Holocene marine terraces and seismic crustal movements in the southern part of Boso Peninsula, Kanto, Japan.

Abstract

The mode and amount of the crustal movements are discussed based on the relative sea-level curve reconstructed from topographiical and chronological data including 36 14C dates. The relative sea-level curve indicates four times sudden sea-level drops at 6 150 yr BP; 4 350 yr BP, 2 850 yr BP and 250 yr BP, caused by seismic upheavals associated with earthquakes. The duration of interseismic period relates to the amount of upheaval associated with the preceding earthquake which measures 5.5m, 5m, 7m and 5.5m respectively. Using the method of least squares, long-term mean uplift rate is calculated at 3.0 mm/yr. from English summary