Sentinel Records Effects Of North Korean Nuclear Blast
Europe’s Sentinel-1a radar satellite has recorded the ground convulsion resulting from North Korea’s underground nuclear blast.
The data provided by Sentinel depicts a rock above the nuclear blast zone going down by up to 7 cm in one area and rising around 3 cm in another.
Germany’s Institute for Geosciences and Natural Resources (BGR) released the imagery of the aftermath. The Institute provides advice to the federal government on matters related to the Comprehensive Nuclear-Test-Ban Treaty (CTBT).
The Sentinel employs a technique called interferometry for sensing surface movements. The interferometry operates by finding the difference in “before” and “after” radar pictures of the Earth’s surface. the technique detects even subtle ground movements.
The North Korean media described the 6th of January event as a miniaturized hydrogen bomb detonation.
However, there has been no independent confirmation of this claim.
North Korea has performed four nuclear tests so far, in the years 2006, 2009, 2013 and 2016. All the nuclear tests were performed at the same site, called Punggye-ri, also known as P’unggye-yok, in a remote region in the east of the country, near the town of Kilju.
The Sentinel imagery refined the estimates of location that were picked up by the international seismometers. Sentinel-1a got its first view of the test site following the explosion on 13 January.
“This is a very important result because in the past the location of nuclear tests was based only on seismological data and now we have an indication from other technologies,” said BGR’s Nicolai Gestermann.
Dr Gestermann said that the estimated yield was 10 kilotons of TNT-equivalent, plus or minus three kilotons.
He said that the characteristics of the blast were very similar to the previous explosion conducted in 2013, suggesting the 6 January was not a hydrogen blast.
The BGR scientist was presenting his institute’s work here at the European Geosciences Union General Assembly.
The image provided by Sentinel was compared with an observation acquired on 1 January. The effects of both subsidence and uplift is evident in the imagery provided.
Seismologists say the bomb test had a magnitude of 5.1.