28. Tsunami Behavior of the 1923 Kanto Earthquake at Atami and Hatsushima Island in Sagami Bay

熱海・初島において,1923年関東地震津波について,地震体験者の住民から聞きとり調査を行った.熱海では当時の海岸から約200m,地盤高がT.P.上7m以下の市街地に浸水したことが分った.熱海中心部の海岸では津波の高さは7.0～8.0mと推定される.一方,初島では地盤が隆起して集落内に津波は侵入せず,津波の高さは1.8m程度であった.The Kanto tsunami of Sept, 1, 1923 hit the south Kanto district on the Pacific coast of central Japan. At Atami located in the western part of Sagami Bay, 162 houses were washed away. In this paper, the tsunami behavior at Atami and Hatsushima Island is investigated from the visual observation of inhabitants. The tsunami front ran up 200m into Atami Town and ground about 7.0m above M.S.L. was inundated. The inundation height at the coast seems to be 7.0-8.0m. Hatsushima Island, located 10km southeast of Atami, was uplifted almost uniformly by about 1.8m by the 1923 Kanto earthquake (Ms=8.2). Although many houses were damaged by the earthquake, the tsunami did not inundate the village. The tsunami height was only 1.8m. Such being the variety of tsunami height, a short-period wave may be preeminent at the corner of the bay