MISC

2001年9月

Magma prospecting in Usu volcano, Hokkaido, Japan, using magnetotelluric soundings

JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
  • N Matsushima
  • ,
  • H Oshima
  • ,
  • Y Ogawa
  • ,
  • S Takakura
  • ,
  • H Satoh
  • ,
  • M Utsugi
  • ,
  • Y Nishida

109
4
開始ページ
263
終了ページ
277
記述言語
英語
掲載種別
DOI
10.1016/S0377-0273(00)00320-6
出版者・発行元
ELSEVIER SCIENCE BV

We carried out magnetotelluric (MT) soundings across Usu volcano, Hokkaido, Japan, which has been active since 1663. The objective was to image an intrusion expected below the formation of 180m-high cryptodomes formed during the 1977-78 eruption.
A NE-SW two-dimensional resistivity model has been obtained from the inversion in the frequency range from 0.01 to 10,000 Hz. The major features of the resistivity section are as follows: (1) a 50-m-thick surficial resistive (1000-10,000 Omega m) layer corresponding to the lava layer; (2) a relatively conductive (10-1000 Omega m) layer from the surface to 200 m depth, corresponding to Quaternary sedimentary and volcanic rocks; (3) beneath the Quaternary formations, a thick (2-4 km) conductive (1-500 Omega m) layer of altered Tertiary volcanics distributed widely in the volcanic edifice; (4) a resistive block (500-1,000 Omega m) in the Tertiary layer from 200 to 400 m in depth beneath the summit crater, forming a striking contrast to the rest of the conductive Tertiary layer and probably indicating a cooling intrusion at shallow depth; (5) pre-Tertiary formations consisting of a high resistivity (1000-10,000 Omega m) layer overlying a conductive layer, with the top of the Pre-Tertiary becoming shallow to the northeast; and (6) no deep conductive anomalies corresponding to a magma chamber inferred from petrological studies. (C) 2001 Elsevier Science Ltd All rights reserved.

Web of Science ® 被引用回数 : 40

リンク情報
DOI
https://doi.org/10.1016/S0377-0273(00)00320-6
CiNii Articles
http://ci.nii.ac.jp/naid/30004768371
CiNii Resolver ID
http://ci.nii.ac.jp/nrid/9000239248799
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000172140200002&DestApp=WOS_CPL

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