Depositional paleoenvironment and a historical earthquake in the Miyazaki plain, south Kyushu, Japan

Ikuta, Masafumi; Niwa, Masakazu   ; Takatori, Ryoichi*; Kamataki, Takanobu*; Tanabe, Hiroaki; Kurosawa, Hideki*

After the 2011 Tohoku Earthquake, probability and scale of giant earthquakes in the sea off Japan have been re-examined. The Central Disaster Management Council of Japan proposed a source model of hypothetical Nankai trough giant earthquake including the Hyuganada region. Historical data show that the 1662 Hyuganada Earthquake caused tsunami inundating the offshore part of the Miyazaki City and subsidence of about 1m. Here we began first geological survey to examine the geological evidence showing such giant earthquake in the Miyazaki City. In this study, we identified the changes of the depositional environment indicating the regional subsidence due to the 1662 historical earthquake.