Australian researchers develop new method to more accurately spot underground nuclear tests

Phys.org  February 7, 2024
Currently possible mis-classification of explosions as earthquakes currently limits the use of screening methods for verification of test-ban treaties. Researchers in Australia showed that populations of moment tensors for both earthquakes and explosions are anisotropically distributed on the hypersphere. They described a method that uses these elliptical distributions in combination with a Bayesian classifier to achieve successful classification rates of 99 per cent for explosions and 98 per cent for earthquakes using existing catalogues of events from the western United States. The 1983 May 5 Crowdie underground nuclear test and 2018 July 20 DAG-1 deep-borehole chemical explosion are the only two explosions out of 140 that are incorrectly classified. Application of the method to the 2006–2017 nuclear tests in the Democratic People’s Republic of Korea yielded 100 per cent identification rates. They provided a simple routine MTid for general usage. According to the researchers their approach provides a means to rapidly assess the likelihood of an event being an explosion and can be built into monitoring workflows that rely on simultaneously assessing multiple different discrimination metrics… read more. Open Access TECHNICAL ARTICLE