[MIS12-P09] Tsunami deposits and tsunami wave source of the southern part of Okushiri Island, Hokkaido
Keywords:tsunami deposit, okushiri island
In the Okushiri area of South Hokkaido, a tsunami history approximately 3,000 years before is clarified based on an investigation of tsunami deposits. On the other hand, the tsunami history before approximately 3,000 years ago is unclear. In this study, boring exploration was carried out at the Wasabiyachi area for the purpose of analysis of the previous tsunami deposit. As a result, the event sand layer which suggested the beach origin was recognized in twenty horizons after approximately 7,400 years ago. As a result of examined the change of the sedimentary facies etc., in several horizons, this area may uplift at the same time as tsunami.