Clustering analysis of seismicity in the space-time-depth-magnitude domain preceding the 2016 Kumamoto earthquake, Southwestern Japan


Ansari K., Bae T.

INTERNATIONAL JOURNAL OF EARTH SCIENCES, cilt.110, sa.1, ss.253-261, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 110 Sayı: 1
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1007/s00531-020-01950-5
  • Dergi Adı: INTERNATIONAL JOURNAL OF EARTH SCIENCES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aquatic Science & Fisheries Abstracts (ASFA), CAB Abstracts, Geobase, INSPEC, Pollution Abstracts
  • Sayfa Sayıları: ss.253-261
  • Karadeniz Teknik Üniversitesi Adresli: Hayır

Özet

This analysis is an extension of the studies based on the space-time-magnitude domain nearest-neighborhood distances (n) obtained from two successive earthquakes. We included epicentral depth as a parameter, and established a new analytical solution for seismicity clustering in the space-time-depth-magnitude domain. The proposed technique was applied to SW Japan seismic observation data for 2011-2018, and revealed that the temporal, spatial, and epicentral (T, R, E) components of the joint distribution for n were prominently bimodal, indicating the presence of two, statistically distinct, earthquake populations. We used the Lomb-Scargle periodogram (LSP) to generate a power spectrum preceding the Kumamoto earthquake, and detected the periodic component of unequally spaced points for log(10)n (logarithmic scale of n). The LSP showed a dominant peak corresponding to the time period between foreshocks and aftershocks, due to the highest number of recorded n observations. The technique presented in this paper can be applied globally for any time period and any seismotectonic zone preceding large earthquakes of interest.