Matsushiro earthquake swarm
The Matsushiro earthquake swarm (
Overview
The Matsushiro swarm lasted from 1965 to 1967 and generated about 1 million earthquakes.[2] The total sum of energy from all the tremors was approximately equivalent to an M6.4 earthquake.[3][4] This swarm had the peculiarity to be sited just under a seismological observatory installed in 1947 in a decommissioned military tunnel. It began in August 1965 with three earthquakes too weak to be felt, but three months later, a hundred earthquakes could be felt daily. On 17 April 1966, the observatory recorded 6,780 earthquakes, with 585 of them having a magnitude large enough to be felt, which meant that one earthquake could be felt every 2 minutes 30 seconds on average.[5] The phenomenon was clearly identified as linked to a magma uplift, perhaps initiated by the 1964 Niigata earthquake which happened one year before.[6]
References
- ^ 日本国語大辞典,デジタル大辞泉,世界大百科事典内言及, 日本大百科全書(ニッポニカ),精選版. "松代群発地震とは". コトバンク (in Japanese). Retrieved 2021-05-26.
{{cite web}}
: CS1 maint: multiple names: authors list (link) - ^ "松代群発地震(1965年8月3日) | 災害カレンダー". Yahoo!天気・災害 (in Japanese). Retrieved 2021-05-26.
- ^ "松代群発地震_松代地震観測所". www.data.jma.go.jp. Retrieved 2021-05-26.
- ISBN 978-4-621-30560-7
- ^ "Matsushiro earthquake swarm". www.data.jma.go.jp. Retrieved 2017-10-31.
- .