[S-SS12] Statistical seismology and underlying physical processes

[SSS12-02] Natural time analysis of seismicity before the 2016 Kumamoto earthquake

*Kei Katsumata¹ (1.Institute of Seismology and Volcanology, Hokkaido University)

Keywords:seismicity, Natural time analysis, Kumamoto earthquake

Natural time analysis of seismicity was presented by Varotsos et al. (2011) and improved by Sarlis et al. (2013). Sarlis et al. (2013) defined beta-value that is a statistical parameter calculated using seismic activity and natural time, and they argued that the beta-value for the seismicity before the major earthquakes with M7.6 or larger in Japan became minimum several days to a week before the main shock. In this study we applied the method developed by Sarlis et al. (2013) to the seismicity before the 2016 Kumamoto earthquake (M7.3). As a result, the beta-value was minimum on October 20, 2013, that is, approximately 2.5 years before the Kumamoto earthquake. This result seems to be not consistent with those obtained by Sarlis et al. (2013).
Sarlis et al. (2013) Minimum of the order parameter fluctuations of seismicity before major earthquakes in Japan, PNAS 110(34), 13734-13738.