Wave sources of the 17th-century tsunami deposits in western Hokkaido, Japan using sediment transport modeling

Abstract

Sediment transport modeling is a powerful tool for identifying wave sources of paleo-tsunami deposits because it can reproduce not only the thickness distribution but also the sediment features. The giant earthquakes in the Kuril Trench have uncertainties in the magnitude depending on the extent to which tsunami deposits widely distributed along the Pacific coast of Hokkaido can be correlated with each other. Multiple tsunami deposits have been found in Kabari, northern Hidaka, Hokkaido, and their wave sources are expected to provide a significant constraint on the tsunami magnitude. We reproduce two layers of tsunami deposits around the 17th century with sediment transport modeling using possible wave source candidate models. The Mt. Komagatake collapse and Kuril Trench earthquake models reproduce the two layers of tsunami deposits, indicating the tsunami distributions along the Pacific coast of Hokkaido are reproduced without Mw > 9 earthquake models.