Japan Geoscience Union Meeting 2016

Presentation information


Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS34] The 2016 Kumamoto Earthquake and related crustal activities

Thu. May 26, 2016 3:30 PM - 4:45 PM Poster Hall (International Exhibition Hall HALL6)

5:15 PM - 6:30 PM

[MIS34-P51] Geometry and kinematics of surface fault ruptures produced by the 2016 Mw 7.0 Kumamoto earthquake: Computerized X-ray tomography analysis of three dimensional fault geometries in basement-induced oblique-slip faulting

*Keiichi Ueta1, Kazuo Mizoguchi1, Keitaro Komura1, Shiro Tanaka1, Toshinori Sasaki1, Koutarou Aiyama1, Yasuhira Aoyagi1 (1.Central Research Institute of Electric Power Industry)

The 2016 Mw 7.0 Kumamoto earthquake produced surface ruptures along the Futagawa and Hinagu fault zones. The surface ruptures consist of ENE-WSW trending right-lateral faults, WNW-ESE trending left-lateral faults and ENE-WSW trending normal faults. We perform sandbox experiments by using X ray CT scanner to analyze the kinematic evolution, as well as the three –dimensional geometry, of faults in basement-controlled oblique-slip faulting. The geometry of the shear bands (Riedel shear and antithetic Riedel shear) in the experimental model shows a strong resemblance to the surface ruptures along the Futagawa fault zone. These complex surface ruptures may result from the effect of thick overburden consisting of Quaternary sediments and pyroclastic- flows.