2021/09/27 by Ivan Kitov, Kitov, Ivan, Dmitry Bobrov +3
Computer Science · Earth and Planetary Sciences · #Earthquake Detection and Analysis #FOS: Physical sciences #Geophysics (physics.geo-ph) #High-pressure geophysics and materials #Physics and Society (physics.soc-ph) #Seismology and Earthquake Studies #earthquake and tectonic studies
paper · pdf · doi:10.48550/arxiv.2110.10071
openalex publication_date 2021/09/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The multi-master method based on waveform cross-correlation has found several\naftershocks of the third (DPRK3) and the fourth (DPRK4) announced underground\nnuclear tests conducted by the DPRK on 12.02.2013, and 06.01.2016,\nrespectively. The second DPRK test had no reliable aftershock hypotheses at the\nlevel of the method sensitivity and resolution. The closest to the test site\narray station USRK was not operational before 20.12.2008 and the first DPRK\ntest cannot be analyzed by the multi-master method based on waveform templates\nfrom two IMS stations - USRK and KSRS. The largest aftershocks of the DPRK3 and\nDPRK4 are close in magnitude to the first aftershock of the DPRK5 on\n11.09.2016, and many aftershocks of the DPRK6. Three big aftershocks of the\nDPRK3 occurred on 25.05.2014, i.e. 467 days after the mainshock. The DPRK3\naftershock found at 6:43:03 UTC had a relative magnitude of 2.91. There were\nfound two aftershocks of the DPRK4: on 19.02.2016 (0:28:07 UTC) and on\n02.07.2016 (19:52:27 UTC). The largest aftershocks of the DPRK3 and DPRK4 could\nbe interpreted as related to the cavity collapse process likely followed by a\nchimney collapse, not reaching the free surface, however, as no noble gases\nand/or radionuclide particles were detected. Seismic signals from all events\nfound before the DPRK5 (09.09.2016), had a high level of cross-correlation with\nthe waveform templates of the DRPK5 and DPRK6. These signals prove the shape\nsimilarity, and thus, the close spatial proximity of the seismic events after\nDPRK3/DPRK4 to the DPRK5/DPRK6 aftershocks. There were no other events found by\nthe multi-master method since 01.01.2009, even when the highest resolution\nregime was used. The resolution and sensitivity of the multi-master method were\ntuned and tested using the data after 09.09.2016.\n