[S-SS34_29AM1] 活断層と古地震

[SSS34-05] 伊豆半島南端と清水平野沿岸部の地震性隆起

*北村 晃寿¹、小林 小夏¹、大橋 陽子²、横山 祐典²、宮入 陽介² (1.静岡大学、2.東京大学)

キーワード：伊豆半島南端, 清水平野沿岸部, 地震性隆起, 完新世, 安政東海地震

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.