文章基本信息

标题：Self-potential anomaly of Satsuma-Iwojima volcano
本地全文：下载
作者：Wataru Kanda ; Sin’yo Mori
期刊名称：Earth, Planets and Space
电子版ISSN：1880-5981
出版年度：2014
卷号：54
期号：3
页码：231-237
DOI：10.1186/BF03353022
出版社：Springer Verlag
摘要：We conducted self-potential (SP) surveys twice at Satsuma-Iwojima volcano where an intense fumarolic activity continued for more than 1000 years from a summit crater of Iwodake, a lava dome of rhyolite. A positive anomaly of 200 ∼ 250 mV was detected on the Iwodake edifice, although the survey area was limited because of the steep topography and existence of high temperature fumaroles. The anomaly seems to be centered at the summit crater of Iwodake and can roughly be explained by a pair of conduction current source and sink located around the sea level beneath the summit crater. Depth of the current source might indicate the upper end of a liquid-phase water upflow zone, where the liquid-phase water vaporizes due to heat and depressurization. The above model does not explain the additional positive SP anomaly around the summit crater and on the western flank. The anomaly around the su mmit might be caused by suppression of meteoric water downflow by high temperature volcanic gases. The positive anomaly on the western flank might be caused by local fluid upflows associated with fumaroles on the flank.