Artificial Intelligence (AI) has the potential to revolutionize the very ways we live our lives and make our world more sustainable and equitable. Today’s AI based methods, which are still nascent and narrowly applied, are already providing means to innovate and impact everything including science, environment, energy, health, and climate. AI impacts the U.S. Department of Energy (DOE) across...
From 2006, when Tunisian IMS station (PS42 and IS48) started sending data, the NDC-TN has made a concerted effort to effectively participate in the verification regime of the Treaty and to implement obtained knowledge and capacities at the national, regional and international levels.
This poster will give you an idea on how the NDC-TN:
• Ensures the smooth functioning of the stations and the...
Madagascar has never had a big earthquake until now. The biggest earthquake had a magnitude of 7 Richter, and not on land but in the ocean. The highest magnitude on land was below 6 Richter. The central part of the big island is the most active seismically. It can be clustered into three zones. Two of them are a Cenozoic volcanic area, which are Itasy and Ankaratra, from the north-west and the...
Brazil does not have its NDC yet, but its creation has recently been discussed and, to contribute to these discussions, we have written the book The Brazilian Participation in the verification of CTBT, which presents the importance of an NDC, the advantages obtained with the its creation and demonstrated importance of CTBT in the control of nuclear weapons and in the construction of a solid...
In this study, a comparison is made between in-situ infrasound recordings in the microbarom band and simulations using a microbarom source model. The recordings are obtained by the 'Infrasound-Logger' (IL), a miniature sensor that has been deployed as biologger near the Crozet Islands in January 2020. The sensors provide barometric and differential pressure observations that have been obtained...
The CTBT IMS hydroacoustic sensor network composed of 6 hydrophone stations and 5 T-phase is part of the global CTBT verification regime. The hydrophone stations consist of hydrophone triplets. Each hydrophone is suspended in the ocean at a depth close to the SOFAR channel axis and anchored by a riser cable to the ocean floor. The geometry of the triplets and dedicated data processing allow...
Sources including volcanic eruptions and buried explosions have been shown to produce directional infrasound radiation. However, infrasound sensor deployments generally consist of instruments placed on the Earth’s surface. Therefore, directional sampling of the radiated acoustic wavefield (especially at angles close to vertical incidence) is generally limited. This insufficient wavefield...
Despite the progress made both in hardware and numerical techniques, 3D acoustic propagation for stratified oceans in cartesian coordinates, is still a challenge. In 2019, an approach to this problem restricted to short-range distances, using the Boundary Element Method (BEM), was reported (Li et al. J. Comput. Phys. 392, (2019): 694-712.). The BEM is a widespread method that exhibits certain...
This study presents a vespagram-based approach for comparison between infrasound data recorded at the ground and simulated microbarom soundscapes in multiple directions simultaneously. Data recorded during 2014-2019 at the IS37 station in Bardufoss, Norway, have been processed in the framework of velocity spectrum analysis in order to generate images that present a signal power depending on...
Space-temporal distribution of seismic activities in Western and Central Uzbekistan is considered. Four groups of strong earthquakes in the regions were analyzed. The pattern of redistribution of the accumulated tectonic energy in the form of seismic activity in the regions is revealed. In a west-east direction, an increase in the depth of earthquakes is noted. Deviations from the regularity...
The ocean is subject to complex dynamics that can produce time variant sound speed gradients with horizontal scales with potential to impact medium to high frequency acoustic propagation. Some of these features can critical grazing angles that may result in horizontal sound refraction, producing areas of stronger and weaker energy, time delays in the acoustic arrivals and changes on multi-path...
Sumatra and West Java have a high potential for geological disasters, including volcanic eruptions and earthquakes. In the last two years BMKG has significantly increased the number of seismic stations in this area, by utilizing seismic waveforms recorded by the BMKG seismograph network of earthquake monitoring stations spread across the Sumatra (110 stations) and West Java (48 stations) for 5...
Offshore seismic surveys with airgun array sources are currently widespread in all the oceans. They constitute one of the most powerful and systematic impulsive noise sources in marine environments. The sound pulses from large airgun arrays generate signals that contain sufficient energy in the 5-60 Hz band to propagate ocean-basin scales at ranges of hundreds to thousands of kilometres. Under...
We analyze foreshock activity in the Iranian plateau by investigating the occurrence patterns for isolated M >= 5.5 earthquakes from 1968 to 2018. Among the 165 mainshocks with M >= 5.5 (after excluding 12 aftershocks, 6 swarms and 9 doublets), 18 percent are preceded by at least one foreshock within 30 days and 20 km. However, the number of events in each foreshock sequence is significantly...
The CTBTO Library has created an extensive analysis of the CTBTO scientific communication. This was possible using bibliometric and scientometric techniques, through key network visualizations to represent its contribution to the global scientific community during the last 25 years of international collaboration.
In the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification...
A gravity analysis and Interpretation are carried out using data collected by Sun-Oil Company in the area west of Khartoum between latitudes 15◦ -17◦ N and longitude 30◦-33◦ E. The data released in a Bouguer anomaly map at scale of 1:500,000 and a contour interval of 5mgal.The target is to analyze and interpret the gravity data in terms of surface and subsurface geology. The qualitative...
Anthropogenic noise pollution may mask natural sounds, which are fundamental to survival and reproduction of wildlife, especially for marine cetaceans as they are highly dependent on underwater sounds for basic life functions.
In the 21st century, shipping in the ocean has increased significantly and causes low frequency (10–100 Hz) noise which affects or hinders vital communication of...
This paper investigates the sensitivity of two cumulous convection schemes – Grell and Emmanuel – under RCP8.5 scenario drought severity over Congo Basin (CB). The analysis were conducted using a multiscalar drought indices, standardized precipitation index (SPI) for several time scale –3,6,12,24,48 months –during the decades 2021-2030 ; 2031-2040 ; 2051-2060, and 2071-2080. The results...
This study examines the assessment of the seasonal forecasts of the North American Multi-model Ensemble (NMME) Project in Central Africa (CA) using deterministic and categorical methods focusing on the rainfall variable. This assessment is made for the June through August, March through May, and December through February seasons at 0-5 months, lead-times which are consistent with many regional...
We investigate seismic attenuation characteristics of the Canadian portion of the northern Appalachians. Coda Q is determined using 389 earthquakes (1.8 =< M =< 3.9) recorded on four stations of the Canadian National Seismic Network (CNSN) in New Brunswick from 1985 to 2020. For comparison, we divide the study area into northern and southern portions, each with two seismic stations and 162 and...
Nigeria joined the international community to welcome the adoption of the Comprehensive Test Ban Treaty (CTBT) by the United Nations General Assembly on 10th September 1996, as a veritable tool to prohibit “any nuclear weapon test explosion or any other nuclear explosion” anywhere in the world. Nigeria signed and ratified the CTBT in September 2000 and September 2001 respectively. Baseline...
Algeria suffered frequently from effects of destructive moderate sized and strong earthquakes because of the seismotectonic setting on the boundary of African and Eurasian tectonic plates. On May 14th, 2010 at 13 h 29 m GMT, a moderate earthquake of magnitude Md 5.2 (CRAAG – Algeria) struck Beni-Illmane a village located about 200 km southeast of Algiers. The main shock caused substantial...
The CTBTO mission has been linked since the beginning of the Treaty to cooperation models between diverse stakeholders in science, technology and policies areas in order to make its task more effective and comprehensive.
Nevertheless, there is still a long way to go in this regard and many actors must be incorporated on the effort to build a real awareness, to ensure joint initiatives can be...
The hydroacoustic component of the IMS network consists of a series of five island-based seismic stations and six cabled hydrophone installations located in the Indian, Pacific and Atlantic Oceans. In this study, we focus only on hydrophone stations, which provide low back ground high quality data: each one of these stations hosts a set of three hydrophones deployed at a depth of the SOFAR...
The first round of consideration of the construction of a nuclear power plant in Kazakhstan began in the mid-90s. The second time, with serious intentions, talking about construction of a nuclear power plant started in the mid-2000s. And for the third round, activity in the construction of a nuclear power plant in Kazakhstan dates back to 2013-2014 with government commission recommending two...
The I48TN is one of the 60 International Monitoring System (IMS) stations of the Comprehensive nuclear Test Ban Treaty Organization (CTBTO) characterized by its location in the heart of the IMS Infrasound network (Figure 1.a). The ability of the IMS infrasound network to detect atmospheric nuclear explosions and other signals of interest is strongly dependent on station‐specific ambient noise....
In this study, the diurnal variation of the rainfall amount, frequency and intensity, and the rainfall with different durations, as well as its intra-seasonal variability are analysed using rainfall data from 18 stations over Ndiaganiao (area located in western Senegal) during the period 2007-2015. Our results show that the mean rainfall amount and frequency peaks are observed around 1800...
The 4 August 2020 tragic Beirut ground truth explosion is of great interest to test the infrasound component of the IMS network, especially in terms of localization accuracy and energy estimation. Although the event was detected by five infrasound IMS stations located from 2 400 km (I48TN, Tunisia) to 6200 km (I11CV, Cape Verde), the early location capability from such a sparse network remains...
This presentation will examine the extensive efforts of the CTBTO Technical Secretariat to advance public awareness of the Treaty, and will explore what NGOs have done to further this effort. Most important, it will investigate the avenues that academics, NGOs, and scientific experts can pursue, in particular in cooperation with each other and with respective governments. The CTBTO has...
Based on observations from monitoring stations or other platforms, unknown atmospheric pollutant emission sources, including source location, strength, and temporal variations, can be estimated using inverse modeling techniques. In such applications, 3D-particle Lagrangian dispersion models are usually employed, and the source-receptor sensitivities are calculated in either forward or...
The interactive seismological analysis system used by default at the Venezuelan NDC (Funvisis) is the SEISAN, which offers a complete package of programs for seismological analysis and for research purposes. Geotool, although it does not have a seismological research program package, is a software with a graphical interface that allows to display and analyze seismic events interactively. Both...
The objective of this study is to build and then evaluate a statistical model of seasonal forecasts in Cameroon. A study was carried out in the five agro-ecological zones of Cameroon with the test stations of Kaélé, Meiganga, Nkongsamba, Yaoundé and Kribi. This study consisted of developing statistical forecast models at each of these stations which were then evaluated first over their...
University, indispensable for research, is one of the pillars of the prosperity and security of future generations. The diversification of research impose new ethical rigor hanging in the dissemination of the results. Responsible management of research in universities requires active commitments from relevant institutions.
The progress in free access to information on the internet shows an...
The six CTBT IMS hydroacoustic hydrophone stations, comprising 11 triplets in total, record continuous data sampled at 250 Hz. Marine mammal vocalizations are frequently identified in these recordings and form an integral part of the HA stations’ undersea soundscapes, as reported in numerous scientific publications. During regular IMS hydrophone data quality checks, occasional short duration...
2026 marks the 30th anniversary of the adoption of the CTBT and the establishment of the CTBTO. One of the most powerful tools that can help the CTBT enter into force is the young generation. We hope that the CTBT Youth Group could break this vicious circle.
We are aiming to establish a project to raise awareness for the young generation and to educate them. We have already assembled a team...
This is the research and educational project for CYG members, which involves them in the CTBT research. The participants will work in groups of 4-5 people. Their research topic may include Verification Issues, Article XIV, CTBTO in the context of the nonproliferation regime, Science diplomacy, CTBTO and climate change, non-nuclear related applications of the IMS, et cetera. Each group will...
CTBTO Youth Group represents a unique platform of almost 1000 members from diverse backgrounds,connecting science and policy in an interdisciplinary way. The platform provides opportunities through nuclear disarmament and non-proliferation education to involve its members in various track 2 diplomacy channels creating a safe space for active engagement, learning and exchange between peers...
The CTBTO Youth Group (CYG) was launched in 2016 and since then has around 1000 members. But this membership would not have been possible without effective and proper communication among members and with the CTBTO staff. The objective of the paper is to share successful communications model of the CTBTO Youth Group. The results suggest that this experience could be helpful for other youth...
While awaiting signals from a nuclear test, the International Monitoring System (IMS) routinely detects many events that are attributed to atmospheric processes and referred to as perturbators or noise. These events, known to cause false detections, are an important source of difficulty in the network processing operated at the International Data Center (IDC). Because many thousands of events...
Acoustic-wave detection from man-made sources like explosions and artillery is of interest both for civilian and military purposes. Infrasound propagation from surface sources is controlled by a complex interplay between source location, winds, atmospheric attenuation, and topography. The seasonal and stochastic variability of stratospheric and tropospheric winds is known to play an important...
What are the determinants of public support for nuclear proliferation? Fielding two survey experiments to nationally representative samples in a non-nuclear weapon state, we provide micro-level foundations for the acquisition of nuclear weapons. We find individual support for proliferation augments as existential threats loom large and it diminishes when external security is plentiful. Results...
In this research, a local earthquake magnitude formula (ML and MLv) was developed for measuring earthquake magnitude in northern Thailand and determined station magnitude corrections. By using data from 31 seismic stations of the Earthquake Observation Division, the Thai Meteorological Department and CTBTO Chiang Mai seismic station, analyzed 148 earthquake events from 2009 to 2019 to find the...
Soft soil effectively changes the behaviour of seismic wave propagation and this is important for urban areas. Waveform modelling is one of the methods we can go through site effect and check how the underlying structure could amplify incoming waveform and how will affect low and high rise buildings. In this study, we have monitored a situation with and without soft soil on some existing...
Nuclear accidents are capable of exponential damage, and in particular can be the reason for acute environmental degradation. Radioactive contamination can occur for multiple reasons like damage in the nuclear reactors, from nuclear waste and also from the temporary storage of spent radioactive fuel. Radioactive emissions are fundamentally airborne and guarantees contamination for the next...
In the midst of the Covid-19 pandemic, a need has arisen to rethink our way of working. As Disaster Risk Reduction and Mitigation is increasingly taking the spotlight so are education for Sustainable Development and the overarching framework of the SDGs. An important aspect that needs to be (re)considered to address future risks is the role education and life-long learning play.
In this...
The present work seeks to study the seismic upper mantle discontinuities of the northwestern part of South America and report the results of the first P-to-S radial receiver function investigation of the 410 km and 660 km depth discontinuities that bound the mantle transition zone (MTZ) beneath Colombia. In order to calculate the receiver functions and generate a first-order approximation of...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is operating and maintaining the international monitoring system of seismic, infrasound, hydroacoustic and airborne radionuclide facilities to detect a nuclear explosion over the globe. The monitoring network of CTBTO, especially with regard to infrasound and hydroacoustic, is quite unique because the network covers the globe, and...
Infrasound is one of three waveform technologies of the Comprehensive Test Ban Treaty (CTBT) verification regime. The International Monitoring System (IMS) network records manmade and natural sources of infrasound signals (bolides, spaceflight activity, sonic booms, volcanic eruptions, quarry blasts, earthquakes...). To identify these sources we need to download and process data, and analysts...
Calculation of moment tensors of weak seismic events is challenging. Quite often we face a lack of stations and inaccurate velocity models. However information on moment tensors is important for understanding origin of the events (explosions, natural and induced earthquakes) and seismotectonic regime of the area. We re-analyzed two methods of retrieving moment tensors: (i) Inversion of...
Effects of reservoir filling are studied well during past decades by increasing monitoring stations around dams. In this study, a period of more than 10 years of seismicity around Seymareh dam (a major dam Southwestern Iran) is monitored and thousands of minor earthquakes around the lake is processed and evaluated before and after reservoir filling. Various parameters of active locations and...
As an artificial radionuclide, I-131 rarely appears in a natural environment, while RN22 monitoring system sometimes finds I-131 each year in air samples, especially in winter. The highest I-131 activity is 3 Bq while MDC for HPGe is 0.08Bq. The Gaussian model is applied to backtrack a possible resource of Iodine near RN22. The activity of cosmogenic radionuclide Be-7 in air samples is...
Instrument response issues are common in seismology, and they can hinder research. We use large data sets to develop models that will predict high-frequency seismic amplitudes, which requires extensive quality control. To identify response and station health issues, we have collected time histories of noise measurements near (but not restricted to) midnight to eliminate diurnal variations, and...
Some countries have signed the CTBTO nuclear test ban treaty but are reluctant to ratify it. This can have several causes: Either their selfish aspect which can lead them to do not accept a total control by the preparatory commission of CTBTO, or the diplomatic relations are not very well strengthened between CTBTO and these countries.
We believe that the installation of National Data Centers...
In recent years with the installation of the NDC-Costa Rica since 2010, improvements have been made in advances in data analysis by CTBTO tools to the states party of the treaty. On the part of the NDC-Costa Rica, the real-time inclusion of IMS seismic stations and OVSICORI local seismic stations for monitoring local, regional, global seismic and infrasonic events automatically through...
Following an eruption series at Kadovar Island, Papua New Guinea, the hydroacoustic datasets acquired by CTBT International Monitoring System (IMS) hydroacoustic (HA) hydrophone station HA11, Wake Island, were examined. HA11 is located approximately 3500 km northeast from Kadovar. Active eruptions restarted in January 2018 after a quiet period of three centuries. Cross-correlation analysis...
Infrasound research conducted at Los Alamos National Laboratory (LANL) in recent years has included development of tools for signal analysis, propagation modeling, and uncertainty quantification. Many of these tools have been licensed as open source software, made available for download at the LANL Seismoacoustics Github page (https://github.com/LANL-Seismoacoustics), and are utilized by...
An explosion was reported on the 4th of October in the Port of Beirut (Lebanon), by IMS infrasound stations. News reported that the explosion was due to a large quantity of ammonium nitrate stored in the port that exploded (equivalent to around 1.1KT of TNT). The infrasonic signal was observed by several infrasound IMS stations, among them the Tunisian one (IS48). Data was processed with...
Infrasound radiated during periods of weather changes is an almost continuous background against which infrasound monitoring of explosions in the atmosphere is carried out. In this work the results of study of temporal variations of the characteristics of infrasound (amplitudes, coherences, grazing angles, azimuths and horizontal phase speeds) detected during a passage of warm and cold fronts...
Small-scale atmospheric perturbations known as gravity waves (GW) are critical to infrasound propagation simulations as they alter the propagation path of the waves, causing detections at infrasound stations that remain unexplained when only large scale atmospheric features are considered. Therefore, it is important to investigate ways of accounting for these perturbations in the atmospheric...
This presentation gives examples on how to process and analyse data obtained in realtime from the IMS through the newly developed SeedLink service available on the Global Communications Infrastructure (GCI), using the seismic analysis software package SEISAN. Furthermore, we show how to integrate sensor data and metadata and event parametric data from the CTBTO with locally collected data....
Various type of magnitude scales are recognized for estimating the earthquakes size. Magnitude is one of the significant factors for a unified earthquakes catalog which is needed for seismic hazard assessment and disaster management. The variation in magnitude value from seismological agency to other stimulated the researchers to study the regression relationship between the magnitudes. The...
Introducing the concept of nuclear non-proliferation can be done with various approaches, including cultural approaches. Through the cultural approach, the introduction can be done by understanding the cultural products of a society, one of which is the Javanese society: a keris.
As a cultural product, Javanese people use keris as weapons or accessories or collections. For the Javanese...
In this research, the difference between the velocity of Rayleigh and Love waves is used to determine radial anisotropy beneath the Zagros belt. The continuous ambient noise data are processed to image 2D tomographic dispersion maps from the period of 8 to 50 s. Then, a quasi-3D shear wave velocity and radial anisotropy model are calculated by joint inversion of the Rayleigh and Love local...
Central Asia is tectonically complicated with high seismic activity. Over the past 150 years four great earthquakes occurred with magnitudes exceeding 8. Seismic monitoring is one of the most important problems of the region, having both scientific and social significance. Since many years, NORSAR (Norway), the Institute of Geophysical Research (Kazakhstan), and the Institute of Seismology...
To advance the understanding of the tectonic processes shaping the African continent, we construct the first continental-scale shear-wave velocity (Vs) model of the lithosphere from the joint analysis of ambient seismic noise and earthquake data recorded by ~1529 seismic stations in and around Africa. We apply the widely used ambient noise cross-correlation and earthquake two-station methods...
To solve the ambiguation in corresponding signals from same sources recorded in different arrays, a multi-infrasonic sources location method is proposed. This method is based on the conservation of acoustic momentum in audibility zone during long-range infrasonic propagation in the atmosphere. In a rocket launch observation experiment, progressive multi-channel correlation method is utilized...
IS42 is one of International Monitoring System (IMS) infrasound stations, located in the Azores islands in the North-Atlantic Ocean.
Stromboli volcano is located in a small Italian island in the Mediterranean Sea. It is probably the world's best-known volcano due its spectacular basaltic explosions interspersed by lava fountains up to 250 m occurring every ≈10 minutes. Following the...
A central tenet of MEPhI Science Diplomacy Club (SDC) activities is building bridges in the field of scientific and technological cooperation. The Club aims to construct an intergenerational dialogue by cultivating good working relations with high-profile experts in the field of non-proliferation, disarmament and nuclear test ban. The cornerstone of SDC policy is building educational and...
Microbarometer arrays are used for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) using infrasound waves. In addition, the microbarometers also measure pressure variations that are due to various meteorological phenomena with a resolution that exceeds that of typical barometers. The value of these high-resolution observations for the monitoring of extreme weather is...
Abstract: In view of the low accuracy of the far-field modeling of underwater explosion sound propagation, the normal mode-parabolic equation method is used to carry out the modeling of hydroacoustic propagation to optimize the ability of far-field propagation simulation. This method combines the advantages of the normal mode model method and the parabolic equation method, adopts local normal...
Nepal is exposed to intense seismic activity, including devastating earthquakes. The National Earthquake Monitoring and Research Centre (NEMRC) was established under the Department of Mines and Geology (DMG) to monitor those earthquakes. It also alerts the Nepalese authorities and population about the location and magnitude of the felt earthquakes to support rescue and relief operations at the...
The six hydroacoustic hydrophone stations within the CTBTO’s International Monitoring System comprise a total of 11 triplets. These triplets have a 20-year design life with no scheduled underwater segment maintenance actions and are based on a linear non-modular design which offers the advantages of high reliability and efficient deployment in one continuous operation. However, a triplet...
Increased urban development, occasional volcanic swarms, and large earthquakes surrounding the Kingdom of Saudi Arabia (KSA) have contributed to a renewed interest in understanding seismic hazard and risk within the Kingdom. In response, the KSA has expanded the national seismic network over the past several decades. Now, a sizable collection of local and regional data provides an...
Nepal is a peace loving country and signed Nuclear Non-Proliferation Treaty (NPT) in 1970. Nepal became a Signatory of Comprehensive Test Ban Treaty (CTBT) in 1996 with the commitment of using nuclear energy in improving human health, world peace and prosperity and security - not for military purposes. The Nepalese Government has recently passed a law on Radioactive Material (usage and...
Education and training of young professionals in the nuclear industry are one of the Nuclear University primary objectives. In achieving this goal, it is vital that attention must be paid to all aspects of the development and use of nuclear power and nuclear technology. Future generations must understand and share the responsibility for the stability and safety of our entire world. CTBTO has...
Storytelling can be a powerful tool for change and social activism. This essay proposes a storytelling blog as a platform to raise awareness and engagement with the goals of the CTBTO, namely, bringing the CTBT into force and working toward global deproliferation of nuclear weapons. Embracing Shampa Biswas’s broader conception of nuclear harms, such a project could work to make the harms of...
Nyepi is a rare activity in the world that only exists in Bali, where all of human outdoor activities stop for a day. This study used Nyepi to measure its impact on changes in weather parameters measurement in Bali. The purpose of this study is to see the effect of Nyepi on the ratio of daily average temperature to duration of solar radiation as well as daily average air humidity at four...
The International Monitoring System (IMS) of the CTBTO includes hydroacoustic stations composed of underwater hydrophones placed at the depth of the SOFAR channel. Since the hydroacoustic component of the network is designed to detect underwater nuclear explosions, events of special interest are impulsive underwater explosions. Among these, we studied several underwater explosions detonated...
Presently, National Institute for Earth Physics operates two infrasound stations deployed on the Romanian territory: IPLOR 4-element array of 0.6 km aperture, and, under cooperation with AFTAC (USA), BURARI 6-element array of 0.7 km aperture.
As many military bases are deployed across Europe and Near East region, signals from supersonic aircraft activity are detected routinely at the Romanian...
Although earth fissures have occurred in some parts of the country, they have not been well-documented or studied in detail. Recent field investigation into the formation and extent of earth fissures in Chikwawa District, reveal their formation due to erosion as well as tensional cracks within the affected area as a result of groundwater withdrawal from the alluvial sediments. Several...
The Stromboli volcano is known for its persistent explosive activity, with hundreds of explosions every day ejecting ash and scoria up to heights of several hundreds of meters. Such a mild activity is however punctuated by lava flows and major explosions that represent a much larger hazard. On July 3 and August 28 2019, two paroxysmal explosions occurred at Stromboli, generating an eruptive...
The Primary Seismic Array PS19 GERES and the Infrasound Array IS26 are located in the Bavarian Forest and are operated by the Federal Institute for Geosciences and Natural Resources (BGR). From 2017 to 2019 extensive GERES refurbishment and recapitalization construction works were performed in the area which also had an impact for local population and tourists as cabling exchange disrupted...
OSI is the ultimate pillar of the CTBT verification regime. Available only after the Treaty’s EIF, it implies rapid deployment of a large amount of equipment and personnel. To maintain the operational readiness of the OSI segment, the CTBTO develops a network of exercises of different type and scale.
Hosting an IFE, a BUE or an OSI Regional course is a process that requires a lot of...
The creation of the CTBTO Youth Group is just one example of successful outreach and education being made accessible for individuals not already involved in nuclear/security circles. The entry into force of the Treaty is not just dependent on high-level talks but also influenced by civil-society. This is where museums, cultural, historical, and scientific centers are necessary for the...
Due to stringent entry into force provisions, the Comprehensive Test Ban Treaty (CTBT) has yet to enter into force, despite a provenly effective comprehensive verification regime and widespread support. Meanwhile, the Treaty on the Prohibition of Nuclear Weapons (TPNW)--a more aspirational treaty with a broader scope and lower entry into force requirements--received enough ratifications to...
On this research we present a probabilistic seismic hazard map for Bolivia (PSHBO-2019), this is the first map that integrated all variables available within the geo hazard for our country. We propose 13 seismic zones based on epicentral distribution, stresses and geology context, we applied the well know method for hazards assessment integration to all variables to have the maximum probable...
Explosive volcanic eruptions produce powerful infrasound signals that are frequently recorded by the International Monitoring System (IMS). We are developing and testing methodologies to detect, locate, and characterize volcanic infrasound globally using data from the IMS. Challenges remain in attributing an infrasound event to a particular volcano, in part because source locations can be...
On 18 June 2020, energetic underwater acoustic T-phase signals were recorded at the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) hydrophone station HA03, located at the Juan Fernandez Islands, Chile. In this work, we investigate the origin of these T-phases, which were associated to an M7.4 submarine earthquake with epicenter in the Kermadec Trench located...
Iraq is a country subject to seismic activity associated in a belt Zagros-Taurus which is caused by the collision of the Arab plate with the Eurasian plate. Where the Arab plate is affected by three types of tectonic boundaries: divergent boundaries, convergent boundaries, seam boundaries. The Arab plate moves north-east, leading to the expansion of the area of the Red Sea and the Gulf of Aden...
On 1 October 2015, the cargo ship SS El Faro was lost approximately 120 km east of Long Island, The Bahamas, during the Hurricane Joaquin. Here, we analyze underwater sound phases potentially associated with the loss of this vessel, recorded by station HA10 of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) located at Ascension Island, Mid-Atlantic Ocean....
The international monitoring system (IMS) of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) has basically completed the planned construction of 60 infrasound stations in the world. The general infrasound signal processing technology of IMS is the progressive multi-channel correlation (PMCC) method, which includes TDOA algorithm. The common limitation of location algorithm based...
The National Data Center in Chile is established at the Chilean Nuclear Energy Commission. Its principal mandate is to verify the compliance of the treaty and the storage of the data we receive. For this very reason, the NDC has a large amount of data available to be used by the scientific community. The problem is that this is not very well known today. To solve this issue, it started the...
The postseismic slip that follows large earthquakes is typically a few tens of percent of the coseismic moment, while the postseismic slip following small earthquakes appears to be comparable to the moment. Here I estimate the postseismic slip following intermediate-magnitude earthquakes and find that it is intermediate between the two, about 40% of the coseismic moment. The variation in...
Probabilistic Seismic Hazard Assessment (PSHA) for the state of Uttarakhand (280-320 N and 770-810 E) has been investigated considering two Next Generation Attenuation (NGA) models. Results are presented in terms of PGA for various return periods for each district. Initially, based on seismicity and seismtectonic characteristics the whole region has been defined into four seimogenic zones...
The seismic hydraulic diffusivity is investigated to examine the implications fluid circulation has on the seismic activity at a geothermal prospect. The effect that fluid circulation has on the seismic activity is achieved by estimating the seismic hydraulic diffusivity from a source that originates from a point where the pore pressure propagates from for a distance (r) and time (t) from a...
Earthquake disaster mitigation is required to perform in DKI Jakarta which is the Capital of the State of Indonesia. To find out the geological characteristics of the study area such as soil type and rock type, an HVSR analysis was performed. The amplification value and dominant frequency can be used to estimate the level of building damage due to earthquake, damage to buildings due to the...
The present seismological study, focused around Algarve region, was carried out through a cooperation project between the Universities of Évora (Portugal), Lisbon (Portugal), Strasbourg (France) and the IPMA (Lisbon, Portugal). To locate the seismic events and find the local velocity structure of the epicentral area, the P and S arrival times at 38 stations are used (Geostar stations,...
Investigation of the lithospheric shear-wave velocity as a clue helps to improve our understanding of Iranian plateau evolution. Therefore, we estimate shear wave velocity models beneath profiles perpendicular to the Zagros strike by using trans-dimensional Bayesian inversion of the Rayleigh wave group velocity dispersions at periods of 5-120 s. Our velocity models, in line with the support of...
The seismicity change in time in the seismically active region around the central part of the Baikal rift zone (BRZ), the South-East of Russia, was investigated using the statistical estimate of the seismicity level (SESL’09) procedure [Saltykov, 2011]. The method is based on calculating the statistical distribution function of the decimal logarithm of the total seismic energy within a given...
Pacific Island member countries have a combined population of about 2.3 million people. Nuclear tests in these islands significantly impacted humans and environment. More than 300 nuclear tests were carried out in the Pacific from 1946 to 1996 in the atmosphere, underground and underwater. Recently Prime Minster of Fiji, made a statement on behalf of 12 Pacific countries to UNGA and presented...
An attempt has been made to calculate different thermodynamic parameters to check the severity of thunderstorms during the pre-monsoon season of 2013-2015 in Bangladesh. In this paper, 60 weak to severe thunderstorms events which were recorded by the Bangladesh Meteorological Department (BMD) are investigated. Lifted Index (LI), Showalter Index (SI), Total Total Index (TTI), Convective...
Humanity may be destroyed by its very own progress of successfully harvesting or releasing atomic energy. For my country and for me personally, this is not a concern: Kazakhstan was the first country who joined and signed for NWFZ in 2008. Our country learned an important lesson from the tragedy of Semei.
Nuclear weapons are not just short time weapons. They are long lasting guns, which will...
There is a growing understanding in the international community of the catastrophic humanitarian consequences of the use of nuclear weapons on individuals, society, the economy and the environment. However, recent efforts by non-nuclear weapons states and civil society to encourage nuclear powers to prioritize nuclear disarmament that culminated in the adoption of the Treaty on the Prohibition...
To study the earthquakes and better understand the tectonics in Myanmar, Earth Observatory of Singapore (EOS) has been collaborating with local seismic monitoring authority to install (30) broadband seismic stations. With the broadband collected data, we have used them to study the site classification, earthquakes relocation and constrain the velocity structure.
We defined our EOS’s broadband...
We present recent advances and results of reprocessing the IMS infrasound dataset from its beginning until early 2021. A new implementation of the Progressive Multi-Channel Correlation (PMCC) algorithm enables characterization, with a single processing run, of coherent noise in log-spaced frequency with one-third octave bands from 0.01 to 5 Hz. Such an array processing algorithm enables better...
The CTBTO capacity building project includes a capacity building system (CBS), training courses, technical visits, et cetera. The CBS that has been established in Jordan is helpful in integrating data acquisition, processing and analysis using the NDC in a box, which was developed by the IDC. The training courses and technical visits helped on how to use the CBS and software package (NDC in...
Since the year 2000 the German Aerospace Center (DLR) facility near Heilbronn, Germany, has conducted main engine tests of the European ARIANE-5 rocket.
Infrasound signals from these tests have regularly been observed during the last two decades at IMS station IS26 at a range of about 320 km in easterly direction.
While a majority of these tests produced signal observations when carried out...
Nigeria lies within the West African sub-region and the country is believed to be aseismic in nature. Despite this view by prominent geoscientists, the country has witnessed both historical and instrumental earthquakes since 1933. The recent recorded chains of events with moment magnitudes ranging from 3.0 to 3.4 in Nigeria, were located in Kaduna state and Abuja. Reasons which include shallow...
Seismic hazard assessment for any region in the world has become a very serious and difficult task for seismologists, civil engineers and decision makers. Probabilistic hazard studies are conducted at the Observatorio San Calixto (PSHBO-2019) to estimate the maximum peak ground acceleration integrating all available variables, however no strong motion time-series (waveform) were applied due to...
On 7 April 2012, a massive snow avalanche occurred in the north-western mountains of Pakistan, close to the Indian and Chinese borders. To mitigate its future hazard, different triggering mechanisms have been investigated in this study. The avalanche signal was clearly recorded on both infrasound and seismic stations, located at varying distances between 300 and 450 km. The avalanche occurred...
UAE strong motion network consists of 62 stations distributed all over the country to construct UAE-Ground GSM “ShakeMaps” for existing urban areas and areas under strategic development. Additionally, structural design parameters will become available for verification and calibration of the seismic design code. Forty stations are equipped with shallow borehole EpiSensors and fourteen stations...
On 4 August 2020, a warehouse of ammonium nitrate exploded in Beirut, Lebanon, leading to loss of life and property. Infrasonic signals from this event have been detected across the Middle East, Europe and North-Africa. The furthest IMS station that detected the signal was IS11 (Cape Verde) at over 6000 km distance.
The features of the observed infrasonic signals were unusual for the time of...
A function of global monitoring of nuclear explosions is the development of Earth models for predicting seismic travel times for more accurate calculation of event locations. Most monitoring agencies rely on fast, distance-dependent one-dimensional (1D) Earth models to calculate seismic event locations quickly and in near real-time. RSTT (Regional Seismic Travel Time) is a seismic velocity...
This research assesses the seismic hazard and deaggregation in the State of Kuwait. For this purpose, the historical and instrumental seismic catalogues of Kuwait and the active Zagros Seismic Belt were compiled, unifying the magnitudes, removing unnecessary earthquakes (seismicity declustering) and considering the completeness of the catalogues. Multi-seismotectonic models for the Kuwait...
In this study, we show results from ambient noise tomography at the KTB drilling site, Germany. The Continental Deep Drilling Project, or ‘Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland’ (KTB) is at the northwestern edge of the Bohemian Massif and is located on the Variscan belt of Europe. During the KTB project crustal rocks have been drilled down to 9 km depth and several...
The celerity-range model used for both association and location in the standard automatic and interactive analysis at the International Data Centre (IDC) of the Comprehensive Nuclear-Test-Ban Treaty Organisation, has not been updated for over 10 years. The NET-VISA automatic association algorithm (Arora et al., 2013) currently providing additional information to IDC analysts, is based on...
The Preparatory Commission for the CTBTO (Commission) routinely process time-series data from a global network of seismic, hydro-acoustic, and infrasound (SHI) stations. The data are processed to detect, build, locate, and screen events that may have characterization parameters similar to those from nuclear explosions. The observation and processing systems are required to be sensitive to...
The COVID-19 pandemic is a major topic of interest for the SnT2021. The global nature of it produced a resilience test for many, and in particular for a global monitoring system, such as the CTBTO’s, that relies on continuous data gathering, transmission and analysis. The objective of this series of two events is to provide the audience with pertinent case histories and lessons learned from...
The nuclear tests announced by the DPRK provided an opportunity to test methods and gain experience with respect to the estimation of the absolute and relative event location, depth and magnitude. However, this experience is limited to one specific test location. Much broader experience can be gained by applying modern analysis methods to the vast amount of data recorded on more than 2000...
Forty years ago, the first global seismic tomographic models revealed the presence of two large, antipodal, structures at the base of the Earth's mantle, now known as "large low shear velocity provinces" (LLSVPs), that had no obvious relation to surface geology or mantle dynamics as understood from plate tectonics theory, and as reflected in near surface seismic structure.
With the expansion...
MEPhI Science Diplomacy Club (SDC) aims to nurture a new generation of experts who are curious about cross-cutting issues at the interface of science and international relations, who are willing to bridge diplomatic challenges & technical solutions and who are eager to learn more about current challenges including nuclear test ban, non-proliferation and disarmament.
The SDC members...
As part of its qualification process by the PTS, the SPALAX-NG - noble gas - New Generation system was operated from October 2018 to April 2019 on the CEA/DAM premises near Paris (France). The new generation system’s high performances contribute significantly to increase the number of detections and to improve the knowledge of the radioxenon background. Indeed, in this study, a major dataset...
In the context of the nuclear non-proliferation regime, the On-Site Inspection of the CTBTO play a mayor role for verification. OSI is when Scientists from different fields and diplomats get together with a common aim: “to identify signs from a nuclear explosion”. Only a perfect match between science knowledge and diplomatic skills can assure full success for an OSI. The crucial issue is how...
The aim of this work is to apply both a parametric and a non-parametric statistical method to the 133Xe activity concentrations measured at noble-gas stations of the IMS of the CTBTO, in order to investigate the atmospheric background and the anomalous values. The parametric method consists of two control charts: a single-observation chart sensitive to large variations with respect to the mean...
Bangladesh, a Comprehensive Test Ban Treaty (CTBT) signatory country since 24 October, 1996, is the 54th state to ratify CTBT on 8 March, 2000. Auxiliary Seismic Station (AS007 BRDH) in Bangladesh, accredited as an internationally certified station, receives the seismic data from International Data Center (IDC) of CTBTO. The seismic station AS007 was established to monitor the activities of...
This work is the result of a joint collaboration between the Italian and the Mauritanian National Data Centers. Radionuclide station RN43 in Mauritania was established in Nouakchott on 6 November 2006. The historical analysis of the occurrence of relevant radionuclides at RN43 over the past ten years showed that the main contributor was Cs-137, causing several level 3 and level 4. A...
The CTBTO Link to the database of the International Seismological Centre (ISC) is a service provided on behalf and by arrangement with IDC/CTBTO. The Link enables PTS and National Data Centres (NDC) with dedicated access to long-term definitive global datasets maintained by ISC using specially designed graphical interfaces, database queries and non-IMS waveform requests. This service gives...
Environmental 125Xe, 127Xe, and 129mXe have been observed during testing of a next-generation xenon measurement system, Xenon International. The observations of these three radioxenon isotopes occurred during routine testing at the Xenon International manufacturing facility in Knoxville, Tennessee, USA, and they are believed to be the first observation of these isotopes in environmental...
Close acquaintance with details of the CTBTO’s International Monitoring System and the International Data Centre can tempt a keynote speaker to present the work as highly complicated, with success coming only via enormous effort. But stepping back from details such as the very size of datastreams received by headquarters in Vienna, and of datasets accumulated after nearly 25 years of...
In support to the Comprehensive Nuclear-Test-Ban Treaty, the worldwide scientific community - via the CTBT SnT Conferences - has the opportunity to build partnerships and encourage knowledge exchange, allowing the CTBTO to remain at the forefront of the relevant technology for test-ban verification. The SnT Conferences are organized biennially by the Preparatory Commission for the...
Estimating the radioxenon background based on a multi-input-multi-model ensemble modelling approach at IMS stations having frequent detections was the main goal of the 3rd ATM-Challenge.
The Challenge included four selected IMS stations. Participants were invited to calculate contributions to the signal captured in daily samples at CAX17 (St. John’s), DEX33 (Schauinsland/Freiburg), SEX63...
In recent years, there has been a rapid increase in social scientific studies using polling techniques to better understand nuclear issues. Scholars have shown public opinion in numerous countries on subjects such as nuclear proliferation, deterrence posture, and links between civilian and military nuclear technologies. These studies are important contributions for improving decision-maker...
NorthStar has embarked on two parallel paths to produce Mo-99 and other medical radioisotopes without use of any uranium material. The first path, which was approved by the US FDA in February 2018, is via neutron capture utilizing a research reactor. In this pathway, NorthStar can use either high-purity natural molybdenum discs or can use target material of enriched molybdenum-98. This...
Atmospheric gas detection is a primary means for detecting and verifying underground nuclear explosions. Subsurface gas migration is governed by a complex system of unknown variables, including the interaction between geology, explosion-induced stresses and corresponding rock damage patterns that provide primary gas flow pathways. The U.S. is conducting a series of highly instrumented...
The IMS Network of 80 particulate and 40 radioxenon measurement systems is one of its kind in several ways. The global coverage combined with high time resolution contributes to a unique, steadily growing data set available to all CTBT member states.
The requirements of the verification regime, formulated more than 25 years ago, prompted the development of new measurement technologies, such...
In this study, using a machine learning method, in particular, a deep learning approach, we propose for the first time a model of Beta-Gamma coincidence radioxenon spectra classification. Specifically, by means of real data from the noble gas system in Charlottesville (USX75) as part of the International Monitoring System (IMS) operated by CTBTO between 2012 and 2019, we apply the convolution...
Fault rupture in a subduction zone often causes devastating earthquake and tsunami hazards. Therefore, understanding a slip behavior along the fault is a crucial scientific topic and a deeply socially relevant problem. To understand the slip behavior along the fault, there are two kinds of essential geophysical datasets. One is seafloor displacement as a surface response of a fault slip, and...
The uppermost mantle structure beneath East Africa is investigated by inverting the Pn traveltimes to obtain a model of P wave velocities. The previous Pn tomography models of the region have been expanded. A total of 2870 new Pn travel time measurements of local and regional earthquakes have been made and modeled, improving the resolution of the uppermost mantle velocity structure across...
NET-VISA is a Physics-Based Generative Model of global scale seismology. The model includes a description of the generation of events which include under-water and atmospheric events, the propagation of waveform energy from the events in multiple phases, and the detection or mis-detection of these phases at the network of stations maintained by the International Monitoring System (IMS) as well...
The Israeli National Data Center is responsible for monitoring and characterising the seismicity of the Eastern Mediterranean region. The accuracy of seismic locations is mostly affected by the velocity model used, and no clear picture of the variations in seismic velocities in Israel has emerged in the recent years. We gathered a large dataset of seismic travel times recorded in Israel and...
Deep Learning Travel Time (DeLTTa) is a deep-learning method and computer code for emulating seismic-phase travel times that are based on a 3-dimensional (3D) Earth model. Greater accuracy of travel time predictions using a 3D Earth model are known to reduce the bias of event location estimates and improve the process of associating detections to events. However, practical use of 3D models is...
The center of the Sea of Marmara, the region between the locations of 1912 Mürefte and 1999 Izmit M_w7.4 earthquakes, is prone to creating a large earthquake. The main objective of our study is to determine 3D dynamic earthquake rupture scenarios, considering non-planar and heterogeneous stress distribution in the Sea of Marmara. In this study, it is the first time that we attempt to generate...
In this work, we develop an algorithm for automatic identification of repeating seismic events such as aftershocks and mine explosions. Identification of such events will help to improve the quality of automatic bulletins and to lighten the analysts’ burden. The algorithm constructs a low-dimensional representation of the examined data by using a variant of a non-linear dimensionality...
CTBT monitoring for nuclear explosions is based on detection of waveform signals and the related event localization and on detection of traces of treaty-relevant radioisotopes in the atmosphere. However, 25 years ago it was a challenge to obtain a clear link between a seismic event and a series of radionuclide detections. This was changed when the proper Atmospheric Transport Modelling (ATM)...
Accurate estimates of the depth of seismic events allow determining whether they are associated to a given tectonic structure. It is also a good discriminator between earthquakes and explosions. However, automatic depth determination at teleseismic distance remains a challenge: the depth phases (pP, sP), reflected on the free surface, are sometime difficult to pick in the ...
The International Monitoring System (IMS) infrasound network is well positioned to record atmospheric nuclear explosions, but algorithmically classifying and characterizing these events is challenging. Difficulties stem from the variable and dynamic atmosphere that modulates acoustic transients at regional to global distances. Machine learning (ML) is well suited to classify infrasound...
High-resolution tomographic images of the MiddleEastern region are essential to accurately locate ground motion events during nuclear monitoring programs. The purpose of this study is to retrieve detailed models down to lowermantle beneath the Middle Eastern region using a set of reliable regionally observed teleseismic P arrival times from the ISC-EHB bulletin (Engdahl et al., 1998). Our...
The COVID-19 pandemic is a major topic of interest for the SnT2021. The global nature of it produced a resilience test for many, and in particular for a global monitoring system, such as the CTBTO’s, that relies on continuous data gathering, transmission and analysis. The objective of this series of two events is to provide the audience with pertinent case histories and lessons learned from...
The CTBT IMS employs four monitoring technologies: seismology, infrasound, hydroacoustics and radionuclide (both particulate and noble gas). It is vital that the PTS stays abreast of new developments related to all sensor types to maintain its high-performance level, and network sustainability, in order to safeguard and improve the Treaty Verification capability. This panel will discuss new...
The Lop Nor Test Site is located in Xinjiang Province in the Peoples Republic of China, about 600 km away of Kazakhstan. From 1964-1996, there were 47 nuclear tests, including 3 surface, 19 atmospheric, and 25 underground. During this time, the USSR operated monitoring networks of sensitive seismic stations having both analog and digital instruments.
A seismic catalog and bulletin was...
Films from historic nuclear testing enable new analysis of the shock propagation and buoyant cloud rise with material entrainment, furthering understanding of the time-evolution of the entrained mass. Many late cloud films were captured from at least two positions, enabling accurate characterization of the cloud development and trajectory. A generalized framework is developed to capture the...
A literature review is presented on historic atmospheric radionuclide monitoring data that were associated with nuclear test explosions. It covers reports related to tests conducted between 1964 and 1996. Most of these tests occured in the atmosphere but observation of nuclear debris from venting of underground nuclear tests were also found.The review is limited to off-site monitoring and many...
For the International Monitoring System (IMS) to be effective, it is vital that nuclear explosion signals can be distinguished from natural and man-made radioactivity in the atmosphere. The International Data Centre (IDC) applies standard event screening criteria, with the objective of characterizing, highlighting, and thereby screening out, events considered to be consistent with natural...
2021 is 70-years from the day when nuclear explosion of 38 Kt yield was conducted at STS and recorded at Borovoye area. Following first successful experiment and field works, the Special Division of IPE USSR decided to establish “Borovoye” geophysical observatory. In 1961, it recorded UNE of 2.6 Kt from Nevada Test Site at ~10 thousand km distance.
“Borovoye” Observatory is one of the most...
In principle, OSI could be conducted anywhere on the earth. Communication is mission critical for OSI. 10 years have passed since the last Directed Exercises of OSI communication in Jordan. Some of the communication equipment suggested by the exercise, mostly old fashioned radio communication, would find its restrictions for meeting the practical requirements of OSI. Based on cognitive...
The Lawrence Livermore National Laboratory (LLNL), Michigan State University (MSU), and national data centers in Central Asia (Kazakhstan, Kyrgyzstan and Tajikistan) digitized analog seismic bulletins in order to produce a new, unified seismic catalog. The main objective of the project is to provide a reliable seismicity map for new probabilistic seismic hazard analysis of Central Asia. The...
Understanding the radioxenon background at the radionuclide stations in the IMS network is important to improve the verification capability of the network. The background at the IMS station SEX63 in Stockholm Sweden has been studied in the time period between 2012 to 2019 using data from the IMS SAUNA II system. From 2017 data have also been evaluated from the co-located SAUNA III system....
We have created a unified seismic bulletin of Central Asia to improve event locations and knowledge of seismic hazards. The national data centers and seismic networks of Kazakhstan, Kyrgyzstan, and Tajikistan have digitized paper historic bulletins of earthquakes with mb3.0 and greater from this region of Eurasia for 1949-2009. Soviet-era data covering portions of Uzbekistan, Turkmenistan,...
Most equations used to predict the ground motion produced by explosions were developed using confined blasts that were detonated with the intention of breaking rock for mining or tunnelling. Ground motion is usually recorded by geophones or seismometers. The air blast produced by open-pit blasts and explosions on the surface can pose a significant risk, thus microphones and pressure gauges are...
The On-Site Inspection (OSI) Team shall converge to the possible test location applying various permitted inspection techniques using approved equipment within /set timeframe (technical & political significance). OSI relevant noble gases such as Argon and Xenon from the potential test(s) (underground) may reach the atmosphere through venting and/or atmospheric pumping (depending upon local...
Indonesia is in an earthquake prone area, not only tectonic earthquakes but also non-tectonic earthquakes. Non-tectonic earthquakes are unique, because they rarely happen. However, in the last decade there have been many non-tectonic earthquakes recorded by seismic sensors due to volcanic activity. Therefore, we need to validate the earthquakes, whether they are caused by tectonic or...
This paper evaluates the desirability of noble gas stations network coverage in the International Monitoring System of the CTBTO for the detection of 1 kt nuclear explosions. It was assumed all the 39 noble gas stations become active, the annual average of MDC was used for each certified station and the MDC of Non-Operational Stations was considered 0.24 mBq/m3. In this regard, the daily...
An IMS-like noble gas system is in operation at AWE (Aldermaston, UK) and can collect and measure the radioxenon content in environmental air samples. When operated in this mode, data produced is analysed at the UK National Data Centre (NDC) as part of the in-house radionuclide (RN) analysis pipeline. This work discusses a number of significant detection events analysed using the operational...
An OSI could be conducted anywhere. Due to the concept of the comprehensive nuclear test ban, an OSI inspection area could be in an extremely challenging environment. A simulation platform could be a solution both from the perspective of health and safety and mission efficiency. This work would propose a compact transportable visualized 3-D simulation platform to provide decision making and...
The atmospheric dispersion modeling of radionuclides is used to obtain responses to emergencies by estimating radiation effects, associated with the atmospheric release of radioactive materials. Nowadays, almost all software used for these purposes, is based on the Gaussian model, which provides fast and conservative means that consider regions free of obstructions and simple weather...
Digitization of analog seismograms from past nuclear tests are critical for monitoring because many historical tests occur within unique geologic environments. To utilize this digitized data, it is important to know the frequency characteristics of the seismic channel that generated the seismogram to accurately correct for instrument response and recover ground motion. Calibrations can vary...
Seismic networks are a source of valuable data for seismological research. For a few years in cooperation with the French CEA/DASE broadband seismic network in Armenia has been upgraded. Among various tasks in seismological research, the modern network allows improving the quality of the catalog.
The seismicity of the Armenian Upland relates to the Arabian-Eurasian plate collision, which is...
A general code has been developed to describe two phase flow, tracer transport and thermal effects through a fractured porous medium on the Darcy scale under the action of constant or time dependent pressure fluctuations. The fractures are modeled as surfaces with specific properties. The fluid properties can depend on pressure and temperature.
The equations for flow, tracer concentration...
Xenon emissions from medical isotope production facilities (MIPFs) and other nuclear installations affect the verification capability of the International Monitoring System (IMS) of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). In an effort to minimize the impact of this radioxenon and in order to mitigate, in general, the radionuclide emission, Atmospheric Transport Models...
Various techniques of Atmospheric Transport Modelling were applied after announced DPRK nuclear tests in order to support the analysis of potentially connected radionuclide detections. Forward dispersion forecasts from the test-site predicted potentially affected IMS stations; forward ATM for known background sources assessed their potential contribution to measured concentrations.
In case...
The concentrations and distributions of natural and anthropogenic radionuclides and heavy metals in surface water, groundwater, and soil samples of the site of Rooppur Nuclear Power Plant which is being constructed were investigated with the aim of evaluating the environmental radioactivity and radiation hazard and associated health risk assessment. Water and soil samples were collected and...
Through the International Monitoring System (IMS) of the Comprehensive Nuclear Test Ban Treaty (CTBT) and through their continuous work despite COVID-19, we still benefit from IMS data and the International Data Center (IDC) products. We analyzed many events that occurred and detected via infrasound stations. As the meteor in Turkey on 27 May 2020 which was analyzed with software DTK-(G)PMCC...
Most of underwater explosions show characteristics of bubble pulse and reverberation effects. Therefore it is most important to find these two phenomena in order to identify an underwater explosion for any sinking and/or missing a ship or a submarine. The best known studies to find bubble pulse and propagation effects are spectral analysis and cepstral analysis. The review technologies for...
Worldwide monitoring of radioxenon is a necessary component of the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The current IMS design foresees 40 radioxenon stations around the world to provide a 90 % detectability of a 1 kt nuclear explosions within 14 days. Radioxenon stations have the capability to measure four radioxenon isotopes; 131mXe,...
A variety of factors influence the atmospheric background of ubiquitous radionuclide signatures, like xenon-133, measured at International Monitoring System (IMS) stations. Variability in the radionuclide background obscures the categorization and discrimination of signals from nuclear weapons testing and civilian and industrial activities tied to medical radioisotope production and nuclear...
This study combines ground magnetic and Very Low Frequency Electromagnetic (VLF-EM) geophysical investigation techniques to evaluate the economic potential of mineralized pegmatite veins for gold and associated metallic deposits. Twenty five carefully planned magnetic and VLF-EM profiles, each, were occupied east and west of a reference profile purposively established on an identified...
According to CTBT treaty, Ground Penetrating Radar (GPR), together with magnetic and gravitational field mapping and electrical conductivity measurements, are non-destructive geophysical detection technology which can achieve effective detection of OSI anomalies or artifacts underground. As a matter of fact, GPRs have been commercially widely used for decades to conduct safety inspection of...
Countries seeking a quick bomb or would-be nuclear terrorists have eyes on poorly secured sites that contain significant quantities of high enriched uranium, (HEU). HEU is the material of choice for states or terrorists that seek to proliferate stealthily without testing their weapons. It is therefore critical to make current stocks of HEU as inaccessible as possible. One of the most effective...
The global atmospheric dispersion and deposition of radionuclides released from the Fukushima Dai-ichi nuclear power plant accident was modelled using the EMAC atmospheric chemistry – general circulation model at different esolutions (equivalent to ∼50 km and ∼110 km Gaussian grid). The model accounts for emissions and transport of the radioactive isotopes 131I and 137Cs, and removal...
Isotopic activity ratios of radioxenon measured in IMS noble gas samples are routinely obtained that might indicate a gas release from an underground nuclear test, although actually caused by atmospheric emissions from nuclear facilities. A robust method is required that tests the isotopic activity ratios of samples of special interest against a set of all relevant release scenarios that could...
COVID-19 is an infectious disease caused by the new coronavirus SARS-CoV2, recently discovered and for which there was no history of human pathologies. Currently COVID-19 is a pandemic that affects many countries around the world.
The objective of this presentation is to apply safe work protocols to protect people from any situation that implies a potential risk of contagion with COVID-19,...
The objective of this study is to apply the kernel density (KD) approach to generate and investigate probability distributions of isotopic ratios for radioxenon releases from certain types of sources. KD equations for nuclear facility releases are derived from the data set of the radioxenon emission inventory of all nuclear power plants and all nuclear research reactors, as well as selected...
Radioisotope Production Facility in Serpong, has produced and processed I-131 which can be dispersed to residential areas and the environment around the Serpong Nuclear Zone (SNZ). Measurement of the air release dispersion I-131 using an old analogue tool is not functioning, and only a charcoal filter is functioning in the stack of the isotope production facility. Measurement of the I-131...
The Fission Radioisotope Production Plant of Argentina, located at the Ezeiza Atomic Center, produces 99Mo since 1985 irradiating targets with High Enrichment Uranium. In 2002 the targets have been changed by Low Enrichment Uranium.
Facilities that produce radioisotopes by fission increase the background of noble gases in the environment, especially radioactive xenon.
This background could...
The Geophysical Survey of the Russian Academy of Sciences and Michigan State University are working to recover, preserve, scan, and digitize the historic seismograms of Soviet Peaceful Nuclear Explosions (PNEs). The Soviet Union detonated 122 PNEs from the mid-1960s through the late 1980s. The PNEs were conducted in a wide range of geologic settings and geographic locations, thus representing...
The monitoring system of NNC RoK comprises five seismic arrays, eight 3-component stations, and three infrasound arrays. Every year, the network in Central Asia registers and processes some 20,000 seismic events. Among the total bulk of such processed events, about 5,000 events are blasts of different characters. Mainly, they are industrial quarry blasts. The technique has been developed and...
Two events of magnitude ($m_{b}$) 3.6-3.8 occurred in southern North Korea (NK) on 27 June 2019 and 11 May 2020. Although these events were located about 330-400 km from the known nuclear test site, the fact that they occurred within the territory of NK, a country with a recent history of underground nuclear tests, made them events of interest. We used P/Lg ratios from regional stations to...
Wildfires broke out on the 3rd of April 2020 in the Chernobyl exclusion zone, and the fires lasted for several weeks. As a consequence, measurable amounts of Cs-137 were re-suspended into the atmosphere and observed through the IMS network. Over the period of April - May 2020, the International Data Centre reported a significant increase in the number of Cs-137 detections compared to the same...
At SnT 2019 the development of an On-Site Inspection system for managing OSI equipment and software was reported. The system, now called, EIMO – the equipment and instrumentation management system for OSI – has been further expanded and rolled out as a production system. The custom browser-based system is used for recording and tracking both OSI inspection gathering and support equipment. This...
The potential benefit of ensemble dispersion modeling for CTBTO applications was investigated using input data from the ECMWF-Ensemble Prediction System (EPS). Five different test cases - among which are the ETEX-I experiment and the Fukushima accident - were run. For those test cases run in backward mode and based on a puff release it became evident that Probable Source Regions (PSRs) can be...
A series of measurements of multiple anomalous treaty relevant radionuclides at several measurement stations in Sweden and Finland, including the Stockholm aerosol sampler (SEP63) in the International Monitoring System (IMS), occurred in the summer of 2020. The cause and source of these radionuclides is still unknown. The laboratory re-measurement of the split IMS sample revealed that...
A series of earthquakes occurred within the year 2020. These earthquakes were felt both on land and sea. IMS stations in Africa, Europe, and North America that were at teleseismic distances from the epicentre recorded these events. The earthquakes of 3 June & 1 September for Chile and 18 June for New Zealand were analysed using data from seismic and hydroacoustic stations at teleseismic...
We demonstrate here the advantages of combining data from local seismographs with IMS data in the analysis of both local and distant events. The implementation of new IMS to SEISAN and IDC to SEISAN links makes the integration much easier than before. These links are the results of a project funded by the EU (CELEX 02018D0298-20200423) to facilitate the use of IMS and IDC data at NDCs using...
Mine blasts are an example of repeating seismic/infrasound events with very close epicenters. In some areas, hundreds of mining blasts per year are measured by the IMS and built by the IDC. Waveform cross-correlation is a natural method to detect repeating signals. The IDC has been testing a prototype WCC-based pipeline to find repeating mining events matching the event definition criteria...
A general description of INVAP STAX monitor final status is shown, including calibration and software/hardware configuration.
First measurements results obtained in a real Noble Gas emission environment (MIPF plant at Ezeiza Atomic Center, CNEA, Buenos Aires, Argentina) are presented. Equipment measurement ranges, mainly focused to low flow rate and high activity concentration emissions,...
During the year 2020, apart from the global pandemic, there have been several global incidents that were recorded by IMS stations. As Turkish NDC, we have selected three of these events to be analyzed. The first event is the fragmentation of a meteorite/bolide on 27 May 2020 that was observed by many cities over the Northeastern part of Turkey, the second event is the Fireworks factory...
We investigate the origins of seismic S-waves generated by the Source Physics Experiment (SPE), which was conducted near the north end of Yucca Flat at the Nevada National Security Site (NNSS), United States. Understanding the generation of S-waves from underground chemical explosive sources provides physical understanding of regional event screening methods that rely on P-wave and S-wave...
Geophysical characterizations of unconsolidated sediments can be correlated with the invasive geotechnical investigations considered as a scientific basis for land use planning and development. In this study, Centerless Circular Array (CCA) having 2 Hz frequency (short period with a circumscribed radius of 2 m) seismometers were used to estimate the subsurface velocity profile, whereas...
The goal of the third ATM challenge is to perform atmospheric transport modelling in order to estimate radioxenon observations at selected IMS stations in the northern hemisphere for an extended period in the year 2014 (June to November). This estimation is needed for calibration and performance assessment of the verification system as described in the Treaty. The best estimates for Xe-133...
High Frequency infrasound are produced generally by explosion, aircraft, storm or lightning…(Campus and Christie, 2010). High frequency infrasound signals are detected by I33MG at the azimuth around 39°. To perform the study, IMS infrasound data from I33MG and I19DJ are processed by mean of PMCC method. After investigation these events are correlated with oceanic storms in the Indian Ocean. In...
Radionuclide observations made by the International Monitoring System are an important part of the CTBT verification regime, as it allows to discriminate between conventional and nuclear explosions. Atmospheric transport and dispersion modelling can link known sources with such observations. However, sometimes observations are made for which the source parameters (such as the release amount,...
The “Flexible Lagrangian particle dispersion model” FLEXPART is used in the IDC as well as by many of the participants in the Atmospheric Transport Modelling Challenges. As a truly flexible model, it may be used in forward and backward mode and it has many other parameters that can be set by users. All of these options influence the CPU and memory requirements as well as the accuracy of the...
The infrasound array at Piszkés-tető, Hungary (PSZI) has been operational since May, 2017. Since then PSZI has collected hundreds of thousands detections. These include detections both from known and unknown sources. The categorization of the detections would be important for future automation. The objective of this study is to identify and collect those detections that belong to local and...
The ENEA Traceability Laboratory in Bologna utilizes a portable HPGe gamma spectrometer Trans-SPEC-DX-100T for in situ monitoring campaigns and to evaluate the possible presence of radioisotopes in the environment (e.g. waste assay measurements, emergency response, nuclear safeguards inspection).
The instrument is also used in the laboratory to characterize radioisotope concentrations in...
Seismic moment tensors provide information not only about the geometry of a seismic source (tectonic – DC – part) but also with non-tectonic information such as volume changes (isotropic – ISO – part). This feature is crucial to discriminate explosive sources from others, which can hint to a nuclear test. However, that part is often not well resolved by standard methods. Measuring rotational...
In the present study we analyze infrasound signatures of 1001 rocket launches for space missions recorded at stations of the International Monitoring System between 2009 and mid-2020. We include all surface- or ocean-based launches within this period with known launch time, location, rocket type, and mission name; whereas launches of sounding rockets and ballistic missiles for scientific and...
The NDC-CR has promoted the use of the infrasound methodology in Costa Rica and in the LAC region with the installation of permanent (IVTCR) and temporary (I069CR) stations in the country, as well as with the organization of regional workshop in the field (Infrasound workshop 2019 jointly by CTBTO and NDC-CR).
The I069CR and IVTCR identified different infrasound sources. Among the most...
Since 2018, the inclusion of infrasound monitoring in active volcanoes in Costa Rica with local networks has been implemented by OVSICORI-UNA. In addition, at the end of 2018, two portable infrasound arrays were installed, such as I69CR and IVTCR in cooperation with CTBTO and UNIFI. The NDC-CR includes the integration of IMS stations such as I20EC, I51GB, I08BR, I09BR, thus making it possible...
On March 4, 2020 the Infrasound Stations I03AU, I05AU and I47ZA detected the South Indian Ocean event at 20:26:40 UTC. This detection belonged to a fireball that had a TNT yield equivalent of 1 kiloton (Kt). The infrasonic signals were observed by the three infrasound arrays that are part of the International Monitoring System (IMS) located in Australia and South Africa. The PMCC method was...
Strong neutron sources may generate significant amounts of radioxenon by activation of stable xenon. Radioxenon emission from some nuclear research reactors and from spallation neutron sources are dominated by neutron activation as the production process. The isotopic ratios are different from fission gases. Activation generates Xe-135 to Xe-133 activity ratios like fission but the activated...
As gaseous and particulate signatures are produced during an underground nuclear explosion, it is important to understand their transport to the surface for subsequent atmospheric transport and detection. By understanding the transport throughout the subsurface, the atmospheric measurements have the potential to allow for a better understanding of the fractionation and total release fraction...
In Soviet times, large chemical explosions were conducted on the territory of Kazakhstan with different purposes (industrial, investigative, military). The parameters of these explosions are quite well known, but can be further elaborated by special investigations using contemporary methods. Furthermore, these explosions can be used as ground-truth events for the calibration of regional...
The sole purpose of an OSI as specified in Article IV of the Treaty is “to clarify whether a nuclear weapon test explosion or any other nuclear explosion has been carried out” and “to gather any facts which might assist in identifying any possible violator.” OSIs are to provide this clarity through the collection of information and the detection of relevant observables within the Inspection...
Seismic networks are a source of valuable data for seismological research. Since 2010 in cooperation with the French CEA/DASE, the broadband seismic network in Armenia has been upgraded. Digital seismological stations were deployed in the territory of Armenia and they are providing data that enabled to conduct of various research activities, including the study of microseismicity and active...
Atmospheric dispersion modeling and radiological safety analysis is performed for the public outside a radioisotope production facility (RPF) in case of hypothetical radioactive Iodine spilling and leakage from a hot cell. Potential human error is expected and the column that holds iodine may be broken causing it to spill on the radioactive cell floor. The ventilation exhaust system is...
The project ABC-MAUS is undertaken by a collaboration of the Austrian Ministry of Defense, Joanneum Research, the Austrian national weather and geophysical service Zentralanstalt für Meteorologie und Geodynamik (ZAMG), including the Austrian National Data Center (NDC), as well as the private company GIHMM. The aim is to develop a strategy of protection for chemical, biological, radiological...
The project ABC-MAUS is a collaboration between the Austrian Ministry of Defense, Joanneum Research, the Austrian national weather and geophysical service Zentralanstalt für Meteorologie und Geodynamik (ZAMG), including the Austrian National Data Center (NDC), as well as the private company GIHMM. The aim is to develop a strategy of protection for chemical, biological, radiological and nuclear...
The 2018 rift zone eruption of Kilauea volcano was accompanied by a remarkable and episodic collapse of its summit. Between May-August the eruption and collapse sequence included over 70,000 earthquakes (M≥0) and 54 major earthquakes (M≥5). We analyzed the seismicity in the Kilauea summit region and estimated seismic full moment tensors with their uncertainties for the 54 M≥5 events. These...
The aim of this work is to apply a non-parametric statistical methodology to the radioxenon activity concentrations measured at noble gas stations of the International Monitoring System of the CTBTO, in order to investigate the radioxenon atmospheric background and the radioxenon anomalous values. The proposed non-parametric statistical methodology does not require any assumption on the...
NDC Preparedness Exercises (NPE) are regularly performed to practice the verification procedures for the detections of nuclear explosions in the framework of CTBT monitoring. In the event of NPE2019, a fictitious state RAETIA announced that a reactor had an incident and some radionuclides were released into the atmosphere. Both the IMS data and data from a fictitious neighbour state, EASTRIA,...
Radionuclide isotopic composition analysis is an important and reliable tool for determination of the artificial radionuclide source. As each anthropogenic emission could be characterized by its own unique radionuclide composition, these „fingerprints” make it possible to determine the evidence of radionuclide contamination source. Gamma spectrometric measurements were performed with the...
The Operations Support Centre (OSC) is a crucial element for effective preparation for an on-site inspection (OSI); its organization and proper functioning directly impact the degree of inspection team preparedness before departing for the inspected State Party. The OSC will be activated within a couple of hours after the DG has received a request for an OSI, and it must immediately become...
One challenge of On-Site Inspection (T2.2) is preparing for deployment to unknown locations with unknown resources. A critical element of a functional Base of Operations is stable and reliable electricity. The current diesel generators and UPS system has been enhanced with a hybrid power system that adds the ability to accept power from other generation sources, such as solar. An increased...
The aim of this work is to apply a parametric statistical methodology to the radioxenon activity concentrations measured at noble gas stations of the International Monitoring System of the CTBTO, in order to investigate the radioxenon atmospheric background and the radioxenon anomalous values. The proposed parametric statistical methodology is based on the “Statistical Process Control” method...
In 2017, the Government of Japan has decided to make a voluntary contribution to further enhance the capabilities of the CTBTO verification regime. In that framework, two transportable noble gas systems were deployed in Horonobe and Mutsu. They respectively started operating in February 2018 and March 2018. Continued operation of the two systems is now financially supported with funding from...
The recovery and digitization of legacy seismogram waveforms is critical for research of historical events in nuclear monitoring. We are improving the digitization process by applying an interpolation algorithm and examining the frequency recovery of the potential records. The implementation of a Piecewise Cubic Hermite Interpolating Polynomial (PCHIP) interpolation algorithm improves the...
The development of the seismograph network in Indonesia has been massive in the last two years. As more and more seismographs are installed, it is hoped that continuous data and high-quality data will be obtained. The presence of noise in seismic waveforms greatly disrupts the identification of earthquake events. Various potential sources of seismic noise exist, such as: ocean waves,...
The recovery and digitization of Peaceful Nuclear Explosions (PNEs) from the Soviet Era provides a unique opportunity to study the geology and geophysics of seismically quiescent regions. Due to the improved digitization and excellent recovery of the analog signals, these now-digital seismograms can be used with modern seismic modeling techniques. PNEs can be modeled as point sources and since...
CTBT treaty clarifies that “The DG shall have the primary responsibility for the security, integrity and preservation of samples. The DG shall, in any case, establish a stringent regime governing the collection, handling, transport and analysis of samples”. This work is dedicated to the engineering application of IOT/RFID technology to the CTBT technical framework and real OSI scenarios and to...
One of the possible manners to conduct a clandestine, unannounced underground nuclear explosion may be a test in a tunnel under a mountain. At the Semipalatinsk test site (STS) of the Soviet Union, 209 underground nuclear tests were conducted in the tunnels. Radioactive noble gas (RNG) release of various intensities occurred at ~40% of the tests. In 1996, the Khlopin Radium Institute conducted...
The most common mussel species in Rio de Janeiro State is Perna perna. It is an edible Mylilidae that has been cultivated in many places at Brazilian coast from Espirito Santo to Rio Grande do Sul States. Ten kilograms of flesh of mussels with a size of 5 to 8 cm were collected annually in the town of Arraial do Cabo, Rio de Janeiro State (23o S and 42o W) from 2002 to 2009. These organisms...
Rapid full source characterization is strongly recommended for providing pertinent information after the occurrence of an event of interest such as a nuclear test. Full moment tensor inversion using long-period seismic waveforms recorded at regional distance has shown its relevance for confirming the isotropic component of a seismic source. In order to rapidly determine the full source...
The annually laminated sediments deposited in Lake Kevojärvi (69°45N, 27°00'E) in the municipality of Utsjoki in Northern Finland were investigated for radioactivity. A freeze cores recovered from the 35-m deep basin preserve a distinct succession of annual laminations deposited between 1909 and 2015. The basic varve structure was composed of a detrital snowmelt layer and an organic-rich...
A climactic eruption phase on December 22, 2018 triggered the collapse of the southwest flank and summit of Anak Krakatau stratovolcano, generating a tsunami which struck Sumatra and Java. We employ a selection of remote moored hydroacoustic (H08S, 3,307 km; H01W, 3,720 km) and infrasonic (IS06, 1,156 km; IS07, 3,475 km; IS52, 3,638 km) stations of the International Monitoring System (IMS) to...
Half-lives of radioisotopes are thought of as absolute constants of Nature. However, since the 1980s several experiments indicated that small percent or sub-percent level temporal modulations may exist, potentially correlated to variations of the solar neutrino flux. The issue has been debated by the nuclear theory community, since it would imply some new mechanism influencing weak decays,...
The Lawrence Livermore National Laboratory (LLNL) and the Institute of Earth Sciences (IES), Ilia State University developed a project to generate a new seismic catalog for Georgia. The main objective of the project was to provide a reliable seismicity map that can be effectively used in a new probabilistic seismic hazard analysis for Georgia. Monitoring centers in Armenia and Turkey have...
An earthquake happened in 18 May 2020 early morning in the Kiruna underground iron ore mine (Northern Sweden) having a magnitude Mw 4.2. Following the earthquake, the mine was immediately evacuated because of the risk of aftershocks. This event is the largest mining-induced earthquake that has ever taken place in Scandinavia and it produced signals recorded by three infrasound arrays at...
Seismoacoustic measurements of surface explosions in Sweden are presented. In northern Sweden, near Kiruna, three explosions at one tone each were carried out in August 2020. Further, during 2019, a single considerably larger explosion took place in mid Sweden. For all explosions, seismic and infrasound measurements were made with both temporary and permanent stations in IMS as well as...
We present the results of seismoacoustic wavefield geophysical measurements carried out at Lake Baikal in the winter of 2020. A system of six special autonomous geo-hydroacoustic buoys, capable of continuously functioning at least for a week, was used as measuring equipment. Each individual buoy consists of a recording system, a seismometer-velocimeter, a hydrophone and wireless data...
This work describes the determination of the shielding against ionizing radiation from atmospheric dispersion arising from a radiological accident in a small nuclear reactor (SMR). Among the radionuclides from the inventory of this reactor, the contribution of Cs-137 was considered for simulation in HotSpot (analytical modeling) and ANSYS (numerical modeling), of the concentration and total...
The National Institute For Radioelements (IRE), located at Fleurus in Belgium, is an important emitter of radioactive xenon into the atmosphere. These emissions are not harmful to the environment, but can interfere with the very sensitive noble gas detection stations that are part of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty Organization. Radioxenon stack emission...
Measurements of gas collected from locations surrounding historic underground nuclear tests have identified that Ar-39 produced during a nuclear explosion can remain in the subsurface decades after the event occurred. As an activation product produced by the interaction of neutrons with geologic potassium, Ar-39 is produced in significant quantities in almost any underground nuclear explosion....
Considerably high levels of Ru-106 were measured by some air monitoring stations in Europe at the end of September and beginning of the October in 2017. Routine measurements revealed Ru-106 levels that vary between 10 to 100 mBq/m3 with maximum values reaching as high as 150 mBq/m3 during this period. Based on this motivation, a mathematical modeling study for the atmospheric transport of...
Measuring airborne radioactivity typically requires large, static installations, limited in number and geographical distribution. By measuring the activity of matter deposited to the ground (by dry settling or wet scavenging), one can complement detections of airborne activity and improve overall data availability.
Many ways exist to detect deposited activity, such as using rain basins...
The source-term estimation of the radionuclides detected at IMS stations by using adjoint atmospheric transport modeling (ATM) is a vital part in the CTBTO monitoring and verification Regime. Webgrape software was developed by CTBTO International data center to assist the state signatories in the verification purposes of radionuclides detections. However, the source determination of an event...
Anthropogenic radionuclides of fission and activation products are frequently detected by most IMS stations located on the African continent with varying concentrations in the years 2011 to 2020. This study assesses the spatial and temporal variation of Cs-134 and Cs-137 in ground-level air at IMS stations located on the African continent from 2011 to 2020. Spatial and temporal base analysis...
The STAX (Source Term Analysis of Xenon) project aims at the development of a worldwide network to measure radioxenon isotopes released from medical isotope production facilities. A software package has been developed to fully process STAX data from secure data acquisition at the back end, to interactively viewing data at the front end. This presentation focusses on the analysis of data and on...
The International Monitoring System (IMS) is part of the verification regime of the CTBT; in addition, civil and scientific applications are a possible additional benefit that State Signatories could gain from participation in the Treaty verification regime. One of the four technologies used in the IMS is the infrasound network composed of 60 array stations when the network is complete and...
The most important indicators for an underground nuclear explosion during a CTBT on-site inspection are the radioactive xenon isotopes 131mXe, 133Xe and 133mXe and the radioactive argon isotope 37Ar. Knowledge of how these isotopes vary and potentially correlate in different types of soil is essential to be able to discriminate between the natural background and a signal from a nuclear...
At 11:40 (UTC) on 7th July 2011, a series of accidental explosions occurred in the town of Abadan, Turkmenistan. The Turkmenistan government listed the cause of the accident as the ignition of pyrotechnic matter intended for fireworks, which then spread to military storage areas, where an estimated 5,000 - 50,000 tons of ammunition was stored (Boggs et al., 2013).
The explosions are clearly...
We constructed travel-time curves for eastern Tien-Shan using historical seismograms of underground nuclear explosions from the Lop Nor test site in the Peoples Republic of China. We measured the arrival times of the main seismic phases on seismograms from 1969-1996 stored in the analog archives of Kazakhstan as well as digital stations from Kazakhstan and Kyrgyzstan. In total, more than 500...
This study on the nuclear release timing aims analysing radioxenon isotopic activity ratios in three-dimensional space. The methodological approach and the characterization of the 3D usability threshold considered in this study were presented during SnT2019 and INGE2019. This presentation focuses on comparison to civilian sources from fission and activation.
Obviously three isotopes are less...
Lightning strokes create powerful wavefields of seismoacoustic nature, which we refer to as thunder. Unfortunately, even though bolts of lightning received much attention in such fields as physics of plasma and meteorology, less research was conducted to investigate the thunder itself.
A radio tower on the top of the Gaisberg mountain in Salzburg is permanently instrumented with electrical...
The UK National Data Centre (NDC) operates a series of custom-developed software tools for the automatic processing, analysis, archiving and interpretation of radionuclide (RN) data from the International Monitoring System (IMS). The tools include an RN Pipeline for the analysis of radionuclide data (noble gas and particulate), and a series of simulation pipelines to provide accompanying...
Two ultra-sensitive gamma-spectrometry systems are being used to measure environmental samples collected from the Hartlepool Nuclear Power Station in the United Kingdom. The work is being performed as part of the Xenon Environmental Nuclide Analysis at Hartlepool (XENAH) collaboration between Pacific Northwest National Laboratory (PNNL, USA), the Atomic Weapons Establishment (AWE, UK) and EDF...
When complete, the International Monitoring System (IMS) will include 170 seismometer stations. These stations consist of various seismometer types, and are located in a range of geological and tectonic settings. The data recorded can be used to determine the body-wave magnitude (mb) of a seismic event, which is used in the mb:Ms event screening criterion applied at the International Data...
Gamma spectroscopy measurements are a key component of an on-site inspection conducted under the Comprehensive-Nuclear-Test-Ban-Treaty. Radiometric aerial survey has proven to be an efficient way to cover large areas, however the spatial distributions of features smaller than the survey altitude are smeared out and their radioactivity concentration is underestimated. Moreover, the inspected...
The development of an airborne physical simulator to support the development and testing of airborne OSI equipment configurations as well as facilitating ground-based training for airborne operations was reported at SnT2019. This paper provides an update to the project, summarises the difficulties of transforming a dilapidated airframe into a multi-purpose structure and describes its...
Ground-truth (GT) recordings of low-yield quarry blasts at near-source distances provide a means of assessing the accuracy of seismoacoustic arrays in detecting and characterising explosive events. Infrasonic recordings from surface explosions generally show superior signal-to-noise (SNR) ratios compared to seismic detections, however dynamic atmospheric conditions introduce uncertainty. For...
A study of a large explosion in Beirut, Lebanon, explores the use of non-seismic constraints to supplement the seismic data yield estimates. The explosion yield is estimated by fitting overpressure to the equivalent of a 1kT overpressure curve as a function of radius from the explosion ground zero. Overpressure is estimated using explosion damage evaluations from publicly available sources...
Scientists from the U.K. and the U.S. are collaborating to perform measurements involving three different radionuclide monitoring techniques with the collective goal of better characterizing radionuclide emissions of a nuclear power reactor and how those might affect the International Monitoring System. The Xenon Environmental Nuclide Analysis at Hartlepool (XENAH) collaboration will perform...
The International Monitoring System (IMS) was designed based on planned sensitivity estimates, such as radionuclide (RN) system minimum detectable concentration (MDC), but without knowledge of background levels. Recent background simulations and atmospheric transport modeling calculations show that for most of the Earth, using MDC values is still reasonable. However, for a number of locations,...
We review the impact of the COVID-19 pandemic on Global Seismographic Network (GSN) operations. GSN stations, of which 50 also serve as IMS auxiliary Seismic Stations, have been designed to operate autonomously with very little operator intervention for long periods of time. These design goals have been strenuously tested with the advent of the COVID-19 pandemic, as travel by both local...
Evidence has shown that besides radioxenon from fission, release of activation-generated radioxenon can occasionally be observed at noble gas systems of the International Monitoring System (IMS). The literature appears to show conflicting results for the isotopic ratios from activation of stable xenon in the releases from nuclear research reactors (NRRs). This study uses ORIGEN simulations to...
We describe the standard pre-COVID mode of operations for the Canadian National
Seismograph Network, a large continental-scale monitoring network, and for the associated IMS stations in Canada. We examine how the operational posture has evolve and then discuss the manners in which the posture was found suitable and unsuitable to respond to the challenges and constraints of the COVID-19...
This presentation addresses the history of the CTBT hydroacoustic network, from its broad definition during negotiations of the Treaty through its establishment over the 25 years following the opening for signature of the CTBT.
Hydroacoustic network discussions during the negotiation of the CTBT will be addressed, including rationale for decisions that were made. The network concept was...
The CTBTO International Data Centre (IDC) initiated the development of novel software applications for modernizing automatic processing and interactive analysis of radionuclide data from the International Monitoring System (IMS).
The ongoing projects aim at completing the migration to open source license free software, unifying the processing tools for particulates and noble gas,...
General Dynamics Mission Systems (GDMS) overcame new challenges and implemented innovative strategies to maintain International Monitoring System (IMS) minimum requirements during the COVID-19 pandemic. GDMS focused on five areas: on-site spares, enhanced training material, refined quality assurance processes, development of remote preventive maintenance, and the health and wellbeing of team...
The CTBTO Provisional Technical Secretariat is responsible for supervision and coordination of the IMS network operations, and for providing assistance to assure proper functioning of IMS facilities. Station Operators are responsible for the operation of the IMS facilities, in accordance with the Operational Manuals, while complying with facility specific contracts, agreements and...
IMS seismic arrays are predominantly formed using multiple vertical sensors with a single three-component (3-C) seismometer co-located at one site. The deployment of fully 3-C seismic arrays, such as ARCES (PS28) and SPITS (AS72), offers the possibility to take additional advantage of the coherency on the horizontal components. For the case of S-phases, this has the potential to significantly...
We have engaged in broad-area regional monitoring for Mongolia and nearby regions, applying cross-correlation to long time windows for Lg-waves. For 2012 to 2016, using 4777 templates from a longer time-period, detections were made on searches of continuous data for a sparse network of IMS array stations, plus six long-running three-component open stations. Many candidate events were...
Location algorithms have relied on simple, one-dimensional (1D) velocity models for fast, seismic event locations. The fast-computational speed of these models made them the preferred type of velocity model for operational needs. Higher-dimensional (2D-3D) seismic velocity models are becoming readily available and provide more accurate event locations over 1D models. The computational...
The global pandemic of the past year has put a substantial amount of strain on many systems, with the CTBT monitoring regime being no exception. At the same time, the crisis has proved to be a significant and valuable resilience test. This panel explores the impacts of the COVID-19 pandemic on the establishment, operation, maintenance and sustainment of the IMS monitoring network, and the...
In 2018 the 51st Session of Working Group B (WGB-51) of the Provisional Technical Secretariat of the Preparatory Commission for the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) noted potential applicability of remotely operated vehicles (ROVs) for OSI purposes, but their practical use raises several serious issues that WGB should discuss at its future sessions.
Implementation...
Security constraints of an On-Site Inspection dictate air-gapped isolation of networks, introducing challenges for the reliable provisioning and updating of distributed mission-critical software systems employed during an OSI. Further goals include process transparency and operational robustness, while accommodating domain-specific requirements. To this end, we propose a technical framework...
The importance of mathematical modeling lies in the implementation of complex calculations and analysis of results using known computational methods. Mathematical modeling provides a qualitative and quantitative prediction of the behavior of an object or a system in cases their study is difficult in reality.
The aim of this work was to create mathematical software that allows modeling...
At the time of the opening of the Comprehensive Nuclear-Test-Ban Treaty for signature in 1996, machine learning was a relatively young but already established data analysis method in some fields. However, in seismology it had not reached a sufficient level of maturity to be considered for Treaty monitoring purposes. Furthermore, machine learning requires computational capabilities that...
Electrical Resistivity Tomography (ERT) geophysical technique has been applied in this study to evaluate the base metal and gold mineralization potential of Iperindo in Ilesha Schist Belt, southwestern Nigeria, where commercial exploitation capable of generating revenue and employment for the inhabitants has been challenged by lack of /inadequate subsurface geological/geophysical information....
In the context of the Comprehensive Nuclear Test Ban Treaty (CTBT), CEA/DAM developed about 20 years ago the SPALAX (Système de Prélèvement Automatique en Ligne avec l'Analyse du Xénon) system, which is used in the International Monitoring System to detect xenon releases following a nuclear explosion. This system is still under continuous improvement. In particular, CEA/DAM continues to work...
The purpose of this panel is to generate discussion about how data and data analysis approaches can improve IDC processing, and how to go about introducing new approaches at the IDC. It will leave participants with a better understanding of where data analysis improvements are still desired by the PTS, what new tools are emerging which might be intriguing to apply to our scenarios, where new...
A nuclear explosion results in a complex combination of signals including radioactivity released to the environment, seismic, infrasound, and hydroacoustic. The International Monitoring System (IMS) was established to detect these signals and analysts around the world train in the interpretation of them. However, the unique combination of signals indicative of a nuclear explosion is only fully...
Radiation detection devices comprise a detection unit and a signal evaluation unit, each adapted for the specific application of the device. Traditionally, signals of radiation detectors were evaluated utilising analogue methods, such as the standardised NIM electronics. Developments towards compact, high-performance digital hardware resulted nowadays in the application of digital data...
NDC Preparedness Exercises (NPE) are an opportunity to practice the verification procedures for the detection of nuclear explosions in the framework of CTBT monitoring. The NPE 2019 scenario was developed in close cooperation between the Italian NDC-RN (ENEA) and the German NDC (BGR). The fictitious state RAETIA announced a reactor incident with release of unspecified radionuclides into the...
Underground nuclear explosions produce an immense change in pressure and temperature concentrated around the source origin. This results in the formation of characteristic static and dynamic phenomena. This study highlights the potential of using time-lapse seismic to identify ground zero by monitoring post-explosion dynamic phenomena. Time-lapse seismic is successfully employed in the oil and...
One of the most important goals of any seismic network, is the ability to locate more accurately seismic events. Accordingly, accurate stations distribution, plays an important role for achieving that goal. In this study, we present a fully automated stochastic method for calculating the optimal station distribution inside a permanent/temporary seismic network. Using fuzzy self-tuned...
Distributed optical fiber sensors (DOFSs) utilize specialized source and detection systems to convert optical fibers into linear arrays of sensors. Since early experiments in the 1980s, a range of methodologies has been developed to sense a diverse set of variables with varying sensitivities and precisions based on communication-grade as well as purpose-built optical fiber cables. Over the...
Infrasound has proven to be useful for localizing events, especially in the context of the CTBT. Among the usual approaches, the Bayesian inference is often favored as it provides the posterior probability density function (PDF) for source parameters. In these methodologies, propagation models are constructed by numerically propagating signals through a set of plausible atmospheric...
The NCPA has developed an external calibrator system which is nearing maturity. This calibrator is attached as a replacement sensor lid for the Hyperion sensor, and injects the signal into the back volume of the Hyperion sensor. When the external calibrator is mated to the sensor, the integrated sensor-external calibrator package behaves as a self-calibrating sensor. The external calibrator...
Infra-AUV is a new EU project that will establish primary measurements standards for low frequency phenomena across the fields of airborne and underwater acoustics and vibration (seismology). Combining expertise from the national measurement institutes and geophysical monitoring station operators, it will develop both high-precision laboratory-based methods of calibration and methods suitable...
In order to improve the confidence in the results of measurements carried out in the field, on-site metrology is a key step. With the medium-term objective of being able to deploy a portable metrology system on different infrasound stations, CEA-DAM has tested an innovative system for calibrating its infrasound sensors. The first tests were conducted in November 2019 and September 2020 as...
Since its establishment in 1997, the CTBT IDC has been receiving data continuously from an increasing number of hydroacoustic stations. These stations are at present composed of 11 hydrophone triplets in the ocean and 5 T-stations (seismometers) on land monitoring for nuclear explosions in the oceans. This presentation summarizes advancements in the IDC automatic processing system from the...
Disaster Risk Reduction is one of the most significant themes of discussion in the contemporary global debate regarding attainment of sustainable future. The CTBTO is a unique treaty which has been contributing towards Disaster Risk Mitigation with the help of its well organized verification system for years.
In 2011 when Tohoku witnessed a massive earthquake with tsunami, CTBTO monitoring...
The accurate simulation of atmospheric transport and dispersion requires a numerical weather prediction model that is able to resolve both mesoscale meteorology, such as a storm front or sea breeze, and microscale meteorology near the plume source, which is strongly influenced by the presence of complex terrain (i.e., mountains or dense urban development). Current generation numerical weather...
MEMS instruments are more commonly known as inexpensive instruments to create seismic monitoring systems. As a result, independent efforts would have access to the required data stream to start analysis and applying new-generation models to continuously detecting patterns that increased creativity amid managing risks of major earthquakes. In project Earling, such data helps to distinguish...
Retrospective eruption characterization is valuable for advancing our understanding of volcanic systems and evaluating our observational capabilities, especially with remote technologies (defined here as a space-borne system or non-local, ground-based instrumentation which include regional [15-250 km range] and remote [>250 km range] infrasound sensors). Two of the largest explosive volcanic...
There is rapidly expanding interest in the application of seismological tools for exploring the structure and dynamics of the seafloor from the inner core to the nature of the ubiquitous sediments which cover most of the seafloor. New technologies are making access to the oceans less expensive, while recently acoustic telemetry has supported the continuous transfer of data from broadband...
The West African region is generally considered a stable continental area with few active tectonic features. However, several earthquakes have struck the area in historic and recent times. The region has records of damaging earthquakes dating as far back as 1615. Major events which had magnitudes between 6 and 7 occurred in 1862, 1906, 1939 and 1983. The seismicity is not well known due to the...
With global increases in population and air traffic, our ability to forecast when and where a hazard will occur is of prime importance. In the case of volcanic eruptions, forecasting is not limited to when and where an eruption will take place, but also when and where the impact of such an eruption will be felt. Cross-boundary volcanic ash from explosive volcanic eruptions is hazardous. The...
Microbarom signals are generated by wind-waves at the ocean surface and propagate all around the globe through the stratosphere and ionosphere. Microbaroms dominate the coherent infrasound ambient noise measured anywhere on Earth, with a particular peak for periods around 5 s. This ubiquitous signal can be used to monitor the medium in which it propagates, allowing to probe the properties of...
The Fentale-Dofen magmatic segment was shown to be more active than other volcanic centers in the northern Mid Ethiopian Rift by a temporary seismic experiment, conducted between 2001 and 2003 (Keir et. al., 2006). However, the activity observed during the EAGLE experiment is not swarm like but randomly scattered in time. In this study, we characterize rarely observed seismicity in the Fentale...
Our latest comprehensive reprocessing of the IMS infrasound database covers the period from January 2003 to December 2020, representing up to 53 stations considered. The resulting catalogue of coherent signals obtained using the Progressive Multi-Channel Correlation (PMCC) array processing algorithm with a one-third octave frequency band configuration permits more accurate signal and source...
The infrasound component of the IMS is not only capable of detecting nuclear-test explosions, a wide variety of natural and anthropogenic sources are continuously measured by the network.
A rich infrasonic wavefield is recorded by station I18DK, located in Northwest Greenland. I18DK is located in an unique environment far above the polar circle. Operations started in 2004, enabling long-term...
The IS08 infrasound array in Bolivia contributes to the International Monitoring System of the Comprehensive nuclear-Test-Ban Treaty Organization since 1999. Real time data, which are received at the Bolivian National Data Center (Observatorio San Calixto, OSC) through a VSAT link, are used on a daily basis for scientific and civil applications. Installed in the Central Andes, IS08 has...
High-quality open data from global and regional networks such as the Global Seismographic Network and the EarthScope Transportable Array have enabled a wide range of transformative, cross-disciplinary research that has far exceeded original expectations. The networks consist of well operated and distributed stations with long-term recording histories, and were designed to facilitate studies of...
Intergenerational dialogue and mentoring are key in building the next generation of STEM and nuclear non-proliferation experts. In fields that are considered highly technical and difficult to enter, such as STEM and arms control, good mentors that provide guidance for both career and personal growth can encourage young professionals to break barriers and create lasting change. To inspire and...
Positioning and navigation are essential for inspectors in the Inspection Area, which is probably a place of nowhere in the world.They would lead the inspectors to the potential Ground Zero together with the guidance of OSI search logic.They are also very important for most of the OSI measurements, which are normally geo-referenced, such as SAMS, CPT, multispectral imaging. With the...
An invaluable tool in characterization of any receiver, propagation path, or detection system, is a source with known and repeatable signal characteristics. This talk will discuss engineering development and evaluation of a coherent (non-explosive, periodic, with controlled duration) infrasound source with frequency capabilities in the sub-hertz to several hertz band. Design of a sound source...
The South African radionuclide laboratory (ZAL14) supporting the Comprehensive Test Ban Treaty’s International Monitoring System (IMS) is situated at the South African Nuclear Energy Corporation. The laboratory is equipped with two ultra-low background HPGe detectors gamma-spectrometry systems (Canberra BEGe5030 and BEGe65) of which the BEGE5030 has been certified for analysis of IMS...
The United Kingdom National Data Centre (UK NDC) has developed a novel tool for the analysis of radionuclide (RN) detection events on the International Monitoring System (IMS). An automated process for the fusion of RN and atmospheric transport modelling (ATM) data streams has been produced which efficiently compiles a wealth of information in a single source and puts interactive virtual maps...
Recent advances in convolutional neural networks (CNNs) have brought impressive detection capabilities to one- and three-component seismic stations. Still, the highest sensitivity to repeating events is obtained by beamforming signals over a seismic array. We propose a new neural network architecture that combines the two, by introducing a two-dimensional convolutional layer that encodes the...
A new algorithm for processing beta-gamma coincidence spectra based on the maximum likelihood and non-negative least squares (NNLS) methods is presented. The algorithm allows simultaneous processing of the signal in all regions of interest (ROI). This approach has a number of advantages over the net count calculation (NCC) algorithm and provides a solution to the problem of processing...
This research demonstrates a new accurate automated method for seismic first arrival picking that is based on a mathematical approach with considering the fractal dimension of seismic traces. Reliable and accurate detection of the first arrival is a key step for the determination of seismic parameters. In this work, we introduce an adaptive mathematical triggering algorithm by considering the...
This research describes a new damping system for optical seismic sensors that, is based on eddy currents. In the last decade, scientists have been considered optical approaches for readout systems of seismic sensors. So, the use of reliable and high-performance damping systems in this category of seismometers is very important. This has led us to build a damping system based on the eddy...
Seismic signal processing aimed at extracting relevant information is often faced with the problem of the presence of disturbing signals, which can be generated by different sources of noise. This problem is all the more glaring when the seismic event of interest is so weak that it is drowned in noise, and can therefore pass without being noticed. We propose in this paper a new method which...
Seismic event depth is used for event characterization and location and is estimated using the vertical component of the velocity at the source and half the time interval between a direct P seismic phase and a similar shape echo, reflected from the surface, named depth phase or pP. The signal-echo separation can be estimated with cepstral methods designed for shallow-event cases when the P and...
Radioxenon analysis is a critical part of monitoring for underground nuclear explosions. Algorithms that determine the activity concentration of a sample were developed over many years and continue to be updated as lessons are learned from automated radioxenon analysis systems. During Xenon International testing in the U.S., a large activity 133Xe spike caused false positive hits for 133mXe...
In the framework of a tabletop-exercise of the Austrian NDC scheduled ground detonations within a week in November 2020 were monitored. Therefore, a local network was deployed. Additional to the permanent seismic station ABNA in the vicinity, the NDC deployed two seismic broadband stations with co-located low-cost seismic and infrasound sensors as well as a mobile infrasound array.
After...
According to OSI Operation Manual, IT/ISP living and working areas should be well-protected. Scenarios like the management of the different living and working areas for IT and ISP, require entry permission granted separately to either IT or ISP members. This work would provide a customized management supporting system solution to the above mentioned scenario. The system is based on Artificial...
Advancements in AI/ML are creating a paradigm shift in virtually every sector of the tech industry. Among the endless applications, AI vision technology based on Deep Neural Network, finds its strength at image processing, pattern recognition and image interpretation, which can be utilized for manufacturing, medical diagnosis, and OSI. Current OSI search logic relies on finding and identifying...
This paper analyzes the possibility of applying higher - order statistics - third - order cumulants for isolation and autonomous determination of the moment of physical change in the observed environment. The proposed methods and algorithm make it possible to analyze all those phenomena: sound, infra sound, seismic and others that are essentially non-linear and non-Gaussian. As a result of the...
Magnitude measures the strength of an earthquake and is an important parameter for earthquake / underground test discrimination.
The IDC computes body magnitudes from the amplitude to period ratio recorded at network stations. Radzyner et al. (2017) showed that there was superior consistency of magnitudes across stations when the magnitude is computed as a linear function of the ratio, but...
In this research, a new approach based on the moiré technique is presented to calculate the displacement of the suspended mass in seismometers. The oscillating system consists of a spring-suspended mass whose position is monitored using the moiré technique. To form the moiré pattern, two similar Ronchi grating are used so that they are facing each other without physical contact. One of the...
Seismic event source identification is one of the vital and primordial tasks in seismic signal processing. Indeed, the first goal of seismic signal analyst is to recognize the source of each recorded seismogram. For example, one of the main goals of CTBTO is to identify nuclear explosion from natural seismic events. Several complex methods have been studied in the previous researches.
The aim...
According to scenarios of Comprehensive Nuclear-Test-Ban Treaty On Site Inspection (CTBT OSI), a kind of wide spectral imaging spectrometer based on aviation platform (including UAV) is proposed. The methods of detecting and recognizing nuclear test based on optical remote sensing are summarized, and several application fields using hyper spectral data are analyzed, such as detecting the...
Sabah is the most seismically active state in Malaysia where it has recorded higher number of moderate seismological activities for the past decades. The seismicity record of Sabah shows the presence of two distinctive seismic zones, which are Ranau in Kota Kinabalu and Lahad Datu in the southeast of the region. The IMS network setup by the CTBTO has successfully detected seismic events...
In this study, we aim to develop a new approach using machine learning and data mining algorithms to estimate the activity concentration of radioxenon isotopes of any unknown sample without extensive mathematical calculations from calibrated raw spectra. So far, several methods have been applied such as the region-of-interest (ROI) and the simultaneous decomposition analysis tool (SDAT) to...
An Earthquake with a magnitude of 7.4 Mw with a depth of 10 Km that occurred in the Central Sulawesi province on Sept. 28, 2018, at 18:02 (WITA) triggered a Tsunami with a height of up to 5 meters and Liquefactions in Palu City. Based on the results of radon gas monitoring at Tadulako station, which is ~71 Km from the earthquake epicenter shows before the earthquake occurred indicating an...
Large aftershock sequences cause problems for the International Data Centre (IDC) because the seismic event rate increases dramatically during an aftershock sequence, making correct association of arrivals difficult for the automated pipeline. Aftershock sequences can continue for days or even months after a large earthquake and although aftershocks aren’t events of interest for treaty...
Automatic recognition of seismic event source has been a primordial task since the introduction of digital seismic networks. Nowadays, this task becomes more important due to the huge quantity of data recorded continually and the need for real time results. Different approaches have been addressed in the literature. Currently, artificial intelligence techniques have attracted increasing...
Since 1994, the Kazakh NNC RK has operated the contemporary monitoring system that includes seismic and infrasound stations. Five stations are included in the IMS: PS23, AS57, AS58, AS59, IS31. The main goal of the NNC RK network is monitoring of nuclear explosions in support of the CTBT. The data of NNC RK network are actively used in civil tasks, for example, to estimate the seismic hazard...
Today with growing processes of globalization geopolitical and economic role of Arctic region in the world is also constantly growing. The Arctic region is becoming the center of building a new system of global and regional security, which also contributes to the growing interest of States in the development of this region, and leads to the expansion of active economic activity.The increasing...
The analysis system for CTBT radionuclide monitoring data is developed by the CNNDC. The system realizes the functions of automatic acquisition, database storage, automatic processing, interactive analysis and statistical query of IMS radionuclide monitoring data. A comprehensive assessment is carried out. The results show that the data analysis system has the capability of detection and...
Phase arrival time estimation for tele-seismic signals is a critical and fundamental step in the detection and localization of nuclear explosions and seismic study in general. Typically, this process involves heavy human interaction with more than half of all automatically detected arrivals being manually re-timed by a human analyst. Developments in Artificial Intelligence and specifically in...
This poster describes progress in 2020 of classifying IMS particulate radionuclide spectra into “likely normal” (Cat. 1,2) and “requires scrutiny” (Cat.3,4,5).The aim is to assist IDC radionuclide analysts by reducing their workload of “normal” spectra, which are the majority of IMS spectra.
The method described here is entirely ignorant of radionuclide science. The point of these efforts...
The International Monitoring System Division (IMS) of the CTBTO aims to maximize the data availability from the radionuclide monitoring systems. The detectors at the radionuclide stations require a calibration whenever a new detector is installed or the geometry is changed.
The maintenance unit of the IMS division is responsible for assisting the Station operator during calibration,...
One of the implementations to support the CTBT instrument measurement is radionuclide identification. An automatic real-time identification radionuclide can be an option for some applications, including monitoring of environmental contamination and prevention of nuclear terrorism. This research is about the automatic algorithms that provide feedback about the presence of any radiations...
Radionuclide event formation needs reliable detections. Because of the relatively large uncertainty in atmospheric transport modelling, which radionuclide event formation relies on, radionuclide event formation benefits from higher quality measurement analysis, specifically minimizing the number of false positive and false negative detections. This work proposes a quality scale that...
Three-component stations traditionally rely on polarization analysis to estimate the backazimuth of each arriving wave. Unfortunately, these polarization estimates suffer from both high error and low confidence, and contribute very little to the downstream association algorithms at the IDC. Here, we present BazNet, a deep neural-network-based backazimuth predictor for three-component stations....
The IMS Operational Manuals for waveform stations require that IMS stations be calibrated regularly. Since 2012, the PTS had relied mostly on electrical calibration to meet that requirement.
However electrical calibration comes with some challenges (no traceability, integration and sustainment issues, high operating costs…).
A part of the geophysical community, including Station Operators,...
Following the spike of above ground nuclear testing in the 50s, carbon dating has become very difficult to perform and most scientists have started to move to other dating methods if they wished to date anything from the 50s to the this day. We look at how the fission products Carbon-14 and Cesium-137 have affected our environment and why it is important to ratify CTBT to prevent damage like this.
Remote sensing satellite data provide opportunity to obtain information about the surface of the earth at different spatial and spectral resolution. Satellite imagery has been used since the 1960s for reconnaissance studies and has since had large number of applications including, disaster mitigation planning, agricultural development, resource monitoring and surveillance purposes. A large...
The fast-pace developments in scientific innovations introduced many new challenges for man-kind. The 21st century is facing many non-traditional security threats like climate change, pandemics, refugees’ crises, resource scarcity etc. Both security and non-traditional security threats pose hinderance in the process of sustainable development and disaster risk mitigation efforts.
On one hand...
Characteristic features of infrasound waves observed in the Antarctic reveal physical interaction involving surface environments around the continent and Southern Ocean. An infrasound array (100 m spacing) by using three sensors (Chaparral Physics Model 25, with a detectable frequency range of 0.1-200 Hz), together with a broadband barometer (Digiquartz Nano-Resolution Model 6000-16B...
The automatic classification of seismic events is an absolute necessity when dealing with an important amount of data. Moreover, the classificationneeds to be achieved almost in real time. Due to the importance of an automatic task, various approaches have been proposed in the literature. Numerous approachesare based on features related to time domain, when othersexploit the frequency...
Increasing windstorm occurrences significantly affect human lives, especially communities living in densely populated areas. However, windstorms commonly occur in a short period, with unexpected timing and at random places. Therefore, wind hazard maps must be developed to build resilience actions within communities. Bogor City area is used as a sample study and this research utilised GIS in...
Coincidence Detector Systems have the potential to increase IMS network sensitivity for Treaty Verification purposes. The study presents the first test implementation of a coincidence detector system for measurement of particulate samples at the CTBTO Test Station VIP00, located on rooftop of Vienna International Centre in Vienna – Austria. The prototype dual/coincidence system setup and its...
Aliasing is caused by discrete sampling below the Nyquist frequency. In order to recover the harmonics of shape in a signal, it is necessary to use a sampling rate at least twice the highest waveform frequency (Shannon Theorem). This means more volume of storage or more bandwidth for transmission. If we could overcome this limitation, we can reduce the sampling rate by less than twice the...
NDC-in-a-Box is an independent software package developed, distributed, and supported by PTS, which is intended for NDCs to establish a verification regime with a number of functions including receiving, archiving, processing and analysing data from IMS stations. To simplify installation and configuration of NDC-in-a-Box package, most software tools and applications are provided via a...
Weather forecast is essential for precision measurements involving meteorology related CTBT scenarios. Weather parameters recording is also very critical for routine maintenance of IMS stations. Looking at the IMS network all over the globe, it would be very important to get to know the local weather situation to support the normal operation of the four categories of IMS stations in the middle...
In CTBT treaty and OSI Operation Manual, Initial Overflight and Additional Overflight would be arranged to provide IT opportunities to understand the overall situation of Inspection Area and conduct specific inspections such as visual observation and multispectral imaging. In the past exercises and training, manned helicopters have been used for a long period of time. With the development of...
Multilateral arms control and disarmament treaties would require, instead of National Technical Means (NTM), International Technical Means (ITM) as verification solution, due to its efficiency and transparency characteristics. With the rapid development of commercial space technology, space based remote sensing and communication technologies are no longer dominated only by a few states or...
The SINAMOT (Sistema Nacional de Monitoreo de Tsunamis), is responsible for increasing Costa Rica tsunami preparedness, by characterizing the threat, increasing community preparedness and strengthening the existing tsunami warning standards of practice.
The National Tsunami Warning Center (NTWC), SINAMOT evaluates tsunami hazard models including near and far field scenarios. We use several...
We see that the process of globalization approaches its virtual pick. However, the key drivers for risk assets are still in place. One of those risk assets is nuclear assets.
Now, when world community is facing global concerns, such as disaster risk mitigation, climate change studies, the Sustainable Development Goals and lockdown policies. Governments forced to implement radical strategic...
The Sustainable Development Goals were approved by the United Nations to lead the way for a better world. Designed to respond to global challenges, the SDGs are answers to questions related to poverty, climate, prosperity, environment, peace, justice, et cetera.
Unfortunately, only a decade away from achieving these SDGs, the countries of the central Sahel (Burkina Faso, Mali and Niger) are...
During SnT19 we presented our work on defining the sources of hydroacoustic signals in the Indian ocean and looked at how the IMS can contribute to SDG 14. During the analysis we only managed to process three months of data from IMS HA04, HA08 and HA01. This time, we processed more than 12 months of non-stop data from those same stations. Data processing was performed using PMCC method with...
The International Data Centre (IDC), which is present in Vienna, receives information from the International Monitoring System (IMS). The IMS has radionuclide, seismic, and hydroacoustic stations around the globe which gather data about air quality, land and oceans respectively. This regularly updated scientific data can be used by the “students of Environmental Science and Global...
Infrasound sensors deployed in the IMS Infrasound Network are of high performance so they can meet the strict IMS minimum requirements. The PTS in its effort to deploy state-of-the-art infrasound sensors has been performing continuous technology watch for the last 11 years on high quality infrasound sensors. More recently, the PTS also started monitoring developments in the field of low-cost...
The CENALT (CEntre National d’ALerte aux Tsunamis) has been operating as the French TSP (Tsunami Service Provider) since 2012. Its objective is to disseminate warning messages towards the French national civil protection agency and the international subscribers, in less than 15 min following a tsunamigenic earthquake in the Western Mediterranean Sea and the North-East Atlantic Ocean. Early...
Seismic waveform data are generally contaminated by noise from various sources. To date, the most common noise suppression methods have been based on frequency filtering. These methods, however, are less effective when the signal of interest and noise share similar frequency bands. We implemented a seismic denoising method that uses a trained deep convolutional neural network (CNN) model. In...
The lack of information regarding land structures that are prone to deformation can have an impact on the failure of infrastructure development in the New Capital City Region. Therefore, it is necessary to conduct a study on the deformation that occurred in the area, as initial information in determining the location for safer infrastructure development based of the soil structure. This study...
Iran's economic sanctions, along with the ever-increasing advances in digital technology and the presence of high-level experts, have made Iran one of the pillars of producing high-tech geophysical equipment in the Middle East, and will close the competition with the products of major corporations such as nanometrics and guralp. At present, high-precision digital recording equipment with...
According to paragraph 69(d) of Part II of the Protocol to the CTBT, future OSI inspectors are permitted to analyse environmental samples from above, at and below the surface to detect anomalies. These analyses shall take place at the OSI field laboratory which must be designed for ready deployability, set-up and in-field operation.
The OSI action plan for 2016-2019 aimed at improving and...
Enviroearth has developed over the past few years Wind Noise Reduction System (WNRS) of advanced technologies that meet all the requirement and configuration for each of the infrasound stations topology over the whole IMS Network. Among the continuous improvements made to the design of these systems systematically associated with micro barometer sensors, we will mainly present the possibility...
All broadband, low noise velocity borehole sensors manufactured have limited high frequency response. In this paper, results from the 89 mm diameter measuring only 600 mm long VBB very low noise sensor with 250 Hz High frequency corner (-3 dB points at 360 seconds and 250 Hz) is presented.
The high loop gain feedback sensor modules are based on mechanical long period suspension system. The...
Nuclear activity is a significant threat to the world peace. Monitoring such activities is important but in many cases it cannot be done in real time. Remote sensing and geospatial analysis play an important role in detecting the signatures resulting from these activities. These events leave impressive or disguised deep or superficial signatures on the environment, such as changes in the water...
A novel first-look cadmium zinc telluride (CZT) detector is being developed by Pacific Northwest National Laboratory (PNNL, USA) in collaboration with General Dynamics – Mission Systems (GD-MS, USA). The compact gamma-spectrometer is designed to be installed within the air intake plenum of the Radionuclide Aerosol Sampler Analyzer (RASA) design of International Monitoring System (IMS)...
IMS radionuclide concentration data is accessible through the CRTooL. It contains detected concentrations for all kinds of radionuclides, categorized as noble gas (Xenon) and particulates, standing for natural, activation and fission-products.
The ultimate role of these data is to find and then identify any event that is related to the verification regime of the CTBT. Identification of events...
Beta-gamma detectors are utilized extensively for the detection of radioxenon, but the beta detection is primarily performed with a plastic scintillator cell. Two areas of improvement for plastic scintillators are the sample carry-over (“memory effect”) and energy resolution. While the scintillator can be coated to remove the memory effect, the energy resolution must be improved with a...
Next-generation gamma-gamma coincidence measurements have the potential to significantly improve the confidence of detection of particulate radionuclides relevant for nuclear explosion monitoring purposes. Sophisticated laboratory systems have demonstrated order-of-magnitude improvements for radionuclides such as Ru-106/Rh-106, Cs-134 and Ce-144. However, the implementation of these systems at...
In this work, a committee machine was used to combine supervised and unsupervised artificial neural networks to discriminate between Earthquakes and quarries blasts. The unsupervised network is used as a measure of accuracy for the results of the supervised neural network. The unsupervised Self-Organized Map (SOM) and the k-means clustering algorithms are used to estimate support and...
Quantitative methods that enable multi-physics waveform fusion support explosion monitoring and general research in geophysical processes that comprises background emissions for explosion monitoring. We offer a constructive method to fuse statistics that we derive from multi-physics waveforms and improve our capability to detect small, above-ground explosions over methods that consume single...
Typically, data-driven learning works best when we can exploit expectations from our data domain. For example, the development of recurrent neural network architectures to deal with the temporal dependence in language, geometric deep learning for 3-D problems, and physics-constrained Bayesian learning for more interpretable dependencies. Yet it can be unclear how to interject expectations, and...
Creare has previously designed an electrostatic precipitator (ESP) collection system as a drop-in enhancement and replacement for the current RASA, the U.S. built Radionuclide Monitoring Station, as presented at S&T2019. This current work incorporates a full new design for the next generation of monitoring stations, RASA 2.0, with several significant improvements including advanced detectors,...
Nuclear test event data as acquired by the sensors at the terminal ends can be used to create multiple possible simulations of the event using any basic model. Alternatively, events can be created in an simulation environment generating stimuli producing data as of the recorded event. This can be done by adjusting input variables like yield, surface condition coefficients, depth variations,...
Stratodynamics proposes to deploy its NASA designed infrasound sensor aboard a constellation of long duration, high altitude balloons in collaboration with Project Loon.
By leveraging Project Loon’s distributed data centre computation and blended Analogue Ensemble (AnEn) machine learning techniques, a balloon deployed infrasound sensor could enable revolutionary observations from around the...
For the past 3 years, rotation of ground motion can be measured with a portable broadband instrument. Thanks to its expertise in fiber-optic gyroscope learn into navigation market, iXblue have been able to offer a product line called blueSeis to bring the unmatched performance of this technology from submarines to seismic field.
However, not everything has been straightforward, and there is...
VNIIA is the premier ROSATOM organization in implementing the CTBT and is currently performing a cluster of research activities:
- provides scientific methodological support and develops hardware and software solutions to ensure the CTBT OSI activities, carries out a comprehensive assessment and foresee of technical abilities within the verification regime for compliance with the CTBT,...
Discriminating between explosions and earthquakes is necessary for building hazard maps and monitoring applications. Previous studies have used classical ML techniques based on the amplitudes of various phases. More recent methods based on Deep Learning use the full seismic waveform; however, they rely on detections made by nearby stations. These methods are inapplicable for global-scale...
The impacts of multiple stressors on the ocean and the associated risks of abrupt state shifts can be explored through ocean system interactions, risks, instabilities, synergies and Arctic Ocean climate predicting models.
The draining of pools underneath the glacier and glacier retreat is attributed to increased carbon dioxide and green house gases.
Hence, efforts are made on the...
A ship-based air-gun survey was conducted contemporarily with distributed acoustic sensing (DAS) observations using an abandoned submarine cable. Measurements were compared between DAS and co-located hydrophones on the seafloor. DAS measures the Rayleigh back-scattering variations along a fiber-optic cable, of the same kind as the IMS HA hydrophone stations’ trunk cables, using incident laser...
Earthquake swarms observed before the 2006 and 2011 Nyamulagira eruptions were analysed. The activities and hypocenter distributions of these earthquake swarms were mainly examined.
The former swarm was characterised by a higher seismic activity than the later. Although the two swarms accompanied eruptions, most of the swarms observed in 2006 and 2011 were not followed by any eruptions. These...
In recent years, a new prototype of a geo-hydroacoustic buoy has been created at the IPE RAS. The buoy is designed to collect acoustic, hydroacoustic or seismoacoustic data in various environmental conditions. It can be installed in onshore and offshore wells. The main purpose of the buoy development was its use for operations in the Arctic latitudes as an element of distributed drifting...
The identification of the Palu-Koro Fault has been conducted. The study method used is a merging scientific discipline of geology and geophysics. Field data acquisition, processing, analysis and modeling in the laboratory using geological and geophysical techniques became the main framework in this study.
Acquisition of geological investigation including fault-slip at 19 points and 30...
Current techniques used for analyzing beta-gamma spectra measured by radioxenon systems are based on Regions-of-Interest (ROIs) covering relevant decay modes. The ROIs are set in the detector calibration procedure, and the same ROIs are used for all samples. However, the optimal ROI limits generally will be different for each sample. We present at new method where the optimal ROI settings are...
The International Monitoring System (IMS) is comprised of multiple types of sensors that provide verification information. While each piece of information is useful for verification, the full benefit of multi-technology measurements has not been fully taken advantage of. Data Fusion is an approach that seeks to integrate disparate sources of data into a unified and comprehensive event...
The scope of the prototype presented in this work was to create a compact and flexible sensor array, reliable enough to be used in volcanic monitoring. In order to achieve this objective, we used an Spartan-6 L X 45 FPGA as the base of the embedded system, getting the capability of continuous acquisition at a configurable velocity up to 50 ksps. In addition, the equipment has some features as...
Natural disasters are a serious disruption to the functioning of a community involving significant damage and loss of human life that the community cannot overcome with its own resources. The effects are often cumulative and felt over time and space. Thus, it is imperative to put in place a good prevention and risk management system that makes it possible to optimize actions, especially when...
The National Nuclear and Radiological Emergency Plan (NNREP) provides the basis for a national level response to a radiation emergency in Nigeria that is effectively integrated with an accompanying international, national and local response plan to establish a timely, organized and coordinated emergency response by the Nigerian Authorities to promptly and adequately determine and take actions...
Selby, (2008, 2011) developed a Generalized-F method, (Gen-F), to enable application of an F-statistic detector to small-aperture arrays where correlated background noise would otherwise degrade performance; and in 2013, he introduced an innovative time-frequency approach that further enabled application of Gen-F to arrays independent of aperture. Tests of the method on the IMS arrays have...
In the context of the Comprehensive Nuclear Test Ban Treaty (CTBT), the CEA/DAM developed the SPALAX (Système de Prélèvement Automatique en Ligne avec l'Analyse du Xénon) about 20 years ago which is used in the International Monitoring System to detect xenon releases following a nuclear explosion. The new generation of the system has been successfully developed by the CEA and CEGELEC Défense....
A method for detecting radioactive argon 37Ar produced in the soil by the nuclear reaction between 40Ca and fission neutrons is used for monitoring and detection of underground nuclear tests. In this regard, a relevant problem is to extract argon from soil gas with the elimination of impurities and conduct radioactive analysis. An industrial technology of low-temperature air rectification...
This presentation is an overview on radionuclide analysis procedures at the IDC. There are three sets of approaches currently, the single channel analyser curve for particulate, the least squares regression on gamma- and X-rays peaks of xenon isotopes for high resolution spectra and the net count calculation method for beta-gamma coincidence spectra for noble gas, which are based on...
The system is an alpha/beta detector able to determine the independently alpha and beta contaminations based on PSD (pulse shape discrimination) capabilities of the scintillator and the real time digital pulse processing of fast electronic readout. The detector is designed for measuring alpha and beta emitter contamination on large air sampling filters and to complement the high-resolution...
The background seismic noise in Venezuela has been studied using broadband stations of the Red Sismológica Satelital Nacional (RSSN) (Netcode VE), including stations AS117 and AS118 of the auxiliary network of the IMS. To calculate the most representative values of noise at a given period, the method proposed by McNamara and Buland (2004) has been applied.
For periods lower than 1 s, the...
It has been proposed that the use of gamma-gamma coincidence methods could lower the detection limit for the detection of certain relevant radionuclides, such as 140Ba. Gamma coincidence measurements have the advantage of significantly lowering the background at the cost of lower overall efficiency. Modelling efforts indicate that a net gain in detection limit can be achieved. Several...
Discrimination between earthquakes and explosions is an essential component of nuclear test monitoring. Discrimination methods currently used by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) are often ineffective for regional events, particularly in Israel’s region.
For instance, five seismic events whose epicenters lie near the Sea of Galilee (Lake Kinneret) were reported...
The international monitoring network of radionuclide stations of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has been built up for the last 20 years. This mature monitoring network has now reached a phase where a technology upgrade for some systems has become necessary. The Cinderella G2 is a commercial automated particulate air sampling...
I31KZ, Kazakhstan, has been in operation for almost twenty (20) years. Over this period, the specific experience was gained of operating the array in hard-to-reach areas in harsh environmental conditions such as strong winds, low temperature in winter months and flooding in springtime. This experience and lessons learned allowed to minimize the risks of potential damage and loss of...
Noble gas stations installed on the IMS are designed to detect low level concentrations of radioxenon in the atmosphere. In order to improve sensitivity, one can either increase the volume of air sampled or lower the minimum detectable activity. Designing new detectors allows noble gas station developer to play on both grounds.
After 5 years of research and development, high resolution...
Seismology data analysis is becoming a challenge due to the exponential growth of continuous data being stored. In this study we present and compare two methods to massive detect earthquakes: the matched filter and fingerprinting. We have tested matched filter over several study zones of interest: in the Western part of Mexico to study general seismic activity, in the Isthmus of Tehuantepec in...
Gaseous fission products have been produced via neutron irradiation of a uranium target and extracted using a custom gas processing system for measurement on a high-resolution beta-gamma coincidence detection system. The gas was extracted and measured in two stages in order to measure the prompt and delayed fission products. This poster presents an overview of the system used to extract...
37Ar is an indicator of an underground nuclear explosion. This radioisotope is produced via 40Ca (n, α) 37Ar reaction through neutron activation of 40Ca included in the rocks near to the nuclear explosion location. The relatively long half-life of 35 days compared to CTBT-relevant radioxenon isotopes results into 37Ar activity becoming stronger than radioxenon activity approximately 50 days...
Radioxenon detection systems chemically separate and purify xenon from the collected atmospheric sample. These systems reject radon to a high degree during this processing step. On occasion, radon will make it to the nuclear detectors and its progeny will interfere with the radioxenon measurement. The minimum-detectable-concentration values of an atmospheric monitoring system will also be...
Rotational seismometry is an emerging perspective area of science for further developing of seismic monitoring. The quality of manufacturing measuring devices is improving. New instruments are being developed. Accuracy of measurements is increasing. Data processing algorithms are being improved. However, the absence of standardized metrological schemes for developers, manufacturers and users...
The microbarometer for infrasound monitoring systems was developed by FSUE VNIIA, the leading organization of the State Atomic Energy Corporation Rosatom for the implementation of the CTBT.
The microbarometer is used to receive infrasonic vibrations of atmospheric pressure and is intended for use in facilities of the CTBT International Monitoring System.
Compared to existing analogues, the...
In order to play a more important role in the OSI activities organized by CTBTO, such as inspector training, the single technique test or exercise, build-up exercises (BUEs) and the OSI integrated filed exercise (IFE), et cetera, the Northwest Institute of Nuclear Technology (NINT) manufactured one brand new OSI radioxenon processing system (or XESPM-III Mark II). Comparing with the XESPM-III...
In the last 500 years, more than 75 tsunamis have been documented in the Caribbean and the adjacent regions. Since 1842, 3446 deaths associated with tsunamis have been reported. On August 21 2018, a magnitude 7.3 earthquake occurred just off the northern coast of Venezuela and caused tremors in several nearby countries. A tsunami was not expected, nonetheless the Pacific Tsunami Warning Center...
Activity ratios of paired isotopes detected at IMS radionuclide stations can be used to not only discriminate a nuclear test from civil nuclear releases, but also determine the explosion time under assumed scenarios. A function of the isotopic ratio with time from the explosion time up to the stop of collection can be derived, based on Bateman equations of given decay chains. It is not a...
Multivariate analyses of fission product activities have previously been successfully used to determine the history of spent nuclear fuel from gamma measurements. A high dimensional data-set is projected to a one- or two-dimensional space using e.g. Partial Least Squares (PLS) regression to the parameters of interest, such as reactor type, burnup, initial enrichment and cooling time. Previous...
The environment of infrasound stations is characterized by mesoscale wind speed and temperature fluctuations that affect the temporal variability of the Atmospheric Boundary Layer (ABL). While the statistical characteristics of turbulence are poorly constrained, modeling such statistics appears to be crucial since each sensor of infrasound stations is subject to this local noise that may mask...
The discrimination between the highly variable radioxenon background caused by normal operations of nuclear facilities and CTBT-relevant events is a challenging but crucial task. For this reason, the radioxenon background at IMS noble gas systems must be sufficiently characterized and understood. The scientific methods and software tools to do this can still be significantly enhanced. This...
The International Monitoring System (IMS) includes waveform sensor stations connected to a centralized processing system in the International Data Center (IDC) in Vienna. While the performance of the IMS is known to be related to atmospheric properties, the usual approach at the IDC still relies on expert judgments and simple models to incorporate the environmental knowledge. In this work, we...
For several decades, CEA/DAM is developing noble gas detection systems for nuclear test detections. In particular, CEA/DAM developed the SPALAX system which started to integrate the CTBTO IMS network in Tahiti in 2002. In 2015, CEA/DAM started the conception and realization of the SPALAX New Generation (SPALAX-NG) integrating the results of several years of R&D on material adsorbents and...
Quality Control (QC) measurements are taken to monitor and correct for gain drifts in radioxenon nuclear detectors. The measurement is performed by placing a $^{137}$Cs source near the detector and measuring the position of the 662-keV photoelectric peak in the NaI detector and determining the endpoint for the Compton scatter distribution, but there is much more information that can be...
An extensive phase identification (i.e. Pg,Pn,Sg,Sn,Lg) and analysis is still pending in order to better precise the location and nature of the main seismic events (5.1 and 4.8 Mw) that took place within the two branches of the Boconó fault in Las Gonzalez sector in Western Venezuela. Along with these two events (Nov 14th and 11th) in 2015, an intense aftershock sequence of almost one thousand...
The international monitoring network of radionuclide stations of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is supported by 16 radionuclide laboratories. As part of a continuing performance evaluation programme for these laboratories PTEs have been organised for the particulate and noble gas measurement capabilities of the IMS laboratories....
Development of methods to track beta-gamma detector gains is important to the accuracy of radioxenon system measurements. Typical gain monitoring and correction is done using a mixed 137Cs/154Eu source, which results in several gamma-ray lines that can be fit by Gaussian distributions, and gain adjustments made to bring the peaks into the expected channel. The beta detector on the other hand...
The evolution of the SPALAX systems, now equipped with a high resolution beta/gamma detection equipement (PIPSBox/HPge), led CEA/DAM to develop dedicated spectrum analysis algorithms. The first developments were presented to CTBTO noble gas experts during the “Paris equation” meeting in March 2018.
Lately, CEA/DAM conducted a computer-based study to evaluate those algorithms. A large low...
Shallow earthquakes with Mw>8-9 usually create extensive aftershock activity with thousands of events with mb>3.5. This is a tremendous challenge for IDC automatic and interactive processing, with the Tohoku-2011 earthquake being a prime example. The SHI IDC processing is fine-tuned to find the smallest events (with fixed human resources), and thousands of similar events within a very short...
Remote sensing plays a critical role in seismotectonics monitoring of active fault systems. In quest of finding the main geophysical parameters to be surveyed by geospatial and in situ measurements in an integrated monitoring system, this study is focused on the analysis of some earthquake activities recorded in the study area. Specific precursors can be reliably detected using satellite...
An event detection method based on deep neural network combined with the average wave speed ratio of multiple stations is proposed for detecting local events under the global sparse seismic network. Firstly, the method uses multi-task convolution neural network to detect and identify the direct P and S phases, as well as estimate their arrival time. Then a joint network of GAN and LSTM is used...
Complex infrasound wavefields (containing multiple simultaneous waves with different slowness vectors) pose a challenge for traditional array analysis. We approach this problem using a dense array (22 sensors) as a field method, and secondary infrasound from earthquakes as a research target. Secondary infrasound from earthquakes contains potentially useful information on ground shaking, but...
Characteristics of seismic tremors in April 2015 were investigated at Syowa Station, in the Lützow-Holm Bay (LHB), East Antarctica. To examine the relationship between surface environment in a particular cryosphere variation, MODIS satellite images were utilized for comparison with the tremor events. Since a large volume of sea ice was discharged in April 2015, along with large icebergs passed...
Seismic monitoring and observation is a vital and main function of the Seismological Observatory Section of the Solomon Islands. The Solomon Islands are formed from part of a complex of Melanesian island arcs and are located on the South West Pacific Region NW of Papua New Guinea and SE of Vanuatu Islands. Due to tectonic settings of a complex plate of convergent zone, the seismicity of the...
This paper focuses on assessing the vulnerability of buildings at Nyanyano (Ghana) in case there are future earthquakes. Seismic data(local and CTBTO) was used as basis to forecast the occurrence of future earthquakes. Thirty buildings were sampled throughout the area and grouped into the different types according to European Macroseismic Scale (EMS-98) based on what was used for their...
Lack of in-depth seismic hazard studies (SHS) for West Africa (WA) has negatively impacted planning and disaster risk management. Using modern techniques for SHS, this study aims to address such challenges. WA’s earthquake catalogue was updated from various data sources including CTBTO. The seismotectonic setting of WA is assumed to be either, a stable continental crust or a shallow crustal...
NET-VISA has benefitted tremendously from the interaction between its developers and CTBT State Signatories experts. One way that this interaction has taken place is through the delivery of data sets processed with successively enhanced versions of the software, with feedback from the experts. We present the results of a full simulation of operational results conducted offline with a recent...
The Reviewed Event Bulletin (REB) of the IDC is the final product of interactive analysis, but also represents a set of seismic (S), infrasound (I), and SI events, which can be used for the analysis of the REB consistency. Continuous comparison of the event hypotheses obtained in routine automatic and interactive analysis with these historical events also helps to improve the REB completeness....
Indonesia Tsunami Early Warning System (InaTEWS) as National Tsunami Warning Centre (NTWC) and Tsunami Service Provider (TSP) for the Indian Ocean region countries, as well as ASEAN Earthquake Information Center (AEIC). In InaTEWS operational, BMKG is responsible for monitoring, analyzing, and disseminating earthquake information and tsunami early warning. Based on BMKG’s master Plan up to...
Researchers around the globe have been carrying out studies related to short-term earthquake predictions. The studies use various approaches of observation methods to find the early signs of anomalies, both physically or chemically changes before the occurrence of earthquakes, as known as precursors. One of the precursors is the emergence of total electron content (TEC) anomaly within the...
Xenon monitoring systems are a crucial component of the verification system of the CTBT. As part of the IMS, these systems are monitoring the atmosphere for potential xenon releases originating from nuclear explosions. The efficient adsorption and desorption of the xenon isotopes in adsorbent materials is essential for their detection.
Recent studies on xenon adsorption in porous materials...
Radioxenon measurements use the net-count method to determine the activity for the radioxenon isotopes of interest. Detected decay events are plotted on a beta-gamma coincidence histogram and events are tallied inside regions-of-interest specific to a given radioxenon isotope. The boundaries of these regions are based on both the resolution of the detector and the physics of the emitted...
Despite the prudent importance of monitoring weather and climatic trends, the cost of setting up weather monitoring experiments and devices prove to be costly and even with available costly solutions, they are without standardization rendering the data collected from them unusable for scientific enquiries or examinations. The objective of the work described in this paper is detail the...
The recently developed open source FREAR tool improves nuclear event analysis by using Bayesian inference principles to estimate key source term parameters using measurements from distant radionuclide monitoring equipment in combination with Atmospheric Transport and Dispersion Models (ATDM). Trials on real world reconstructions have demonstrated clear and dramatic improvements over...
This paper presents the results of extensive tests conducted for more than 4 years, towards the realization of a portable backpack systems for the measurement and identification of radioactive material and at the same time determine in real time, without the support from experts, presence of SNM isotopes: U, Pu-239, PuWG, UWG, Am-Be, Am-Li, or their combination with masking sources and...
Following the January 12, 2010 Mw 7 Haiti earthquake, the shaking intensity near the epicenter was overestimated and the spatial extent of the potentially damaging shaking was underestimated. This was due to the lack of seismometers in the near-source region at the time of the earthquake.
Besides seismic-waves, earthquakes generate infrasound, i.e., inaudible acoustic-waves in the...
On 12 January 2020, Taal Volcano (Philippines) had a strong phreatomagmatic eruption producing a 10-15 km ash column and ashfall reaching as far as Quezon City (~80 km). Taal is one of the most dangerous volcanoes known, with 34 eruptions since 1572, and eruptions being phreatic, phreatomagmatic, strombolian or plinian (e.g. 1954). Increased volcanic activity has been observed for a year but...
The materials relative to impulse source detection from SnT 2015, 2017 and 2019 were summarized using methods of maximal likelihood ratio according on information collected at the infrasonic IMS stations.
New criteria of infrasound IMS station efficiency were defined according on priority areas of network selection method control.
The present work reveals the influence of the signal...
The vast majority of International Monitoring System (IMS) seismic detections are associated with small events that are detected by only one station. Large numbers of small-event detections at each IMS station increases the probability of the International Data Centre (IDC) automatic system building false events. We test whether detections of small, repeating local events (e.g., mines) can be...
The coda magnitude method of Mayeda and Walter (1996) provides stable source spectra and moment magnitudes (Mw) for local to regional events from as few as one station that are virtually insensitive to source and path heterogeneity. The method allows for a consistent measure of Mw over a broad range of event sizes rather than relying on empirical magnitude relationships that attempt to tie...
This method allows us to determine the most reliable OSI area coordinates and the probability of the infrasound source occurrence by using the signal detection results, time of signal event and an azimuth of the signal according to information from IMS stations.
The method is based on the construction of the complex probability map and furthers its analysis according to CTBT OSI area limits....
Time-frequency distributions (TFDs) are useful tools for nonstationary signals analysis. Due to the presence of unwanted cross-terms, useful information extraction from TFDs has proven to be a challenging task, in particular when analysing noisy real-life signals.
One way to suppress the cross-terms is by employing compressive sensing methods that enforce sparsity in the resulting TFD. In...
The Baksan Neutrino Observatory of the Institute for Nuclear Research of the Russian Academy of Sciences is a unique engineering facility, which is a system of underground mine workings in the Andyrchi mountain massif (at a depth of 2 km from the surface and 4 km from mine enter) located twenty kilometers from the Elbrus volcano down the Baksan gorge in the Neutrino village. The unique...
One of the main noise-causing factors in precise long-period seismometry is temperature fluctuations of mechanical elements of devices and sensitive sensors, as well as temperature oscillations in their interior space. To reduce such noise level it is possible to apply adaptive filtering of seismic signal based on elements temperature acquisition. However, to date, this way it was not possible...
The worlds first radioxenon array was installed in Sweden during 2020-2021. The array consists of five so called SAUNA CUBE units, placed with 200 – 500 km inter-distance. Each CUBE unit has a measurement sensitivity for 12-hour samples comparable to the SAUNA II systems presently used in the IMS, but to a fraction of the cost. Array design, experiences from installation, and first months of...
An evaluation of several Hyperion 5313A infrasound sensors was performed in order to determine the length of time it takes for the sensors to thermally equilibrate under a variety of environmental conditions. The motivation for performing these tests was to aid in determining suitable procedures for station operators to follow when installing these sensors. Thermal equilibration occurs when...
CEA/DAM, in partnership with the startup Fullscale, has developed a compact board, targetted to easily integrate any equipment with accurate dating needs.
Based on GNSS reception to get an absolute time reference anywhere in the world, the Timing Board provides standard PPS signal and NMEA frames, and optionnally a stabilized 4 MHz clock. Its extra-small size and very low consumption (<40 mW)...
This report presents on the recent tsunami that hit coasts of the Indonesian Island of Central Sulawesi. Indonesia, due to its location has experienced numerous tsunamis in recent times. The 2004 Indian Ocean tsunami is one of the most devastating among them. The latest one on 28th September 2018, at 18:02:44 a strong tsunami accompanied an earthquake of Mw 7.5 and left the state of Central...
District of Cilacap is located on the southern coast of Java island, in the area near to the subduction zone between the Indo-Australian Plate and the Sunda plate which has high earthquake activity. One of the biggest tsunami events ever recorded in the past is the tsunami event known as the Pangandaran tsunami. The July 17, 2006 tsunami originated from the Mw 7.8 earthquake on Pangandaran...