MISC

2002年

Resistivity structure across Itoigawa-Shizuoka tectonic line and its implications for concentrated deformation

EARTH PLANETS AND SPACE
  • Y Ogawa
  • ,
  • S Takakura
  • ,
  • Y Honkura

54
11
開始ページ
1115
終了ページ
1120
記述言語
英語
掲載種別
DOI
10.5636/eps.54.11_1115
出版者・発行元
SPRINGER HEIDELBERG

We investigated the deep crustal resistivity structure across Itoigawa-Shizuoka Tectonic Line (ISTL), one of the most dangerous active intraplate faults in Japan, by use of wide-band magnetotelluric (MT) method. The 28 MT stations were aligned perpendicular to the ISTL. A two-dimensional model was created in transverse magnetic (TM) mode where electric currents flow in N60degreesW-N120degreesE directions. The model showed good correlations with the surface geology. In particular, we found a thick (similar to6 km) surface conductor to the east of ISTL which corresponds to the heavily folded sedimentary layer. The Japan Alps to the west of the ISTL is characterized by the resistive upper crust, where the pre-Tertiary rocks crop out. The Japan Alps is underlain by a conductor below 15-20 km depth, which is consistent with the low seismic velocity anomaly. We also found a localized shallow conductor corresponding to the Mt. Tateyama volcano. The most important feature is the conductor in the mid-crust directly under the area of active folding to the east of the ISTL. This may imply a localized zone of fluids because of the enhanced porosity in a shear zone. The recent seismicity clusters in the resistive crust underlain by the conductor, and this suggests the fluid involvement in earthquake generation processes.

Web of Science ® 被引用回数 : 33

リンク情報
DOI
https://doi.org/10.5636/eps.54.11_1115
CiNii Articles
http://ci.nii.ac.jp/naid/80015754846
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:000180666700021&DestApp=WOS_CPL

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