Japan Geoscience Union Meeting 2015

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Symbol S (Solid Earth Sciences) » S-SS Seismology

[S-SS29] Fault Rheology and Earthquake Dynamics

Sun. May 24, 2015 4:15 PM - 6:00 PM A05 (APA HOTEL&RESORT TOKYO BAY MAKUHARI)

Convener:*Wataru Tanikawa(Japan Agency for Marine-Earth Science and Technology, Kochi Instutute for Core Sample Research), Takeshi Iinuma(International Research Institute of Disaster Science, Tohoku University), Yuta Mitsui(Department of Geosciences, Graduate School of Science, Shizuoka University), Hideki Mukoyoshi(Department of Geoscience Interdisciplinary Graduate School of Science and Engineering, Shimane University), Chair:Yuta Mitsui(Department of Geosciences, Graduate School of Science, Shizuoka University), Takeshi Iinuma(International Research Institute of Disaster Science, Tohoku University)

4:45 PM - 5:00 PM

★ [SSS29-12] Crustal deformation and stress accumulation process in and around the Atotsugawa fault system

*Youichiro TAKADA1 (1.Disaster Prevention Research Institute, Kyoto University)

Keywords:Atotsugawa Fault, Stress Field, GNSS, InSAR

I introduce recent two extensive surveys conducted in and around the Atotsugawa fault system. First is the joint seismic observation by university group during 2004 to 2008. With this seismic data, I have estimated the focal mechanisms of small earthquakes and tectonic stress field by using stress inversion methods. Second is to estimate the inter-seismic crustal deformation with very high spatial resolution using GNSS and InSAR time series analysis. The estimated stress rotation can be explained by a viscoelastic dislocation model assuming cumulative slip deficit relative to surrounding part up to several tens of meters. On the other hand, the geodetic data indicate strain concentration near the fault trace, which may require a minor change of the fault model. However, the velocity fields still include systematic error coming from atmospheric and/or tropospheric disturbances. Farther noise reduction is required to constrain the physical model.