Emerged Abrasion Platforms on Enoshima Island, Kanagawa Prefecture and Uplift Associated with the 1703 Genroku Kanto Earthquake

Abstract

 There are two emerged abrasion platforms on Enoshima Island, Kanagawa Prefecture, Southern Kanto district: the 4.0-meter-high Ryoshimachi surface, and the 1.0–1.3-meter-high Iwaya surface. Both emerged prior to the 1703 Genroku Earthquake. Considering uplift due to the 1923 Taisho Kanto Earthquake and non-seismic subsidence since the Genroku Era, uplift due to the 1703 Genroku Earthquake was 0.7 m or less, assuming that the height of Ryoshimachi surface before the Genroku Earthquake was 3 m or higher. This indicates that uplift of the Genroku Earthquake at Enoshima was smaller than that of the Taisho Earthquake, and the focal regions of the two earthquakes were different in the Sagami Bay. These two earthquakes are not repeating earthquakes at the Sagami Bay area.