10:00 AM - 10:15 AM
[SSS10-11] The seismic attenuation structure in the focal area of the 2016 Kumamoto earthquake
Keywords:The 2016 Kumamoto earthquake, seismic attenuation, Futagawa - Hinagu fault zone
Small scale heterogeneity in the earth is evaluated from attenuation factors of seismic waves as Q-1 value. We analyzed data before and after the 2016 Kumamoto earthquake and estimated the Q-1 values for both intrinsic and scattering attenuation. To estimate spatial distribution of the attenuation factors, Del Pezzo et al. (2016) had proposed a method in which the spatial weighting functions for estimated Q-1 values of many source-receiver pairs was adopted. However, the weighting function was not applicable to our data because of various hypocentral distance until several tens kilometers. Therefore, in this study, we consider the appropriate weighting function by Monte-Carlo simulation and estimate the Q-1 structure in the hypocentral area of the 2016 Kumamoto earthquake.
We used data by JMA, NIED, Kyoto and Kyushu Universities. We are grateful to Dr. Hoshiba for the computation program of Monte-Carlo simulation.