[SSS06-P02] Development of a high-frequency earthquake rupture imaging method at the regional scale; application to the 2016 Kumamoto earthquakes
Keywords:earthquake rupture, crustal earthquake, regional back projection
We investigate a volume containing the rupture area and localize in space and time extended zones with relatively large energy release in the studied frequency band. Those extended zones are the high frequency generation areas and they are compared to the location in space and time of asperities derived from strong-motion waveforms inversion [Asano et al. 2016; Kubo et al. 2016; Kobayashi et al. 2017]. We establish a first link between the size of the generation areas and the amount of released energy by studying, as simple cases, point source-like earthquakes. Furthermore, an iterative back projection method [Yao et al. 2012] is applied to remove step by step from the records the pulses associated with the main strong groung motion area in order to be able to identify secondary generation areas.