Coastal landform changes and knickpoint migrations at northern Sanriku coast, NE Japan

Abstract

River knickpoints are detected from longitudinal profiles of rivers at Northern Sanriku coast, Northeast Japan. Based on formation ages of former wave-cut angles, migration rate of river knickpoints are estimated. Strong control of base rock physicality on the migration rates is suggested. Formation ages of the knickpoints are estimated between marine oxygen isotope stage 15 to 11. Discussions on the formation ages including late Quaternary tectonics at Sanriku coast, original landforms that may have controlled geomorphological changes and hydrological conditions are upcoming issues.