Nuclear weapons, arms control, nuclear detection, North Korea | Homeland Security Newswire

North Korea’s nukesMountain collapsed in North Korea after most recent nuclear test

Published 14 May 2018

As North Korea’s president pledges to “denuclearize” the Korean peninsula, scientists published the most detailed view yet of the site of the country’s latest and largest underground nuclear test on 3 September 2017. The new picture of how the explosion altered the mountain above the detonation highlights the importance of using satellite radar imaging, called SAR (synthetic aperture radar), in addition to seismic recordings to more precisely monitor the location and yield of nuclear tests in North Korea and around the world.

As North Korea’s president pledges to “denuclearize” the Korean peninsula, an international team of scientists is publishing the most detailed view yet of the site of the country’s latest and largest underground nuclear test on 3 September 2017.

The new picture of how the explosion altered the mountain above the detonation highlights the importance of using satellite radar imaging, called SAR (synthetic aperture radar), in addition to seismic recordings to more precisely monitor the location and yield of nuclear tests in North Korea and around the world.

The researchers reported their results in the journal Science.

That explosion took place under Mt. Mantap at the Punggye-ri nuclear test site in the country’s north, rocking the area like a 5.2-magnitude earthquake. Based on seismic recordings from global and regional networks, and before-and-after radar measurements of the ground surface from Germany’s TerraSAR-X and Japan’s ALOS-2 radar imaging satellites, the team showed that the underground nuclear blast pushed the surface of Mt. Mantap outward by as much as 11 feet (3.5 meters) and left the mountain about 20 inches (0.5 meters) shorter.

Berkeley says that by modelling the event on a computer, they were able to pinpoint the location of the explosion, directly under the mile-high summit, and its depth, between a quarter and a third of a mile (400-600 meters) below the peak.

They also located more precisely another seismic event, or aftershock, that occurred 8.5 minutes after the nuclear explosion, putting it some 2,300 feet (700 meters) south of the bomb blast. This is about halfway between the site of the nuclear detonation and an access tunnel entrance and may have been caused by the collapse of part of the tunnel or of a cavity remaining from a previous nuclear explosion.

“This is the first time the complete three-dimensional surface displacements associated with an underground nuclear test were imaged and presented to the public,” said lead author Teng Wang of the Earth Observatory of Singapore at Nanyang Technological University.