JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

S (Solid Earth Sciences) » S-SS Seismology

[S-SS07] [EE] Surface Ruptures During Earthquakes: Mapping, Analyses, and Hazard Assessment

Wed. May 24, 2017 1:45 PM - 3:15 PM Poster Hall (International Exhibition Hall HALL7)

convener:Koji Okumura(Graduate School of Letters, Hiroshima University), St?phane Baize(Institut de Radioprotection et de S?ret? Nucl?aire), Nobuhisa Matsuta(Okayama University Graduate School of Education), Takashi Azuma(National Institute of Advanced Industrial Science and Technology)

[SSS07-P13] Investigation of off-fault displacement

*Naoto Inoue1, Naoko Kitada1, Yasuhiro Matsumoto2, Tsutomu Takahama2, Tonagi Masao2, LUIS ANGEL DALGUER3, Kojiro Irikura3 (1.Geo-Research Institute, 2.KOZO KEIKAKU ENGINEERING Inc., 3.Aichi Institute of Technology)

Keywords:fault displacement hazard, secondary fault

Discontinuous distributed fault displacements occur around the primary surface rupture in the earthquake. Evaluation of off-fault displacement is important for mitigation of fault displament hazards. There are two types of off-fault displacement in the view point of a prediction problem. The displacement does not occur only on the active fault, but also off the active fault. Petersen et al. (2011) introduced mapping accuracy for the strike-slip fault. We estimated the mapping accuracy of several Japanese earthquakes at distinct fault side, i.e. hanging-wall/foot-wall by measuring distances between active fault traces and primary surface ruptures. Based on estimation of the mapping accuracy of strike-slip fault, narrow bell-shaped displacement profile across the active faults was inferred. On the contrary, wide bell-shaped displacement profile was estimated and the center shifted to the foot-wall side, in the case of the reverse-fault. The other off-fault displacement is the displacement on the secondary faults. This type of displacement of reverse fault focuses on the hanging-wall. These differences are important to estimation of fault displacement hazard.

Acknowledgments: This research was part of the 2014-2016 research project ‘Development of evaluating method for fault displacement‘ by the Secretariat of Nuclear Regulation Authority (NRA), Japan. A part of displacement data was used from Kagohara et al. (2007), which was partly supported by the Grant-in-Aid for Scientific Research (no. 17200053) by Ministry of Education, Science, Sports and Culture.