Japan Geoscience Union Meeting 2014

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

[S-SS34_29AM1] Active faults and paleoseismology

Tue. Apr 29, 2014 9:00 AM - 10:48 AM 502 (5F)

Convener:*Takashi AZUMA(National Institute of Advanced Industrial Science and Technology), Nobuhiko Sugito(Faculty of Humanity and Environment, Hosei University), Satoshi Tonai(Department of Applied Science, Faculty of Scienece, Kochi University), Toshikazu Yoshioka(Active Fault and Earthquake Research Center, National Institute of Advanced Industrial Science and Technology), Chair:Taku Komatsubara(Institute of Geology and Geoinformation, Advanced Industrial Science and Technology), Nobuhiko Sugito(Faculty of Humanity and Environment, Hosei University)

10:00 AM - 10:15 AM

[SSS34-05] Coseismic uplifts of the southern Izu Peninsula and the coastal area of Shimizu Plain

*Akihisa KITAMURA1, Konatsu KOBAYASHI1, Yoko OHASHI2, Yusuke YOKOYAMA2, Yosuke MIYAIRI2 (1.Shizuoka University, 2.The University of Tokyo)

Keywords:Coseismic uplifts, southern Izu Peninsula, Shimizu Plain, Holocene, Ansei-Tokai earthquake

We examined coseismic uplift events in the coastal area of the Shimizu Plain, and at the southern end of the Izu Peninsula. On the basis of lithologies, fossil contents, and radiocarbon dating, we identified geological and paleontological evidence for abrupt changes in depositional environments related to coseismic uplift associated with the AD 1854 Ansei-Tokai earthquake. We estimated a maximum coseismic uplift of 1.2 m and post-earthquake gradual subsidence of ca. 0.6 m. Radiocarbon dating of the emerged sessile assemblages at the southern end of the Izu Peninsula, central Japan suggest that at least four coseismic uplift have occurred in the area, during 3387-2485 cal yr BP, AD 570?820, AD 1000?1270, and AD 1430?1660.