swabesi (Serpong) and TRIGA 2000 (Bandung) — using...
On 25 August 2024, at approximately 06:50 UTC, several stones from an achondrite meteorite fell around the town of Nqweba, Eastern Cape, South Africa, following a widely observed meteor fireball and detonation. The infrasound station I47ZA, located in Boshof, South Africa (about 590 km north-northeast of Nqweba), detected an atmospheric disturbance generated by an energy release between...
The Tsunami Programme of the UNESCO-Intergovernmental Oceanographic Commission (UNESCO-IOC) coordinates tsunami warning and mitigation activities around the globe. As of today, 21 National Tsunami Warning Centres (NTWC) in 20 CTBT Signatory States benefit from the agreement between the CTBTO PrepCom and UNESCO allowing transmission of real-time IMS data to NTWCs recognized as such by UNESCO....
Proponents of nuclear deterrence generally see it as a stabilizing factor in state security relations. However, it might have contributed to the destabilization of climatic security instead. Today, climate crises are affecting states in multiple ways and there is a developing census that it is becoming a key security threat to humanity. However, there is little understanding of how the...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operates an advanced network system of the International Monitoring System (IMS) designed to detect nuclear explosions. Beyond its primary mission, the IMS's network of seismic, infrasound, hydroacoustic, and radionuclide stations provides invaluable data that can be used by researchers for climate change studies. This presentation...
This study assesses the need for an infrasound station facility in Indonesia, with Ujung Kulon, West Java as one of the potential sites. Indonesia relies on infrasound data from nearby countries limiting independent monitoring of detail events. Data from IMS stations like I06AU, I39PW and others provide insights, however are insufficient for comprehensive monitoring.
The installation of an...
This study examines the profound psychological effects of nuclear weapons proliferation on global populations. The constant threat of nuclear conflict creates a pervasive sense of fear and anxiety, impacting mental health and societal stability. Historical instances, such as the Cold War, highlight the long-term psychological stress experienced by individuals living under the shadow of...
The history of earthquakes in the southern region of Java Island has seen large earthquakes with Mw above 7.0, including earthquake and tsunami events in 1921 (Mw 7.6), 1994 (Mw 7.6), 2006 (Mw 7.7) and 2009 (Mw 7.3) which occurred along the Java subduction. The location of the tsunami modeling study with coordinates 6,750 LS - 7,499 LS and 106,249 BT - 106,750 BT. The study was conducted...
Bali Island is one of the areas in Indonesia that is categorised as a tsunami-prone area due to the existence of the Java Megathrust in the southern segment of Bali, which holds a maximum magnitude of up to M 9.0, which can trigger a tsunami. This study aims to model tsunami wave heights and wave arrival times based on the maximum earthquake scenario in the southern Bali megathrust zone. The...
Aircraft crashes into oceans generate unique hydroacoustic pressure signals detectable across vast distances. This study leverages data from the Comprehensive Nuclear-Test-Ban Treaty Organization’s hydroacoustic network to examine the acoustic signatures of historical aircraft incidents. Specifically, the analysis revisits the disappearance of Malaysia Airlines Flight 370 (MH370) and explores...
The 2020 Atlantic hurricane season was one of the most active on record, with tropical storms Eta and Iota causing widespread disasters in Nicaragua, Honduras, and Guatemala. These storms triggered floods and landslides in Guatemala, leading to fatalities, disappearances, and significant damage to housing and livelihoods, exacerbating a humanitarian crisis already strained by COVID-19...
The World Meteorological Organization (WMO) supports its Members and related international organizations such as the IAEA and the CTBTO regarding nuclear incidents and accidents and the determination of possible source regions related to anomalous, treaty-relevant radionuclide measurements. To respond to nuclear emergencies 24/7, Ten WMO Members WMO Integrated Processing and Prediction System...
As part of the Xenon and Environmental Radionuclide Analysis at Sizewell (XENAS) experimental campaign, a UK-based Pressurised Water Reactor (PWR) nuclear power station (Sizewell B) has provided access allowing measurement of several radionuclide monitoring process routes. This work aims to provide an overview of the experiment, discuss its motivations, present the results obtained to date and...
The CTBTO is renowned for its success in building up the CTBT verification regime, collecting and analyzing data, and sharing timely information with state signatories to monitor compliance with the Treaty. Post-entry into force (EIF), the CTBTO could broaden its role as a public communicator to address disinformation surrounding allegations of nuclear testing. A notable example of this...
The three-dimensional (3D) spatial analysis of radioxenon isotopic activity ratios can be used to determine the source type of a nuclear event without any knowledge of the time of its generation. This method requires at least a triple detection from the same sample among the four CTBT-relevant radioxenon isotopes, which are 131mXe, 133mXe, 133Xe, and 135Xe. The 3D space of three different...
The full moment tensor solution (MTS) allows characterisation of the source mechanism by resolving the six independent components of the source moment tensor. Determining the proportion of isotropic and deviatoric moment released by a source is essential to distinguish between explosion and earthquake sources. However, complications occur because explosions can produce deviatoric deformation...
Public awareness of the differences between nuclear explosions and natural earthquakes is crucial for national safety, especially in Indonesia, a country renowned for its seismic activity and demographic diversity. According to the BMKG Indonesia, this country experienced approximately 10 789 earthquakes in 2023. This frequency poses a unique challenge for communicating the distinctions...
At the International Data Centre (IDC) real time data goes through a three-step process to determine if there is an event. These three steps in seismic/hydro/infrasound (SHI) operations are station processing, network processing and interactive review. Inside each of these steps are algorithms that conduct various tasks (e.g. detection, categorization, location). Many of these algorithms,...
Our undergraduate course titled “Nuclear Weapons and Arms Control” was created at the University of British Columbia (UBC) in 2014. The course has proven to be a very successful awareness and outreach effort and a model for future nuclear weapons education. From 2014 to 2024, the nearly 1000 students enrolled in the course have engaged in the science and politics of nuclear weapons and arms...
Sandia National Laboratories is developing the Geophysical Monitoring System (GMS) for modernization of the United States National Data Centre waveform processing system, now focused on development of interactive analysis capabilities (IAN). The United States provides open source releases of GMS software to support International Data Centre (IDC) Re-engineering. The latest GMS release includes...
The identification and precise location of earthquakes are essential for understanding seismicity and mitigating associated risks. This research focuses on utilizing state of the art deep learning methods, specifically PhaseNet, to enhance the accuracy of seismic phase picking and event localization. By analyzing 19 years of continuous seismic data from a gas storage field in Iran, our study...
Acoustic, hydroacoustic and seismic signals that are most often of practical interest are those whose nature is impulsive. The appearance of such forms of impulses is a consequence of the sudden release of energy at a location in a relatively short time. Estimation of the time of arrival of these signals, on several spatially distributed sensors, enables locating the place where these...
We present an end-to-end LLM engineering platform for fine-tuning, evaluation and registration of custom models and adapters. Our platform, built on top of open-source tools, provides a comprehensive suite of components for data processing, fine-tuning, evaluation and deployment of LLMs. Key features include pipeline orchestration for batch-oriented workflows, model training and fine-tuning,...
This study evaluates seismic activity in the Americas region over the past five years using data from the Seismic Event Bulletin (SEB) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). By applying the Gutenberg-Richter law, key seismic parameters (a and b) are calculated to estimate recurrence intervals and maximum expected magnitudes for localized subregions. Using magnitude...
In this study on the use of IMS station data, the seismic event of October 12, 2024, at 17:43 UTC, in the northwest of Costa Rica will be analyzed, using nearby seismic stations and including non-IMS stations from the local OVSICORI-UNA network. Additionally, the results of the analysis of the main infrasound events detected by the portable array station I69CR will be presented, along with...
The use of Machine Learning (ML) methods in seismology has gained significant attention in recent years, driven by the availability of large, high-quality datasets. While ML is applied to various seismological tasks, it is most commonly used for seismic signal detection, phase picking and classification. Recent studies show that deep learning models such as EQTransformer, PhaseNet and...
Data recorded for monitoring a global nuclear-test-ban treaty are a mixture of useful signals, ambient and measurement noise. Suppressing these noises and increasing the signal to noise ratio is a significant task. The paper describes a way to suppress the mentioned noises, so that by applying the proposed method, the signal to noise ratio is increased by more than 20 dB. This result is...
Low magnitude monitoring of explosions is an expanding field of interest, but due to low SNR and station coverage it is difficult to identify them. We hope to explore these limitations by using simple features from regional events and easy to implement machine learning algorithms to classify earthquakes vs explosions. Using the CNRST bulletin, we collected 4542 regional waveforms for both...
Continuous monitoring of environmental and cultural noise levels is critical in selecting and maintaining seismic station sites, especially in regions undergoing rapid urbanisation. Cultural noise is of particular concern for stations near densely populated or industrialising areas, where human activities generate vibrations that interfere with detecting and analysing seismic signals. This...
The ability of automatic data processing at the CTBTO results in identifying and estimating parameters for phases detected by the IMS stations. These processes contribute to provide automatic event locations generating the Standard Event List3(SEL3). During interactive analysis, the SEL3 event solutions are refined by modifying, or re-estimating phase attributes. These actions include: (1)...
The effective detection threshold of the CTBTO seismological network is a key tool for prioritizing repairs of primary and auxiliary seismic stations. However, many seismic networks implement it manually or semi-manually, using programs that delay the calculation and visualization process and are prone to errors.
This study aims to develop an algorithm to automate the calculation of the...
In order to be able to detect and characterize small magnitude events, even those with long propagation distances, seismic arrays are perfectly adapted tools with their high detection capabilities. We have studied the possibility to improve the detection and the localization of local and regional seismic events by using data from only one array.
International Monitoring System seismic...
We compared the locations of earthquakes with magnitudes greater than 3.0 that occurred around the Korean Peninsula from 1 January 2010 to 11 April 2024 between the KIGAM (Korea Institute of Geoscience and Mineral Resources) catalog and the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization) IDC (International Data Center) REB (Review Event Bulletin) earthquake catalog. We initially...
The CTBTO Link to the database of the International Seismological Centre (ISC) is a service provided by arrangement with IDC/CTBTO. The Link provides PTS and National Data Centres (NDC) with dedicated access to long term definitive global datasets maintained by the ISC. Functionality includes specially designed graphical interfaces, database queries and non-IMS waveform requests. This service...
For the accurate determination of local earthquake hypocenters, it is necessary to have reliable and good quality P- and S-wave readings. Data quality control is an important step to correct or filter anomalies that can occur during phase picking. The Chatelain method (Chatelain, 1978) is first applied to facilitate VP/VS ratio calculation. This method is based on calculating the differences...
We present our work on training and the application of deep learning algorithms for the automated phase picking of body waves on the the IMS network. We train new IMS data based seismic phase pickers from both EQTransformer and PhaseNet architectures. Phase picking is a necessary step before event localization and characterization and deep learning based models have been proven to perform well...
Accurate modelling of infrasound transmission losses is essential for evaluating the performance of the International Monitoring System (IMS) infrasound network. The parabolic equation method provides accurate loss modeling but is computationally expensive for operational monitoring applications. To address this, a previous study trained a Convolutional Neural Network on regionally simulated...
On the night of 22 November 2022, at 22:22 UTC, a fireball was observed in the sky over Dellys, a town in north-eastern Algeria. According to eyewitness reports, the celestial body was seen travelling from the south-west to the north-east. Two recently installed infrasound stations recorded the signal from this trajectory, enabling the determination of some of the meteor's characteristics. The...
The production of high-quality event bulletins relies on high-accuracy and high-precision hypocentral locations and low completeness magnitude. The Terceira Rift provides an ideal setting to study rifting processes due to its seismicity and volcanism, driven by slow transtensional deformation between the Nubian and Eurasian plates. This study leverages data from the UPFLOW project, including...
The performance of earthquake detection and localization within the seismic network of Thailand was analyzed, encompassing the Thai Meteorological Department (TMD) network, which serves as the main authority for monitoring seismic activity in Thailand and adjacent regions, along with the seismic network of the Department of Mineral Resources (DMR) and the CMAR array of the CTBTO. The minimum...
Accurately distinguishing between nuclear explosions and earthquakes by manual discrimination or automatic discrimination is crucial in the field of seismic signal analysis. The technique of manual discriminating takes a lot of time, and it can occasionally become inaccurate. Thus, a high-accuracy automatic discrimination method is required. An inaccurate assessment of inherent seismicity of a...
Infrasound sensing is essential for the global detection and precise geolocation of bolide events. However, discrepancies often arise between observed back-azimuths — the arrival direction of infrasound signals — and theoretical predictions based on the bolide's peak brightness location, especially for shallow angle entries. Shallow entry angles result in complex, extended acoustic signals...
The rapid detection, location and classification of seismic events, particularly offshore, has become increasingly important in a world where critical infrastructure on the seabed has been the subject of several damaging incidents. Given the intense political focus on the events, it is equally important to provide data to deescalate a situation if events have natural causes as it is to help...
The accuracy and completeness of the International Data Centre (IDC) seismic bulletins, such as the Late Event Bulletin (LEB) and Reviewed Event Bulletin (REB), are essential for global seismic monitoring of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). This study assesses the contribution of scanning processes for missed events during the interactive analysis and their...
Infrasound monitoring usually requires ground truth information from other sources in order to classify a detection. Here, we present an ensemble model that combines a Random Forest trained on simple features derived from the Progressive Multi-Channel Correlation (PMCC) technique with a Neural Network trained on spectrograms calculated from the waveforms to overcome the necessity of ground...
Sandia National Laboratories is developing the Geophysical Monitoring System (GMS) for modernization of the United States National Data Center waveform processing system, now focused on development of interactive analysis capabilities (IAN). The United States provides open source releases of GMS software to support International Data Centre (IDC) re-engineering. Sandia has recently integrated...
The generation of synthetic seismograms through simulation is a fundamental tool of seismology required to run quantitative hypothesis tests. A variety of approaches have been developed throughout the seismological community and each has their own specific user interface based on their implementation. This causes a challenge to researchers who will need to learn new interfaces with each new...
Sandia National Laboratories is developing the Geophysical Monitoring System (GMS) for modernization of the United States National Data Center waveform processing system. The GMS development effort is now focused on development of interactive analysis capabilities (IAN) to replace the ageing Analyst Review Station. IAN now includes capabilities to filter, rotate, and beam station data; measure...
Volcanic eruptions generate infrasound, which consists of low-frequency acoustic waves below 20 Hz. This phenomenon is valuable for monitoring volcanic activity, particularly in regions where local sensor networks are impractical. The expansion of infrasound stations of the International Monitoring System (IMS), along with advancements in infrasound data analysis, has improved the detection of...
Temporal variations of the noise conditions constrain the ability to detect and identify signals of interest at infrasound stations. Station-dependent factors that contribute to the noise include wind and turbulence. A coherent source of ambient noise at the global infrasound station network of the International Monitoring System are microbaroms from the oceans, which vary seasonally such that...
Discrimination between explosions and earthquakes is a major challenge in the field of seismology. This task is important not only to meet the expectations of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) but also to refine seismic bulletins used in regional seismicity research, seismotectonic analysis and seismic hazard assessment.
Seven models using different machine learning algorithms...
Seismic signal classification plays a critical role in monitoring and understanding seismic activity by attributing each detected event to its source, such as earthquakes, quarry blasts, volcanic events or nuclear explosions. Traditional methods, such as cross-correlation-based approaches, offer the advantage of not requiring large databases or explicit feature extraction. However, these...
We assess the impact of the Event Definition Criteria (EDC) on the IDC bulletins from the perspective of introduced changes in IDC processing and growing number of IMS stations during the last decade.
Two main changes in IDC processing contributed to the increase SEL3 events reviewed by analysts – infrasound processing since 2016 and introduction of NET-VISA as additional associator to...
The Neighbourhood Algorithm is a grid search method that optimizes a user-supplied objective function over a computational domain using Voronoi cell tesselation. The algorithm is a method for solving geophysical inverse problems with the additional benefit of not requiring the estimation of travel-time derivative information (Sambridge, 1999)
In this application a misfit function for...
Routine analysis of infrasound data began in early 2010. Since then, analysts at the International Data Centre have reviewed more than 117 700 automatically built SEL3 infrasound events and included 62 700 events in the Late Event Bulletin (LEB). Of these, 34 800 events met the Reviewed Event Bulletin (REB) event criteria. Analysing infrasound data presents several challenges. These include...
On February 6, 2023, at 01:17 UTC and 10:24 UTC, two devastating earthquakes with magnitudes of Mw 7.7 and Mw 7.6 struck, with epicenters located in Pazarcık (Kahramanmaraş) and Elbistan (Kahramanmaraş), respectively. These earthquake couples are one of the most destructive earthquakes occurred in recent history affecting 11 provinces in Turkey’s Southeast region and causing more than 53 000...
To study impulse sound of shell explosion position in a far field over 5 km even for nuclear explosion’s position. One new way was designed to perform clear spot image of source position with accurate result, that is a reverse beam-forming of burst pulse sound. Meanwhile, time-delay variance used to estimate source’s coordinates and sound’s average velocity suggested the sound’s propagation is...
Discriminating tectonic events from artificial ones poses a significant challenge, particularly when both sources are small and geographically close. This issue is common in regions with quarries for rock blasting and tectonic seismic activity. This study focuses on distinguishing tectonic events from quarry explosions by integrating seismic and infrasound data collected from stations in Sete...
The Punggye-ri nuclear test site in North Korea, historically not seismically active, has likely experienced significant stress changes from the six nuclear tests, particularly the largest in 2017. These stress changes have facilitated the triggering of seismicity in the surrounding area long after the tests. Using multi-channel correlation detectors (Gibbons, 2012) at the IMS seismic arrays...
Recorded seismic data are generally contaminated by noise from different sources, which masks the signals of interest. We implemented a noise suppression approach based on the mathematical morphology theorem. The method involves compound operations of dilation and erosion using structuring elements of varying lengths and decomposes an input noisy waveform into several time functions with...
We present NPLoc, a machine learning model designed to accurately locate earthquakes within a permanent seismic network. This model predicts earthquake origin time, hypocenter, magnitude and its associated uncertainties as rapidly as possible. This approach uses temporal patterns extracted from earthquakes within a seismic network and utilizes the Histogram-Based Gradient Boosting method. To...
Monitoring of phenomena in the atmosphere and at shallow depth of burial using infrasonic signals is often performed via automated detection, localization and characterization with refinement using interactive tools for an identified event of interest. Ongoing infrasound research and development at Los Alamos National Laboratory includes development and evaluation of various signal analysis...
In the field of seismic monitoring, the three critical tasks of phase picking, association and location are interconnected and tightly coupled. Current seismic monitoring methods typically tackle phase picking, association and location separately, and most existing phase picking methods focus on single-station waveform data processing. Graph Neural Networks (GNNs) are deep learning frameworks...
In this presentation, we demonstrate how to use the IMS FDSN web service to download and analyze seismic data. Specifically, we show how to integrate IMS waveforms and phase-picking data with locally collected datasets, and how to process this information to determine event locations and magnitudes.
For our analysis, we utilize the seismic analysis software package SEISAN. SEISAN (see...
The NET-VISA software package features a physics-based probabilistic model combined with a heuristic inference algorithm to identify the most likely set of seismic events corresponding to a series of detections by a global seismic network. It has been enhanced to detect events occurring in three mediums — rock, air and water — and supports seismic, hydro-acoustic and infrasound sensors.
The...
The Standard Screened Event Bulletin (SSEB) is a sub-sequent automatic product of the Standard Screened Bulletin (SEB) produced by the International Data Centre (IDC). The SEB is a post-location processing of the Reviewed Event Bulletin (REB) that includes the event characteristics that are used to screen out seismoacoustic events generated from natural or non-nuclear man-made phenomena. The...
The data fusion automatic pipeline at the CTBTO aims to provide the most complete summary of signals observed by the International Monitoring System (IMS) by linking event information formed from seismic, hydroacoustic and infrasound (SHI) detections with radionuclide detections. The sensitivity of an IMS station sampling period to a possible release location is estimated using backward...
Deep learning approaches are effective for earthquake detection and phase picking. However, challenges in existing research include using non-uniform datasets, such as training on limited event distances and excluding noise samples. Models trained exclusively on local events often fail to perform well on teleseismic signals, while models trained only on signals struggle with robustness in the...
Recently, involving the capabilities of artificial intelligence (AI) to solve problems in exploration seismology attracted increasing interest. One example is the use of recurrent neural networks to estimate seismic activity. These networks can process time-series data, allowing to model dynamic processes through time-dependencies. Clustering to segment seismic data helps identify different...
Limestone mining activity close to site KAPI (CTBTO) has been clearly visible through the land clearing from satellite imagery. The BMKG Region IV Makassar team has visited the site to analyze noise from heavy equipment activities that operate around the site, consisting of a bucket excavator on 25 August 2023 and a breaker excavator on 23 January 2024. Noise from the activities of these two...
To support National Data Centers (NDCs) in their ability to process IMS data, the Provisional Technical Secretariat provides the NDC in a box software package. Many NDCs do real time processing of continuous data from IMS waveform technology stations, with a particular focus on seismic monitoring data. This data can be used for verification purposes, as well as for civil and scientific...
The Swedish National Sesmic Network (SNSN) currently operates 80 broadband seismic stations. In addition, SNSN receives real time data from about 120 stations located in Norway, Finland, Denmark, Germany, Poland, the Baltic States and Russia. SNSN processes the waveform data of this virtual network using the SeisComp and Earthworm systems in parallel. In order to screen out spurious events, we...
The increasing volume and complexity of seismic data require advanced techniques for efficient signal classification, particularly in monitoring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). This study introduces a robust approach using Convolutional Neural Networks (CNNs) to automate seismic signal classification, significantly improving both accuracy and classification...
At the International Data Centre (IDC), data received from the network goes through a three-step process (station processing, network processing and interactive review) to determine if a combination of detections can be built into an event. One of the major steps in determining if an event can be built or not is the phase classification of the detected signals. For acoustic data, phases are...
Stockwell transform, commonly known as S Transform (ST, Stockwell et al., 1996) is an extension of the continuous wavelet transform (CWT) and involves an inverse frequency-dependence of the localizing Gaussian window as well as a modulating phase factor, which result in better frequency resolution than CWT or short-time Fourier transform (STFT). We are leveraging that advantage by implementing...
Research on Graph Neural Networks (GNNs) has advanced rapidly, with recent architectures successfully applied to seismological tasks such as earthquake source characterization and event association. Inspired by advancements in traffic forecasting and temporal knowledge graph completion, we propose dynamic GNNs that integrate graph convolutional layers and autoencoders to capture...
An accurate discrimination between nuclear and conventional explosions requires a systematic analysis of signals in a wide range of physical domains, including waveforms (seismic, atmospheric infrasound and hydroacoustic waves) and radionuclides (particulates, noble gases), as well as other potential sources of information. The final joint-fusion analysis is crucial and presents several...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) continuously seeks innovative methods to enhance the accuracy and reliability of its monitoring systems. This study introduces the Characteristic Curve Method, a novel approach designed to mitigate daily variations in observatory data, which pose significant challenges in the analysis and interpretation of seismic and nuclear...
A mobile seismo-acoustic array, RAPAR (RAsPberry ARray) was constructed with six Raspberry Shake-Booms, which are relatively small and cheap equipment. RAPAR is a stand-alone equipment with geophone, acoustic sensor, digitizer, solar power supply and LTE communication system but without a wind noise reduction system. RAPAR was deployed six months in a small peninsula, Homigot, located in the...
To contribute to the identification and mapping of active faults and their geometries in and around Cartago, Costa Rica, scientists from the Costa Rica Volcanological and Seismological Observatory at the National University (OVSICORI-UNA) and from the United States Geological Survey (USGS) have joined efforts to install and operate an urban, dense array of seismic nodes. The network consists...
We will present the results of testing of a new self-calibrating infrasound sensor design, developed by Hyperion. This design integrates a sound source and system controller logic into the body of a Hyperion infrasound sensor. Both analog and digital versions of this design were constructed and tested. The calibrator produces a sinusoidal pressure signal with amplitude and frequency specified...
The department of Seismology and Acoustics (RDSA) at the Royal Netherlands Meteorological Institute (KNMI) monitors seismic and acoustic activity in the Netherlands with a dense network of seismometers and infrasound sensors. An important motivation for measuring infrasound in the Netherlands is to discriminate between vibrations originating from the solid earth, e.g. earthquakes, and from the...
The International Monitoring System (IMS) network relies on four technologies: seismic, infrasound, hydroacoustic and radionuclide. The draft IMS Operational Manuals for waveform technologies outline the requirements for establishing, maintaining and verifying the performance of IMS stations. Since 2011, the Provisional Technical Secretariat (PTS) has collaborated with the global community to...
Distributed Acoustic Sensing (DAS) is revolutionizing seismology by repurposing existing and purpose-built fibre cables as seismic sensors. While DAS faces challenges, such as higher noise levels and single-component limitations compared to traditional sensors, it offers significant advantages. These include extensive sensing lengths, high sensor density and fine spatial resolution. Curved...
Currently, the world is undergoing the second quantum revolution. While the first revolution resulted in a wide range of transformative technologies, including nuclear weapons, developments emerging from the second revolution, including a range of promising quantum technologies, seem to be enhancing the monitoring capabilities of the CTBTO. This study explores the potential of quantum sensing,...
Infrasound data recorded with Romanian stations BURARI and IPLOR are processed and analyzed on routinely basis at NIEP by using capabilities of NDC-in-a-Box, i.e., DTK-PMCC, DTK-GPMCC and DTK-DIVA software.
This study focuses on the numerous and repeated high frequency signals (above 1 Hz) detected mainly from consistent sources related to the intense military activity caused by bombardment...
With the installation and certification of the International Monitoring System (IMS) station IS42 in 2011, the Azores archipelago became an infrasound sentinel of the North Atlantic Ocean. After more than a decade of detecting global infrasound activity including microbaroms, Atlantic storms, man-made activities, bolides, earthquakes and far-field volcanic eruptions, a second infrasound array...
The seismic wave field is fully described by six components: three components of translation and of rotation (6 degrees of freedom, 6-DoF). As rotational amplitudes are small, for a long time seismology confined itself to half of the available information by using only translation. However, since roughly two decades, rotational ground motions are observable. Since a couple of years, even...
Broadband seismometry is a foundational instrumentation technology enabling measurements of seismicity for test ban treaty verification. Seismic monitoring networks typically comprise many stations distributed geographically on the Earth’s surface or seafloor. Seismic station data used for test ban treaty monitoring purposes must be trustworthy, meaningful and reliable. The seismic instruments...
Seismometer electrical calibration at IMS stations has long been depended upon to ensure the accuracy of seismometer performance. At best, electrical calibrations provide confidence that the seismometer performance has not changed since the time of installation. However, as an absolute measure, electrical calibrations may not result in a sufficiently accurate or traceable measure of...
We are hosting a colossal seismic activity of the Fentale-Dofen magmatic segment to date in the main Ethiopian rift starting from September 2024. This earthquake swarm is caused by a dike intrusion beneath Fentale volcano and laterally migrating north toward Dofen volcano with a total lengt of over 40 km shown by both seismicity and InSAR data. Thousands of earthquakes with maximum magnitude...
The PS26 station was established in Niger in 2005 on a granite batholith. The PS26 data is of unrivaled quality and contributes to strengthening the verification system within the IMS. The station remains in no capable mission, but there is hope to see this station getting back within the network. In this work, we will use data from the PS26 station in order to show its contribution by...
Verification of events is a very important task for national monitoring systems. The Ukrainian NDC demonstrates this ability at least at the regional level. As an example, consider the event at the Kakhovka HPP dam that occurred on May 5, 2023. The estimated time in the source is 23:34:50 UTC. Determining the exact time of the event was accompanied by certain difficulties. First, its low...
On 26 October 2024, the Israeli Defence Forces (IDF) announced they triggered an explosion of 370 T in an underground Hezbollah facility in southern Lebanon, ~1 km off the Israeli border, generating a seismic moment equivalent to a M3.6 earthquake. Four seconds after detonation, the Geological Survey of Israel’s (GSI) Earthquake Early-Warning System, Truaa, identified the explosion as a M5.2...
In the EMPIR Infra-AUV project, HBK-DPLA extended the frequency range of the reciprocity calibration technique to achieve reliable primary calibrations to frequencies below 40 mHz. It was also demonstrated that secondary calibration based on HBK’s commercially available low frequency calibration system can be made of suitable microphone types down to similar frequencies. After the project,...
Initial calibration can be done in a laboratory using specialized test equipment, but to check calibration of instruments over their lifetime in the field requires different processes. We discuss two particular challenges: site response and temperature sensitivity.
A method for field calibration with respect to a portable reference sensor has been demonstrated by Michaela Schwardt. This...
Calibration activities are one of the minimum requirements for stations of the International Monitoring System (IMS), as specified in the IMS Operational Manuals. The ongoing efforts to maintain and recapitalize the infrasound stations of the IMS network have led to the installation of passive calibration capabilities and well-characterized elements, with a new generation of sensors and Wind...
Ice cover monitoring has been recognized as a critical task in environmental studies for hazard mitigation and critical alerts reporting. Current observation methods of changeable ice thickness often fall short in terms of accuracy, completeness and cost efficiency. Distributed acoustic sensing (DAS) uses fiber optic cables as sensitive elements and presents a promising alternative to the...
A seismic network’s primary objective is to provide high-quality data for monitoring earthquakes, analyzing their sources and studying the structure of the Earth. The good quality of seismic data is obviously important but can only be achieved if many different factors are considered. The quality assessment was verified by using the seismic waveforms from a total of 537 permanent broadband...
The impact of temperature variability in the environment of a seismometer has the potential to affect its operating performance and should be well understood for sensors within the IMS. In this study, GS-13 passive seismometers are collocated with broadband CMG-3T seismometers at two seismic sites near Sandia National Laboratories’ FACT site. The operating temperatures of the seismometers are...
On 20 June 2024, a powerful sonic boom shook the inhabitants of Elba Island (Tuscany, Italy) and was heard in a huge area on the Tuscan coast. The unknown phenomenon generated infrasonic and seismic signals which were recorded by three infrasonic arrays deployed in Elba Island (ELB), on Mount Amiata (AMT, southern Tuscany) and in Aosta Valley, and by 20 seismic stations located throughout...
Infrasound can be detected in nature and human activities, such as earthquakes, volcanic eruptions, mudslides, supersonic flight, etc. The monitoring of infrasound sound pressure signal mainly depends on the infrasound sensor, and the accurate measurement of infrasound sound pressure mainly depends on the calibration of the infrasound sensor.
Since the NPL developed laser-pistonphone to...
A pressure gauge at the seafloor is key sensing instrument for geophysics and oceanography. Pressure change over time can be consent to the seafloor deformation associated with plate convergence in the plate subduction zone or the magma injection near the submarine volcanoes, etc. It is also suggested that pressure change at the seafloor can be partly reflected by the ocean current variations,...
Ecuador is a country surrounded by a great variety of natural hazards. Hence, it is necessary to carefully watch seismic and volcanic activity within the country, which requires a great number of resources. The Geophysical Institute of EPN (IG-EPN) oversees monitoring activities in the country, however, budget is usually a problem. With over 300 monitoring sites, IG-EPN must manage the way of...
In this work, a monitoring system has been developed to measure the variations in the magnetic field produced at the Chiles volcano, located in Ecuador on the northern border with Colombia. Additionally, an array composed of 12 one-component sensors arranged in various geometric configurations has been implemented in order to detect seismic and infrasound signals. The system refers to a...
Mysterious seismoacoustic events were reported at the beginning of 2022 near Helwan city. The majority of these events were recorded in our Egyptian National Seismic Network (ENSN). The source characteristics of these events were unknown. In May 2022, a temporary infrasound array station was established with a small aperture of 450 meters in Helwan. Throughout the six-month monitoring period,...
During infrastructure works in the port of Rijeka, an unexploded WWII aerial bomb was discovered at a depth of 19 meters. The bomb measured 298 cm in length, 70 cm in diameter, and weighed 986 kg, including 690 kg of explosives. Due to its size and the proximity of residential and infrastructure facilities, it was deemed unsafe to neutralize the bomb at its discovery site through a controlled...
The ocean is key to understanding climate change, sea level rise, tsunamis and earthquakes. The ocean is difficult and costly to monitor. Over the last decades, dedicated submarine cable systems have been supporting science and early warning, as well as monitoring for nuclear test explosions.
The Science Monitoring And Reliable Telecommunications (SMART) Cables Initiative is working to...
Sometimes, powerful quarry explosions can generate an acoustic infrasonic signal, and this can be recorded on seismic sensors. The appearance of an acoustic wave can be seen on seismograms, which are calculated based on the speed of arrival of the wave. If the azimuth coincides with the azimuth of the explosion, and the speed is V=0.33 km/sec, then we can confidently say that this signal was...
Moment tensors encode seismic source mechanisms and magnitudes, providing a basis for classifying seismic events. The moment tensor is a 3×3 symmetric matrix representing three orthogonal dipoles, with their magnitudes and orientations defining the mechanism. Decomposing the tensor into eigenvalues and a rotation matrix enables analysis and classification of source mechanisms on the lune...
The design details of the Ultra Broad Band (UBB) borehole feedback seismometer are presented including stable Hole-lock camping mechanism. The complete sensor stack weighs less than 20 Kg with a diameter of 89 mm.
The instrument has no mechanical resonances below 400 Hz. We achieved the bandwidth extension to high frequencies with improvements of the mechanical design, i.e. the arrangement...
Since 2006, the Democratic People's Republic of Korea (DPRK) has conducted a series of six nuclear tests in the region of Punggye-ri, the latter claimed as a hydrogen bomb test, which occurred in September 2017. The estimated yield of these events ranged from 1 to 300 kilotons, based on various analyses, including seismic data and satellite imagery. The latest test was the most powerful,...
This paper presents the results of seismic data analysis related to a chemical explosion that occurred at a warehouse in Tashkent city (data 27.09.2023 UTC:21-52 ). The explosion caused significant destruction and was accompanied by the release of shock and seismic waves, which were recorded by seismological stations in the region.
The study includes an assessment of the explosion...
Uncontrolled space debris re-entries are a growing international concern, posing an increasingly greater risk on the ground as Earth orbit grows more crowded. Characterising the passage of these objects through the atmosphere is key to understanding the risks they pose, especially in evaluating whether any debris may have reached the ground. Using an example of a spent orbital module...
The Source Physics Experiments (SPE) are a series of controlled chemical explosions at the Nevada National Security Site to gather observations to verify and validate explosions' physics-based numerical models and understand the genesis of shear waves to improve nuclear discrimination and monitoring capabilities. Executed between 2011 and 2016, Phase I encompassed six collocated chemical...
An experimental infrasound array, combined with collocated seismic sensors, detected in Southern Brazil an event characterized by waves arriving simultaneously at both types of sensors. This suggests a common source for the waves, traveling at the same velocity. However, different source types could satisfy these conditions. This study analyzes signals recorded by a four-element infrasound...
T-waves are hydroacoustic waves that propagate as guided waves over long distances through the ocean, representing energy trapped in the Sounding Fixing and Ranging (SOFAR) channel. T-waves resulting from earthquakes have complex waveforms and simulations suggest that their long wavetrains are generated by scattering of upward traveling seismic energy at a rough seafloor and multiple...
This poster presents the Algerian Network for Infrasound (ANIs), a pioneering project aimed at establishing a comprehensive network of low-cost infrasound devices across Algeria. In its initial phase, the project involves the deployment of four infrasound sensors in the northern part of the country, with two devices operational since June 2022. Preliminary data from these two operational...
Emerging small seismometers and infrasound sensors hold transformative potential for strengthening the CTBT verification regime. These portable, relatively inexpensive instruments provide high-resolution data that are essential for the detection and location of events that may indicate nuclear testing. Unlike traditional equipment, they are more affordable and accessible, allowing deployment...
VNIIA is a leading company of Rosatom State Atomic Energy Corporation in CTBT implementation, which currently performs a range of research. Three types of new seismometers of the VNIIA family were designed:
- A seismometer Type 1 – a vertical short-period seismometer for installation in boreholes;
- A seismometer Type 2 – a three component broadband seismometer for installation on a...
Over the years, Enviroearth has developed Wind Noise Reduction Systems (WNRS) of advanced technologies based on comprehensive CTBTO requirements and configuration range over the whole IMS infrasound station Network.
This work involves the continuous implementation of new manufacturing methods, installation processes and accessories’ technical innovation, making it adaptable to any situation...
A method to estimate yield and depth of explosions when accompanied by both DC and strong CLVD contributions will be presented. This paper will point out an amplitude deficiency in the CLVD green functions (GFs) constructed using no-torque three-orthogonal force dipoles (FDP). Vertically symmetric CLVD GFs are smaller by a factor of 2 than the DC source ZDD/RDD GFs, which is not accounted in...
Atmospheric Transport Modelling (ATM) is a key component of National Data Centres (NDCs) verification capacities. ATM links the detections of radionuclides to their sources, i.e. releases of radionuclides into the atmosphere, be they particles or noble gases. As such, NDCs rely on the knowledge of atmospheric dispersion primarily to provide the best possible estimate of the release scenario –...
Legacy seismograms contain unique data about past events, nuclear explosions among them, crucial to study and analyze past and present monitorization efforts. Unfortunately, many collections of these original data and their related accessory documentation are still in risk because of inadequate storage conditions and lack of proper recognition. At many institutions personnel and resources...
Indonesia is prone to tsunamis caused by seismic (e.g. submarine earthquakes) and non-seismic events (e.g. volcanic activity). Five massive tsunamigenic earthquakes with very different rupture lengths occurred in different parts of the Sunda–Java Trench from 2004 to 2010. This work investigates T-phases recorded at IMS hydrophone stations HA1 and HA8 triggered by these five earthquakes using...
Shallow-water environments, such as the Argentinian continental shelf, present challenges for monitoring underwater acoustic events due to high transmission losses (TL) at low frequencies. While the International Monitoring System (IMS) hydroacoustic network is highly proficient in detecting global low-frequency signals, its coverage in coastal zones is relatively limited due to...
The New Manual of Seismological Observatory Practice, NMSOP, is a compendium of seismological knowledge needed to run seismic networks and observatories. It is intended to facilitate the use and analysis of digital data acquired by seismic networks with a general focus on modern systems. Nevertheless, most of the Nuclear Explosions that occurred in history were recorded on analog...
Recently, a large amount of data, indicating induced seismicity in area of large underground nuclear tests (UNE), has been accumulated. Such studies were conducted on Amchitka Island (USA), Nevada Test Site (USA) and Semipalatinsk Test Site (USSR). Researchers considered three types of impacts: seismic activity associated with the destruction of the explosion cavity, induced tectonic activity...
This panel will discuss the real, current detection capability of the IMS, addressing all technologies, individually as well as the fusion between them, and the impact on AI on improving the detection capabilities. The panel will discuss the evolution of IMS detection capabilities with time, the level of development of IMS technologies and processing algorithms, and the benefits of...
Sound energy density between 50 and 100 Hz in the northeast Pacific Ocean increased roughly in proportion with global shipping tonnage in the second half of the 20th century, consistent with expectation for ambient sound dominated by contributions from distant shipping. Increases were larger in the frequency range 10-40 Hz than can be explained by increased tonnage alone, with largest...
In recent years, the seismological community has recognized the critical importance of preserving analogue seismic data. However, Germany was lacking strategies for preserving these records. Here we present the preliminary findings of our feasibility study, which evaluates the potential for digitizing all analogue seismic data in Germany.
Initial inventory of the contents of German analogue...
Monitoring and modeling of ship sound are crucial due to its large contribution to underwater ambient sound. The NAVISON (Navis Sonus) project, sponsored by the European Maritime Safety Agency (EMSA), addresses this issue by calculating hindcast (2016–2023) and forecast (2030, 2040, 2050) shipping sound maps for all European seas. These maps focus on two decidecade frequency bands (63 Hz and...
Turbulent pressure fluctuations around infrasound sensors, known as wind noise, are the primary factor masking infrasound detections of interest, such as signals generated by natural hazards. Identifying deployment sites with sufficiently low wind noise levels is crucial for achieving good signal to noise ratios. Noise levels are expected to correlate with local topography, which influences...
The Comprehensive Nuclear-Test-Ban Treaty, describes the sole On-Site Inspection (OSI) techniques that can be used for the verification process. Over the years, there have been rapid advances in technology which have changed the scope of equipment, software and data analysis providing both increase in efficiency and enhancement in resolution.
We are currently in the preparatory phase before...
As infrasound sensors have become more compact and highly accurate, the true picture of various phenomena is becoming clearer through precise and dense observation.
Considering such kind of background, we attempted to observe the infrasound signals generated by explosion events to understand the actual state of waveform deformation and attenuation due to propagation. We know that the...
The Provisional Technical Secretariat (PTS) of the Comprehensive Nuclear Test Ban Treaty Organization’s (CTBTO) has been actively working on the build-up of the On-Site Inspection (OSI) element of its verification regime over the course of the last years. One of the essential tools in these efforts is the conduct of exercises as a valuable opportunity to test, validate and further enhance the...
Sustaining the International Monitoring System (IMS) network, operated by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), has become one of the key focus areas of the CTBTO as the installation and certification of more than 90% of the IMS network facilities is complete. The network has evolved over time from the initial focus on station installation and certification, to...
The oceanic swell is a global and continuous source of infrasound known as microbaroms. The infrasound stations of the International Monitoring System routinely detect microbaroms depending on acoustic waveguides that form in the middle atmosphere (MA) and the upper atmosphere (UA), roughly between 30 and 120 km. Operational meteorological products are biased at these altitudes essentially due...
National Data Centres (NDCs) are pivotal to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime, enabling States Parties to independently analyze data from the International Monitoring System (IMS). Beyond treaty verification, NDCs contribute to national security, scientific research, and disaster management. The abstract outlines a comprehensive framework for establishing and...
Jet stream winds play an important role in our daily weather. Accurate wind and temperature estimations in the upper troposphere can lead to better medium to long term weather forecasts. However, continuous measurement in the upper troposphere poses challenges, resulting in relatively sparse data. This study revisits previous research done in the 1960s and 1970s, on the use of ground based...
This panel will provide a forum for engaging a wider community to contribute to the OSI techniques development via utilizing data from OSI Exercises and Field Tests for the development and testing of new, innovative approaches. It will add emphasis on engaging early-career experts and experts from the under-represented geographical regions. While OSI Exercises are focused on the assessment of...
To address the mandate as given under the CTBT Protocol (part I, paragraph 22), to provide technical assistance to States, the International Data Centre (IDC) is responsible for a dynamic Capacity Building and Training Programme. The provision of software is a fundamental part of the assistance, as it provides the States; through their National Data Centres – NDCs; with resources to enable...
The detection of seismic and infrasonic signals from nuclear explosions has traditionally been constructed around one-dimensional signal processing methods. However, such traditional approaches are quite different from the artificial interactive analysis and detection modes. In fact, when conducting interactive processing manually, personnel complete the relevant work by relying on the visual...
It was recently reported by Siraj & Loeb (2023) that an ‘interstellar meteor’, potentially part of an alien spaceship, burnt up over the Pacific Ocean in 2014. These authors attempted to use seismic data produced by the bolide to pin-point a re-entry location, from which they claimed to recover pieces of the object from the seafloor. We will show, using both seismic data and IMS infrasound...
A network of seismoacoustic arrays, each of which combine seismic and infrasonic sensors into a single integrated array design, provides a unique capability to detect, locate, and characterize various sources of mechanical waves. Since 1999, Southern Methodist University and Korea Institute of Geoscience and Mineral Resources have cooperatively designed, built, operated, and upgraded six...
Magnetic field mapping, as one of the continued period technologies, plays a vital role for on-site inspection. Looking back into the recent science and technology development history, magnetic sensing has been under decades of development. This work would propose a high performance magnetic sensor based on the giant magnetoimpedance effect of special magnetic materials (i.e., the impedance of...
In a world shaped by generational shifts, gender inclusion, and geographic diversity, the role of National Data Centres (NDCs) in advancing the CTBT verification regime is more critical and more dynamic than ever.
In this keynote, Magdalene Wanyaga a geoscientist, draws on her hands-on experience with the CTBTO’s International Monitoring System (IMS), the International Data Centre (IDC), and...
The resonance seismometry is one of the CTBT’s permitted techniques during an on-site inspection (OSI). In order to enhance the capabilities of the OSIs, we have developed a method for detecting a deep underground cavity based on the analysis of seismic ambient noise data called the Finite-Interval Spectral Power (FISP). The FISP method has become part of the draft of Concept of Operations for...
Several series of explosive experiments aimed at understanding the signals from underground chemical explosions have included seismic observations made using Distributed Acoustic Sensing (DAS). In all experiments, the spatial density of DAS provided an unprecedented context for exploring topics such as geomaterial response over the course of an explosive experimental series, the influence of...
Infrasound networks play an important role in detecting atmospheric events such as meteors, bolides and fireballs, significantly contributing to global monitoring and atmospheric studies. On July 28, 2022, at 01:36:08 UTC, a bolide was detected over the Pacific Ocean, near South America, at coordinates 6.0°S and 86.9°W, at an altitude of 37.5 km, velocity of 29.9 km/s and a total energy...
Vegetation stress and its impact on plant biology is postulated as an indicator of ground motion during an underground nuclear explosion (UNE); however, its scale, longevity and detectability remain unquantified. To expand the body of work on this topic, a laboratory experiment was performed to investigate the spectral response of leaves from three evergreen plant species from different...
This panel will focus on strengthening the National Data Centre (NDC) community through sharing experience and collaboration at multiple levels: at the national level, it will highlight internal coordination among institutions, showcase successful national collaborations, and share best practices and lessons learned within individual NDCs; at a regional level, the panel will explore mechanisms...
Passive Seismic Monitoring (PSM) is the only geophysical technique allowed by the CTBT during the initial period of an on-site inspection. The goal is to reveal even the smallest expectable aftershocks of an underground nuclear explosion to the inspection team to locate the test site to the precision of a few hundreds of meters. With the full PSM network of some 50 small arrays deployed, M$_l$...
The 2024 Experiment, conducted from 16 to 27 September 2024, focused on the production of automatic and analysts generated products. During the experiment, the International Data Centre (IDC) generated a series of Reviewed Event Bulletins (REBs). To ensure an objective comparison, three randomly selected REBs were compared against a baseline bulletin created by an experienced team. The...
In preparation for the Integrated Field Exercise (IFE) and based on lessons learned from the past field exercises, the equipment and implementation section of the On-site Inspection (OSI) Division of the Provisional Technical Secretariat has entered into an advanced stage of OSI support and deployment infrastructure integration. The OSI field laboratory deployment and operational layouts were...
During 2024-2025, a state of the art data collection and storage system was created at the Kazakhstan National Data Centre. The system is designed to reliably store all information received by the Data Centre and provide this information for further processing and scientific analysis. Data sources for the created system are data received both in real time and any archive data from various...
The rapid evolution of information technology has revolutionized traditional ways of working and helped to create tools to support the technical divisions of the Commission in their activities. By benefiting from it, a data-driven software tool “Network Summary in The Multi-Technology Integration Portal (MuTIP)”, is being developed to streamline International Monitoring System (IMS)...
Integrating data from various monitoring technologies has become essential to detect and mitigate the spread of malicious code in modern digital ecosystems. However, the heterogeneity and complexity of data sources present significant challenges to ensure smooth and accurate detection. This paper presents an AI-based framework for detecting malicious code that leverages a deep learning...
The Meteorology, Climatology and Geophysics Agency (BMKG) is a government agency that has the task of providing data and information services for meteorology, climatology and geophysics as well as delivering information to the public and related agencies. BMKG empowers and relies on the VSAT network, which works 24 hours, 7 days a week. The BMKG VSAT communication network is a system that...
In this research, we will present our recent developments of using streaming platforms in Continuous Data (CD) distribution. This research aims to utilize an asynchronous and loosely connected framework between senders and receivers for the transfer of the continuous raw data of the seismic, hydro-acoustic and infrasound (SHI) stations. We will demonstrate the implementation using various...
The Global Communications Infrastructure (GCI) network is how the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization fulfills its responsibilities related to receiving and distributing data and reporting products to the verification of the Treaty [Article IV. Verification, Section A, Paragraph 14 (a)]. Since it started in 1998, this network has evolved and is...
Data quality assessments for five BMKG stations (PSI, LEM, BATI, SIJI, and JAY) which included as auxiliary stations in the CTBTO International Monitoring System have been conducted. The Probabilistic Power Spectral Density (PPSD) analysis was applied to determine the level of background noise around the sites to assess the reliability of sensor placements for seismic monitoring. Meanwhile,...
The Meteorology, Climatology, and Geophysics Agency (BMKG) is an agency that has an obligation to present earthquake data to the people of Indonesia. The earthquake data presented is obtained from 507 earthquake sensor sites spread throughout Indonesia. Earthquake data from all sensor sites is sent to servers located at the BMKG Center in Jakarta and the BMKG in Bali. Data transmission is...
Building on its extensive experience in providing turnkey power solutions for remote scientific stations, Enviroearth has focused on improving its solutions by developing a new, standardized solar-powered power cabinet for stations with low power requirements. It addresses the challenges faced by remote locations, where reliable, sustainable energy sources are critical. Initially designed for...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operates the International Monitoring System (IMS), a global network of 306 certified facilities, comprising seismic, hydroacoustic, infrasound, and radionuclide technologies, transmit data to the International Data Centre (IDC) via the Global Communication Infrastructure (GCI). The IMS is essential for detecting and verifying...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) utilizes and oversees daily processes through a rigorous framework, relying on extensive procedural manuals, protocols, and regulatory guidelines. Accessing and interpreting these complex documents can be time consuming and require deep domain expertise, creating challenges for staff members across various operational and...
The Anatolian region, characterized by complex fault systems such as the North Anatolian Fault, East Anatolian Fault and the extensively deforming fault systems in the Aegean and Mediterranean regions, serves as a natural laboratory for earthquake studies. These fault systems create a highly dynamic and seismically active tectonic environment. The Kandilli Observatory and Earthquake Research...
The ASF056 auxiliary station borehole seismometer was malfunctioning, and the local operator in the State Party lacked the financial resources to cover the costs of replacing and upgrading the outdated equipment. Through the efforts of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) and the Jordan Permanent Mission, the European Union (EU) provided a significant donation to...
The increasing complexity of software development in the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) necessitates the adoption of innovative tools and techniques to enhance productivity and efficiency. LLM-based AI code assistants have emerged as a promising solution, offering capabilities such as autocomplete, code refactoring, error detection and correction, chat based...
The International Monitoring System (IMS) is a unique global network designed to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Complementary to three waveform technologies, the 80-station radionuclide network provides continuous worldwide monitoring. This radionuclide network is further supported by 16 specialized laboratories, which offer independent expert...
The implementation of Internet of Things (IoT) based Earthquake Early Warning Systems (EEWS) in Indonesia faces challenges in the efficiency of data communication lines to ensure real time earthquake detection. Currently used internet lines include VSAT private network, public GSM 4G, and GSM 4G leased line, with varying performance in terms of connection speed and stability. In addition,...
Extreme wildfires have become more frequent and widespread in recent years, causing negative impacts on society, infrastructure, air quality, terrestrial and aquatic ecosystems. The International Monitoring System (IMS) facilities operate worldwide in remote locations, sometimes in regions regularly suffering from forest fires. This could pose a significant risk for a station’s routine...
The International Data Center produces automatic event bulletins, which are subsequently verified by analysts. Analysis of 2014-2023 data shows that less than 50% of events reported in the first list (SEL1) were also included in the Late Event Bulletin (LEB). Reducing the number of misformed events could significantly ease analyst workloads. To address this, we introduce a method for assessing...
This paper explores the strategic implementation of the Elastic Stack (ELK) for enhancing observability and logging capabilities within the Secure Web Portal (SWP). The ELK stack, comprising Elasticsearch, Logstash, and Kibana, was integrated within SWP to create a comprehensive logging system. By connecting all application logs to a central Syslog instance, data was stored in Elasticsearch....
Lithium batteries are constantly evolving. Their applications are diverse and varied, ranging from small portable electronic devices to large energy storage. These batteries offer the best specific energy (capacity/weight ratio) on the market, have a longer lifespan and can have high depths of discharge. They operate in extreme environments. This makes them ideal for International Monitoring...
Hourly maps with the average and worst-case event detection capability of the seismic component of the CTBTO’s International Monitoring System have, for many years, been accessible via CTBTO’s secure web portal. The basis for these maps is estimates calculated by the Threshold Monitoring method, which has been part of CTBTO’s processing pipeline since the establishment of the International...
The Comprehensive Nuclear-Test-Ban (CTBT) International Monitoring System (IMS) network comprises two global seismic networks: a primary, based on 50 stations, and an auxiliary, based on 120 stations. Both networks undergo ageing and obsolescence, as the equipment is reaching more than 20 years of operation in the field and, in some cases, is no longer supported by equipment providers. Keeping...
In recent years, OVSICORI-UNA has made a significant investment in communication, storage and data protection technology, such as intelligent storage systems with deduplication and real time backup. Through this implementation and a redundant link, we ensure that the data from our auxiliary station AS25 is well protected, with almost zero data loss. The previous data protection capacity is...
Infrasound sensors have been installed for national purposes at the site of the Hagfors seismic array in Sweden. The co-location of the infrasound sensors with the central elements of the International Monitoring System (IMS) auxiliary station (AS101) facilitated straightforward deployment by leveraging the existing infrastructure. Acoustic inlets were designed and produced in-house using...
NORSAR is the Norwegian National Data Centre (NDC) and operates six stations of the International Monitoring System. These are the primary seismic arrays NOA/PS27, ARCES/PS28, the auxiliary seismic array SPITS/AS72, the auxiliary single seismic station JMIC/AS73, the infrasound array IS37 and the radionuclide station RN49. It is crucial to have a stable power supply with a sufficient battery...
In the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the CEA/DAM developed the SPALAX-NG (Système de Prélèvement Automatique en Ligne avec l'Analyse du Xénon – New Generation) certified in 2021. From this date, it was introduced in the International Monitoring System to detect xenon releases following a nuclear explosion. This system is still under continuous improvement. In...
A total of 332 seismic stations operated by the Meteorology, Climatology, and Geophysics Agency (BMKG) utilize Global System for Mobile Communication (GSM) to transmit seismic data. Stable communication ensures the quality of transmission and the availability of seismic station data. Link Quality Estimation (LQE) can measure link quality based on physical metrics, thereby improving network...
To account for an ageing software and benefit modern computing capabilities, the International Data Centre (IDC) started a major programme ten years ago called IDC seismic, hydroacoustic and infrasound (SHI) Reengineering with the goal of creating a modernized, open-source software for SHI data processing and improving maintainability and extensibility to the system. This poster highlights...
The Provisional Technical Secretariat (PTS) runs a radionuclide network QA/QC programme for samples measured by the International Monitoring System (IMS) radionuclide particulate stations on a periodic and continuous basis. The purpose of the radionuclide network QA/QC programme is to verify station performance (by ensuring that produced data are of acceptable quality, the station poses...
The present project has the purpose of describing the design and developing many systems protections against lightning through the analysis of the ground resistivity and the application of the standards of IEC 62305, in order to solve problems that are produced through the impact of an atmospheric discharge in the telecommunications nodes.
The design will be made primarily from the analysis...
The Atmospheric Transport Modelling (ATM) pipeline is essential for linking radionuclide measurements from the International Monitoring System (IMS) to potential source locations. Operated by the Comprehensive Nuclear-Test-Ban Treaty Organization's International Data Centre (CTBTO-IDC), it has been fully functional for many years. Despite its effectiveness, several components need refinement...
Technical specifications for IMS stations require accuracy of calibration results to be within 5% and 5-degrees for amplitude and phase of the nominal response, respectively. Taking into consideration that the operating temperature for equipment components is specified between -20oC to +45oC, the sensors and dataloggers must assure operational quality within their nominal response specified...
This paper details the integration of Elasticsearch into the Secure Web Portal (SWP), a platform that States Signatories use to access vital resources related to the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The previous SWP system, which relied on a traditional relational database (Oracle), faced some limitations with performance, scalability and data access. To address these challenges,...
Harnessing nanotechnology, smart dust is revolutionizing nuclear detection and urban safety. These sub-millimeter autonomous sensors detect radiation, toxins, temperature and vibrations, integrating with IoT and machine learning for real time monitoring and predictive analytics. Quantum based AI further enhances its detection capabilities, making smart dust a vital tool in security. Smart dust...
For data generated by seismic monitoring networks to be useful and trustworthy, they must be sufficiently accurate and precise. While it is necessary that seismic instruments comprising networks be appropriately accurate and precise, that is not sufficient, as there are additional factors that determine seismic station accuracy. To help network operators compile and manage a set of necessary...
The Danish NDC and the Danish Embassy are organizing a panel debate on fiber sensing at the upcoming SnT2025. Fiber sensing is in the process of transforming how we detect signals from explosions and earthquakes. National seismic networks around the globe are working on methodologies for including Distributed Acoustic Sensing (DAS) in their daily work, a technology that also has enormous...
Since the beginning of the nuclear era, the international community has debated ways to reduce the risks of nuclear weapons and their proliferation. In 1996, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was adopted by the United Nations General Assembly, with the aim of banning nuclear test explosions. The treaty obliges State Parties to refrain from conducting nuclear tests and includes...
Noise levels at a waveform station can be analysed by computing Power Spectral Density (PSD), which is an important quality indicator for waveform data recorded by the International Monitoring System (IMS) seismic, hydroacoustic and infrasound network. The continuous monitoring of the PSDs as part of the quality control process ensures that the IMS network is operating efficiently, and that...
Since the 1960s, the Swedish Defence Research Agency (FOI) and its predecessor organizations have conducted seismological measurements in the Swedish region of Värmland. Established in 2001, the Hagfors station (HFS) serves as an auxiliary seismic array within the International Monitoring System (IMS) network. In 2021, the station underwent significant upgrades, including the installation of...
The modernization of the Puerto La Cruz seismic station (PCRV), carried out in 2023 thanks to the support of the European Union Fund and the Provisional Technical Secretariat, has significantly increased the availability of high quality seismic data at the International Data Centre and the National Data Centre. This improvement has reinforced global seismic monitoring networks, enabling more...
To secure data delivery to National Data Centres (NDC) with cloud infrastructures, a new communication method was developed to address this growing demand. This solution utilizes Linux Docker containers running programmable VPN clients, offering a highly flexible approach to deployment. VPN Docker can be deployed within minutes on any Linux-based software or hardware platform, ensuring the...
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We have compiled ground truth seismic events for the period of 2007-2024 that occurred within Australia. These events originated from either natural seismicity or mining-induced seismicity and mining blasts. Each event has been assessed on individual criteria, including the surface rupture, satellite imagery, temporary seismic installations or aftershock kits. GT events range from GT-1 to...
We developed a computer code to derive a crust and upper mantle velocity structure for southwest Iran (Firuzabad region) in the central Zagros by an application of the two events, single station method of Rayleigh wave phase velocity dispersion analysis. Three sets of digital recordings of large earthquakes in the Firuzabad region in 1994 and 1995 made at the Iranian Long Period Array (ILPA)...
A new seismicity map for Kenya is compiled from nineteen catalogs with 7,726 events spanning 1895 to 2020. The magnitude ranges from Mw 2.5 to 7.0 and a b-value of 0.60, for three magnitudes of completeness (Mc) 3.1, 4.0, and 4.8. The seismicity reveals a complex and dense seismic activity across Kenya, where the South Kenya Rift and the Nyanza Rift have the highest seismicity trending...
In our present research, we have analysed and interpreted the aeromagnetic data and anisotropy of magnetic susceptibility (AMS) fabrics to highlight the structure and tectonic settings of the study area. We used horizontal gradient and tilt derivative to identify deep sources and faults. We applied the Euler Deconvolution technique to provide reliable information. The results indicated...
The Vrancea region is renowned for its intense seismicity, encompassing both crustal and intermediate-depth earthquakes derived from distinct sources. Crustal seismicity is primarily associated with the deformation of the overlying crust, while subcrustal earthquakes arise from a vertically extended source zone between 60 and 180 km within a sinking lithospheric slab. This unique region...
The Comoros Volcano Observatory has recorded significant seismic activity through the local seismic network in recent years. The evolution of the local seismicity, often assessed as volcano-induced seismicity, raises numerous inquiries on the seismo-volcanic hazards and the Magnitude records in the Comoro Archipelago. Data from the Karthala Volcano Observatory (KVO) bulletin between 2017 and...
We investigate seismic attenuation characteristics of the Charlevoix seismic zone that is located ~100 km downstream from Quebec City and is the most seismically active region of eastern Canada. We determine Coda Q using 583 earthquakes (2.0 ≤ M ≤ 5.4) recorded at seven stations of the Canadian National Seismic Network from 1992 to 2022. We find that the highest Q0 (Q at 1 Hz) values are at...
Tens of papers have reported small seismic events at shallow depth in and near the northern regions of the Democratic People’s Republic of Korea. They often characterize the events as aftershocks of specific nuclear test explosions (NTEs). Here, we report an analysis of about six years (2004 to 2010) of seismic data recorded by the Dongbei Seismographic Network (DBSN) that in addition to...
In this study, we developed a local magnitude scale for the southeastern region of Cuba—the part of the island exposed to the greatest seismic hazard due to its proximity to the Oriente fault system. From the 2011–2021 Cuban catalog, 7750 earthquakes with ML > 2 were selected, distributed in the region 19°–22° N, 73°–79° W, and recorded by at least four seismic stations within 500 km of the...
The growing interest in pulse-like ground motions, especially occurring near faults, stems from their potential to inflict significant structural damage due to distinct directivity and fling effects. This study seeks to enhance the identification and classification of these impulsive ground motions by integrating traditional data-processing methods with advanced machine learning techniques....
The East African Rift System (EARS) is a prominent continental rift zone, extending over 3000 km from the Afar Triple Junction to Mozambique. Its Kenyan segment features fault-bounded basins, volcanic activity and seismicity, making it an ideal site for investigating crustal structure and rifting mechanisms. Previous geophysical studies revealed significant variations in crustal thickness...
Probabilistic Seismic Hazard Assessments (PSHA) have not been conducted in large parts of Sub-Saharan Africa (SSA), due to incomplete earthquake catalogues, sparse seismic networks, etc; raising concerns on needed information for planning and disaster risk management. This study aims to bridge this research gap using modern techniques. Updated catalogue from Local Networks, significant data...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) Auxiliary Station AS41 in Jayapura plays a critical role in regional seismic monitoring as a broadband station. This study evaluates the data quality of AS41 using cross-correlation techniques to assess its performance relative to neighboring short period stations. The analysis highlights that AS41 records a significantly higher number of...
The devastating earthquake followed by the tsunami that occurred in Palu, Indonesia, on 28 September 2018 resulted in the death of more than 4300 people and serious damage to more than 12 000 buildings. Earthquake-induced site displacement is critical information for estimating the magnitude of earthquakes. Compared to a seismometer, which the signal clipping when recording in the near-field...
This study presents the development of a comprehensive fault database for Madagascar, created by integrating information from available geological surveys and published articles. We have compiled a detailed catalog of faults throughout Madagascar, incorporating data on fault geometry to determine size, length, and dip angle of the fault, and tectonic setting to identify the relative motions'...
It is well known that structures can be damaged by earthquake shaking caused by the rapid rupture of the fault, which releases the stored energy that can result in significant loss of life and property. For economical and hazard aspects, the general seismological laboratory, seismology department, NRIAG, made the first step of hazard mitigation and vulnerability of buildings and structures by...
We combine seismic and tectonic approaches to apply the empirical relationships between fault parameters and magnitudes to assess the maximum magnitude for the prediction of intensity motion. The Talysh area in southern Azerbaijan, with 3960 km², 38054'N and 48035'E, spreads to the north through the Alborz mountains of Iran. The earthquakes are concentrated mainly in the central part of the...
Oceanic transform faults are important tectonic structures connecting mid-ocean ridge sections, controlling their global morphology, movements, deformation, and rupture process. The complete understanding of these fracture zones relies on earthquake focal depth (Z) estimation. Z is a critical parameter for these tectonic studies that is usually difficult to estimate due to unfavorable...
Undoubtedly, the study of stress tensor inversion and the identification of the types of affected forces in any region are of paramount importance in the fields of seismology and earthquake hazard analysis. In this study, we comprehensively collected all available focal mechanism solutions for earthquakes in the vicinity of Egypt. Utilizing the Kagan angle to assess the homogeneity of the...
On 11 January 11 2022, a powerful 6.5 magnitude earthquake struck Paphos, Cyprus, affecting the broader eastern Mediterranean area. Recorded seismic activity at the AKMS station revealed a PGA of 296.496 cm/s² and a PGV of 5.573 cm/s, indicating intense shaking and rapid motion. Ground motion parameters, including intensity, perceived shaking, potential damage, PGA, PGV, and instrumental...
Global seismic models suffer from heterogenous source and receiver distributions. The greatest gaps are beneath the oceans, ~70% of the Earth's surface. Most teleseismically observed earthquakes occur at plate margins, while most seismic sensors are on land. Ocean Bottom Seismometers (OBSs) offer some improvement in sensor distribution, but OBS deployments are limited in extent and duration....
This poster aims to show the result and method of a study to improve the understanding of Jordan's crustal and upper mantle structure and enhance the local model velocity by integrating seismic data from local Jordanian stations, International Monitoring System (IMS) stations, and non-IMS stations. Building on my previous research titled "Integrate Data from IMS and Non-IMS Stations..." the...
The 5 January 5 1967 Mogod earthquake (Ms 7.5, Mw 7.1) in Mongolia caused significant surface faulting and has long been a focus of seismological studies. Recent collaborative research (2022–2024) between the Institute of Astronomy and Geophysics, Mongolia, and the Korea Institute of Geoscience and Mineral Resources (KIGAM) has advanced the understanding of this fault system. This study...
This study focuses on understanding the crustal and upper mantle structure beneath northern Egypt using seismic data from 500 records collected by the Egyptian National Seismological Network (ENSN). Two broadband stations in the region were used to investigate crustal properties through joint inversion of surface wave dispersion curves (Rayleigh wave phase velocity) and receiver functions...
An advanced analysis was conducted on the triggered 'non-volcanic' tremors (NVT) around Tambora volcano in West Nusa Tenggara, Indonesia by 35 teleseismic earthquakes with a magnitude M>7 and epicentral distance of over 1000 km between 2020 and 2022. The waveform data were taken from the Indonesian Agency for Meteorology, Climatology and Geophysics (BMKG). The identification of triggered...
Lg blockage occurs when the Lg phase has anomalously low amplitude compared to the Pg phase. This phenomenon is often observed for paths crossing oceanic crust, but it is also seen in some continental regions such as the Middle East. Lg blockage is problematic for explosion monitoring because Pg/Lg amplitudes are commonly used as a discriminant; therefore, Lg blockage can cause earthquake...
This study employs Grond, a probabilistic earthquake source inversion framework, to analyse moderate to strong earthquakes (Mw 3.5–6.4) in Albania and the surrounding region. Using seismic data accessed via FDSN and a locally developed velocity model, moment tensor inversion is conducted to characterize complex regional seismicity. While the analysis primarily focuses on natural seismic...
The Kumtor gold mine is located on the northwestern slope of the Ak-Shyirak ridge of the Central Tien Shan, at an altitude of 5200 m. Since 1997, the Kumtor has been carrying out commercial open-pit gold mining; several hundred open-pit blasts are carried out on its territory every year. In addition to blasts, tectonic earthquakes and landslides are recorded on the territory of the deposit....
The southern region of Brazil, comprising the states of Rio Grande do Sul (RS), Paraná (PR), and Santa Catarina (SC), exhibits low seismic activity compared to other regions of the country. However, it has experienced significant events over time. Notable earthquakes include a magnitude 5.9 event in 1939 on the continental margin, a magnitude 5.5 event in 1948 near the Uruguay border, and a...
From 27 September to 2 November 2024, a sequence of moderate earthquakes (magnitudes 4.2 to 5.3) occurred in the Fentale volcanic zone, Northern Main Ethiopian Rift. This region is characterized by active magmatism and volcanism, making it a critical area for studying tectono-volcanic interactions. The seismic events were localized near Fentale, an active stratovolcano, suggesting a potential...
In the Ionian Islands, historical records dating back to 1400 A.D. reveal a recurring pattern of large earthquakes (Mw>7.0) involving multiple fault rupturing, complex rupture dynamics, and/or the triggering of additional earthquakes. Efforts to mitigate future casualties and economic losses require detailed investigations into past destructive earthquakes and seismic hazard assessments at...
From 10 to 19 September 2024, residents of Mpape, a densely populated settlement in Abuja, Nigeria, with a high concentration of mining firms, witnessed a series of vibrations that they thought were from usual ground shakings resulting from regular quarry blasts. The duration (nine days) of the vibrations motivated this research to determine the seismotectonic nature and characterize...
The northernmost region of Aceh contains an active fault capable of releasing energy with significant magnitudes. The magnification energy released along this fault can trigger significant and destructive earthquakes. This is evidenced by the seismic history of the Seulimeum Fault (the northernmost fault) in 1964 (Setiyono et al., 2019), which recorded a magnitude of M 6.5. The earthquake...
This study investigates the spatial-temporal distribution of b-values along five fault areas the Judi fault, Thaple fault, Kathmandu fault, Motihari-Gauri Shanker fault and the Motihari-Everest fault following the Gorkha earthquake (MW 7.8). The study area spans the central Himalayas, bounded by latitudes 26.5°–29° N and longitudes 84°–87° E. An earthquake catalogue comprising 10 500 events...
Seismic location is a crucial problem in event monitoring and the research on improved location accuracy has been driven by efforts to effectively monitor the CTBT. Epicenter location accuracy is affected by many factors, including picking quality of seismic arrival times, accuracy of velocity model and distribution of seismic network. The accuracy of the velocity model will greatly influence...
The Aegean Sea is one of the key regions for the understanding of fundamental tectonic processes, including continental rifting. In addition, the continuous seismicity is attributed to its tectonic settings, which indicates the activities of these tectonics. Thus, tectonics and geodynamics of this region have always been the attention of many interested in earth sciences. Radar altimetry data...
An earthquake swarm is a series of seismic events that occur in a local area over a short period of time. For a cluster of moderate earthquake activities of the earthquake swarm to have occurred within few days before the main shock is unusual in the Solomon Islands seismic activities from past historical seismic data records. However, before the M8.0 earthquake that triggered a tsunami on the...
The Central Andes is a geologically complex region due to various tectonic processes, including extensional and compressional strains. This complexity is particularly evident in areas like the Bolivian Orocline, where a lack of geophysical equipment, such as seismic stations, often hinders studies related to tectonics and seismology. Despite this limitation, new methodologies have been...
The Oman National Bulletin produced by the Earthquake Monitoring Center, Sultan Qaboos University between 2014 and 2024 were combined with regional and teleseismic data from the International Seismological Centre bulletin. The resulting comprehensive bulletin contains 2994 events within our area of interest. We applied a two-step relocation procedure to improve the view of Oman’s seismicity....
The quality of seismic moment tensor catalogs is crucial for studying seismicity, active faults, seismic hazards and seismic risk assessment. The National Seismological Network of Colombia routinely and semi-automatically calculates centroid moment tensor (CMT) earthquake solutions with Mw > 4.2 using different full displacement waveform inversion methods. Recently, the Gisola software was...
North Africa, which includes Egypt, Libya, Tunisia, Algeria, and Morocco, stretches from the Red Sea and Gulf of Aqaba in the east to the Atlantic Ocean in the west. This current study updates the seismic hazard evaluation for North Africa by applying a probabilistic approach. It uses an earthquake catalogue from 112 BC to 2024 AD and a seismotectonic model to assess seismic activity. The...
Studying the seismic risk of buildings and infrastructure in Kuwait is crucial for sustainability and urban development. The probabilistic seismic risk was computed to evaluate the economic and human loss in the Kuwait governorates of Al Farwaniyah, Mubarak Al-Kabeer, Sabah Al Ahmad, Hawally and Al Jahra to help emergency planners design plans to control or mitigate future risks. This study...
The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operates in remote and challenging environments, where a reliable power supply is critical to ensure uninterrupted nuclear-test-ban monitoring. This study proposes integrating solar panel based power systems with real time monitoring technologies to enhance operational sustainability and...
Information and communication technology (ICT) has been changing rapidly and the On-Site Inspection (OSI) Division has embraced these technologies to deploy GIMO/EIMO more efficiently during an OSI. An OSI has challenging constraints of collecting, managing and storing data. Twenty years of server technologies have given organizations the ability to virtualize desktops and servers, decoupling...
In the context of e.g. nuclear explosion monitoring, operating within local networks that feature enhanced security necessitates careful attention to data communication with external systems. The addition of an extra layer of security on the side of the data provider, such as the Comprehensive Nuclear-Test-Ban Treaty Organization's (CTBTO) Global Communication Infrastructure (GCI), introduces...
There is an urgent need to transfer the Seismology Section (SMS) from the Botswana Geoscience Institute (BGI) in Lobatse to the Botswana International University of Science and Technology (BIUST) in Palapye. Once at BIUST, SMS can deliver infinite benefits like involving students to build capacity and develop future scientists specializing in the various technologies used in the Comprehensive...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has been instrumental in strengthening global monitoring networks through its International Monitoring System (IMS). This work specified the role of advanced capacity building system (CBS) installed at the Iraqi National Data Center (NDC) in May 2024, which enhances capabilities in data acquisition, analysis and event...
The majority of the issues that have hindered West African National Data Centers (NDCs) ability to carry out complementary nuclear explosion monitoring (NEM) functions and fill critical research gaps are being gradually resolved through the utilization of International Monitoring System (IMS) data, International Data Centre (IDC) products and the Comprehensive Nuclear-Test-Ban Treaty...
Art is free from limitations, welcomes challenges to the status quo, can make scientific and technical information more accessible and allows those whose voices are not heard in traditional political forums to participate in policy-making. It has the unique potential to change public perceptions and bring awareness to the CTBTO’s mandate by democratizing scientific information and...
To help make visible the National Data Centre (NDC) in Congo Brazzaville, we will share the experience on the daily work of the NDC, including the way to analyse data with the NDC in a box software, with an example of an explosion of an ammunition depot on 4 March 2012 in a military camp in Congo Brazzaville:
- Their missions,
- Their analysis technique,
- Conclusions.
The present summary is a small contribution of the National Authority for Arms Control and Disarmament (ANCAD) to the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) Science and Technology Conference. This work is intended to be the beginning of the development of ANCAD research in the area of monitoring technologies linked to CTBTO. Within the scope of the Comprehensive...
This work presents the result of developing a customized and innovative tool for National Data Centers (NDCs), based on Python. This tool automates the creation and sending of seismic event reports, enhancing the efficiency and speed of critical data communication, allowing the generation of information in multiple languages. It provides a flexible and adaptable tool to specific needs of each...
The installation of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) capacity building system (CBS) at the National Data Center (NDC) of Mexico represents a groundbreaking step in advancing global seismological research and enhancing seismic risk mitigation. By harnessing the extensive data network provided by the International Monitoring System (IMS), this installation...
Since OVSICORI-UNA started using International Monitoring System (IMS) data, there has been significant progress in seismic data use, starting with the improvement of data acquisition systems like SeisComp and later incorporating infrasound and hydroacoustic data from IMS stations. Both the country and OVSICORI-UNA have benefited from various training programmes on the three IMS monitoring...
The monitoring network of the National Nuclear Centre (NNC) includes four seismic and one infrasound station, which are part of the International Monitoring System (IMS). In addition to these stations, the AFTAC arrays, the IRIS-NNC stations located on the territory of Kazakhstan, 11 three-component and two infrasound arrays of the NNC participate in global and regional monitoring as part of...
The Science and Technology (SnT2025) conference, organized by the CTBTO, provides a crucial platform for global discussions on advancements in monitoring and verifying compliance with the Comprehensive Nuclear-Test-Ban Treaty. For Ghana and the broader African continent, these developments hold significant implications for disaster preparedness, climate change and regional security. This paper...
The International Monitoring System (IMS) uses four major technologies in its verification regime. The four technologies, namely seismic, hydroacoustic, infrasound and radionuclide are best suited to monitor the globe for any activities underground, underwater and in the atmosphere. The first three are the known waveform technologies that help to detect and locate events. Kenya, in...
Mali is a landlocked country in West Africa. It is the eighth largest country in Africa, with an area of over 1 241 228 km2. The country is bordered by Algeria, Niger, Mauritania, Burkina Faso, Ivory Coast, Guinea Conakry and Senegal. Mali is a Sahelian country with a tropical and dry climate. Strong winds that blow during the seasons generate aerosols in the air. Depending on the...
National Data Centres (NDCs) are crucial national technical organizations responsible for advising their authorities on verifying the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Standardizing processes and providing essential hardware, software resources, technologies and techniques for monitoring, acquisition, processing and data analysis are vital for optimizing the use and interpretation...
The International Monitoring System (IMS) training programme for station operators, established in 1998, has been revised to meet evolving operational needs and ensure compliance with the draft IMS Operational Manual. This updated strategy addresses the diverse requirements of station managers, local operators, PKI operators and station operators, focusing on optimal performance and data...
The CTBT, an international agreement aimed at prohibiting all nuclear explosions, was signed by the Philippines on 24 September 1996, and subsequently ratified on 23 February 2001. In alignment with its commitments under the CTBT framework, the Philippines operates the radionuclide monitoring station RN52, situated in Tanay, Rizal. Managed by the Philippine Nuclear Research Institute, it is...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) represents a cornerstone in global efforts to eliminate nuclear weapons testing. However, achieving its universalization and entry into force remains a challenge. This presentation explores the concept of nuclear tourism as a transformative tool to raise public awareness about the catastrophic consequences of nuclear weapons testing. By...
The Seismology Laboratory of Paraguay originated from a bilateral agreement between Paraguay and the United States, through the United States Geological Survey (USGS), in the early 1990s. This agreement enabled the installation of a broadband seismological sensor and a short period sensor. Years later, Paraguay signed and ratified the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which led to...
The integration of virtual technologies offers transformative potential for advancing the CTBT’s objectives, particularly in building technical capacity among youth and early career scientists. By leveraging tools such as seismic and infrasound data analysis platforms, remote sensing simulations and interactive virtual labs, the CTBTO can provide accessible, scalable training in...
This paper describes the result of hydroacoustic data processing using the Comprehensive Nuclear-Test-Ban Treaty Organization's hydrophones HO1W, HO8S and HO4N during the period between 2018 and 2020 by the National Data Centre (NDC) in Madagascar. The main objective is to apply and follow the recommended steps described by the Provisional Technical Secretariat at the NDC forum website...
The National Data Center (NDC) of Jordan has been in operation since 2014, and many developments have taken place in the NDC-JO until today. The Provisional Technical Secretariat updated NDC-JO components, provided technical assistance and training courses. Enabling us to effectively participate in the Comprehensive Nuclear-Test-Ban Treaty verification regime and improve the capabilities of...
Like several States Signatories, an auxiliary seismic station installation agreement was signed on 22 May 2001 between Senegal and Mr Wolfgang Hoffmann, Executive Secretary of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). It entered into force on 24 March 2006. In the same vein, Senegal, like all States Signatories, has access to the data of the International Data Centre...
The natural phenomena, auroral electrojet arcs displays is observed periodically as the displays of bright lights in the sky in the polar latitudes regions, for both the Northern and Southern Hemispheres of the Earth. The auroral electrojet arcs display generate low frequency acoustic signals in the process which are sensitive to the sensors of the infrasound array network under favourable...
Eroding trust among Annex II states and Russia’s de-ratification of CTBT continue to hinder its entry into force (EIF). The stagnation in Annex II ratifications underscores the importance of universalising CTBT norms through regional cooperation. ASEAN presents a compelling case for such an approach: while all ASEAN Member States have ratified the CTBT, the region remains susceptible, yet...
The CTBTO plays a pivotal role in the prevention of nuclear weapons testing and the enhancement of global security. The fulfilment of its mission is contingent upon the continued development of its technological capabilities, as well as the maintenance of a positive public perception of its relevance and effectiveness. This study examines the manner in which public perceptions of science and...
Increasing urban development combined with damage from recent earthquakes highlights the need for resilient infrastructure and a better understanding of seismic hazard. During the past several decades, the expansion of national seismic networks and data collection in the Middle East has improved seismic monitoring and contributed to emergency preparedness and response. Lawrence Livermore...
While scientists and specialists have been persistently doing research and exploring every potential to push CTBT earlier ratification, people in other fields gradually turn their attention from this issue over time. It’s therefore increasingly crucial now and in the future to educate younger generation, raise the public’s awareness and keep the decision makers alert on the importance of CTBT...
We established an initiative in Nepal to introduce seismology in schools, with a focus on education and citizen seismology. This program currently encompasses 33 secondary schools for: (1) the establishment of a network of affordable seismometer within the participating schools, and (2) the incorporation of earthquake-related education into the curriculum. We have prepared educational...
The volcanically and seismically active Main Ethiopian and East African (Kenya) rifts are linked in a complex zone within the Turkana Depression bounded by the Ethiopian plateau to the north and East African plateau to the south. Subsurface imaging beneath Lake Turkana and surrounding sub-parallel basins reveals multiple half-graben basins bounded by N-S striking normal faults. The objective...
Traditional methods of science outreach, such as face to face courses and workshops, often face challenges such as limited resources and logistical obstacles. In Latin America and the Caribbean, where access to technology can be uneven, engaging the public with scientific knowledge requires innovative approaches. Recognizing the growing popularity and accessibility of mobile technology,...
In the framework of the Comprehensive Nuclear-Test-Ban Treaty Organization Mentoring Programme for early career women in science, technology, engineering and mathematics, experts from National Data Centers (NDC) served as mentors. The Austrian NDC, which is managed by a female seismologist, decided to take part in this initiative. The Provisional Technical Secretariat (PTS) selected an early...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a vital tool in the global non-proliferation and nuclear disarmament agenda, and in this regard the promotion of the CTBT is imperative. It is not only essential for the CTBT itself and nuclear disarmament issues, promoting the CTBT also contributes to the overall advancement of peace and security. But with the media landscape and the public...
Ghana is in a seismically active region and has experienced two major earthquakes of magnitude 6.5 on the Richter scale in 1862 and 1939. Twenty lives were lost in the two earthquakes and many structures were destroyed. In recent times earthquakes of magnitude 1.0 to 4.8 have been recorded in the country. This study is focused on the recent earthquake activities in Ghana and is intended to...
A 6.6 magnitude earthquake occurred in the Hyuganada Sea off the coast of Kyushu, Japan on 13 January 2025. A 1 m high tsunami was associated with the event triggering the issuance of tsunami advisory by the Japanese government. The underwater eruptions of the Hyuganada Sea generate air waves and pressure waves that were used to study how the application of International Monitoring System...
Global nuclear attitudes have significantly altered over the past five years. Renewed global power competition and destabilizing events have intensified public and policymaker focus on nuclear weapons. Amid this renewed relevance of nuclear weapons in global security discourses, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) emerges as a critical stabilizing framework, offering an...
The Latin American and Caribbean (LAC) region has demonstrated a strong commitment to the Comprehensive Nuclear-Test-Ban Treaty (CTBT), actively supporting its nuclear disarmament and non-proliferation objectives. However, the participation of LAC experts in critical Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) meetings, especially in Working Group B focused on technical and...
Analyzing data and proper interpretation of the analyzed data are important for the operation of NDCs as they provide advice for both scientific and civil applications of these data. Having an analyst that can interpret data from the International Monitoring System (IMS) network is a challenge to some National Data Centres in the African region. To overcome this and enhance capacity building...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) launched a pioneering mentoring program in 2022 to empower early-career women in science, technology, engineering and mathematics (STEM) from underrepresented regions, fostering gender equity and capacity building. Indonesia, a committed CTBTO member state, has played a significant role in this initiative by successfully mentoring...
Visually impaired individuals face challenges in both learning programming and engaging with exhibitions due to the predominantly visual nature of both activities. This project explores tangible block-based programming, where users interact with physical objects to construct computer programs. I am developing a web application that uses the TopCode JavaScript library, 3D-printed fossil models...
After our participation in the 2014 CTBT Academic Forum, we decided to propose a formal course in the Earth Science undergraduate program offered in the Science Faculty at the National Autonomous University of Mexico (UNAM).
In August 2019, the elective course “Application of Earth Sciences in Nuclear Test Monitoring” was first taught for students enrolled in the bachelor’s degree of Earth...
The 2024-10-05 Iran M 4.5 earthquake was a relatively unremarkable reverse-fault event, except that it took place at a time of heightened tensions in the Middle East. Its immediate aftermath saw widespread dissemination of misinformation, and potentially active disinformation, concluding that it was in fact a test of an Iranian nuclear weapon. The ‘evidence’ for many of these claims was based...
The recent experiences gained from the 2024 National Data Centre (NDC) training in Kenya and the NDC workshop in China have given us clear insights into the benefits of an NDC. Such benefits include a country’s active participation in a world free from nuclear explosion, capacity building, access to International Monitoring System data and International Data Centre products, etc. The...
National Data Centers (NDCs) play various roles, such as organizing capacity building events for a critical mass of interested States Signatories of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), sensitizing the public on the danger of a nuclear explosion, providing International Monitoring System (IMS) data, International Data Centre (IDC) products for research and other purposes. Nigerian...
Over the past years, nuclear weapons test monitoring technologies have evolved enormously. This has made it possible to detect nuclear tests in all environments possible. The efficiency of the monitoring technologies and the capability of the analyst play a crucial role in nuclear weapon test monitoring. In this paper, we analyse an NDC Preparedness Exercises (NPE) and also present an overview...
The National Nuclear Security Support Centre of the Technical University of Moldova celebrated its 10th anniversary in October 2014. Established by agreement of the Technical University of Moldova and the Moldovan Nuclear Regulatory Authority, the Centre has been active in educating the younger generation, including in nuclear security, non-proliferation and disarmament.
Over the years...
The capacity building and training (CBT) programme supports States Parties' participation in the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime by enhancing the technical capabilities of National Data Centres (NDCs). It provides tools, training and equipment to help NDCs receive, process and analyse International Monitoring System (IMS) data and effectively utilize...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) remains a cornerstone of global nonproliferation efforts, yet its entry into force is stalled by the non-ratification of eight Annex 2 states. This paper explores the evolving policies of these states — specifically the United States, China, Egypt, Iran, Israel, India, Pakistan and North Korea — to identify key political, strategic and regional...
The field of nuclear diplomacy, nonproliferation and disarmament currently faces significant challenges, including stagnation in advancing key agreements. The Comprehensive Nuclear-Test-Ban Treaty (CTBT), a cornerstone of the global nuclear order prohibiting all nuclear weapon tests, struggles to secure ratifications from Annex 2 States, delaying its entry into force. Integrating gender...
As technology evolves at an increasingly rapid pace, international organizations (IOs) are innovating and using new tools and methodologies to achieve their goals. From verification and monitoring mechanisms to disaster risk reduction and environmental protection, emerging technologies are transforming the ways IOs operate and address global challenges. This panel will explore how...
On 17 June 2013, the container ship MOL Comfort suffered a crack amidships during inclement weather in the Arabian Sea. The ship broke into two sections that sank on 27 June and 10 July 2013, respectively. A triplet of hydrophone station HA08 of the International Monitoring System recorded underwater sound phases associated with the sinking of the two sections. Arrivals derived from...
The computation of 3D acoustic models for long-range propagation in realistic oceanic environments poses significant computational challenges. Here, we present an extension of our GPU-accelerated hydroacoustic transmission loss solver in Julia. This work is built upon a model previously developed by us, enhancing its capability to run in cloud environments with large-memory GPU instances. It...
The International Monitoring System particulate radionuclide station air sampler is a specialized device designed to detect and measure radioactive particles in the atmosphere. It forms part of a global network tasked with monitoring adherence to the Comprehensive Nuclear-Test-Ban Treaty. By continuously sampling the air, these stations play a crucial role in detecting unauthorized nuclear...
In theory, infrasound signals generated by bolides offer a window into understanding source properties, such as shock altitude and energy. However, to accurately leverage these signals, both ground truth and accurate atmospheric specifications are essential, as dynamic atmospheric variations over minutes to hours can affect signal viability, and complex propagation paths may lead to unexpected...
Research on tsunami potential in northern Bali is rarely conducted. Most of the prior research was conducted in the southern region of Bali island due to its geographical location near the megathrust subduction zone. However, the earthquake-triggered tsunami may occur due to the existence of a Back Arc Thrust (BAT) zone in the north of Bali. A Back Arc Thrust (BAT) zone runs across the...
Multiscale atmospheric transport models (ATM) resolve mesoscale meteorology, such as frontal passages, and microscale meteorology near-source, which is often strongly influenced by complex terrain and heterogeneity of the land surface. The ability of material collection stations to detect passing plumes can be strongly influenced by local variations in atmospheric flow, particularly nearby the...
Depth assessment is one of the most difficult, however, most effective event screening methods and is usually achieved by the International Monitoring System using seismic sensors. Analysis of waveforms recorded at hydrophones from a small set of events with similar mechanisms and relatively high SNR, located in Central Sumatra, indicated promising depth sensitivity and dependency of T-phase...
The low attenuation in seawater and the low-velocity layer SOFAR (Sound Fixing and Ranging) channel enable the hydroacoustic stations of the International Monitoring System (IMS) to record acoustic waves over long distances. The French National Data Center uses the Progressive Multi-Channel Correlation (PMCC) method to detect low-frequency coherent waves (< 40 Hz). These detected underwater...
In the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), Côte d’Ivoire benefits from two primary stations: seismic (PS15) and infrasound (I17CI) respectively for monitoring underground and airborne nuclear tests. Upgrading the infrasound station I17CI from four to more sensors is part of the CTBTO’s medium term objectives. Thus, this research...
A low frequency sound source, deployed in the mid-1990s off the North Coast of Kauai at deep sound channel axis, provides a critical tool for measuring the deep ocean temperature across North Pacific Basin. This temperature measurement is enabled by precisely timed transmissions from a cabled sound source and their reception on distant cabled hydrophones. We focus on hydrophone receptions at...
Rapid changes to the Arctic Ocean impact its acoustic environment. As the Arctic warms, the soundscape is modified by changes to the thermohaline stratification of the water column as well as changes in the distribution and morphology of sea ice. Sea ice attenuates sound through scattering and absorption, emits sounds as it deforms and exerts control over the generation of sea surface waves...
The propagation of infrasound through the atmosphere is highly sensitive to small scale disturbances that can significantly influence waveforms. Among these, gravity waves play a critical role and are typically parameterized in General Circulation Models (GCMs). This study investigates the performance of long range infrasound modeling in reconstructing non-orographic gravity waves fields. We...
Whale signals are frequently observed at triplets of hydrophones of the IMS hydroacoustic stations. Fin whale signals emit characteristic time-frequency patterns. Two types of fin whale signals are observed at IMS stations HA11, located close to Wake Island in the Pacific Ocean. Echoing of the signals is clear on the recorded traces and attributed to multiple bottom and sea surface...
Anomalously fast infrasound phases, with unexpectedly high celerities, present a challenge for accurate modeling and detection of atmospheric events over long distances. While fast arrivals are typically confined to short-range propagation (within 300 km) where boundary layer effects are dominant, recent observations reveal celerities exceeding 330 m/s at ranges spanning thousands of...
The Strateole2 campaign deployed superpressure balloons for several weeks in the southern stratosphere. On 15 January 2022, their pressure sensors detected infrasound signals (0.01 to 1 Hz) from the major eruption of the Hunga Tonga Hunga Ha'apai (HTHH) volcano. These signals present differences in amplitude and frequency content compared to recording of ground International Monitoring System...
A method for network selection and localization of global infrasound sources based on propagation velocities and azimuth deviations of infrasound signal arrivals at the infrasound stations of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is developed. The method uses a network likelihood ratio approach, incorporating the Revised Event Bulletin...
Indonesia is at the forefront of earthquake and tsunami disasters due to tectonic and geological complexity. Non-seismic tsunamis caused by landslides and volcanic collapses have become an important new disaster issue in Indonesia since the 2018 Palu and 2018 Sunda Strait events. Based on VSI-ESDM (2024), a dozen active volcanoes were found on the coast and under the sea. Mount Gamalama is an...
The predictions made in this paper about sound propagation situations referred to in the title are based on an analysis of the propagation of acoustic wave motion from an explosive point source of a wide spectral range placed in the corresponding benchmark models: a wedge of fluid and a half-space of fluid, each of which is over an elastic solid bottom where the shear-wave velocity is less...
The issuance of tsunami warnings constitutes a pivotal measure aimed at preserving human life and lessening the impact on local communities. The moment magnitude of the P wave (Mwp) alongside the rupture time duration (Tdur) can be employed as rapid parameters for disseminating tsunami warnings. In this manuscript, we analyze the seismic waveform data sourced from a global network to ascertain...
Infrasound is one of four technologies dedicated to monitor nuclear explosions. It is used as well to study other issues for the benefit of science or to improve human life. Nowadays, rainfall variability is a widely discussed topic due to climate change. This work probes the relationship between rainfall variability and the characteristics of infrasound signals recorded during the dry season...
The results of theoretical and experimental studies of the fine-scale layered structure (anisotropic turbulence) of the middle atmosphere (20-140 km) using the acoustic method are presented. Based on the developed model, the possibility of formation of a fine-scale layered structure of the middle atmosphere by internal gravity waves from meteorological fronts is shown. Vertical and horizontal...
Infrasound signals are used to monitor various anthropogenic and natural sources. To determine precise source locations and energy, an accurate model of wind and temperature from the surface up to the lower thermosphere is necessary, hence operational NWP products are of great importance for routine infrasound monitoring activities. However, many of these models focus on tropospheric...
Numerical modeling of the propagation of atmospheric waves before atmospheric storms in the Moscow region was performed. A three-dimensional version of the high resolution nonlinear numerical model AtmoSym was used for the simulation. Experimental observations from a network of four microbarographs located in the Moscow region were taken as a source of disturbances. Wave characteristics of...
This work investigates the T-phase time residuals (defined as differences between the observed arrival times and their theoretical values) at IMS hydrophone stations HA11 and HA3 in the Pacific Ocean. The work is focused on T-phases from earthquakes in the Ring of Fire recorded between 2001 and 2024. Time residuals of T phases from these regions can typically range from minus 150 to 150...
The peril associated with the eruption of Rokatenda Volcano is not solely attributed to its eruptive products, but it also possesses the capacity to induce a tsunami. This investigation seeks to simulate the timing of tsunami arrival and its height, as well as to model the inundation effects stemming from a landslide estimation that could precipitate a tsunami following an eruption of...
One of important challenges the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has been facing is to put an error bar on its atmospheric transport modelling (ATM) simulations. A well-established approach to address this question by the meteorological community is to run, for a given date, multiple simulations. These simulations constitute an ensemble, whose instances, or members,...
This keynote will present the history of the Group of Scientific Experts’ (GSE) work, the Treaty negotiations and the technical rationale for the Verification Regime as we know it today.
The IMS network was designed in the 1990s, and in the future there might be room for further improvement or optimization considering recent technologies and lessons learned from the many years of operation. The roundtable will be preceded by a keynote presentation about the history of the Group of Scientific Experts’ (GSE) work, the Treaty negotiations and the technical rationale for the...
