Japan Geoscience Union Meeting 2015

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Symbol S (Solid Earth Sciences) » S-CG Complex & General

[S-CG57] Structure, evolution and dynamics of mobile belts

Wed. May 27, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Toru Takeshita(Department of Natural History Sciences, Graduate School of Science, Hokkaido University), Hiroshi Sato(Earthquake Prediction Research Center, Earthquake Research Institute, The University of Tokyo), Koichiro Obana(Research and Development Center for Earthquake and Tsunami, Japan Agency for Marine-Earth Science and Technology), Takuya NISHIMURA(Disaster Prevention Research Institute, Kyoto University), Yukitoshi Fukahata(Disaster Prevention Research Institute, Kyoto University), Aitaro Kato(Graduate School of Environmental Studies, Nagoya University), Jun Muto(Department of Earth Sciences, Tohoku University), Katsushi Sato(Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University), Shuichi Kodaira(Institute for Research on Earth Evolution Japan Agency for Marine-Earth Science and Technology), Takeshi Sagiya(Disaster Mitigation Research Center, Nagoya University), Tatsuya Ishiyama(Earthquake Research Institute, University of Tokyo), Makoto MATSUBARA(National Research Institute for Earth Science and Disaster Prevention), Yasutaka Ikeda(Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo)

6:15 PM - 7:30 PM

[SCG57-P23] Seismic reflection profiling off-Tottori and Fukui, SW Japan, for seismic and tsunami hazards in the Sea of Japan

*Naoko KATO1, Hiroshi SATO1, Tatsuya ISHIYAMA1, Kazuya SHIRAISHI2, Susumu ABE2 (1.ERI, Univ. of Tokyo, 2.JGI. Inc.)

To estimates Tsunami and seismic hazards along the coastal area of Sea of Japan, more detailed survey to identify source faults are needed. A research project funded by MEXT named "the integrated research project on seismic and tsunami hazards around the Sea of Japan" began in FY 2013. To obtain the information of source faults, we performed deep seismic reflection profiling off-Fukui and Tottori area in the southwestern part of Honshu, Japan. Multi-channel seismic reflection data were acquired along four seismic lines in off-Fukui area and five seismic lines off-Tottori in the area within 50 km distance from the shoreline. Total length of seismic line is 190 km in off-Fukui and 280 km in off-Tottori. We used two vessels; a gun-ship with 3020 cu. inch air-gun and a cable-ship with a 2-km-long, streamer cable with 168 channels and 1050 cu. inch air-gun. The survey area consists of stretched continental crust and marked by densely distributed syn-rift normal faults. The thickness of Neogene basin fill is 5 km in off-Tottori and 3 km in off-Fukui. The rift basin fill along the arc-parallel normal faults were strongly deformed in late Miocene by basin inversion. The gently dipping Pliocene sediments cover the folded strata unconformably. Some of the Miocene reverse faults displaced late Pliocene sediments. Latest fault system is high-angle faults, whose displacement is preserved in topographic features. Judging from the patter of reflection the fault system is strike-slip faults.