Good 3D lithospheric velocity models are necessary for reliable epicentre determination. To test different models, we compiled a set of 17 Brazilian reference events, magnitudes 4.0 to 5.1. Only four were truly GT5 events. Most of the events had the epicenter assigned to the middle of the aftershock zone determined by aftershock studies, with origin times calculated with IASP91 table using...
CELESTIA-based Stereoscopic Live Visualization of the Global Challenges integrating monitoring of earthquakes, tsunamis, explosions or radioactive emissions tracked by CTBTO network with the live data stream coming from the Ground and Space-based Telescope Array to track high impact events like 2012 Ural meteor and/or more objects coming from asteroid belt like identified 2012 DA14, 2013 EC,...
On 15 February 2013 at 03h20 UT, a large Earth‐impacting fireball disintegrated over the Ural Mountains. The burning mass produced shock waves that blew out windows, injured hundreds of people and damaged buildings in many surrounding cities. Infrasonic waves generated by the explosion propagated over very long distances. The event was globally detected by 20 IMS infrasonic stations. For the...
To test the hypothesis that high quality 3D Earth models will produce seismic event locations that are more accurate and more precise than currently used 1D and 2.5D models, we are developing a global 3D P wave velocity model of the Earth’s crust and mantle using seismic tomography. In this paper, we present the most recent version of SALSA3D and demonstrate its ability to reduce mislocations...
Searching for radioactivity during On Site Inspection (OSI) is critical to verifying the Comprehensive Nuclear-Test-Ban Treaty. Myriad tools are under development or commercially available for supporting search, but suffer from inadequate user-ability and have closed and proprietary software/hardware architectures. For search during a CTBT OSI, the Lawrence Livermore National Laboratory has...
Ground-truth (GT) events, accurately located with a precision of 5 km (GT5 event) and associated travel times to regional stations are important in developing precise velocity models. The low Brazilian seismicity, with only three continental earthquakes of magnitude five in the last three decades, and the low number of seismic stations explain the difficulty to detect events at regional...
Information regarding the source of radionuclides detected in the atmosphere can be obtained by comparing the observed activity concentrations and their ratios to those expected from various types of sources. Nuclear explosions with various fuels as well as reactors and irradiation facilities all yield different inventories of radionuclides, and the signatures finally observed are also...
The infrasonic-seismic associated events are very important in the International Data Centre (IDC) bulletins, but about 85% automatically associated infrasonic-seismic events are false events at present. A new infrasound signal association method based on the seismic seed events from Standard Event Lists (SELs) or Late Event Bulletin (LEB) together with the background knowledge is proposed....
The experience of monitoring using 3D seismic array is discussed: devices, programming, data processing and geophysical results. The array was created for seismic monitoring purposes on Chirkey hydropower plant dam in Caucasus region, Russia. Chirkey dam is a reinforced concrete construction 235 m height built in seismic hazard region.
The aims are: 1) to control the stresses within the dam...
Network simulations have long been used to assess the performance of monitoring networks to detect events for such purposes as planning station deployments and assessing network resilience to station outages. Unfortunately, the tools used for these simulations are not widely available and are not based on modern software standards. For these reasons, we are developing and planning to openly...
A tool that shows connectivity between waveform events and radionuclide detections has been developed. CTBTO’s mission is to monitor compliance with the CTBT and to provide a set of independent data to the States Signatories to assist them in fulfilling their CTBT verification task. For this purpose, CTBTO operates networks of sensors to detect waveform signals and subsequently localize the...
A complete analysis of candidates for underground nuclear explosions detected in the IMS requires the combined use of seismic and radionuclide data, as well as atmospheric transport modelling (ATM). A new method performing such analysis automatically has been developed and tested at the Swedish NDC. The algorithm is implemented in a new pilot software called SEICON. The software calculates a...
We explore the utility of additional phases in the initial P-wave packet for a more-transportable source estimator as well as to gain diagnostic insights into the 2013 North Korea-declared nuclear test (NK3). The amplitudes and periods of the "Pa" phase (first zero-to-peak), the "Pb" phase (first peak-to-first trough) and the "max" cycle are measured, with the associated station mb(Pa),...
In recent years, numerous bolide sources have been detected by the IMS infrasound arrays. Even though waveform data can be extracted from recorded signals, only a few parameters are used throughout infrasound research. A majority of results are obtained by employing energy estimates that are based on semi-empirical relations which possess errors. The justification of such estimates is...
Lembang Seismological Station ( LEM ) is one of CTBTO’s stations network located in West Java, Indonesia. This station integrated in Indonesia Tsunami Early Warning System (InaTEWS) since June 2007 and have important role to analyze earthquake in West Java and surroundings area. Therefore, the quality of waveform is very important to localized the earthquake accurately. This research have...
Previous researches suggested that the velocity gradient of upper mantle, heterogeneities in the mantle lid and Moho topography may influence the amplitude of Pn. In order to show which should mainly account for abnormal variation of Pn amplitude, Pn waves of an earthquake occurred on southwest margin of Tarim Basin recorded by CHENGIS and KN network stations are employed, and the amplitude...
Event location is one of the main products of the CTBT verification regime. The first analysis step is to scan the time series at each station for the existence of relevant information and to determine when it arrived. The location and time of the generating event are estimated by solving an inverse problem based on the set of arrival times at the different stations. The location accuracy...
During an on-site inspection (OSI) for the Comprehensive Nuclear Test-Ban Treaty the hypocentre of a suspected nuclear explosion has to be located with a precision of approximately 0.1 km. One possibility is the setup of a local seismic network, the seismic aftershock monitoring system (SAMS), to detect aftershock events caused as a consequence of the explosion. These events show a very weak...
Earthquakes are the expression of the continuing evolution of the Earth planet and of the deformation of its crust and occur worldwide. Armenia lies in the central part of the Armenian Highland and is situated on the north of the collision boundary between the Arabian plate and theEurasian plate. This region is one of typical collision boundaries in the world. The Arabian plate is moving...
1- Legislation
-National Laws
-International Treaties, Agreements and Conventions
2- Co-operation with International Organizations
-OPCW, IAEA, CBRN of Excellent Center, and Partner Nations
3- National Training Programmer
-Military and civilian individual protective equipment
- Protection & assistance in event of incidents involving
Chemical-warfare agents and toxic industrial...
Geophysical methods see a broad range of uses and span a wide range of scales and technologies. While the fundamentals of the field are well understood, there is constant advancement and refinement of the techniques and methodologies.
Applied geophysics appears in support of many human endeavours. Historically, the most common use has been in oil and gas exploration closely followed by...
Large on-surface explosions were conducted by the Geophysical Institute of Israel at Sayarim: 82 tons of strong HE explosives in August 2009, and 10&100 tons of ANFO explosives in January 2011 (initiated and supported by the CTBTO). The main goal was to provide strong controlled sources in different wind conditions, for calibration of IMS infrasound stations. High-pressure gauges were deployed...
Though Albania is an earthquake prone country the first seismological stationdates in 1968. The local instrumental network was finalized in 1976 counting thirteen seismographic stations. It enabled systematic monitoring of the microearthquake activity in the country and led to the discovery of some characteristic features of the recent seismicity of Albania. Stations have been equipped with...
Ambient noise seismic tomography study is a new method that uses noise to depict the structure of the surface layer. The purpose of this research is to represent the thicknes of sediments in the area of east java and discover faults in east java. This study combined with data on regional gravity anomaly study, to compare the result from ambient noise tomography study. Ambient noise tomography...
Plutonium 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" finger prints" make it possible to determine the evidence of radionuclide contamination source reliably. In order to find out the Chernobyl accident influence,...
The field of time-frequency analysis provides a set of powerful tools for analyzing and processing nonstationary signals, i.e. signals with time-varying spectra. Majority of real-life signals are generally classified as nonstationary; some examples being acoustic signals, seismic signals, communication signals, etc. Time-frequency representations provide valuable information on the nature of...
An update on earthquake recurrence for the region has been presented with the aid of spatial distribution of seismicity and tectonic features utilizing earthquake data of 1808-2008. Nineteen seismogenic sources were delineated on the basis of certain seismological and geomorphological criteria for the estimation of repeat times of earthquakes to derive the predictive relations. These relations...
More than seven weeks after North Koreas third nuclear test conducted on February 12 2013, unique combinations of the xenon isotopes 131mXe and 133Xe were detected at the IMS stations JPX38 in Japan and RUX58 in Russia within five days of each other. The consistent and coherent picture obtained from isotopic ratios in combination with station history and atmospheric transport modeling...
ABSTRACT ANALYSIS OF (TEC) TOTAL ELECTRON CONTENT VARIATION RELATED WITH LARGE EARTHQUAKES IN SUMATRA-INDONESIA By : ( Hendri Subakti , Indonesia) Satellite enables to measure the number of Total Electron Content (TEC). It exists along ionosphere between the signal beam and GPS receiver. The calculation of TEC differential ( dTEC ) and slant TEC use the Sumatra GPS Array network data. It is...
Todays increased computing power of even a simple desktop computer makes it feasible to routinely use new methods for analysing or detecting transient seismic signals. Here we compare time-frequency representations of surface waves using the Wigner-Ville distribution (WVD) with other typically employed methods, such as the multiple filtering technique (MFT) used to measure group velocities....
Earthquake that struck Jogjakarta on May 27th 2006 (lokal time) gives negative impact to life and it became of no awareness disaster. Previously, there are many researches that developed a system which can give signal to earthquake pre-detection. One of them is Seismo-Ionosperic Coupling. This research, explain phases in Ionospere before and after shock. Electron densities in vertical...
ANGLE software for semiconductor detector efficiency calculations (angle.dlabac.com) has been in use for 19 years now in numerous gamma spectrometry analytical laboratories all around the world. It allows for the accurate determination of the activities of gamma spectroscopic samples for which no "replicate" standard exists, in terms of geometry and matrix.
ANGLE is characterized by (1)...
There is little experience with application of electrical and active seismic methods that can be applied during the continuation period of an on-site inspection (OSI), one of the verification methods of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Controlled source audiomagnetotelluric (CSAMT), dipole-dipole resistivity, and induced polarization electrical measurements were carried out...
Thirty-five VLF-EM profiles, 140 VES and relevant hydrogeological data were acquired along regular grids/profiles for detailed terrain/subsurface mapping of Ijebu-Ode which is situated within a problematic transition zone, between the Precambrian Basement rocks and Cretaceous sediments of Dahomey Basin, in southwestern Nigeria, where unique geological structures, complex coexistence of...
We first present location results using the RTM method (Reverse Time Migration, e.g. Walker et al., 2011) applied to explosion events listed in the TAIRED catalogue (TA Infrasound Reference Event Database), recorded by the USArray. We compare our results to the TAIRED solutions (http://www.iris.edu/spud/infrasoundevent). Good agreements between both solutions are found. In a second stage, we...
Single and multiple seismic array stations can provide an exquisitely sensitive monitoring capability for nuclear test sites which exceeds significantly that for general seismicity using standard algorithms. We here outline some methods for enhanced seismic monitoring employed at NORSAR. A detection on a single array with parameters consistent with a signal anticipated from a given site can...
There is a growing concern about the potential for destructive earthquakes caused by human activity.
Studies of seismicity related to impoundment of reservoirs, injection of fluids in a well, withdrawal of
fluids and mining activity, all bear evidence to the presence of critically stressed rocks in the earth’s
crust, where in small stress changes, induced by human activity, trigger...
As part of its mandate, the CTBTO’s nuclear explosion monitoring programme aims to maintain its sustainability and long-term effectiveness for the verification regime. The Technology Foresight Programme aims to identify and review potential future technologies, which is also consistent with the aims of the Science and Technology conference series. As part of the Foresight activities, a...
Monitoring radioactive gases and particulates is a vital component in arms control and nonproliferation treaty verification. The International Monitoring System (IMS) established in the CTBT specifies 80 radionuclide monitoring stations located around the world. While the official stations cover vast tracts of the world, there are large sections of the globe that have not been surveyed for...
In the framework of the International Noble Gas Experiment (INGE), a field measurement campaigns is being carried out in Kuwait Institute for Scientific Research (KISR) to establish the radioxenon baseline data for the Gulf region and to provide assessment in establishing ambient air global noble gas monitoring system of Comprehensive Nuclear Test Ban Treaty Organization (CTBTO). The CTBTO...
ARISE proposes to design a new infrastructure that integrates different station networks in order to provide a new "3D" image of the atmospheric dynamics from the ground up to the mesosphere with unprecedented spatio-temporal resolution. These networks are: - the International infrasound network developed for the verification of the Comprehensive nuclear Test Ban Treaty (CTBT). This system is...
The location of the noble gas station AUX09 in Darwin is particular in its position relative to the seasonally oscillating position of the Inter Tropical Convergence Zone (ITCZ). Darwin is located in the Southern Hemisphere but is influenced by the Australian-Indonesian Monsoon with advection of northern air masses during the Australian Summer (wet season). It is affected by south-easterly...
The International Monitoring System (IMS) developed by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is a global system of monitoring stations, using four complementary technologies: seismic, hydroacoustic, infrasound and radionuclide. Data from all IMS stations are collected and transmitted to the International Data Centre (IDC) in Vienna, Austria. The radionuclide network...
Bangladesh is located in a seismically active region close to the plate boundary between the northward moving Indian plate and the Eurasian plate. Historically Bangladesh has been affected by six earthquakes of large magnitude, 7.0 (Richter) or greater, within the last 250 years. Three of them had their epicentres within the country. In the absence of seismic instrumentation, strong motion...
For both operational daily information on expected radioactive xenon background levels and the fast evaluation of possible sources for real detections at DEX33, an automatically running ATM forecasting and backtracking system is set up at the German NDC (BGR, Hannover) in close cooperation with Federal Office for Radiation Protection (BfS, Freiburg). The station operator and radionuclide...
Aftershock sequences following large earthquakes create problems for data centers attempting to produce near real-time event bulletins. The greatly increased number of events requiring processing can overwhelm analyst resources, reducing the capacity for examining events of monitoring interest. Waveform-correlation methods have shown promise for automatically identifying groups of events...
The French NDC operates a network of 40 seismic stations in France. A major part of the events located in the English Channel concern submarine explosions, most of them being conducted by French Navy. The clear identification of earthquakes is important to understand the tectonic of this region. We developed a method to identify marine explosion. Underwater explosions generate a gas bubble...
The reliable, automatic detection of low-SNR seismic events is not yet feasible without a large amount of false-positive detections, i.e., false alarms. This applies especially to temporal local networks with exposed seismic stations and a-priori unknown noise conditions and event signatures, as in an OSI seismic aftershock monitoring. To overcome this problem, we use a multi-path approach. As...
The calibration of seismic sensors is a fundamental step in the implementation, the monitoring and the maintenance of seismic stations. The technique of removing a step of current from their signal coil is one of the most used with geophones. However, in some particular circumstances, where the probe is directly placed on the ground surface, a high level of background seismic noise can alter...
Earthquake was frequently occurred in Aceh and in some cases with tsunami potentially. In this research we identify earthquake with tsunami potential. The purpose of this study to analyze the shape and location of ocean bottom earthquake source to observe the pattern of tsunami wave propagation by means of the cross section area bathymetry maps of the study. The research method used well and...
At regional distance, the assessment of the source time function of moderate magnitude events is often a difficult task due to bad knowledge of the Source-station seismic Green’s function. Several studies have already demonstrated the capability of the regional coda wavefield to provide valuable information on the seismic source. Nevertheless, all the current methods are based on the use of...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) obliges each State Party to undertake not to carry out any nuclear weapon nuclear explosion or participate in the carrying out of such. States Parties undertake to cooperate for facilitating the verification of compliance with this Treaty. The verification regime of the CTBT uses cutting-edge technologies and scientific methods to monitor...
CTBTO noble gas system has been introduced to the provisional operations since 2011 and the data analysis system was upgraded in 2012 to accommodate also categorization of the results. Basic categorization scheme has three levels: Level A: no radioxenon detected, Level B: radioxenon detected and concentration is typical for the station, Level C: radioxenon detected and the detection is not...
Celerity vs. range models can be used for the association of infrasound automatic detections, for event location and for the validation of acoustic propagation simulations. Signals recorded from ground truth events are used to establish celerity vs. range models, but data coverage is uneven in both space and time. To achieve a high density of regional recordings we use data from USArray...
The April 11, 2012 Sumatra Earthquake, has very large magnitude Mw = 8.6 and allegedly caused huge tsunamis but the reality is very low only H = 0.3 m. We categorize this incident as an outer-rise earthquake and depth = 40 km. The calculation of source parameters using the teleseismic wave characterized as the tsunamigenic earthquake withseismic moment Mo = 6.3E+21 Nm, seismic energy E =...
Since July 1991 s.d. April 2012 has occurred 27 earthquakes generated tsunami with magnitude Mw > 6.5. The aim of this study is to characterize these events based on the ratio (Q) between seismic waves radiated energy (E) and seismic moment (Mo), source duration (To), tsunami height (H), focal mechanism of focus and the depth. The authors obtain the vertical component broadband seismometers...
Medical isotope production facilities constitute a serious challenge to the interpretation of xenon isotopic information collected by the International Monitoring System (IMS) and analyzed by the International Data Centre (IDC). The monitoring community has grown to understand much about the size, temporal character, and isotopic composition of medical isotope xenon from several well-known...
The Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler short period seismic stations.
The Zentralanstalt für Metereologie...
It has been recognized that ambient radio-xenon activity concentration monitoring could be used for the purpose of identifying the nuclear nature of an explosion. Therefor four detection systems have developed to monitor ambient radio-xenon which three of them have worked based on beta-gamma coincidence method. A Monte Carlo code FLUKA was used to model geometry of ARSA, SAUNA and ARIX...
CTBTO runs FLEXPART operationally on a daily basis in backwards mode to estimate sources of aerosols and noble gases detected at over 80 stations distributed throughout the world. For simplicity, these runs are performed under the assumption of no convective or depositing processes. With the acquisition of enhanced computing resources, it is now possible to consider runs of higher complexity....
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) has remote radionuclide monitoring followed by an On-Site Inspection (OSI) to clarify the nature of a suspect event as part of its verification regime. An important aspect of radionuclide measurements on site is the discrimination of other potential sources of similar radionuclides such as reactor accidents or medical isotope production. The...
This study shows that the observations of infrasound signals from the third underground nuclear test carried out by North Korea on 12 February 2013. The infrasound signals generated from their test site were detected by South Korea’s infrasound network operated by KIGAM as well as the two nearby IMS infrasound stations, IS45 and IS30. Compared with detection results of the second test in 2009,...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a network of certified laboratories that perform high-resolution gamma-spectrometry on global air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), the use of advanced Compton suppressed systems has been investigated to reduce the Compton continuum and improve detection...
Teleseismic observations from the International Monitoring System’s (IMS) global seismic network provide complementary information to national and regional earthquake monitoring. Standard Event Lists (SEL1-3) from the International Data Centre (IDC) provide automatic short term feedback on significant events observed globally, while Reviewed Event Bulletins (REB) provide comprehensive global...
ARISE (Atmospheric dynamics Research Infrastructure in Europe) project seeks to improve the understanding of the dynamics of the atmosphere using complementary sounding methods (infrasound, LIDAR and airglow measurements). The project involves more than 40 institutes, including the CTBTO which is the main provider of infrasound data and Toulouse Volcanic Ash Advisory Centre (VAAC) which is...
Kazakhstan, the Kyrgyz Republic and Norway have for a number of years cooperated on a program in the area of capacity building for verification of compliance with the Comprehensive Nuclear-Test-Ban Treaty, on the basis of financial support from the Norwegian Ministry of Foreign Affairs. The cooperating institutions are the Institute of Geophysical Research (IGR) of the National Nuclear Center...
The Civil and Scientific uses of CTBT Data and Products in Comoros is a reality considering Natural Hazards and Catastrophes related to the "Karthala" volcano activities in Comoros, which for some year’s eruptions, brought important releases of ashes and gases. The oceanic aspect is also affected by the fact that the 2004 Indonesian Tsunami is recorded with up to 6.7 run ups in several coastal...
The Infrasound Technology Roadmap (ITR) projects existing technological accomplishments into near-future technical targets that can sustain the CTBTO’s effectiveness and relevance to the verification regime. The ITR has a time horizon of seven years, and its activities are closely aligned to the Provisional Technical Secretariat’s Technology Foresight Program, which extends its perspective to...
Seismic data, is naturally a non-stasionary signals that have different frequencies and in the form of time. Non-stasionary signal is the seismic waves generated by elastic disturbances that propagate from one city to another, in a medium, namely the earth. Characteristics of seismic data needs to be researched and analyzed for parameters of tectonic eartquake which arrival time determination...
For the years, seismic geophone production technology has monopolized to industrial countries and
developing countries were less engaged in this field. Recent scientific researches and extending of
exploration seismology in developing countries has persuade them to work on this important filed of
instrumental seismology as a base of safe and low cost instrument production.
As our case,...
The Egyptian National data center is an organization working with the treaty verification as integrated part of the Egyptian National authority with technical Expertise in the monitoring technologies. One of the main NDCS rule is the comparison between the seismological bulletins of both International Data Center (IDC) and local networks, to measure the capability of IDC to detect the local...
Signals from the announced nuclear test in North Korea on February 12, 2013, were routinely detected and rapidly identified by the Norwegian National Data Center using both a site-specific alert algorithm and using multi-channel correlation detectors on several IMS seismic arrays with signals from both the 2006 and 2009 DPRK events as waveform templates. Using data from IMS seismic stations...
In 1957, international geophysical year, very first seismic station was installed in Mongolia and seismic monitoring started from this year. The Mongolia is seismically active region and generally, seismic activity of Mongolia is associated with the deformation induced by the collision between India and Eurasia. Several strong earthquakes took place in Mongolia last century. The Mongolian...
Plostina infrasound station (IPLOR) is a 6-element array, with 2.5 km aperture. Since January 2013, all IPLOR instruments are Chaparral Physics microphones. Additionally, six 3C BB seismic sensors, three electrometers and three 3C fluxgate sensors are collocated with the infrasonic instruments. A weather station is installed at the central element (IPH4). Seismo-acoustic data and information...
The Pacific Northwest National Laboratory (PNNL), the Comprehensive Test-Ban-Treaty Organization (CTBTO) and willing local partners have made a series of measurements in a number of regions to better understand radioactive xenon measurements in hopes of improving discrimination of background sources and potential nuclear explosions. A measurement campaign was conducted in Northern Japan with...
National Superconducting Cyclotron Laboratory (NSCL) is a world-leading center in rare isotope research and education. The NSCL mission is to understand the atomic nucleus and the experimental program encompasses a wide variety of techniques related to charged particle, photon, and mass spectroscopy of radioactive isotopes. A sustained research and development effort toward future detector...
Zarqa governorate is one of the important governorates in Jordan. It is the second populated after the capital Amman,the location of Zarqa gives it a great importance because it lies on the main high ways leading to Syria, Iraq and Saudi Arabia, most of Jordan's industries, power plants and strategic projects are located in Zarqa, which gives it a special importance. The Nakamura's technique...
Local, regional and global research of the Earth’s interior is the oldest goal of seismology. Seismic networks are and will be probably forever the only tool that enables study of the detailed structure and physical properties of the Earth. The inherent error in regional and global networks are as high that can’t give accuracy to determine the exact trend and depth of seismic sources and...
Existing radioxenon detectors for nuclear explosion monitoring typically use either scintillator based beta/gamma coincidence detectors or germanium based gamma only detectors. Silicon detectors have a number of potential advantages (high resolution, low background, sensitivity to both photons and electrons, and no memory effect) and have been shown previously to be a possible alternative to...
The authors of research propose development of a new effective method for locating a nuclear test by using tritium. The objects of the study were in the test area (wells, tunnels), as well as epicenter of surface and excavation explosions of the Semepalatinsk Test Site.
At each object was carried out tritium distribution through ecosystem elements - surface and groundwater, air, snow,...
During an infrasound field campaign clear infrasound signals were observed on 16 February 2012. Media reports suggested a gas explosion source in Luxemburg, but an inquiry with the Federal Armed Forces (Bundeswehr) Airforce Information Center confirmed a supersonic flight at approximately the same time and in the same region. This case thus provides the opportunity of identifying the true...
Inverse modeling, also known as data assimilation, provides effective tools for reconstruction of a nuclear accident by the means of combining measured data with a numerical simulation of the accident. Application of advanced methods based on repetitive evaluation of the model, e.g. Monte Carlo methods, requires high computational power. This need becomes even more urgent when real-time...
Remote yield estimation of the underground nuclear explosions is possible by the inspection of different seismic phases. The most important seismic parameters are the amplitude, body wave and surface wave magnitudes. Therefore, to estimate the yield of the DPRK explosion (Feb 12, 2013), we need to find the necessary relationships. In Iran, near to 85 stations from the Iranian Seismological...
The Korean Peninsula is located in the far-eastern
Eurasia plate, and belongs to intraplate seismicity
regime with low seismicity. The instrumental seismicity
is scattered over the peninsula, with relatively high
seismicity at paleo-tectonic regions that are associated
with paleo-rifting and paleo-collision. The paleo-rifting
is responsible for the separation of Japanese...
The atmosphere is a complex system submitted to disturbances in a wide range of scales, including high frequency sources as earthquakes, volcanoes, thunderstorms, tornadoes, explosions and at larger scales, gravity waves from deep convection or wind over mountains, atmospheric tides and planetary waves. All these waves propagate in the different atmospheric layers submitted to different...
Receiver function technique is applied to evaluate the Moho depth and Vp/Vs ratio on the territory of Bulgaria. Bulgarian National Seismological Network (BNSN) is equipped with broad-band seismometers and digital acquisition systems. It enables application of modern techniques of analysis of the velocity structure in Bulgaria. The method was applied to eleven stations of BNSN.
The obtained...
Recommends using first motion of P-wave for filtration of phenomena. Positive shifts should be observed in first arrivals of longitudinal waves in all directions from an explosion. Our practical observations showed that it is not always possible to discriminate an explosion using these criteria. In some cases on the seismograms of the same explosion obtained in different azimuths from an...
A total number of 250 earthquakes recorded by more than 5 stations from Egyptian seismic network around the Gulf of Suez were relocated and the seismic stations correction for P-wave is estimated using joint hypocenter determination method. Five stations TR1, SHR, GRB, ZAF and ZET have minus signs in station P-wave travel time corrections and their values -0.235, -0.366, -0.288, -0.366 and...
Analytical simulation methods help us to understand real behavior of earthquake physics and nature which can give us some measurable parameters to discriminate earthquakes, to make realistic hazard plans and to create reliable data bank of earth motion synthetic record, where true data is not available. In order to enable reliable estimation of the ground motion response to an earthquake, 3D...
Reliable source mechanism estimates for small-to-medium sized seismic sources are important for monitoring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). For sources located in regions where there are no dense local networks of seismic stations, often there are only a small number of stations recording surface and body wave signals with high signal-to-noise ratios. To obtain...
Measurement of noble gases started in 2011 at the ENEA Italian Laboratory for Environmental and Anthropic Monitoring Measurements and within the framework of the CTBT and the NDC related activities carried out at the laboratory. The present status of the noble gases gamma spectroscopy analysis system will be presented. A completely dedicated HPGe detector has been used: it is a p-type extended...
In this study, we purposed first elastic and anelastic structure of the lithosphere and asthenosphere of the Iranian Plateau is derived by means of tomographic techniques applied to local phase, group velocities and local attenuation coefficients of Rayleigh wave fundamental mode. We used commonly known as Hedgehog nonlinear inversion method to evaluate of the velocity structure. We improved...
The law of conservation of energy states that, energy can neither be created nor be destroyed i.e., energy accumulation at any specified point of time and space is at the cost of energy loss at other points or point keeping the net energy of an ecosystem constant. Means of detecting the energy quantum between tectonic plates can be explored to possibly estimate the total energy quantum and in...
The Environmental Sciences are approaching an important crossroad for understanding complex processes such as Climate Change, Earth's interior and its heat budget, global geodynamic processes. The phenomenological study needs a comprehensive characterization for connecting past-present processes, which can be performed only through time-space markers such as radionuclides. The numerical...
Radionuclide station of CTBTO IMS network RN38 located in Takasaka, at closest distance from Fukushima. The highest values of radioactivity were measured on March, 15-16. Thus, the specific activity of short-lived Iodine-135 (half-life period = 6,6 hour) reached value of 370 Bq/m3, and the ration of Iodine-135/Iodine-131 activities reached value of 23 that pointed to arrival of "fresh" fission...
Quality factor of seismic waves (Q), is one of the important parameters to explain attenuation of seismic waves. By calculating the quality factor in each area we can understand the rate of seismic activity in the region. This quantity has many applications in determination other earthquake parameters, such as moment and magnitude.. According to these applications and the existence of high...
In this study, recordings of free oscillation were made directly on 18 structures in Aqaba, which represent the structural culture of the city. Ground ambient vibration records were conducted at 18 nearby location of each structure. Records were conducted during the cultural activities using three-component seismometer of 2 Hz. Analytical results of structural records, has given the following...
The IMS primary seismic network consists of 50 monitoring facilities where several certified stations are facing equipment obsolescence issues. The search for engineering solutions to replace obsolete hardware components is guided by two primary goals: 1) be compliant with IMS minimum technical requirements and 2) be able to be integrated with the existing system.
In context of technical...
Atmospheric concentrations of radioxenons 135Xe, 133mXe, 133Xe and 131mXe can be used to discriminate between civilian releases and nuclear explosion sources. It is based on the isotopic activity ratio method. It is not clear whether subsurface migration of radioxenons, with eventual release into the atmosphere, can affect the activity ratios due to fractionation. Fractionation can be caused...
The Infrasound Station IS48, in Kesra, Tunisia is part of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty. IS48 was installed in 2006 and is managed and maintained by the Tunisian NDC. Since 2006, the NDC-TN staff has gained and acquired a good experience in the operations and activities related to the station. In addition to that, the good location of IS48 in the middle...
We have performed a comparative analysis of three announced DPRK underground tests using data from International Monitoring System (IMS), including the fusion of seismic and infrasound technologies. Unique similarity between the 2009 and 2013 year waveforms and spectra allows making strong conclusions about the similarity of the source mechanism and the conditions of conduction: depth of...
The decreasing cost of storage and computation power invites new methods of seismic data processing. We use a research database containing tens of millions of waveforms to explore the power of seismic correlation to quantify signal similarities, to discover new events not in catalogs, and to more accurately locate events and identify source types. Building on the very efficient methodologies...
In the afternoon of 25th of August 2012 five strong-motion stations located in Vienna and four broadband stations of the Austrian Seismic Network registered a shock, which occurred due to the detonation of an aircraft bomb from the Second World War. As well 13 stations of the Czech Seismic Network including the auxiliary seismic IMS station VRAC recorded the event. Independent locations were...
The Commission operates a collection of software that processes Seismic, Hydroacoustic and Infrasonic (S/H/I) waveform data, measured at detector stations around the globe. Establishing a National Data Centre (NDC) aids a Member State in assuming its role under the Treaty as it helps to obtain, examine and analyse monitoring data and analysis reports provided by the CTBTO International Data...
Waveform correlation techniques are of great interest for nuclear explosion monitoring because they provide a robust means to significantly lower detection thresholds while maintaining acceptably low false alarm rates. In previous work, using our research group’s distributed computing system, we have demonstrated the ability to monitor 3 years of seismicity in central Asia using our waveform...
KNDC (Kazakh National Data Center) acquires and processes data from seismic and infrasound stations located on the territory of Kazakhstan and adjacent Central Asia countries. At the present time, KNDC receives data from three infrasound arrays - IS31, IS46 and Kurchatov. The new infrasound array Kurchatov, North-East Kazakhstan, was installed on December 2010; IS46 Zalesovo infrasound array...
The Fukushima Reactor accident generated a large data set of global radionuclide observations. The frequent observations of xenon, cesium and iodine isotopes provided an opportunity to examine the performance of atmospheric transport and dispersion models driven by numerical weather prediction models, in particular, the important mechanisms of in-cloud scavenging, precipitation, deposition and...
Medical isotope production has recently been identified as a source of radioxenon in the atmosphere which can pose a potential problem for the International Monitoring System. The quantity of xenon released and the xenon isotopic ratios observed are variable between facilities and also within a facility. The reasons for the differences can be understood with knowledge of the fundamental...
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is supported by a network of certified laboratories that perform high-resolution gamma-spectrometry on global air filter samples for the identification of 85 radionuclides. At the UK CTBT Radionuclide Laboratory (GBL15), a novel cosmic veto gamma-spectrometer has been developed to improve the sensitivity of measurements for treaty compliance....
The CEA Roselend Underground Laboratory near Mont Blanc is a well instrumented facility for evaluating the transport of gases from depth across a highly fractured regime to the surface. At its deepest, the laboratory is 55 m beneath the surface and contains a sealed cavity for gas release experiments. The laboratory allows field scale studies of some aspects of the effect of transport on the...
Precise geoid determination is one of the main current geodetic interests in Egypt. The method of Least-squares collocation (LSC) is used in this research for the computation of geoid in Egypt, combining a geopotentail model complete to degree and order 360 in addition to gravity and GPS/leveling data. No topographic information was taken into account on the area under study.
The threat of earthquakes has compelled the Government of Ghana to fund the purchase and installation of Digital Seismic Network to replace the defunct analogue seismic network. The six remote Libra VSat seismic network is now transmitting the various levels of earthquakes and their frequencies of occurrence successfuly. The software programmes installed gives automatic location and magnitude...
During the Launch phase of the OSI, immediately initiated after Inspection Request has been received, core Inspection Team will need to develop an Initial Inspection Plan and, a need of appropriate tool with access to necessary map libraries represents an essential part of the GIS solution.
Data collected during the Inspection Phase of the OSI, using all 17 different techniques as listed in...
Seismic monitoring of the Comprehensive Nuclear-Test-Ban Treaty requires a uniform coverage of the earth. The global use of waveform cross correlation for monitoring purposes is hindered by the absence of master events outside the zones of seismic activity. To populate the aseismic areas we have studied two principal approaches. Around the seismically active areas, we replicate real events...
Infrasonic microbarom signals are attributed to the nonlinear resonant interaction of ocean surface waves. IMS stations around the globe routinely detect these microbaroms with a dominant frequency of ~0.2 Hz from regions of marine storminess and in the wake of tropical storms. We have produced the predicted global microbarom source field for 2000-2010 from the WAVEWATCH III spectral wave...
We develop a global-scale P-wave velocity model designed to accurately predict seismic travel times at regional and teleseismic distances simultaneously. The model provides a new image of Earth’s interior, but the underlying practical purpose of the model is to provide enhanced seismic event location capabilities. The LLNL-G3Dv3 model is based on ~2.8 million P and Pn arrivals that are...
Geographically, Research Areas Located between Coordinates 7ºS to 7ºN and 92ºE to 107ºE. Free Air Anomaly (FAA) and topography data are Used Retrieved from Global Marine Gravity from Geosat and ERS-1 altimetry and Global seafloor Topography from Satellite altimetry and Ship Depth Soundings. It is use amount of 1 '(1 minute) Latitude and Longitude or the sum of 1.85 Km for acquisition as a...
We present the empirical scaling relationships for the high-frequency ground motion in northern Egypt. Regression is carried out on more than 650 short period vertical seismograms recorded by the Egyptian National Seismographic Network,with Mw from 2.6 to 4.08 and hypocentral distance up to 550 km. The peak ground velocities are measured in selected narrow-frequency bands between 1.0 and 12.0...
The sea bed below the Danish territorial waters is still littered with unexploded mines from World War II. As the mines still pose a potential threat to fishery and other marine activities, the Danish Navy searches for the mines and destroy them by detonation, where they are found. The largest mines destroyed in 2012 are equivalent to 800 kg TNT each. The Geological Survey receives...
The International Data Centre (IDC) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) will ultimately process 170 seismic stations for the purpose of monitoring underground nuclear explosions. However, for most of events with lower magnitude, only sparse network or several stations are able to contribute on monitoring, meanwhile the location uncertainty will be quite large. The...
Five large chemical explosions with well-known parameters which can be used for calibration of regional seismic networks in the Central Asia have been conducted in the territory of Kyrgyzstan. These are three powerful industrial explosions in the Toktogul area: "Burlykiya" (February, 8th, 1975, Yield 702 tons), "Uchterek" (June, 11th, 1989, Yield 1623 tons) and recent double explosion...
The efficiency of cross-correlation (CC) and master event technique in CTBT global monitoring was presented at (Bobrov, 2012), (Kitov, 2013). The main CTBT monitoring goal is successful detection and location of clandestine nuclear explosions, so the CC global monitoring should be focused on extraction of such events first of all. As shown in (Bobrov, 2012), using adequate master may increase...
The rapid recent expansion of broadband seismic networks around the world has paved the way for a new generation of tomographic models of the Earth. These models will yield high resolution — previously achievable only in small-scale regional studies — at large, continental scales, advancing our understanding of the structure and dynamics of the Earth’s tectonic plates. Importantly, they will...
Radioxenon background can be locally complex, and may be due to the contribution of local and distant sources. This study also shows that seasonal variability of the global circulation can affect drastically the local nature of the background. By comparing IMS noble gas stations detections and calculated radioxenon background, it can be highlighted inconsistencies indicating that a local...
This presentation addresses the history of the CTBT hydroacoustic network, from its broad definition during negotiations of the Treaty through its early implementation by Provisional Technical Secretariat. It is based on the experience of the presenter during the negotiations of the CTBT (as chairman of the working group on hydroacoustic monitoring) and in the early days of the PTS (as chief...
Radionuclides in the environment are often observed in particulate form. This aerosol material collected in an air filter will contain a multitude of particles, both ambient particles and particles that contain radioactive material. The amount of radioactivity in each hot particle is a function of its method of formation. Different types of nuclear explosions will create a different particle...
Paragraph 81 of the draft IDC Operational Manual states that "… Events … located in an earlier Standard Event List [SEL] give rise to requests for auxiliary seismic station data, whose aim is to confirm the validity of events and to improve the location estimates. …" We investigate the extent to which the second aim is achieved in current IDC automatic processing. This is assessed from the...
The traditional approach to building an automatic global seismic event list requires that signals detected at different stations, and which belong to the same event, be 'associated’; this is an essential prelude to event location. Invalid signal detections and erroneous associations degrade the validity of many events, perhaps creating massive location errors or fictitious events built from...
It was noted on 11 January 2012 at 01:36;57 a.m - WIB had already happened a shallow tectonic earthquake with epicenter located 2.41 NL, 93.09 EL, precisely 358 South West of Simeuleu-Nias, North Sumatra Province with its Magnitude moment (Mw) : 7.2, with 10 km depth. In the Simeuleu earthquake with Magnitude moment (Mw) : 7.2, we had already estimated its seismic moment in the earthquake...
The great 2011 Tohoku Earthquake (Mw 9.0) occurred offshore of the east coast of Honshu, Japan on 11 March 2011, and strong T-waves generated by the event are recorded in the Hawaii hydroacoustic array operated by International Monitoring System. We examine the back-azimuths of the signals and spectral contents of the T-waves, and we compare them with the rupture models estimated from previous...
A Large earthquake occurred on September 2,2009 at 02:55 local time with a magnitude 7.0 (Mw). BMKG published that the epicenter is located at 8.24S 107.32E and depth 30 km.The source mechanism is thrusting faulting, where the strike direction perpendicular to the trench, raises doubts whether the earthquake is an intraplate or interplate. In this study, we relocate the hypocenter of...
Today, we are in a time of unprecedented change and opportunity in technology and its application to solve real problems. Using information and opinion collected from a variety of sources, an overview of general trends in the Information and Communications Technology world will be presented, with particular reference to large scale data processing and storage and the development of...
The first atmospheric event built only from infrasound arrivals was reported in the Reviewed Event Bulletin (REB) of the International Data Centre (IDC) of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) in 2003. In the last decade, 45 infrasound stations from the International Monitoring System (IMS) have been installed and are transmitting data to the IDC. In early 2010 the...
The International Data Centre (IDC) of the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) automatically processes infrasound data later reviewed by interactive analysis; the detected and located events are being systematically included in IDC products. The IDC works on enhancing the automatic system for the identification of valid signals and the optimization of the network...
The algorithm put forward in this paper is designed for devices that provide ultrashort warning of earthquakes. It is based on the time difference between the arrivals of P and S waves. The difference is small, but rapid identification of a P wave arrival from a large earthquake is useful for mitigating the impact of such an earthquake, in particular, human losses. The method we propose is...
The main purpose of this research is to investigate characteristic of Ultra Low Frequency (ULF) and Very Low Frequency (VLF) pre-seismic signal based on Z/H and resultant spectra ratio. In this method, we analyzed seismic signal and noise before the 2 September 2009 Tasikmalaya earthquake and their aftershock. Then we compared all results to finds the similarities and differences. We have...
The archive of automated and reviewed event solutions residing at the International Data Center (IDC) is a valuable resource for improving the performance of event formation algorithms. Here, logistic regression is used to identify a set of event-centric (explanatory) variables for determining the validity of automated event solutions. The resulting logistic model computes the conditional...
This study analyzes the potential impact of cyber attacks on the verification regime prior to the execution of an illegal nuclear test activity. In this matter, attacks on the availability of measurement stations by jamming their satellite up-links, namely the Very Small Aperture Terminals (VSATs), are relevant. The rationale is that any entity that wants to perform an illegal test activity...
There are currently three ongoing efforts to use Silicon PIN diodes as the beta detectors in beta-gamma systems used for radioxenon measurements [1,2,3]. The high resolution that these detectors have demonstrated for conversion electron have shown that they can significantly reduce the minimum-detectable-concentrations for the two meta-stable isotopes 131mXe and 133mXe. Additional physics...
Air concentrations of particulate radioisotopes are strongly influenced by wet deposition. Therefore the impact of precipitation should generally being included for atmospheric transport modeling applied in the CTBT verification context. Switching on the existing parameterizations for wet deposition in Lagrangian particle dispersion models leads to a more complete representation of involved...
The Centro di Ricerche Sismologiche (CRS, Seismological Research Center) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy...
The availability of power and internet affects the ability of National Data Centres (NDCs) to carry out their verification activities, including the accessing of IMS data and IDC products. Frequent, unscheduled power cuts and poor internet connection are some of the major constraints we face as we thrive to meet the 98% data availability and fulfilling our verification for our seismic station....
The International Monitoring System (IMS) is to consist of 321 monitoring facilities, composed of four different technologies with a variety of designs and equipment types, deployed in a range of environments around the globe. Despite this, the network is expected to reach extremely high levels of data availability which could induce unbearable Logistics Support costs. The IMS is now already...
Noble gases are a key indicator if an explosion was nuclear in nature or not and since World War II the short-lived radioxenon noble gases have been used to detect nuclear activities. In the last 10-15 years with the construction of the International Monitoring System (IMS), the measuring technologies and sensitivities have improved significantly. The sensitivity of the noble gas network is...
We collected the Global Positioning System (GPS) data available in the International GNSS Service database for the days corresponding to two of the U.S. underground nuclear tests that is the Hunters Trophy and Divider, carried out in 1992 at the Nevada Test Site (NTS) and Yucca Flat, respectively. Each total electron content (TEC) of all possible ray paths between the GPS stations and the...
Among one of the most fascinating sea creatures, the blue whale holds a special place. The largest ever living animal, it has been recognized that they can be tracked remotely at large distances at sea using fixed and moored hydrophones. The frequency range (30-100Hz) of their acoustic calls falls within the range of the IMS hydroacoustic stations and it is thus theoretically possible to track...
Ukrainian experimental infrasound network consist of two small aperture infrasound arrays. All array has 3-4 elements and equipped by micro barometers K-304-A type and have aperture around 130-150 m.
Traditional CTBTO data processing using the 20 Hz simple rate and frequency band about 0.02 .. 4.0(8.0) Hz. In the Ukrainian infrasound arrays uses data with 40 Hz simple rate (and possible up to...
The scattering of infrasound from anisotropic wind velocity and temperature fluctuations in the middle and upper atmosphere leads to the penetration of the infrasound field into acoustic shadow zones. Based on this effect a method of acoustic sounding of an atmospheric fine-scale wind velocity vertical structure is developed to retrieve vertical profiles and vertical wavenumber spectra of the...
Volcanic eruptions represent a significant source of low-frequency acoustic energy radiated directly into the atmosphere. During explosive volcanic eruptions, release of overpressure and rapid and sustained injection of mass into the atmosphere are the primary sources of infrasound waves (0.01-20 Hz). The International Monitoring System (IMS) infrasound network of the Comprehensive...
The Neighbourhood Algorithm is a grid-based search method that optimizes a user-supplied objective function over a computational domain using Voronoi cell tesselation. The algorithm is a method for solving geophysical inverse problems that has the additional benefit of not requiring the estimation of travel-time derivative information. In this application a misfit function for infrasound...
The Infrasound experiments have started in Indonesia in 2004, with the support of DASE (French CEA) BMKG installed an infrasound experimental station in the airport of Palangkaraya in Kalimantan. However, this preliminary study which was performed with only one single infrasound station was very encouraging and has demonstrated the potential of using infrasound data and processing for remote...
Over the past decade ocean observing technology for the scientific community has advanced from expeditionary ship based science and data collection to long time series real time ocean observation. This paradigm shift has been achieved through the installation of significant cabled infrastructure systems. Several research organizations have launched a new era of human discovery within the...
Interpretation and understanding of radio-xenon daily sampled within the International Monitoring System demands for an atmospheric transport modelling (ATM) system that delivers the source attribution to the isotopic concentrations measured. Typical Xe-133 releases from medical and industrial isotope production (MIPs) facilities notably contribute to a great part of the regularly measured...
A sophisticated earthquake data recorder, based on ARM technology, has been developed
and improved based on the last standards in the world of seismic data recording assigned for
earthquake studies. Abilities of exact timing, low power consuming, long time field operating
without maintenance, remote access and remote setting of parameters, customizable data
sampling and various modes for...
As part of its mandate, the CTBTO’s nuclear explosion monitoring programme aims to maintain its sustainability, effectiveness and long-term relevance to the verification regime. As such, the Technology Foresight programme of activities identifies technologies that may serve said purpose within the next 20 years.
We have involved the wider seismology, infrasound, hydroacoustics,...
The Khlopin Radium Institute conducts research targeted to creation of highly sensitive low-background installation, capable to satisfy the OSI required range of measuring argon-37 concentration. On the basis of this installation the liquid-scintillation principle of registration of low-energy electrons of argon-37 is used, and condensed argon itself is used as scintillator. Condensed argon...
In this work, we exploit the difference in time-frequency signatures between blasts and earthquakes, as a possible discriminant. Time-varying instantaneous frequency signals will be computed in two ways:
1) We will use the classical method of Taner and Koehler [1]. The instantaneous frequency is obtained by differentiating the instantaneous phase of the analytic signal. If the data is very...
In 2012 in the Fadalto area in the Belluno province several strong rumbles were heard, which eventually scared population and concerned authorities. The Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in cooperation with the Earth Science Department of Florence University installed an integrated real time seismic and infrasound monitoring system in the area to understand...
At EIF of the Treaty, the IMS will consist of 337 facilities supplemented by 40 noble gas systems. Besides for Treaty monitoring purposes, the data from the IMS network and the products derived from them at the IDC can serve civil and scientific applications. The Member States apply various approaches to merge IMS data with their national or regional data. This is encouraged and supported by...
Seismic analysts at the United States Nation Data Center (USNDC) routinely review events from repeating sources (e.g., mines, earthquake sequences). Typically these events are highly correlated and share similar station/phase associations. The USNDC has integrated a suite of efficient empirical signal detectors into the Detection and Feature Extraction (DFX) application that will...
The effects of adding data from open source seismic stations in the waveform processing system at CTBTO/IDC were explored. About 50 stations, located in the whole world and providing open source waveform data, were selected by following criteria: located in areas less covered by IMS stations; provided continuous data and real-time access; broad-band instrumentation; recording data at least 70...
NET-VISA is a probabilistic system developed for seismic network processing. A rich amount of information is hidden inside its Generative Model (GM), an explicit mathematical description of the relationship between various factors in seismic network analysis. An Interactive Model Visualization tool (IMV) is being developed which will make "peeking into" the GM simple and intuitive through a...
Lawrence Livermore National Laboratory works through the National Nuclear Security Administration’s Seismic Cooperation Program to train and pursue joint studies with seismologists in the Middle East and Southeast Asia. These activities offer a model for capacity-building that strengthens regional scientific communities and monitoring of the Comprehensive Nuclear-Test-Ban Treaty (CTBT)....
Methodology and results of two different estimates of the releases from the Fukushima disaster are presented. The first method aims at reconstructing the detailed time series of the emission of xenon-133 and caesium-137 using CTBTO/IMS and Ro5 measurements over the Northern hemisphere plus additional measurements, including deposition data, from Japan. It was published in 2012 in Atmospheric...
In 2012, experts of the Hungarian Institute of Geology and Geophysics (formerly ELGI, Eötvös Loránd Geophysical Institute of Hungary) performed a series of mappings in a test site of Bakony Mountains, Hungary. To detect and delineate an underground storage facility, various methods and devices were applied. Above and inside the military construction, resistivity and seismic profilings,...
We performed the Allan factor analysis on the 1842-2012 seismicity of the Absheron-Prebalkhan seismogenetic zone of Azerbaijan. The historical and instrumental catalog of the Absheron-Prebalkhan region in the Caspian Sea area was analyzed in order to reveal the existence of temporal clustering in the time dynamics of the seismicity. The timespan of the catalog is from 1842 to 2012 and the...
In IMS infrasound processing, incoming data is first treated on the level of individual array stations. Automatic station processing serves the detection of coherent wavefronts as well as estimation of their slowness and azimuth. Additionally, station processing categorizes detections into signal and noise, and also labels incoming signals based on their travel path through the atmosphere. The...
Azimuth and slowness errors are essential for estimating station corrections in order to improve the location quality. Keskin (BRTR) array is a primary seismic array of the IMS (International Monitoring System) network located at near Ankara in the Central Anatolia, Turkey. It consist of 7 array elements are in a circular array geometry with an approximate aperture of 3 km. Array processing...
Since the Comprehensive Nuclear-Test-Ban Treaty was opened for signature in 1996, nearly 80% of the infrasound network has been certified as operational and sending data to the International Data Centre (IDC) in Vienna. Several of the stations have been in operation for close to 15 years. With new advancements in digital recording technology and sensor design, some station operators have...
JISView had been made which is development of AMZTAK software that has function to modeling earthquake focal mechanism. Through the making of GUI some of the functionality built into automatically and added to the system and combined with GIS to support earthquake and tsunami vulnerability analysis in order to become more effective and systematic. Modeling is done using the P-wave phase data....
One sub-task in hydroacoustic signal processing for CTBT verification is automatic discrimination of incoming signals by source type. In particular, signals from any explosive-like source should be reliably identified among a wide range of noise (for example, seaquakes, marine mammals, or ship noise). Previous studies have applied rule-based systems, neural network classifiers, support vector...
About noon of Feb. 12th 2013(KST), the seismic signals from the North Korea’s third underground nuclear test were detected by seismic stations in South Korea, Northeast China and Russia which are distributed uniformly along the boundaries between North Korea and adjacent countries. The relative location to the first event was calculated. The epicenter of the third event was about 400 meter...
85Kr monitoring in USSR-Russia was ceased in 1993, 85Kr concentration activity was 0.9 -0.92 Bq/m3.
The monitoring of Xe and 85Kr radionuclides was renewed since August 2006, and was arranged at the sampling station in Cherepovets city, located in 220 km northward from the Kalinin NPP. Kr-Xe gas mixture was filled in balloon with charcoal and transported to Radium Institute. For the period of...
As a consequence of the Fukushima accident it became obvious that the IMS filter could potentially cause radiological concern for the station operators due to the high air flow rate which can lead to accumulation of sizeable activities on the filters. Also, the data from the filter analysis is not available until more than 52 hours from the collection start (the time of the first preliminary...
The CTBT prohibits nuclear explosions in all environments in an effectively verifiable manner. Its verification regime for monitoring compliance is the most comprehensive ever envisaged in any multilateral instrument. As the CTBT is intended to be of unlimited duration, and bearing in mind the importance of keeping abreast with technological developments and challenges in order to ensure...
The U.S.-designed Radionuclide Aerosol Sampler/Analyzer (RASA) was a key aerosol system of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) in the path of debris from the Fukushima-Daiichi reactor disaster. The releases from the reactor in some ways mimic the possible releases from a nuclear explosion that was partially contained, and operational issues...
Comprehensive Nuclear Test Ban Treaty Organization (CTBTO), through its International Monitoring System (IMS) and International Data Centre (IDC), collects, processes, analyses and stores IMS data to support the implementation of the verification regime.
However, these data may contribute not only to the monitoring of nuclear explosions, but also have a wide range of application in civil...
The calculation of Source Receptor Sensitivity (SRS) fields calculated in backward mode is state of the art of Atmospheric Transport Modeling for CTBT verification purposes. The Lagrangian Particle Dispersion Models FLEXPART and HYSPLIT are available for that purpose using mostly ECMWF or NCEP analysis data for simulations on global domain. Various localization approaches for atmospheric...
Previous work for a test case in the 1999 Xiuyan, China, earthquake sequence has demonstrated that Lg-waves correlate extremely well for this region and can be used to obtain high precision solutions for epicenters using the double-difference technique. Lg-waves are well suited for correlation when available because they are the largest amplitude arrivals on the regional seismogram, they have...
Soil gas sampling methods are a critical, yet underdeveloped, component of subsurface noble gas detection during an On-Site Inspection (OSI). The verification system for the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is intended to detect any nuclear explosion, above or below ground. When a suspected nuclear explosion is detected, an OSI can be called at the site where the nuclear explosion...
The development of high-sensitivity, high-resolution, low-noise and low consumption microbarometers is still a need for infrasound community. Internal calibration of such sensors remains a critical issue for CTBT application. To address this issue, a new sensor called MB3 has been developed by the CEA/DASE, following 20 years of experience with MB2000 series. It is composed of a metallic...
Detection of radioactive noble gases during an On-Site Inspection (OSI) can be strong evidence that a nuclear weapons explosion occurred at that location. The expected subsurface concentrations of radioactive noble gas signatures during an OSI, however, have not been fully established. To begin understanding how to best estimate the radioxenons and 37Ar concentrations at the subsurface after a...
Numerical experimentations were performed to understand the mechanism of intrusion and channeling of regional aerosols over the Kathmandu valley with the applications of regional scale atmospheric transport model by releasing tracers inside and outside the valley. The study reveals that the regional aerosol intruding into the valley with the westerly/southwesterly wind contributes 20 to 80...
Melcepstral coefficients have been extracted from a number of infrasonic hand-digitized atmospheric explosion waveforms from the 1962 Operation Dominic series of atmospheric nuclear tests. These explosions have a distinctive pattern of melcepstral coefficients which can be modeled with synthetically-generated waveforms consisting of a reflective phase from the surface and a direct arriving...
Regional scale spatial and temporal distribution of meteorological flows over different regions of Nepal have been studied with the application of Weather Research and Forecast Model (WRF) incorporating field observations to identify major roots of air mass transport towards Himalayas from the Ganges Plain. The calculation domain consists of triply nested two-way interacting mesh with 9km, 3km...
On-site inspections, though intrusive in nature, is one of the most important and effective mechanism as a verification tool in order for a treaty to achieve its objectives. The IAEA safeguards inspection regime, which verifies the non-proliferation of nuclear weapons, has accumulated broad experience in the methodology and technology of conducting inspections on international, regional or...
A number of projects aim to introduce novel ideas from the computer science community into the IDC data processing pipeline. There is need to develop standard criteria for evaluating their success with respect to each other and to current IDC processing. It is proposed that such criteria be developed in a way that is appropriate to the mission of the IDC, namely to ensure that no nuclear...
Due to our success in studing the opplicability of the micro-gravity investigations in archaeo-prospecting and cave detection, we started to study the resulted unknown features in the Valley of the Queen and Kings from our previous micro-gravity investigations. Some profiles selected to cross the main area of the resulted anomaly.
Due to our success in studing the opplicability of the...
The Roselend Natural Laboratory (French Alps) is a unique facility for studying gas transport in the subsurface and across the geosphere-atmosphere interface. At 55 m depth, a sealed cavity allows for gas release experiments across fractured porous rocks in the unsaturated zone. While many parameters describing the state of the geological system are controlled, analogous gas-tracer experiments...
The usual approach to study infrasound propagation is to compute the acoustic component superimposed to a mean atmospheric state. The justification of such an approach is questionable given that meteorological uncertainties may affect the waveforms in such a way that some arrivals may literally disappear. In the present work, we perform a sensitivity analysis to estimate the role of...
Despite recent advancements in infrasonic technology and modelling, identifying sources of infrasound remains an elusive task. During their passage through the atmosphere, meteoroids produce a range of phenomena, most notably a hypersonic shock, which can be recorded at the ground in the form of infrasound.
Utilizing the recently established Elginfield Infrasound Array (ELFO) near London,...
The use of electrical circuit elements to model physical devices has a long history of success. The analogy between flow of air and electrical current is mathematically accurate; momentum of a section of a gas also called Inertance is directly analogous with the electrical parameter Inductance. The compliance of a transmission vessel (hose or pipe) is directly analogous with electrical...
Seismograms reflect the combined effects of the source, recording instrument, ambient noise, and the propagation path. Especially for recording at distances smaller then 10° the signal is affected mainly by the crustal structure, as waves propagate in the crust and/or along Moho. Therefore appearance of regional seismograms varies strongly, which complicates record interpretation and phase...
As a first step of a more general study on the dispersion of radioactive products from an underground nuclear test, we have tried to define the dynamics of the inert gaseous products migration in the underground environment in which a hypothetical nuclear test has been carried out. The identification of the transport mechanism through the geosphere could be combined with the modeling of the...
The detection capability of the seismic network of the International Monitoring System (IMS) operated by CTBTO can be quantified in terms of a threshold that measures the magnitude of the smallest seismic event that could occur at a location and have a specified probability of being detected and located. This threshold can be inferred from the results of bulletins produced by the International...
Various companies in Russia are engaged in development of such seismometers. Borehole seismometers on the basis of modules SEP-1 and SM-6 as well as seismometers SSKV and SSB3 can be considered the most promising developments for installation at IMS seismic stations.
Modules SEP-1 have been developed with the use of magnet suspension of inertia mass and employment of feedback. There are two...
We apply the P-wave receiver-function technique to invert teleseismic data to investigate the S-wave velocity structure beneath stations RTC and TAM in West Africa. Our results show that the crust beneath RTC is relatively complex with large velocity fluctuations. In the upper crust, a low velocity layer extends from 8 to 12 km deep. This shallow low velocity layer is mainly due to the...
The source mechanism of the September 2, 2009 Tasikmalaya, West Java earthquake is not consistent with the characteristic of the tectonic stress in this region in which the strike direction in general parallels to the present-day trench. In fact, the strike of the September 2, 2009 Tasikmalaya earthquake is nearly perpendicular to the trench. We determined the moment tensor using the near...
Moment tensor inversion method used for determining the focal mechanism earthquakes have large magnitude occurred on the northwestern region of VietNam in recent years. In this study, the inverse results was calculated for the five earthquakes (including 2 aftershocks) have strong levels occurred in 2009 and 2010 on the northwestern region. Seismograms at the seismic stations recorded five...
Aerosol radionuclides (131I, 134Cs, 137Cs) and gaseous radioactive xenon (133Xe) were monitored at Xi’an, China following the accident at the Fukushima nuclear power plant in March 2011. The monitoring results showed that the maximum concentrations of 131I and 133Xe were 3.92 mBq/m3 and 5.5 Bq/m3, respectively, on March 25~27. And the concentrations of all observed radionuclides decreased...
Tens of rockets are launched each year from Baykonuyr space port located in Central Kazakhstan. The rockets flight routes are above several Kazakhstan regions. Since 1994 the IGR RK monitoring network has been operating successfully on the territory of Kazakhstan. The network includes 8 seismic arrays, 7 three-component stations, and 2 infrasound arrays. 5 objects of the system are included...
The well-known radioxenon systems are based on multichannel beta-gamma spectroscopy. Therefore, there always are some technical problems in and periodical calibrations and maintenance. On the other hand, phoswich detectors are simply based one channel. Appropriate design of a phoswich detector is based on accurate evaluations for different phenomena appearing in response generation. Geant4 is...
The purpose of the this work is to examine the political and technical aspects of a verification regime pertaining to the Comprehensive Nuclear Test-Ban Treaty. Mainly two technical issues are studied. One is a detection issue critical to the verification of the treaty. The second is on the sharing of data generated by the IMS. The study will examine other other arms control and disarmament...
The International Monitoring System (IMS) technologies can have civil and scientific applications other than its primary mission which is the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). One of those applications is volcano Monitoring.
The Italian volcano Etna is one of the active volcanoes in the world and its activity is detected by more than one IMS station such as...
The aerosol monitoring component of the International Monitoring System (IMS) was principally designed to detect atmospheric nuclear testing for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Beyond the CTBT applications, IMS radionuclide data also has important Earth science research applications such as climate change, meteorology, solar cycle impacts on terrestrial processes, etc. Na-22...
NET-VISA (NETwork processing Vertically Integrated Seismic Analysis) is a generative probabilistic model of global-scale seismology, as well as an inference algorithm for deducing the most probable seismic bulletin. The overall model has the following main parts: a prior for seismic event locations and magnitudes, a forward model for the transmission and attenuation of seismic waves, a...
The enforcement of the Comprehensive Nuclear-Test Ban Treaty (CTBT) requires the monitoring of acoustic sources in the oceans in order to detect underwater explosions. We present new advanced criteria used to discriminate hydroacoustic phases between explosive events and earthquakes. These criteria can be applied on records from both hydrophones and "T-phase" seismic stations. In the time...
Ocean island flank collapses, landslides, earthquakes, tsunamis, cyclones, flooding, volcanic eruptions are some of the most dangerous hazards in the Pacific as they have the potential to cause damage and loss of life. In the past, Samoa’s heavy dependence on external sources for monitoring geohazards was risky and problematic this dependency highlighted the urgent need to set-up a monitoring...
Measurement of radioxenon gas concentrations in the air is an important part of verification of underground nuclear explosions, and automated measurements have been ongoing for over ten years in the International Noble Gas Experiment (INGE). Lessons learned from system development and field measurements illustrate opportunities for improvement in the next generation systems in the area of...
Since the introduction of radioxenon measurements in the CTBTO, it was found that radiopharmaceutical facilities are responsible for a large portion of nuclear signatures. Radioxenon usually does not cause radiation threats and since it is difficult to filter out, the emissions are substantially depending on production facility type. This is causing a challenge for the CTBT regime, as the...
Since 1994 the IGR RK monitoring network consisted of 4 small aperture, one medium and one large aperture seismic arrays, 7 three-component stations and 2 infrasound arrays has been operating successfully on the territory of Kazakhstan. Owing to good stations location from geological view and characteristics of seismic noise, well considered arrays configuration, most stations positioning in...
Many Radioxenon detector systems used in the International Monitoring System (IMS) and in other applications employ beta/gamma coincidence detection to achieve high sensitivity. While very sensitive to small amounts of radioxenon, the existing systems require careful calibration and gain matching of several detectors and photomultiplier tubes and their organic scintillators show a memory...
The Roselend Natural Laboratory is a unique facility for studying gas transport in the subsurface. By combining experimental and numerical approaches, computer models are developed, calibrated, and validated for future predictive simulations. In addition to long-term monitoring of naturally produced 222Rn and CO2 gas-tracer experiments have been conducted recently with SF6, freon and 3He. The...
After 15 days, radionuclides from the nuclear accident at the Fukushima Nuclear Power Plant in Japan were observed in air at four environmental radiation monitoring stations from north to south of Vietnam: Lang Son, Hanoi, Da lat and Ho Chi Minh City. During the period from March 26 to April 23, 2011, the maximum concentration of isotopes 131I, 137Cs and 134Cs in air measured at four above...
In the framework of the International Monitoring System (IMS), sixty infrasound stations were installed around the world to detect nuclear test of more than 1 kiloton. Besides, these stations can detect and measure waveforms from natural event such as ocean swell, volcanoes, severe weather or from man-made source such as chemical explosion, quarry blast, missile’s path etc. On 15 February 2013...
We still remember the accident in the Institute for nuclear sciences "Vinča", many years ago in the former Yugoslavia. This paper gives insight in the legal framework of the nuclear armament area in the Republic of Serbia. We are speaking about legal framework of peaceful utilization of nuclear energy too. Knowledge is the treasure that folows everywhere its owners. The Government of the...
The ATOC project (The ATOC Consortium, 1998) had the goal of measuring acoustic velocity in the oceans to assess variations of the ocean temperature with various applications, including long term trend monitoring of Earth climate. The method for measuring the velocity variations relied on a few active sources and receivers. Several issues hampered the project, mainly the concern over the...
Based on lessons from 2004 Sumatra Earthquake/Tsunamis and 2011 East Japan Earthquake/Tsunami,
we recognized the importance of real time monitoring on Earthquakes and Tsunamis. Especially, the real time monitoring system using multi kinds of sensors such as the accelerometer, broadband seismometer, pressure gauge, difference pressure gauge, hydrophone and thermometer is indispensable for not...
Tsunami Warning Centers have used Mwp to issue Tsunami Warnings 5–10 min after Earthquake origin time since 2002. However, because Mwp is based on the far-field approximation to the P-wave displacement, we should only very carefully apply Mwp to data obtained in the near field, at distances of less than a few wavelengths from the fault. On the other hand, the surface waves from Great...
Beta-gamma coincidence method is the basis for low-activity radioxenon activity analysis. An important task in an accurate measurement is to precisely calibrate system. Usually it is expensive or even impossible to find a reasonable amount of purified radioxenon gas for calibration purposes. A good alternative is to calibrate using an external gamma-rays source like Cs-137. The main question...
With the Additional Protocol to the Non-Proliferation Treaty, atmospheric sampling analysis of the noble gas Krypton-85, which is a suitable tracer for plutonium separation, was introduced. Our project focused on the investigation of the effects of temporal sampling resolutions to the localizability of tracer sources using atmospheric transport models (ATM). Predefined weekly quantities of...
The importance of atmospheric structures on the infrasonic waveguides has been illustrated in several works using asymptotic techniques. However, these techniques fail to describe the interactions between infrasounds and stratospheric changes, such as the sudden stratospheric warmings. In the present work, we study how breaking gravity waves in the stratosphere impact the long-range...
The IMS is a globally distributed network of monitoring facilities using sensors from four technologies. It is designed to detect the seismic and acoustic waves produced by nuclear test explosions and the subsequently released radioactive isotopes. Monitoring stations transmit their data to the IDC in Vienna, Austria, over a global private network known as the GCI. In order to satisfy the...
Three of four radio-xenon monitoring systems have been developed based on beta-gamma coincidence. Most important step in operation of Xe detection system is calibration by standards. An efficient method to accomplish this step is established using 137Cs gamma source. In that case the source position and detector geometrical design might effect the results. This paper will focus on some...
We develop methods to determine the optimal detection thresholds for the Progressive Multi-Channel Correlation Algorithm (PMCC) used by the International Data Centre (IDC) to perform infrasound station level event detection. Statistical detection theory is used with synthetic data and real ground truth data to determine optimal individual delta time consistency detection thresholds and the...
Continents, islands, plateaus and sea-mounts/guyots with shallow bathymetry, can block the propagation paths of hydroacoustic signals. However, diffraction around smaller structures, such as islands and sea-mounts/guyots, can illuminate parts of the shadow region, exposing portions of the oceans which are not covered by purely 2-dimensional (range/depth) acoustic models. In recent years,...
A high throughput system for processing and detection of radioxenon for On-Site Inspection (OSI) purposes is currently being developed at FOI. To locate an underground event during an OSI it is important to cover and narrow down a large area of interest in a short time period. This will require a large number of sub-soil gas samples to be analyzed per day. Even if samples are combined, a noble...
A high throughput system for processing and detection of radio-xenon for On-Site Inspection (OSI) purposes is currently being developed at FOI. To locate an underground event during an OSI it is important to cover and narrow down a large area of interest in a short time period. This will require a large number of sub-soil gas samples to be analyzed per day. Even if samples are combined, a...
We are designing and testing a new high-resolution gamma-ray spectrometer for on-site inspections under the Comprehensive Nuclear-Test-Ban Treaty: the On-Site Inspection RadioIsotopic Spectrometer—OSIRIS. The instrument provides robust protection for the potentially sensitive aspects of measured gamma-ray spectra, revealing only gamma-ray peak data for selected radioisotopes. We will evaluate...
Upon the acquisition of a new station, the United States National Data Center (US NDC) employs a standardized detector tuning process with the goal of identifying station specific parameters for the automated detection of regional and teleseismic signals. These parameters include: filter passbands, beam deployment, detector configuration, array configuration, and detection threshold. Detector...
The NDC Preparedness Exercise 2012 (NPE 2012) was a fictitious radionuclide triggered test conducted by the National Data Centers (NDCs) of CTBT States Signatories. During the NDC Preparedness Exercise 2012, a fictitious radionuclide scenario originating from a seismic event was calculated and distributed by the German NDC. It was assumed that a selected seismic event was the epicentre of an...
The detection and identification of aftershocks is an important and challenging task for the efficient seismic processing in the CTBT context. In this work we apply a template-based sonogram pattern recognition and a waveform correlation detector in order to identify events which are part of the aftershock sequence. The concept is demonstrated using the February 2004 Dead Sea earthquake with...
The RN52 Radionuclide Monitoring Station in Tanay, Rizal and its surrounding vicinities are annually frequented by severe weather conditions such as heavy rains, thunderstorms, and landslides, which greatly affect the operation and maintenance of the facility, especially the delivery of liquid nitrogen (LN2) necessary for the normal operation of the high-purity germanium detector (HPGe). The...
Periodicity in seismic activity is important in earthquake study, because these patterns may lead to the prediction of large earthquakes. The observations of temporal variation of seismic activity in Northeast India as well as Gujarat and adjoining region indicate that a periodic seismicity probably exists. Study use the data from 1819 to 2006 of shallow earthquakes distributed over Gujarat...
The Processing Engineers (PE) at the IDC are tasked with maintaining all processing parameters for all data streams delivered to the IDC. This includes coordinating the configurations for the operation of the stations/detectors and the usage of the various data streams by the processing software. This information is complex and the maintenance of this information is laborious. As all...
The Cepstral processing has made its mark in a number of applications since the first papers were published in the 1960's. The principal author demonstrated the technique on biomedical data in his dissertation. Subsequent research was done on hydroacoustic, seismic, infrasound, gear-fault, and ground penetrating radar data. In most of these applications, the Complex Cepstrum was used,...
Radionuclide 252Cf is disintegrate main by alpha decay, half-life period T1/2 =2.645 years (97%) and also by spontaneous fission with T1/2 =86 years (3%). Number of spontaneous fissions ~610 fissions . sec-1 .ng-1. Thus, in 252Cf specimen the whole spectrum of fission products (fragments) is formed, including 133Xe, 135Xe ), etc. Xe radionuclides generator is designed as a stainless steel...
During several years the IGR RK has been digitizing historical analogue seismograms of nuclear explosions collected from archives of different Organizations of Kazakhstan, currently a database contains more than 6000 seismograms at regional distances. The digitized historical seismograms allowed to recover and add parameters for more than 40 air and contact explosions conducted at Opytnoye...
Researchers at Pacific Northwest National Laboratory are preparing an experiment intended to simulate the near-field deposition pattern of radionuclides released in a small-scale vent from an underground nuclear explosion. The experiment is designed to release short-lived radionuclides with sufficient activity to enable ground and airborne survey to measure the plume above background over an...
Detection of noble gas fission and activation products resulting from underground nuclear tests is a key component of On-Site Inspections, the most confirmatory of the three verification regimes of the Comprehensive Nuclear-Test-Ban Treaty. Radioxenon and radioargon gases may reach the surface through several mechanisms, each with a characteristic timeline. In order to provide empirical data...
Usually, in the establishment of an NDC for the implementation of the National requirements relevant to the Comprehensive Nuclear Test Ban Treaty (CTBT) numerous challenges are encountered especially in developing countries. Some of these challenges could be frustrating and sometimes have the tendency of dragging the NDC establishment process to a halt.
I can say that we also have encountered...
Under CTBT, many different radionuclide OSI technologies are considered including survey (aerial, vehicle, backpack, and handheld), environmental sampling with laboratory analysis (atmospheric noble gas and particulate, subsurface noble gas, soil, water, and biota), and in situ measurement. Due to the many limitations, such as manpower, time, and field environment, that an OSI will face it is...
Fission gases such as Xe-133 are used extensively for monitoring the world for signs of nuclear testing in the International Monitoring System (IMS). Medical isotope production for Mo-99 is an additional source of radioxenon that has been shown to also be detected in the IMS. Understanding and interpreting interferences from medical isotope production is still a relatively new concept. This...
The seismic network of the International Monitoring System (IMS) operated by CTBTO detects signals that may originate from natural or anthropogenic sources. These signals are processed in the International Data Centre (IDC) of CTBTO to produce bulletins that provide lists of events hypothesised as being the sources of the signals. To do this, observations of signal properties such as arrival...
Since 2002, when the Bucovina (BURAR) array was installed in the north-east of Romania, numerous small-magnitude events were detected, characterized by impulsive first arrival phases. Since most of these events occurred during day time, the purpose of our work is to apply different discrimination techniques to identify the quarry blasts events generated in the array neighborhood. It is...
Peak Ground Acceleration (PGA) is very important for seismic hazard assessment and quick response. One of hazard assessment of potential damage from earthquake is to determine the effect or impact type of ground motion at the specific site. Seismic hazard assessment for quick determination has been developed by using relationship of attenuation of ground motion with site-distant and processed...
Chernobyl accident has shown an importance of maintenance of high level national system of reaction in the case of radiological accident. In Belarus the general assessment of the radiological situation and the control of radioactive contamination of settlements and surface water are carried out by several governmental bodies: Ministry of Emergency Situations and Ministry of Environment...
For the NPE 2012 the trigger scenario was based on a selected seismic event from the Reviewed Event Bulletin serving as starting point for fictitious Radionuclide Dispersion. Hypothetical xenon and iodine radioisotope source terms with isotopic ratios fitting to a nuclear explosion were assumed. The simulated concentration at radionuclide stations of the International Monitoring System were...
The nuclear and radiopharmaceutical industrial emissions of the four CTBT-relevant radioxenon isotopes are detected by the IMS along with possible treaty violations. To better understand the source terms of these background emissions, a joint project between Health Canada (HC), Australian Nuclear Science and Technology Organisation (ANSTO), Pacific Northwest National Lab (PNNL) and Chalk River...
We present results of testing the latest version of our Probabilistic Event Detection, Association, and Location (PEDAL) algorithm. PEDAL uses an Earth model discretized into a dense 3D grid of 427,265 nodes, extended to 4D by the addition of a time dimension. Given a set of seismic observations (arrival time, horizontal slowness, azimuth and associated uncertainties), a 'fitness’ value is...
It has been two decades since the last comprehensive standard model of ambient earth noise was published (PETERSON, 1993). PETERSON model was updated by analyzing the absolute quietest conditions for stations within the GSN (BERGER et al., 2005; MCNAMARA and BULAND, 2004; RINGLER et al., 2010). Unfortunately, both the original model and the updating models did not include any deployed station...
The Regional Seismic Travel Time (RSTT) tomography model has been developed to improve travel time predictions for regional phases (Pn, Sn, Pg, Lg/Sg) in order to increase seismic location accuracy. The RSTT model is specifically designed to permit the use of regional phases for location, especially when combined with teleseismic arrivals. Previously, the RSTT model was calibrated for specific...
On February 12, 2013 North Korea executed the third underground nuclear test at their test site in the vicinity of P'unggyeri. The event excited strong regional Pn and Pg phases compared to the weak regional Lg phase. The seismic waveforms were very similar to those of the North Korea's first and second underground nuclear tests, which suggested nearly collocated epicenters of the three...
We are developing a method for removing periodic noise from recordings to detect weak impulse events. This could be used e.g. for seismic aftershock monitoring during CTBTO on-site inspections (OSI) where weak pulses may sometimes be masked by engine signals. We have continued our work (shown at ISS09, S&T11). By gradually fitting the frequency, amplitude and phase of a sine function to each...
Infrasound is one of three waveform technologies which are part of the Comprehensive Nuclear Test Ban Treaty verification regime. Routine analysis of seismo-acoustic events with associations at infrasound stations started in the beginning of 2010 after six years of offline improvements of the automatic processing. During the past three years over 9000 infrasound events were validated by...
The presented study is a part of the passive seismic experiment PASSEQ 2006-2008. The PASSEQ project aims to study lithosphere – asthenosphere system around the Trans-European Suture Zone (TESZ). Nearly 200 temporary seismic stations were installed along 1200 km long and 400 km wide area from Germany throughout Czech Republic and Poland to Lithuania, and provided continuous recordings from May...
The QA/QC program for Noble Gas systems of IMS Radionuclide network will be based on sample re-analyses at IMS laboratories. In order to ensure the credibility of IMS laboratories as providers of reference results, the laboratories have to be certified and have to undergo a QA/QC program, as well. Part of the laboratory QA/QC program will be regular intercomparison exercises. As a pilot...
This paper presents a Rule-based Interval State Machine Algorithm (RISMA) for monitoring, and analysing the behaviour of interval-based data. The proposed algorithm uses the Interval State Machine (ISM) approach to model any number of interval-based data into well-defined states as well as inferring them. An interval-based state transition model and methodology are presented to identify the...
Radionuclide network of the International Monitoring System (IMS) monitors the presence of the Treaty-relevant radioisotopes in the atmosphere. These radioisotopes may have, however, a non-Treaty-relevant origin. Dispersed in the atmosphere they constitute a background which contributes to the detections at the IMS radionuclide stations. Consequently, the background needs to be understood and...
Romania participates to the verification regime of the CTBT through the NDC and the IMS auxiliary seismic station Muntele Rosu, both operated by the National Institute for Earth Physics. The paper assesses the performance of the IMS at regional scale, i.e. for the Romania’s territory, during 2012. A comparative analysis of the IDC products (SEL3 and REB) and the ROM NDC bulletins for the...
The first RSTT model for Australia has been developed using in-depth seismic velocity information from the region. The model is primarily based on the Australian Seismological Reference Model (AuSREM) that was released in late 2012. The densely-grided P and S wave velocity distributions of the crust and upper mantle of AusREM have been simplified and translated into the 7 layer crustal and...
The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) will ultimately have 170 seismic stations for the purpose of monitoring underground nuclear explosions, in which about 80 percent are currently running. The seismic event location will play an important role in the monitoring process and the accuracy of location is important to the...
With the addition of acoustic sensors to the seismograph stations of the US National Science Foundation EarthScope USArray Transportable Array (TA), there is an opportunity for significant advances in our understanding of infrasound source physics and propagation, as well as coupling between seismic and infrasound waves. Central to these efforts is an improved understanding of infrasound...
In preparation for a field site visit, particularly for CTBTO investigative purposes, a variety of types, scales, and generations of open-source digital imagery can be compared within the framework of commercially-available geographic information systems (GIS) to focus on areas of interest. Simple image comparison from various open sources within GIS afford the opportunity to view...
Today, 16 stations within the IMS network of CTBTO have SAUNA Systems installed for noble gas capability. The activity measurement of the four xenon isotopes, 133Xe, 131mXe, 133mXe, and 135Xe is performed using the very sensitive beta gamma coincidence technique allowing high sensitivity also for the meta-stable states resulting in MDC:s of 0.3, 0.3, 0.3 and 0.7 mBq/m3 respectively. In the...
NDC Preparedness Exercises (NPE) are regularly performed dealing with fictitious treaty violations to practice the combined analysis of all CTBT verification technologies and also for the mutual exchange of information between NDC and also with the IDC. The exercises are organized and coordinated at the German NDC (BGR). The NPE 2012 scenario was based on a selected seismic event from the...
The Seismic Aftershock Monitoring System (SAMS) is an important method during the initial period of an On-site Inspection (OSI) to identify the possible source area of an underground nuclear explosion (UNE). A network of tripartite mini-arrays and single three-component seismic stations will be deployed during an OSI to detect and localize aftershocks in the vicinity of a possible explosion....
Monitoring of seismicity in Nepal Himalaya in collaboration with DASE France lead us to understand the seismotectonics and earthquake nucleation process. Belt of seismicity, at a depth of 10-20 km, follows the front of higher Himalaya. This midcrustal seismic cluster lies within a zone of interseismic stress accumulation characterized by high uplift rate inferred from geodetic measurements....
To pursue the goal of substantially reducing the time of classification, it was necessary to collect much less information about the seismic event itself, and focus on the transition between noise and P input phase. In this experiment, the data used in training and validation were the same as in previous work, and the training procedure was identical. The difference was in the feature...
We used the small-aperture arrays measurements for a few areas in East-European Craton territory and compared the seismic data processing results and regularities revealed during the analyses with the data obtained from geomorphology studies of fault structures. The results confirm most small and micro-earthquakes (up to M~ -2) locate in the fault zones and zones of "dynamic influence of...
Understanding of the seismic background noise is an important step in reducing the noise level of the seismic data. Wind noise refers to vibrations generated by the coupling of wind energy into ground motion. The data demonstrated a consistent correlation between recorded noise levels and wind speed. Signals from desirable events may be obscured by earth noise arising from the wind. Only the...
The three underground nuclear explosions in northern Korean Peninsula bequeathed waves recorded by seismic stations in Northeast China and South Korea. Studies on the three events illustrated that the difference in the locations of the two explosions is tiny on a regional distance scale. The tiny difference could be incorporated to establish empirical source scaling relationships of the two...
The goal of this work was to study the seismicity and to estimate the stress field acting in the Gulf of Aqaba Region. The Gulf of Aqaba earthquakes is mainly concentrated in four zones; the first zone is located in the Hume Basin in the southern entrance of the Gulf. The second zone is located along the Arnona fault between 28.3 – 28.6 and longitude 34.5 - 34.7 degrees; the third zone is...
Seismic and acoustic recordings are particularly important to help identifying and locating industrial blasting sources. We have analyzed seismo-acoustic signals from mine blast for 2000 and 2009 in order to determine detection seismo-acoustic signals of explosion by seismic and infrasound stations. Several large mines in the region routinely generate explosions that are detected seismically...
Belarus and the Baltic States comprise the single seismotectonic region described by the similar geological evolution and common recent geodynamic conditions. The region shows a rather low seismic activity, however some seismic events with a magnitude M ≤ 4.5 were recorded within its limits. Instrumental seismic observations started in the territory of Belarus in 1965 at the Pleshchenitsi...
System of seismological observations in Turkmenistan was established in 1947 when the first seismic station "Ashgabat" was built. The devastating earthquake with magnitude 7.3 which demolished Ashgabat in 1948 gave rise to further development of seismological research and deployment of seismic stations on the territory of Turkmenistan. By 1993 the seismic network of Turkmenistan included more...
Optimal use of on-site inspection radionuclide team resources requires an accurate understanding of the detection sensitivities of the equipment used for the various radionuclide measurement techniques. Parametric analysis of these sensitivities in terms of equipment design and measurement procedures can also provide input to help refine requirements for equipment, data processing, and...
Researchers at Pacific Northwest National Laboratory have recently completed construction of a 14 crystal low-background germanium array. A low-background shield system was also built to house a commercial low background germanium spectrometer. This system will be certified to measure atmospheric filter paper samples collected by the International Monitoring System (IMS). Both of these systems...
CEA/DASE has developed a new digitizer for waveform technologies. It is compatible with all CTBT specifications and requirements, including authentication and command & control / PKI. It allows digitizing 1 to 4 channels at 8, 20, 50 or 100 sps. The full scale input range can either be 40, 20,10 or 5 Vpp. Data are time tagged by GPS, authenticated by using DSS (1024 bits) or ECDSA and sent in...
We report on two near-source explosion data sets to better understand the generation and properties of the scattered P and S wavefields. In the first case, we look at tamped single-fired explosions (~130-270 lbs) shot in Barre granite from the New England Damage Experiment (NEDE) using high-frequency 3-component stations ranging from ground zero to 15 km distance for a variety of explosives...
The announced nuclear tests of 9 October 2006 and 25 May 2009 of the Democratic People’s Republic of Korea are located close to each other, on a global scale, and the Green’s functions at a teleseismic receiver are essentially the same. The differences in the seismograms, apart from the noise, are caused by the difference in the source time functions – the first event (mb(IDC)=4.1) had a lower...
Spatial and temporal variations in the fine layered structure (scales 10m-1km) of the middle atmosphere (20-120 km) have been studied on the basis of data obtained from acoustic sounding within the range of infrasonic waves. Surface explosions equivalent to 10kg -70 t of TNT were the sources of infrasounds. These explosions were set off in different regions of Russia during different seasons....
The diverse range of locations, continuous operation, and system uniformity of the IMS radionuclide network permits an unprecedented opportunity to evaluate long-term systematic effects on HPGe detector stability. An understanding of these effects is often crucial to physics experiments designed to evaluate exotic or anomalous nuclear decays over many years. In a unique effort to investigate...
With increased interest into the radioxenon emission from radiopharmaceutical production, it has become important to study the best methods to incorporate the data into the IDC analysis of radioxenon stations. A first step is to actually obtain stack monitoring data and then to apply atmospheric modeling and isotopic ratios to best screen out mundane medical isotope signatures from daily...
Strong site effect can cause anomalous site amplification and result in massive deviations from general earthquake ground motion prediction. Site amplification was firstly observed at the Austrian Seismic Network (network code OE) during our work on peak ground acceleration attenuation (Jia and Lenhardt, 2011) and this initiated investigations in this paper.
We firstly applied a spectral...
The accelerometer is a triaxial surface package useful for many types of earthquake recording applications. It is suitable for seismology and civil engineering applications. The unit consists of three force balance accelerometer modules mounted orthogonally in a compact aluminum case featuring a bolt anchoring slot and an integrated bubble level. The advanced features of the accelerometer...
Mw 6.4 earthquake hit Bali on 13 October 2011. Strong ground shaking felt in Denpasar, Tabanan, Karangasem and Gianyar. Also felt at many places in Java Island, Lombok Island and Sumbawa Island.
In case of one earthquake might trigger another at nearby stress field, by using rapid calculation of coulomb stress change we analyze aftershock distributions cause by mainshock activity. It has...
Tsunami simulations and inundation analyses are conducted on the northwestern coast of Sabah by assuming earthquake along the Manila Trench (MT) proposed by Salcedo (2010). TUNAMI (Tohoku University’s Numerical Analysis Model for Inverstigation) code is used. To calculate tsunami propagation and inundation we perform numerical simulations of linear and nonlinear shallow water wave equations in...
The presentation deals with the results of data processing from seismic observations conducted along eight parallel profiles of 6 km long and with a 500 m spacing between them on the site of an underground nuclear explosion boreholes. First arrivals curves indicated a low-velocity near-surface layer up to 1000-1500 m/s. With going deeper, velocity changes in the range of 4000-5500 m/s. A...
In this study, we extracted Green's function from ambient seismic noise data in order to get information about the shallow subsurface structure. The waveform cross-correlation technique has been applied for 31 days of recordings of ambient seismic noise at 36 seismographic stations around the DKI Jakarta area. We used the dispersive behaviour of the retrieved Rayleigh waves to infer velocity...
The seismometer is intended for the modernization of existing teleseismic networks for mass observations. The sensors are designed as observatory instruments. A feature of the device offered is the use of a pendulum with a period regulated up to 58 seconds. The vertical pendulum of the seismometer is configured using the Lacoste design. The spring is manufactured from highly stable alloys with...
The purpose of this presentation is to estimate the surface atmospheric pressure fluctuations produced by the passage of the 1 August 2008 total solar eclipse and to compare these pressure fluctuations with those recorded by a temporary network of microbarographs and by the infrasound stations of the International Monitoring System. The surface pressure fluctuations expected at all the...
Nigeria is not located where there are major seismic activities. But in the south western part of Nigeria a fault line the Ifewarw-Zungeru fault is believed to exist. This fault has made it possible for the country to experience pockets of tremors of magnitudes with ranges of 4.3 to 4.5 mostly in the south western part. The dynamism of the earth has made it imperative for early warnings and...
Hydroacoustics constitute one of four technologies on which the International Monitoring System relies. Of the eleven stations involved, five are actually "T-phase" seismic stations located on land in the vicinity of shorelines. We present a review of this concept on the occasion of the 50th anniversary of the deployment of coastal seismometers in French Polynesia, specifically tuned for the...
In radionuclide monitoring, one of the most significant challenges from a verification or surveillance perspective is the source location problem. Modern monitoring/surveillance systems employ meteorological source reconstruction - for example, the Fukushima accident, CRL emissions analysis and even radon risk mapping. These studies usually take weeks to months to conduct, involving...
Recent advances in high-speed electronics and multi-detector configurations have allowed the creation of laboratory detector systems requiring novel spectrum processing algorithms. Adoption of these new system designs led to revolutions in spectroscopy using techniques such as cosmic veto and coincidence counting spectroscopy and other applications. Now, with the advent of large high-density...
Detection capability of the station VRAC were evaluated using comparison of seismic event bulletins containing the results of data processing carried out in the Czech NDC and REB-bulletins of IDC. The detection threshold is linked with roll-off effect in the earthquake frequency magnitude distribution. For the estimation of value of magnitude mb connected with the roll-off effect, various...
The study seeks to evaluate appropriate machine learning algorithms in getting the correlation between Beryllium-7 concentrations in surface air with selected meteorological parameters: precipitation, wind speed, wind direction and relative humidity. It will use the CTBTO IMS radionuclide data from its PHP52 monitoring station (14.58N 121.37E) located at the PAGASA (Philippines Weather Agency)...
One-dimensional velocity models used in earthquake location do not account for lateral heterogeneities found in the crust and upper mantle. The regional seismic travel-time (RSTT) model (Myers et al., 2010) was developed to account for the effects of crust and upper-mantle structure on regional seismic phase travel-times. The IDC propose to implement RSTTs in their production of earthquake...
On 12 February 2013, The Democratic People’s Republic of Korea (DPRK) announced the conduct of a nuclear test. Corresponding seismic event was recorded by IMS, upon which IDC released first automatic estimation (SEL1) of time (02:57:51 GMT), location (41.3386°N and 129.0711°E ) and the magnitude (4.9 mb) of the event in less than two hours time. During the preliminary analysis of the 2013 DPRK...
Environmental sensitivity is sensitivity of instrument to environment (changes of pressure, temperature, magnetic field, etc.). To provide the best quality of the seismic data you have to understand the non-seismic noise sources and how to avoid them. For many years we investigated the effects that changes in external conditions have on the operation of broadband devices. We investigated...
The use of airborne remote sensing and the acquisition of multispectral imagery including infrared are permitted in an On-Site Inspection (OSI) under Paragraph 80 of Part 2 of the Protocol to the Treaty. This paper reports on the findings of field tests conducted by the Provisional Technical Secretariat (PTS) to ascertain the extent to which, and under which conditions, airborne imagery can...
Presently, the Main center of the special monitoring (MCSM) disposes two three-element small-aperture infrasonic arrays on Ukrainian territory that are located near Malin and Kamenets-Podol'skiy cities. The identification of seismic source in mine by infrasonic array can specify was it mining explosion or anthropogenic accident. The monitoring of large-scale atmospheric sources can also be as...
The seismometer is intended for mass observations. The pendulum of the seismometer has a period regulated up to 2 seconds . The feedback circuit is of the force-balance type. As the converter of fluctuations of the pendulum to an electric signal the differential capacitor converter is used with a resolution better 10E-10 m. The sensor electronic self-noise is below the NLNM from 100 sec to...
The CTBTO Link to the database of the International Seismological Centre (ISC) provides the CTBTO and the National Data Centres with a dedicated access to seismological data sets maintained by the ISC using specially designed graphical interfaces and database queries. The Link service gives access to a multitude of products: the ISC/ISS bulletins covering the natural seismicity of the Earth,...
With a mandate to reduce downtime related to use of electric coolers, the Engineering and Development Section of CTBTO started in 2009 a pilot project to evaluate implementation of liquid nitrogen (LN2) generators at IMS Radionuclide stations. A commercially available unit, produced by MMR Technologies, has been tested at IMS stations NZP47 (Kaitaia) during the last 4 years and FJP26 (Fiji)...
Two events crucial for monitoring of nuclear explosions under the CTBT occurred on February 12 and 15 and attracted attention of the mass media and scientists. Seismic waves from the underground event and infrasound waves from the meteorite are of extreme interest as well as various processes of energy conversion at the free surface. Infrasound station I45(RU) collocated with seismic array...
The Transportable Array (TA) component of the EarthScope USArray program is yielding unprecedented observations of seismic and infrasound wavefields, and providing the ability to image earthquake rupture at teleseismic distances and to observe intra-array seismicity at magnitudes of two and lower. The rolling deployment of the 400-station TA has occupied over 1,400 station sites across the...
Europe is currently investing heavily in coordination of its seismological research infrastructures and the products and services they provide through a wide variety of EC and national projects. The current status and on-going developments can described within roughly three categories: • Seismological data, including primary waveforms, metadata and primary measures (arrival times and amplitude...
The Comprehensive Nuclear Test-Ban-Treaty Organization (CTBTO) Capacity Building Project designed to equip and enhance the analytical skills of trainees of the beneficiary states, thereby resourcing Individual States with the requisite technical knowledge to fulfill their obligation under the treaty and make their own judgment of the nature of a suspicious event. The training programs include...
The human factor has special significance in the OSI regime; trained inspectors must implement OSI techniques, and Treaty provisions define both. These Treaty provisions result in a unique inspection regime because of the multiple technologies, the external inspectorate and the last minute definition of the inspection site. In addition to being a multi-national team, the inspection team will...
If a couple of visionary, scientists and daring engineering teams from all around the world managed to design a global system which is composed of several modular components individually, transport these all around the world, attach them to one another and connect them to the International Data Centre to form the International Monitoring System, it will sound very surprising that one of the...
Nuclear emergencies require fast and reliable information for governments as well as for the public and the scientific community. The Fukushima accident illustrated this necessity very well. People, even in large distances to the source of releases like in Europe, wanted to know whether and to which extent they might be affected. For evaluation of the radiological situation the global...
Application of various techniques including data analyses and integration is at the heart of a CTBT On-Site Inspection (OSI). In order to realistically test and develop these aspects, field exercises are conducted on a regular basis. In 2011, the Preparatory Commission approved the conduct of another Integrated Field Exercise, which will be held in Jordan in late 2014.
IFE14 represents a...
Recently the CTBTO has launched a global initiative to facilitate the development of the Regional Seismic Travel Time (RSTT) velocity model on a global scale by forming regional expert groups. Essential to this effort is to collect and develop new ground truth information covering the Southern hemisphere. Ground truth events collected in this project are added to the IASPEI Reference Event...
The morphological analysis method was applied for the extraction of quasi periodic signals from subwoofer. Signals were registered in August 2009 on science station of A.M. Obukhov Institute of Atmospheric Physics. The signals frequencies were 45, 75, 105, 130 Hz. Distance from sources were from 0 to 1255 m. The registration was carrying out during daytime and night. The effectivity of the...
The large-aperture seismic array NOA had a major instrumental upgrade in 1994 and has been operational with the very same configuration until recently. Over time the instruments became obsolete and spare parts were not longer available. NOA consists of 42 sites grouped into seven subarrays covering a total aperture of about 60 km. It had been equipped with 7 broadband 3C-sensors (one in each...
The National Data Centre Preparedness Exercises (NPE) simulate a fictitious violation of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) and are conducted by NDCs for NDCs with the aim to increase the awareness and preparedness of their duties. These exercises are regularly performed with different scenarios. For the NPE 2012 a seismic event from REB was selected as an internal source of a...
The shape of Vanuatu islands is a challenge to accurately locate earthquakes along the Vanuatu trench by the National Warning Center. Therefore regional cooperation between Vanuatu and New Caledonia is the best solution to this challenge. This cooperation is developed by a joint governmental project since January 2011 and through which the Vanuatu earthquake detection system has been...
The Democratic People’s Republic of Korea (DPRK) has announced that it conducted its third nuclear test. The seismic component of the CTBT verification system detected a clear signal from the expected test area in proximity to the locations of the previous tests in 2006 and 2009. The International Data Centre (IDC) estimated the magnitude at 4.9, which is larger than either of the previous...
The CTBT radionuclide monitoring system comprises a total of 80 stations; 63 were operational in March 2011 and able to detect particulate airborne radioactivity worldwide. When completed, 40 of the 80 stations will operate systems that can also detect the noble gas xenon. Certification of the stations results in a high level of technical standardization of the equipment and QA procedures are...
Events in the CTBTO Reviewed Event Bulletin must satisfy 'event definition criteria’ (REB-EDC). For seismic events these specify location-defining signals at a minimum of three IMS primary seismic stations, and a minimum score representing the number and type of location-defining parameters. Additional signal quality checks serve as 'implied’ REB-EDC. EDC were introduced at the prototype...
For the project flexRISK, which was devoted to the investigation of risks and hazards from hypothetical severe nuclear power plant accidents in Europe, atmospheric transport has been simulated for noble gases (no dry and wet deposition) and aerosols (with dry and wet deposition). Simulations were done for 2,800 cases distributed over 10 years so that climatological representativity is given....
Using global earthquake catalogs, we resolve that on average most of the parameters of the Omori law are dependent on faulting styles. Strike slip events, have lower aftershocks rate and K-value than thrust and normal events, respectively. Within the ETAS model strong K- and rate values are driven by high branching ratio. Within the same framework, a relatively higher branching ratio for the...
North Korea conducted the third underground nuclear explosion on February 12, 2013 in the northeastern part of Korean Peninsula, where North Korea executed their first and second underground nuclear explosions. Analysis on the data recorded at seismic stations of Korea Institute of Geoscience and Mineral Resources revealed that a seismic array located in an island of East Sea recorded the...
The great earthquake in Java region caused high tsunami damage for two decades. We determine the source parameters of the earthquakes based on seismic wave calculation. We calculate the formula using the teleseismic wave signal processing with the initial phase of P wave with bandpass filter 0.001 Hz to 5 Hz. The amount of teleseismic stations is 84 broadband seismometers. The results are the...
Seismic monitoring with waveform cross correlation has demonstrated a significant reduction in detection threshold, which may reach 0.5 magnitude units in the areas where master events with high quality templates are available. With the increasing completeness of the Reviewed Event Bulletin, a larger number of event hypotheses are also built in automatic processing. We have applied supervised...
The problem of automatic (in real time) recognition of seismic signals of the occurred earthquake is very important now. It is especially key for autonomous systems operating with an increased level of seismic noise, often having anthropogenous sources of an origin. This situation is typical when sensor systems are installed inside houses and buildings located in large cities or near big...
A web-based graphical user interface has been developed that provides the user with the capability of determining processing-end station state of health information for seismic, hydroacoustic and infrasound stations. The main visual feature is a station x time matrix with coloured cells that provide information on the health of a selected parameter for that time interval, which is usually set...
One of the main missions of the Capacity Building and Training Section of CTBTO is to publish Monthly Performance Reports timely and correctly. The report is based on all Reviewed Event Bulletins which were reviewed by the analysts for each month. These bulletins have the information such as origin times, locations, and magnitudes of the events, which could be used as a basic element for the...
We used the local MERapi AMphibious EXperiments (MERAMEX) data catalog that consists of 292 events from May to October 2004. The new data of regional events in the Java region were taken from the Meteorological Climatological and Geophysical Agency (MCGA) of Indonesia that consist of 882 events, which have at least 10 recording phases at each seismographic station from April 2009 to February...
TONGA - FIJI SEISMIC NETWORK INTRODUCTION. By Rennie Vaiomounga, Geologist, Ministry of Lands, Environment, Climate Change & Natural Resources. Tonga is located at the easternmost edge of the Australian plate and formed oceanic island arc in response to subduction of Pacific Plate beneath the Australian Plate. That cause high Seismic activities. WORK HAVE BEEN DONE Due to active seismic...
The majority of detection algorithms employed to identify signals within infrasound array data (e.g., Fisher-statistic detector, Progressive Multi-Channel Correlation) rely on the signal being coherent, or correlated, across the microbarographs within the array. The signal coherence allows the detector to distinguish signal from incoherent noise. Therefore, in order to optimize signal...
Due to low acoustic attenuation in the ocean, small acoustic events are recorded at ranges of thousands of kilometres on hydrophone arrays deployed in the SOund Fixing And Ranging (SOFAR) channel. On two arrays in the Indian Ocean, signals were identified generated by drifting icebergs that crack, disintegrate and collide. Acoustic source locations estimated from the signal bearings at the...
Accurate earthquake locations are crucial for investigating seismogenic processes, as well as for applications like verifying compliance to the Comprehensive Test Ban Treaty (CTBT). It is known that modeling errors of calculated travel times may have the effect of shifting the computed epicenters far from the real locations by a distance even larger than the size of the statistical error...
Electric and magnetic (EM) fields are generated within ocean currents moving through the earth’s magnetic field, and tsunami flows are also considered to generate EM fields in the ocean although its signal levels are very low. Recent advances in high precision measurements of EM fields enabled the seafloor measurements of the tsunami signals. In order to extract useful information from the...
There is a long history of unusual events (unexpected natural seismicity, man-made seismic events, bolides, etc.) that have caused concern in terms of international treaties or cooperative engagement. These concerns include suspicions of undeclared activities or viability of geophysical data to screen the source of signals with high fidelity. Although most “unusual events” are resolved with...
The Non-Proliferation Experiment (NPE) involved detonating 1 kiloton of chemical explosive in a subsurface cavity which also contained bottles of tracer gases. As an alternative to performing large chemical detonations to simulate gas transport from underground nuclear explosions (UNE), we have developed a new test bed for gas transport, release and detection studies using a former UNE cavity....
Following the claimed nuclear test in the Democratic People's Republic of Korea (DPRK) on 12 February 2013, spectral analysis of radionuclide and ATM simulation were performed by the NDC-2 in Japan which is in charge of analysing radionuclides. There was no detection of artificial radioactive particulates. However, there were several detections of radioxenon, although each activity...
Ninety eight groundwater samples collected from paleo-beach and its adjoining areas were analyzed using ICP-MS. Physico-chemical parameters were also measured in situ. Concentrations of U (<0.01 - 3.40 ug/l), and 4% of shallow tubewells (<30m deep) contained excess the WHO (1998) guideline, 2.0 ug/l and limited in paleo-beach area. Concentrations of Th (<0.01- 1.60 ug/l) and Ce (0.01 - 9.89...
This study suggests shared use of seismic data collectively acquired by different national & global apparatus for disaster prediction research. Techniques like, but not limited to, Pattern informatics have likelihood of success provided global dataset is studied in unison. Three main objectives suggested. Firstly, Event Prediction or Forecasting Secondly, Precise Event Detection and Thirdly,...
CTBTO radionuclide measurement data were widely used to describe the hemispheric-wide dispersion of radioactive aerosols after the nuclear accident in Fukushima in March 2011. Due to their high precision, these data are uniquely qualified for model validation. Especially the differences between the tracer-like noble gases and the aerosol-bound substances allow improved estimates of atmospheric...
The depth of moderate events (M<5.5) is difficult to estimate using regional datasets in poorly instrumented areas. Focal depths should be better constrained by teleseismic data but, in practice, for such small magnitude, the weak signal to noise ratio reduces the range of use; depth estimation remains challenging. However, nowadays, with access to the data of the CTBTO monitoring system,...
The concentrations of tritium have been determined outside "Degelen" site, as well as in settlements Kurchatov, Kaynar and Sarzhal adjacent to the STS. Accumulation of tritium has been estimated in the snow cover over the epicenters of underground nuclear explosions of some adits on "Degelen" site and warfare borehole 1355 on "Balapan" site. The major mechanisms for tritium inflow in the snow...
A quality assurance program for Noble Gas (NG) systems of IMS Radionuclide network is under development at PTS. Spiking NG systems with known amount of Xe-133/Xe-131m and reanalyzing spike samples at IMS Radionuclide laboratories with NG capability is part of the program. Remoteness and very difficult location of some IMS stations is preventing use of these two isotopes - due to their...
We have developed a methodology to construct high-resolution regional lithospheric attenuation models of the earth based on regional P and S-waves. The method uses Pn, Pg, Sn, and Lg amplitudes to simultaneously invert for the crust and upper mantle attenuation structure. The method was initially developed for the Middle East, then expanded to include most of Eurasia, and now we have...
The real time data processing in the IDC will be able to give rapid location parameters of underground nuclear explosion. However for those events with small magnitude there are usually only a few stations near the source or with low enough background-noise level will detect the signals from the event. As a result, the location uncertainty of events will be large and identifying the area for a...
The Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is sponsoring international cooperation activities that enhance the Regional Seismic Travel Time (RSTT) model. In order to assess current and future versions of the RSTT model, we are developing approaches to measure both RSTT prediction accuracy and the impact on seismic event locations. Validation of RSTT performance emphasizes...
At the 29th session of WGB the RF delegation officially stated that the E-training and simulation system software for OSI developed by VNIIA would be a gratuitous contribution of the Russian Federation to CTBT monitoring regime. At present the training system is being updated under the contracts between CTBTO PrepCom and VNIIA.
An expert system computer model that is intended for providing...
Thanks in large part to ongoing dialogue between the medical isotope production and nuclear explosion monitoring communities at events like the annual Workshop on the Signatures of Medical and Industrial Isotope Production (WOSMIP), the challenges that effluents from isotope production can create when monitoring for nuclear explosions are receiving due attention. The two communities have shown...
Tomographic inversion is applied to determine detailed three-dimensional velocity (Vp, Vs) structures beneath the Kalabsha area, Aswan by inverting the arrival time data from 731 events.
The results obtained from three- dimensional inversion shows a low P-wave velocity zone in the north-western side of the Kalabsha area elongated to the east direction around Seiyal fault and to the south...
The reduction of noble gas emissions from large radiopharmaceutical production facilities is a key issue in increasing the sensitivity of the International Noble Gas Monitoring Network. To study the possibility of increasing the efficiency of the current xenon traps in place at the Institute for Radioelements (IRE) a laboratory set-up for stable xenon was realized at SCK•CEN to investigate...
