2011 Volume 67 Issue 2 Pages I_241-I_245
In 2008 and 2009, we made seismic survey in Kesennuma Bay, Miyagi Prefecture, where sedimentation of the tsunami deposits associated with the 1960 Chilean Earthquake caused significant modification of the bay bottom topography. Visual and X-ray CT analysis of lithology, measurements of magnetic susceptibility and its anisotropy, and diatom fossil analysis of piston cores recovered from 3 sites revealed that relatively thick tsunami deposits occur near the narrow segment of the Bay. Abundant occurrence of freshwater diatom suggests a possibility that the tsunami waves transported river sediments into the Kesennuma Bay.