Estimation of Background Noise for International Monitoring System Seismic Stations

2002 ◽  
Vol 159 (5) ◽  
pp. 911-944 ◽  
Author(s):  
M. Bahavar ◽  
R. North
Keyword(s):  
Monitoring System ◽  
Background Noise ◽  
International Monitoring System ◽  
Seismic Stations ◽  
International Monitoring

scholarly journals A Multi-Technology Analysis of the 2017 North Korean Nuclear Test

2018 ◽  
Author(s):  
Peter Gaebler ◽  
Lars Ceranna ◽  
Nima Nooshiri ◽  
Andreas Barth ◽  
Simone Cesca ◽  
...  
Keyword(s):  
Monitoring System ◽  
Body Wave ◽  
Test Site ◽  
Nuclear Test ◽  
International Monitoring System ◽  
Seismic Stations ◽  
Technology Analysis ◽  
Tnt Equivalent ◽  
International Monitoring ◽  
Strong Surface

Abstract. On September 3rd 2017 official channels of the Democratic People's Republic of Korea announced the successful test of a thermonuclear device. Only seconds to minutes after the alleged nuclear explosion at the Punggye-ri nuclear test site in the mountainous region in the country's northeast at 03:30:02 (UTC) hundreds of seismic stations distributed all around the globe picked up strong and distinct signals associated with an explosion. Different seismological agencies reported body wave magnitudes of well above 6.0, consequently estimating the explosive yield of the device in the order of hundreds of kilotons TNT equivalent. The 2017 event can therefore be assessed being multiple times larger in energy than the two preceding events in January and September 2016. This study provides a multi-technology analysis of the 2017 North Korean event and its aftermath using a wide array of geophysical methods. Seismological investigations locate the event within the test site at a depth of approximately 0.8 km below surface. The radiation and generation of P- and S-wave energy in the source region is significantly influenced by the topography of the Mt. Mantap massif. Inversions for the full moment tensor of the main event reveal a dominant isotropic component accompanied by significant amounts of double couple and compensated linear vector dipole terms, confirming the explosive character of the event. Analysis of the source mechanism of an aftershock that occurred around eight minutes after the test in the direct vicinity suggest a cavity collapse. Measurements at seismic stations of the International Monitoring System result in a body wave magnitude of 6.2, which translates to an yield estimate of around 400 kilotons TNT equivalent. The explosive yield is possibly overestimated, since topography and depth phases both tend to ehance the peak amplitudes of teleseismic P-waves. Interferometric Synthetic-Aperture-Radar analysis using data from the ALOS-2 satellite reveal strong surface deformations in the epicenter region. Additional multispectral optical data from the Pleiades satellite show clear landslide activity at the test site. The strong surface deformations generated large acoustic pressure peaks, which were observed as infrasound signals with distinctive waveforms even in distances of 400 km. In the aftermath of the 2017 event atmospheric traces of the fission product 133Xe have been detected at various locations in the wider region. While for 133Xe measurements in September 2017 the Punggye-ri test site is disfavored as source by means of atmospheric transport modeling, detections in October 2017 at the International Monitoring System station RN58 in Russia indicate a potential delayed leakage of 133Xe at the test site from the 2017 North Korean nuclear test.

scholarly journals A multi-technology analysis of the 2017 North Korean nuclear test

Solid Earth ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 59-78 ◽  
Author(s):  
Peter Gaebler ◽  
Lars Ceranna ◽  
Nima Nooshiri ◽  
Andreas Barth ◽  
Simone Cesca ◽  
...  
Keyword(s):  
Monitoring System ◽  
Body Wave ◽  
Test Site ◽  
Nuclear Test ◽  
International Monitoring System ◽  
Seismic Stations ◽  
Technology Analysis ◽  
Tnt Equivalent ◽  
International Monitoring ◽  
Strong Surface

Abstract. On 3 September 2017 official channels of the Democratic People's Republic of Korea announced the successful test of a thermonuclear device. Only seconds to minutes after the alleged nuclear explosion at the Punggye-ri nuclear test site in the mountainous region in the country's northeast at 03:30:02 (UTC), hundreds of seismic stations distributed all around the globe picked up strong and distinct signals associated with an explosion. Different seismological agencies reported body wave magnitudes of well above 6.0, consequently estimating the explosive yield of the device on the order of hundreds of kT TNT equivalent. The 2017 event can therefore be assessed as being multiple times larger in energy than the two preceding North Korean events in January and September 2016. This study provides a multi-technology analysis of the 2017 North Korean event and its aftermath using a wide array of geophysical methods. Seismological investigations locate the event within the test site at a depth of approximately 0.6 km below the surface. The radiation and generation of P- and S-wave energy in the source region are significantly influenced by the topography of the Mt. Mantap massif. Inversions for the full moment tensor of the main event reveal a dominant isotropic component accompanied by significant amounts of double couple and compensated linear vector dipole terms, confirming the explosive character of the event. The analysis of the source mechanism of an aftershock that occurred around 8 min after the test in the direct vicinity suggest a cavity collapse. Measurements at seismic stations of the International Monitoring System result in a body wave magnitude of 6.2, which translates to an yield estimate of around 400 kT TNT equivalent. The explosive yield is possibly overestimated, since topography and depth phases both tend to enhance the peak amplitudes of teleseismic P waves. Interferometric synthetic aperture radar analysis using data from the ALOS-2 satellite reveal strong surface deformations in the epicenter region. Additional multispectral optical data from the Pleiades satellite show clear landslide activity at the test site. The strong surface deformations generated large acoustic pressure peaks, which were observed as infrasound signals with distinctive waveforms even at distances of 401 km. In the aftermath of the 2017 event, atmospheric traces of the fission product 133Xe were detected at various locations in the wider region. While for 133Xe measurements in September 2017, the Punggye-ri test site is disfavored as a source by means of atmospheric transport modeling, detections in October 2017 at the International Monitoring System station RN58 in Russia indicate a potential delayed leakage of 133Xe at the test site from the 2017 North Korean nuclear test.

scholarly journals Performance of the International Monitoring System Seismic Network Based on Ambient Seismic Noise Measurements

2021 ◽  
Author(s):  
Peter J. Gaebler ◽  
Lars Ceranna
Keyword(s):  
Monitoring System ◽  
Body Wave ◽  
Seismic Network ◽  
International Monitoring System ◽  
Detection Capability ◽  
Seismic Stations ◽  
Nuclear Explosions ◽  
International Monitoring ◽  
Test Ban ◽  
Body Wave Magnitude

AbstractAll nuclear explosions are banned by the Comprehensive Nuclear-Test-Ban Treaty. In the context of the treaty a verification regime was put into place to detect, locate, and characterize nuclear explosions at any time, by anyone and everywhere on the Earth. The International Monitoring System, which plays a key role in the verification regime, was set up by the Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization. Out of the several different monitoring techniques applied in the International Monitoring System the seismic waveform approach is the most effective and reliable technology for monitoring nuclear explosions underground. This study introduces a deterministic method of threshold monitoring that allows to asses a lower body wave magnitude limit of a potential seismic event in a certain geographical region, that can be detected by those seismic stations being part of the International Monitoring System network. The method is based on measurements of ambient seismic noise levels at the individual seismic stations along with global distance corrections terms for the body wave magnitude. The results suggest that an average global detection capability of approximately body wave magnitude 4.0 can be achieved using only stations from the primary seismic network of the International Monitoring System. The incorporation of seismic stations from the auxiliary seismic network leads to a slight improvement of the detection capability, while the use and analysis of wave arrivals from distances greater than 120$$^\circ$$ ∘ results in a significant improvement of the detection capability. Temporal variations in terms of hourly and monthly changes of the global detection capability can not be observed. Overall, comparisons between detection capability and manually retrieved body wave magnitudes from the Reviewed Event Bulletin suggest, that our method yields a more conservative estimation of the detection capability and that in reality detection thresholds might be even lower than estimated.

Infrasound station IS25 of the International Monitoring System of the Comprehensive Test Ban Treaty : from design to certification

2021 ◽  
Author(s):  
thomas philippe ◽  
sylvain carre
Keyword(s):  
Monitoring System ◽  
International Monitoring System ◽  
Comprehensive Test Ban Treaty ◽  
Monitoring Tools ◽  
International Monitoring ◽  
Deep Forest ◽  
International Data ◽  
Comprehensive Test ◽  
Test Ban ◽  
Test Ban Treaty

<p>CEA is operating the French segment of the International Monitoring System of the Comprehensive Test Ban Treaty (CTBT). Construction of IMS stations was started on the late 90’ and one last station was pending before completing commitment of France.</p><p>Taking into account experience learned over the years, design was thought to combine enhanced detection capability and robustness. It gives also the opportunity to improve out monitoring tools and technics.</p><p>Station run 9 sensors spread out on a deep forest in Guadeloupe; power is distributed with buried cable while data are received with optical fibre to a central facility from which frames are sent to the International Data Center to the CTBTO. Constructiion was carried out in 2019.</p><p>IS25 was certified by the PTS of the CTBTO in November 2020</p>

Teleseismic slowness-azimuth station corrections for the International Monitoring System Seismic Network

1999 ◽  
Vol 89 (4) ◽  
pp. 989-1003 ◽  
Author(s):  
István Bondár ◽  
Robert G. North ◽  
Gregory Beall
Keyword(s):  
Monitoring System ◽  
Global Network ◽  
Systematic Bias ◽  
International Monitoring System ◽  
Time Data ◽  
International Monitoring ◽  
Event Location ◽  
Systematic Biases ◽  
Predicted Values ◽  
Test Ban

Abstract The prototype International Data Center (PIDC) in Arlington, Virginia, has been developing and testing software and procedures for use in the verification of the Comprehensive Test Ban Treaty. After three years of operation with a global network of array and three-component stations, it has been possible to characterize various systematic biases of those stations that are designated in the Treaty as part of the International Monitoring System (IMS). These biases include deviations of azimuth and slowness measurements from predicted values, caused largely by lateral heterogeneity. For events recorded by few stations, azimuth and slowness are used in addition to arrival-time data for location by the PIDC. Corrections to teleseismic azimuth and slowness observations have been empirically determined for most IMS stations providing data to the PIDC. Application of these corrections is shown to improve signal association and event location. At some stations an overall systematic bias can be ascribed to local crustal structure or to unreported instrumental problems. The corrections have been applied in routine operation of the PIDC since February 1998.

scholarly journals Volcano Infrasound and the International Monitoring System

2018 ◽  
pp. 1023-1077 ◽  
Author(s):  
Robin Matoza ◽  
David Fee ◽  
David Green ◽  
Pierrick Mialle
Keyword(s):  
Monitoring System ◽  
International Monitoring System ◽  
International Monitoring
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