[S-SS28] Active faults and paleoseismology

[SSS28-P08] Offshore active survey "Miura peninsula fault groups" - Result of high-resolution stratigraphic survey-

*Kaharu MATSUSHITA¹, Izumi SAKAMOTO¹, Masatoshi YAGI¹, Takuya ARAKAWA¹, Mikio FUJIMAKI², Shintaro ABE³ (1.Tokai University, 2.Coastal Ocean Research, 3.AIST)

Keywords:Miura peninsula fault groups, Sagami Bay, Kaneda Bay

The Miura peninsula fault groups where is lacated in Miura peninsula is subdivided into 5 fault zones in geologically, such as Kinugasa, Kitatake, Takeyama, Minamishimoura and Hikihashi. But section on the offshore area of Miura peninsula fault groups has yet to be fully realized. Therefore, Tokai University preformed high-resolution stratigraphic survey to confirm a formation, distribution, and displacement of crust around the coastal area of the Miura peninsula fault groups at Sagami Bay and Tokyo Bay (Kaneda Bay) in 2014.
Sagami Bays result has not seen surficial deposit, because of there exposed basement rock. The basement rocks were confirmed that are extension of the peninsula fault groups. But we can not get geological information of theres active histories.
In Kaneda Bay, it was confirmed that shows the structure of strike slip. There were confirmed that are about 1.5 km width to NE-SW direction where there are 3 km offshore of Kaneda Bay. There was no reflector in the surface sediment above the Kaneda bay fault. So, we could not estimate the active histories of these fault.