Measurements of Earthquake Moment Magnitude (Mw) to Estimate Detonation Energy of a Nuclear Bomb as Plutonium-240

Abstract

Observation of nuclear tests carried out by CTBTO utilizes seismic method. Seismic methods can be used to estimate the strength of seismic sources and seismic radiation energy emitted by seismic sources. Seismic waves originating from explosions can be found in the amount of radioactive material using atomic fission equation. From 2006 to 2017, seismic monitoring noted that North Korea conducted a nuclear test six times, namely on 9 October 2006 (mb 4.3), 25 May 2009 (mb 4.7), 12 February 2013 (mb 5.1), 6 January 2016 (mb 5.1), September 9, 2016 (mb 5.3), and September 3, 2017 (mb 6.3). The purpose of this study is to find a comparative value between seismic radiation energy and the energy of radioactive material Plutonium-240. This study used earthquakes originating from the September 3, 2017 nuclear explosion in North Korea. The waveforms used from INCN Station (Incheon, South Korea) were downloaded from IRIS. The processing of earthquake waveforms used Seismic Analysis Code (SAC) utilizing seismic radiation energy of primary wave approximately 30 seconds after the origin time. The results obtained include get moment magnitude (Mw) 6.4, seismic moment (Mo) = 6 × 1018 N.m, and seismic radiation energy (Es) = 3 × 1014 Joule. If energy Q = 4.18 × 106 Joules is energy that can be produced by 1 kg of TNT then the energy released by 72 kt TNT is equal to 72 times the energy released by a nuclear explosion on spontaneous fission of Plutonium-240.