Seismological Evidence for a Low-Yield Nuclear Test on 12 May 2010 in North Korea

Zhang, Miao; Wen, Lianxing

doi:10.1785/02201401170

Cited by 40 publications

(38 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such an azimuthal pattern of P wave polarities indicates that the event is a naturally occurring earthquake. The P / S spectral ratio of regional phases of event 20170923EQ2 are also markedly different from those of explosions in this region (Figure S4), excluding the possibility of event 20170923EQ2 being another explosion (Richards & Kim, ; Zhang & Wen, ; Zhao et al, ). Grid search of all possible double‐couple source parameters shows that the observed P wave polarities can be explained by nearly pure strike slip along the east‐west or north‐south direction with a high dip angle of 50°–90° (Figure ).…”

Section: Focal Mechanisms and Source Depths Of The Earthquake Swarm Omentioning

confidence: 84%

“…Event 20170903CL produced the same first motion for all P waves recorded (Figures c, S1a, and S3b) and completely reversed Rayleigh waveforms (Figures d, S3d, and S8) with respect to those of the nuclear test 20170903EP. This information coupled with the comparisons of P/S spectral ratios of regional phases (Richards & Kim, ; Zhang & Wen, ; Zhao et al, ) with those of nuclear tests (Figure S4) excludes the possibility of event 20170903CL being another explosion. An explosion would not produce the reversed Rayleigh waveforms and the spectral ratios below those of nuclear tests in the region.…”

Section: Source Mechanism Of the Event Eight‐and‐a‐half Minutes Aftermentioning

confidence: 95%

See 1 more Smart Citation

Collapse and Earthquake Swarm After North Korea's 3 September 2017 Nuclear Test

Tian

Yao

Wen

2018

Geophysical Research Letters

View full text Add to dashboard Cite

North Korea's 3 September 2017 nuclear test was followed by several small seismic events, with one eight-and-a-half minutes after the test and three on and after 23 September 2017. Seismic analysis reveals that the first event is a near vertical on-site collapse toward the nuclear test center from 440 ± 260 m northwest of the test site, with its seismic source best represented by a single force with a dip angle of 70°-75°and an azimuth of~150°, and the later events are an earthquake swarm located 8.4 ± 1.7 km north of the test site within a region of 520 m, with a focal depth of at least 2.4 km and a focal mechanism of nearly pure strike slip along the north-south direction with a high dip angle of 50°-90°. The occurrence of the on-site collapse calls for continued monitoring of any leaks of radioactive materials from the test site.Plain Language Summary On 3 September 2017, the Democratic People's Republic of Korea (North Korea) announced that it had successfully conducted a thermonuclear (hydrogen bomb) test. The nuclear test was followed by several reported small seismic events occurring in the region. While there have been intense interests and concerns about what has happened after the nuclear test among the scientific community, governmental agencies, and the public, the nature of those events is unknown. In this study, we present high-precision relative locations and detailed source characteristics of the small events following the test. Seismic analysis reveals that the first event occurring eight-and-a-half minutes after the test is a near vertical on-site collapse toward the nuclear test center from 440 ± 260 m northwest of the nuclear test site, with its seismic source best represented by a near vertical single force, and the later three events on and after 23 September 2017 are an earthquake swarm located 8.4 ± 1.7 km north of the nuclear test site within a region of 520 m, with an event depth of at least 2.4 km. The occurrence of the on-site collapse calls for continued monitoring of any leaks of radioactive materials from the test site.

show abstract

Section: Focal Mechanisms and Source Depths Of The Earthquake Swarm Omentioning

confidence: 84%

Section: Source Mechanism Of the Event Eight‐and‐a‐half Minutes Aftermentioning

confidence: 95%

Collapse and Earthquake Swarm After North Korea's 3 September 2017 Nuclear Test

Tian

Yao

Wen

2018

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…This study successfully applies the M&L technique to microseismic monitoring in a reservoir scale, which is distinctly different from earthquake or nuclear test monitoring in regional or global scale (Zhang & Wen, , ). The iMLT differs from the regular M&L technique in several key aspects.…”

Section: Discussionmentioning

confidence: 99%

Microseismic Monitoring of Stimulating Shale Gas Reservoir in SW China: 1. An Improved Matching and Locating Technique for Downhole Monitoring

et al. 2018

View full text Add to dashboard Cite

We introduce an improved matching and locating technique to detect and locate microseismic events (−4 < ML < 0) associated with hydraulic fracturing treatment. We employ a set of representative master events to act as template waveforms and detect slave events that strongly resemble master events through stacking cross correlograms of both P and S waves between the template waveforms and the continuous records of the monitoring array. Moreover, the residual moveout in the cross correlograms across the array is used to locate slave events relative to the corresponding master event. In addition, P wave polarization constraint is applied to resolve the lateral extent of slave events in the case of unfavorable array configuration. We first demonstrate the detectability and location accuracy of the proposed approach with a pseudo‐synthetic data set. Compared to the matched filter analysis, the proposed approach can significantly enhance detectability at low false alarm rate and yield robust location estimates of very low SNR events, particularly along the vertical direction. Then, we apply the method to a real microseismic data set acquired in the Weiyuan shale reservoir of China in November of 2014. The expanded microseismic catalog provides more easily interpretable spatiotemporal evolution of microseismicity, which is investigated in detail in a companion paper.

show abstract

“…Non-IMS infrasound stations will not be considered here [Che et al, 2009]. A suggested fifth test in 2010 is disputed and will not be discussed, as it would have had a too small yield to be detected with infrasound [Zhang and Wen, 2015].…”

Section: 1002/2016gl068497mentioning

confidence: 99%

On the infrasound detected from the 2013 and 2016 DPRK's underground nuclear tests

Assink

Averbuch

Smets

et al. 2016

Geophysical Research Letters

View full text Add to dashboard Cite

The underground nuclear tests by the Democratic People's Republic of Korea (DPRK) generated atmospheric infrasound both in 2013 and 2016. Clear detections were made in the Russian Federation (I45RU) and Japan (I30JP) in 2013 at stations from the International Monitoring System. Both tropospheric and stratospheric refractions arrived at the stations. In 2016, only a weak return was potentially observed at I45RU. Data analysis and propagation modeling show that the noise level at the stations and the stratospheric circumpolar vortex were different in 2016 compared to 2013. As the seismic magnitude of the 2013 and 2016 nuclear test explosions was comparable, we hypothesize that the 2016 test occurred at least 1.5 times deeper. In such a case, less seismic energy would couple through the lithosphere‐atmosphere interface, leading to less observable infrasound. Since explosion depth is difficult to estimate from seismic data alone, this motivates a synergy between seismics and infrasonics.

show abstract

Seismological Evidence for a Low-Yield Nuclear Test on 12 May 2010 in North Korea

Abstract: Location uncertainty estimation; figures of waveform comparison, location maps, and Pg/Lg spectral ratios; tables of earthquake parameters and Lg-wave amplitude ratios.

Cited by 40 publications

References 26 publications

Collapse and Earthquake Swarm After North Korea's 3 September 2017 Nuclear Test

Collapse and Earthquake Swarm After North Korea's 3 September 2017 Nuclear Test

Microseismic Monitoring of Stimulating Shale Gas Reservoir in SW China: 1. An Improved Matching and Locating Technique for Downhole Monitoring

On the infrasound detected from the 2013 and 2016 DPRK's underground nuclear tests

Contact Info

Product

Resources

About