著者
宇佐美 龍夫 茅野 一郎
出版者
東京大学地震研究所
雑誌
東京大学地震研究所彙報 (ISSN:00408972)
巻号頁・発行日
vol.48, no.5, pp.923-933, 1970-12-05

The relation between Mk and MJ MJ=0.5Mk+4.35 is obtained by the method of least squares, using data from 1926 to 1943. It is shown that the relation can also be applied to earthquakes between 1885-1925. However, for earthquakes before 1885, the relation seems to hold for only large earthquakes with magnitude M(=0.5 Mk+4.85) larger than 8.0. MJ of the great Kanto earthquake of 1923 is given as 7.83 from the seismograms recorded at 3 Japanese stations.
著者
宇佐美 龍夫 茅野 一郎
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.48, no.5, pp.923-933, 1970-12-05

The relation between Mk and MJ MJ=0.5Mk+4.35 is obtained by the method of least squares, using data from 1926 to 1943. It is shown that the relation can also be applied to earthquakes between 1885-1925. However, for earthquakes before 1885, the relation seems to hold for only large earthquakes with magnitude M(=0.5 Mk+4.85) larger than 8.0. MJ of the great Kanto earthquake of 1923 is given as 7.83 from the seismograms recorded at 3 Japanese stations.
著者
宇佐美龍夫
雑誌
日本の歴史地震史料 拾遺二
巻号頁・発行日
2002
被引用文献数
1
著者
宇佐美 龍夫
出版者
公益社団法人 東京地学協会
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.94, no.7, pp.656-664, 1986-01-25 (Released:2009-11-12)
参考文献数
6
著者
髙橋 利昌 浅野 彰洋 大内 泰志 川崎 真治 武村 雅之 神田 克久 宇佐美 龍夫
出版者
公益社団法人 日本地震学会
雑誌
地震 第2輯 (ISSN:00371114)
巻号頁・発行日
vol.60, no.3, pp.193-217, 2008-02-15 (Released:2013-08-20)
参考文献数
40
被引用文献数
1 1

The major earthquakes of M=7 class, so-called Geiyo earthquake, have occurred in the subducted slab of the Philippine Sea plate under Aki-nada and Iyo-nada sea. The upper surface of the Philippine Sea plate is located in the depth from 40-45km in this region. Five Geiyo earthquakes can be found in 1649, 1686, 1857, 1905, and 2001 since 17th century. Magnitudes M of the older 4 events were larger than 7, while that of the last one is 6.7 in JMA (Japan Meteorological Agency) scale. Magnitudes and locations of focal regions of them were redetermined from seismic intensity data by the method of an attenuation curve fitting and of the seismic intensity inversion. Optimal magnitudes of old events were obtained between 6.7 to 6.9. This results show the old 4 events have almost the same magnitude as the 2001 event. One of the possible reasons why the former values were overestimated is that the empirical relation between magnitude and isoseismal area from inland shallow earthquakes was applied to determine the magnitude of the historical intraslab events such as Geiyo earthquakes.
著者
宇佐美 龍夫
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.44, no.4, pp.1571-1622, 1967-03-31

Table of major earthquakes which occurred in and near Japan and accompanied by damages was prepared. The table consists of two parts, the major and auxiliary ones. Earthquakes in Formosa and Korea and outside Japan were omitted from these tables. The only exceptional one is the Chilean earthquake of May, 1960 which brought big damage to Japan.
著者
宇佐美 龍夫 浅野 潤三
出版者
東京大学地震研究所
雑誌
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo (ISSN:00408972)
巻号頁・発行日
vol.47, no.2, pp.271-394, 1969-07-31

A bibliography of field studies on major earthquakes in Japan was prepared. This includes papers concerning the field inspection, seismometrical study, study of related phenomena and investigation on damages which were published before the end of 1965. The list consists of the following items: (1)reference number (2)author's name (3)title of the paper (4)name, volume, year and page of Bulletin in which the paper is published or name of publishers (5)name and year of earthquake studied (6)main subject Date, name, latitude, longitude, focal depth, magnitude and reference number of earthquakes are arranged in another table. Papers are classified by the year of earthquake and main subject and arranged in a form of table.