Identification of Seismic Events on and near the North Korean Test Site after the Underground Nuclear Test Explosion of 3 September 2017

2018 ◽  
Author(s):  
Won‐Young Kim ◽  
Paul G. Richards ◽  
David Schaff ◽  
Eunyoung Jo ◽  
Yonggyu Ryoo
Keyword(s):  
Test Site ◽  
Nuclear Test ◽  
Seismic Events ◽  
The North

scholarly journals Seismological investigation of the 2016 January 6 North Korean underground nuclear test

2016 ◽  
Vol 206 (3) ◽  
pp. 1487-1491 ◽  
Author(s):  
Lian-Feng Zhao ◽  
Xiao-Bi Xie ◽  
Wei-Min Wang ◽  
Jin-Lai Hao ◽  
Zhen-Xing Yao
Keyword(s):  
Body Wave ◽  
Broad Band ◽  
Test Site ◽  
Nuclear Test ◽  
The Body ◽  
The North ◽  
Nuclear Tests ◽  
Master Event ◽  
Fully Coupled ◽  
Body Wave Magnitude

Abstract Seismology plays an important role in characterizing potential underground nuclear tests. Using broad-band digital seismic data from Northeast China, South Korea and Japan, we investigated the properties of the recent seismic event occurred in North Korea on 2016 January 6. Using a relative location method and choosing the previous 2006 explosion as the master event, the 2016 event was located within the North Korean nuclear test site, with its epicentre at latitude 41.3003°N and longitude 129.0678°E, approximately 900 m north and 500 m west of the previous event on 2013 February 12. Based on the error ellipse, the relocation uncertainty was approximately 70 m. Using the P/S spectral ratios, including Pg/Lg, Pn/Lg and Pn/Sn, as the discriminants, we identify the 2016 event as an explosion rather than an earthquake. The body-wave magnitude calculated from regional wave Lg is mb(Lg) equal to 4.7 ± 0.2. Adopting an empirical magnitude–yield relation, and assuming that the explosion is fully coupled and detonated at a normally scaled depth, we find that the seismic yield is about 4 kt, with the uncertainties allowing a range from 2 to 8 kt.

scholarly journals The nucleation of the Izmit and Düzce earthquakes: Some mechanical logic on where and how ruptures began

2021 ◽  
Author(s):  
Michel Bouchon ◽  
Hayrullah Karabulut ◽  
Mustafa Aktar ◽  
Serdar Özalaybey ◽  
Jean Schmittbuhl ◽  
...  
Keyword(s):  
Strike Slip ◽  
Seismic Events ◽  
Fault Geometry ◽  
Brittle Transition ◽  
The North ◽  
Impending Rupture ◽  
Natural Tendency ◽  
Ductile To Brittle Transition ◽  
Mechanical Logic ◽  
Rupture Speed

Summary In spite of growing evidence that many earthquakes are preceded by increased seismic activity, the nature of this activity is still poorly understood. Is it the result of a mostly random process related to the natural tendency of seismic events to cluster in time and space, in which case there is little hope to ever predict earthquakes? Or is it the sign that a physical process that will lead to the impending rupture has begun, in which case we should attempt to identify this process. With this aim we take a further look at the nucleation of two of the best recorded and documented strike-slip earthquakes to date, the 1999 Izmit and Düzce earthquakes which ruptured the North Anatolian Fault over ∼200 km. We show the existence of a remarkable mechanical logic linking together nucleation characteristics, stress loading, fault geometry and rupture speed. In both earthquakes the observations point to slow aseismic slip occurring near the ductile-to-brittle transition zone as the motor of their nucleation.

Sign in / Sign up

Export Citation Format

Share Document