EarthquakesExplosion, collapse, earthquakes: North Korea’s 2017 nuclear test

Published 28 September 2018

The epicenter of the 3 September 2017 nuclear test explosion in North Korea occurred about 3.6 kilometers northwest of the country’s first nuclear test in October 2006, according to a new high-precision analysis of the explosion and its aftermath. The study used regional seismic data collected from a number of sources to locate the 2017 test, and to confirm that subsequent seismic events were not also nuclear explosions.

The epicenter of the 3 September 2017 nuclear test explosion in North Korea occurred about 3.6 kilometers northwest of the country’s first nuclear test in October 2006, according to a new high-precision analysis of the explosion and its aftermath.

The study published in Seismological Research Letters by Lian-Feng Zhao of the Chinese Academy of Sciences and colleagues used regional seismic data collected from a number of sources to locate the 2017 test, and to confirm that subsequent seismic events were not also nuclear explosions.

Their paper is published as part of the journal’s special focus section on the September 2017 North Korean explosion. The body-wave magnitude 6.1 underground test by the Democratic People’s Republic of Korea (DPRK) is the largest such test in more than 20 years, and is the sixth declared nuclear test by the DPRK since 2006. The September explosion is an order of magnitude larger than the next largest test by the country, which occurred in September 2016.

SSA says that Zhao and colleagues used seismic wave data from 255 seismograph stations in the China National Digital Seismic Network, Global Seismic Network, International Federation of Digital Seismograph Networks and Full Range Seismograph Network in Japan to investigate the explosion and three other seismic events that occurred in the minutes and days after.

Although global seismic networks may pick up the signal of underground nuclear tests, the signals they detect are often too weak to be to be used in the kind of location analysis performed by Zhao and colleagues. “The closer to the sources the better,” said Zhao. “However, seismometers cannot be deployed in the North Korean test site due to political issues. Thus, seismologists have developed methods that can be applied to regional seismic data to investigate seismic characteristics of the underground nuclear explosions.”