Surface Rupture of the 2008 Iwate-Miyagi Nairiku Earthquake Observed at Oshu and Ichinoseki Cities, Iwate Prefecture, Northeast Japan

• TSUTSUMI Hiroyuki

  Graduate School of Science, Kyoto University

• SUGITO Nobuhiko

  Graduate School of Environmental Studies, Nagoya University

• KOSHIYA Shin

  Faculty of Engineering, Iwate University

• ISHIYAMA Tatsuya

  Graduate School of Science, Tohoku University

• IMAIZUMI Toshifumi

  Graduate School of Science, Tohoku University

• MARUSHIMA Naofumi

  Graduate School of Science, Tohoku University

• HIROUCHI Daisuke

  Faculty of Education, Shinshu University

Bibliographic Information

Other Title

• 岩手県奥州市・一関市に出現した２００８年岩手・宮城内陸地震の地震断層
• イワテケン オウシュウシ イチノセキシ ニ シュツゲン シタ 2008ネン イワテ ミヤギ ナイリク ジシン ノ ジシン ダンソウ

Abstract

 The 2008 Iwate-Miyagi Nairiku earthquake (M_w 6.9) struck an area where no active fault was known prior to the earthquake. The earthquake was shallow and large enough to produce scattered and discontinuous surface ruptures. To better understand the source processes and seismotectonic setting of the earthquake, we mapped the coseismic surface ruptures observed at Oshu and Ichinoseki Cities, Iwate Prefecture. The NNE- to NNW-trending surface ruptures appeared at three localities: (1) between Mochikorobashi and Ochiai, (2) Itagawa, and (3) southwest of Shinyu hot spring. Most of the surface ruptures are fold scarps up on the west, which are consistent with source fault models based on geodetic and seismological data. These surface ruptures appear to be associated with a reverse slip on west-dipping faults imaged by seismic reflection profiling, which originated as Miocene normal faults and have been reactivated as reverse faults since the Pliocene. Some of the ruptures appeared along preexisting tectonic scarps, although these scarps are short and discontinuous. Geomorphic expression of the causative faults of the 2008 earthquake is weak. Integration of geomorphic, geologic and geophysical data is necessary to identify active faults in areas where crustal strain is distributed to multiple fault strands and thus the tectonic landform of each fault is not well developed.

Journal

• Journal of Geography (Chigaku Zasshi)

  Journal of Geography (Chigaku Zasshi) 119 (5), 826-840, 2010

  Tokyo Geographical Society

Keywords

• The 2008 Iwate-Miyagi Nairiku earthquake
• Iwai Hills
• surface rupture
• active faults
• source fault model

Details

• CRID: 1390282679205696896
• NII Article ID: 10030370343
• NII Book ID: AN00322536
• DOI: 10.5026/jgeography.119.826
• ISSN: 18840884
• ISSN: 0022135X
• NDL BIB ID: 10893475
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I10893475
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed