著者

高橋 正樹

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.39, no.4, pp.191-206, 1994-09-20

参考文献数

66

被引用文献数

6

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Late Quaternary polygenetic volcanoes in Japanese islands can be classified into two types based on the distance of vent migration : the stable and unstable vent types. The eruptive center of unstable vent type has migrated longer distance (exceeding 1.5 km within 10,000 years) than that of the stable one. The stable vent type constructs a symmetrical cone, contrarily the unstable vent type shows an elongated cluster of small stratovolcanoes. The unstable vent type is generally present in the regional or local extensional stress field, because independent open fractures are easily developed under the extensional stress regime ; the occurence of each type also depends on the crustal strain rate and/or strength of the basement. The eruption rate of stable vent type is larger than that of the unstable one ; it is probably because the high efficiency of magma transport to the surface can be realized by the stable vent.