A small tsunami was generated by the Urakawa-oki earthquake (M=7.1) near Cape Erimo, southern Hokkaido, on March 21, 1982. At Urakawa, the initial disturbance of the present tsunami began with an upward motion simultaneous with the earthquake occurrence. The first wave period was 16min and the third wave was the highest with a semi-amplitude of 80 cm. According to the author's method based on the attenuation of wave-amplitude with distance, the tsunami magnitude (Imamura-Iida scale) are estimated to be m = 0. This rank is average for an earthquake having a magnitude of M=7.1. The source area of the present tsunami which inferred from an inverse refraction diagram is located along the coast from Urakawa to Shizunai. The length of the tsunami source is 40 km and the width 20 km. The tsunami source area agrees with the aftershock area. From the analysis of the initial tsunami motion on the records, an average uplift of 14 cm may have occurred at the sea-bottom of the source area.
雑誌名
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo
巻
57
号
3
ページ
525 - 535
発行年
1983-01-17
ISSN
00408972
書誌レコードID
AN00162258
フォーマット
application/pdf
日本十進分類法
453
出版者
東京大学地震研究所
出版者別名
Earthquake Research Institute, University of Tokyo
1982年浦河沖地震による津波
ji0573006.pdf
(692.52KB)
