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ID 25978
本文ファイル
著者
Tanikawa, Wataru
Shimamoto, Toshihiko
キーワード
Friction coefficient
permeability
thermal pressurization
NDC
地球科学・地学・地質学
抄録(英)
We carried out low- and high-velocity friction tests on fault rock samples from shallow boreholes on the Taiwan Chelungpu fault and measured their fluid transport properties under high pressure with the objective of explaining the different seismic behavior in northern and southern sections of the fault during the 1999 Chi-chi earthquake. Our results of low-velocity friction tests demonstrate that fault gouge from the southern section of the fault exhibits velocity-weakening frictional behavior, whereas gouge from the northern section exhibits velocity-strengthening friction. Friction in the northern gouge decreased strongly with increasing wetness, whereas friction in southern gouge samples was not affected by wetness. A rapid reduction of friction was observed immediately after the onset of slip in high-velocity friction tests. The results of high-velocity friction tests were similar for all fault gouge samples tested, though permeability in the northern fault zone was lower than that in the south. Numerical modeling indicated that thermal pressurization in the northern fault zone promoted stress reduction and fault instability during slip, whereas it did not in the south. This contrasting seismic behavior between north and south is caused mainly by differences in fluid transport properties of the slip zones. More efficient thermal pressurization in the north explains the large slip displacement there. The results of our low-velocity friction tests are consistent with nucleation of the Chi-Chi earthquake in the south and propagation of the rupture from south to north.
掲載誌名
Journal of Geophysical Research - Solid Earth
114巻
開始ページ
B01402
出版年月日
2009
出版者
American Geophysical Union
ISSN
0148-–0227
NCID
出版者DOI
言語
英語
NII資源タイプ
学術雑誌論文
広大資料タイプ
学術雑誌論文
DCMIタイプ
text
フォーマット
application/pdf
著者版フラグ
author
権利情報
Copyright (c) 2009 American Geophysical Union
関連情報URL
部局名
理学研究科