IAG-IASPEI 2017

Presentation information

Poster

Joint Symposia » J02. Recent large and destructive earthquakes

[J02-P] Poster

Fri. Aug 4, 2017 3:00 PM - 4:00 PM Shinsho Hall (The KOBE Chamber of Commerce and Industry, 3F)

3:00 PM - 4:00 PM

[J02-P-09] Characterized source model for estimating strong ground motions during 2016 Tottori-ken Chubu Earthquake

Susumu Kurahashi1, Kojiro Irikura1, Ken Miyakoshi2 (1.Aichi Institute of Technology, Aichi, Japan, 2.Geo-Research Institute, Osaka, Japan)

Strong ground motions from the 2016 Tottori-ken Chubu earthquake (Mw6.2) struck in Kurayoshi city, Tottori prefecture, on Japan Sea side, on October 21, 2016. PGA of 1494 gal was observed at TTR005 (Kurayoshi,epicentral distance: 6km) station. We estimated the characterized source model, which explain broad-band strong motions, during this earthquake based on the results of the waveform inversion using the strong motion data and the empirical Green's function method.
First, we analyzed the slip distribution during this earthquake using the multi-time window linear waveform inversion method (Sekiguchi et al., 2000). Target frequency range is 0.1-1.0Hz. As a result, large slip area was constructed round the hypocenter. Seismic moment of the estimated model is 2.0*10^18Nm.
Next, the characterized source model was constructed based on the slip distribution from the waveform inversion. We extracted asperity from the slip distribution and high rate area (HRA) from the moment rate distribution by the criterion of Somerville et al. (1999). The area and location of the asperity and the HRA are estimated to be nearly the same.
Finally, we analyzed the SMGA model using the empirical Green's function method (Irikura, 1986). We attempted to examine whether the strong ground motions at TTR005 located very near the fault plane are simulated. Target frequency range is 0.3-10.0Hz. As a result, the location of the SMGA is nearly the same as the estimated large slip area from the waveform inversion results. The scaling relationship SMGA area versus seismic moment is consistent with on that of combined area of asperities versus seismic moment by the previous study (Irikura and Miyake, 2001). The asperity, the HRA and the SMGA of this earthquake are collocated with nearly the same area.