著者
三宅 康幸 小坂 丈予
出版者
特定非営利活動法人 日本火山学会
雑誌
火山 (ISSN:04534360)
巻号頁・発行日
vol.43, no.3, pp.113-121, 1998-06-10 (Released:2017-03-20)
参考文献数
14
被引用文献数
2

A steam explosion occurred at about 14:30 JST, February 11th, 1995, in the hot-spring area near Yakedake volcano, central Japan. More than six workers were near the site of the explosion for the road construction, and four of them were buried by the ejected material and killed. A small initial explosion began at the bottom of a 4m deep moat dug by a backhoe and it was followed by the maximum explosion, which ejected about 6,000m3 of blocks (maximum length is more than 2m) and mud, with steam and volcanic gas. The ejecta contain gravels of welded tuff, granite and mesozoic sedimentary rocks, which are the components of a pyroclastic dike of Pliocene age, and pumiceous lapilli tuff derived from the terrace sediments covering the pyroclastic dike. The explosion caused a landslide from the western cliff and the vent was buried by the slid debris, most of which was blown away by the second explosion. All of these processes took place within a few minutes. A small depression (20×5m2) on the west of the mound of the ejecta may represent part of the vent; its depth is estimated to be about 60m or more. Gaseous S02(<30ppm) and H2S(<90ppm) were detected at the explosion site for three days after the explosion. The chemical composition of gas collected from the holes drilled after the explosion were nearly same as the gas from the summit crater of the Yakedake volcano. Because a wall-like Low-Q zone is suggested by seismologists beneath Yakedake volcano and the explosion site, it is most probable that there existed a magma beneath the explosion site and that the heat for the explosion was supplied by the magma and gas exsolved from the magma.

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1995年2月の中ノ湯水蒸気爆発って安房トンネルのどこかだと思ってたら上高地の入口の河岸なんだ。https://t.co/5bR9TqD4is
長野県安曇村中ノ湯における1995年2月11日の水蒸気爆発 https://t.co/wsaJtIy9Z0 安房トンネル建設中の水蒸気爆発事故の詳細をやっと見つけた。
@shikakuyama2454 っhttps://t.co/Bfb1U26sB9
昨日、メンテ明けの後、「なんかバグがありそうだなー、暫く様子見るかー」って、うっかり「山さいがねが」のサイト見てて、気づいたら「中ノ湯 水蒸気爆発事故」について検索していたなど。 1995年安房峠の爆発事故の詳細な論文見つけたわ。 https://t.co/CerRwjca7i

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