On September 9, 1969, an earthquake with magnitude 6.6 occurred in the central part of Gifu Prefecture. Aftershocks were recorded with a temporary seismographic network equipped with high frequency instruments. This study shows the general aspects of the aftershock sequence. The daily number of aftershocks, including very small events, was found to decrease according to a rather simple formula, n(t)=k/t, during the early part of this sequence, whereas the rate of decrease changed at about 40 days after the main shock and the daily number was well represented by an exponential law n(t)=k'exp (-λt) till the end of February 1970. The hypocenter distributions indicated the fact that just after the main shock the foci were clustered only on the northeastern side of the fault, deduced from the focal plane solution of the main shock and they, afterwards, spread gradually towards both sides of the fault, forming a peculiar pattern of distribution of foci. An attempt was made to relate this pattern to the geotectonic structure of the focal region.
雑誌名
東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo
巻
48
号
6
ページ
1195 - 1208
発行年
1971-02-27
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
アイテムへのリンクの際はタイトル右肩にある「Permalink」をご利用ください！
Please use "Permalink" at the top right of the title when linking to items!
67.岐阜県中部地震-1969年9月9日-の余震について
ji0486014.pdf
(708.45KB)
