Coseismic and postseismic deformation related to the 2007 Chuetsu-oki, Niigata Earthquake

Yusaku Ohta, Satoshi Miura, Takeshi Iinuma, Kenji Tachibana, Takeshi Matsushima, Hiroaki Takahashi, Takeshi Sagiya, Takeo Ito, Shin'ichi Miyazaki, Ryosuke Doke, Akira Takeuchi, Kayo Miyao, Akihiko Hirao, Takahiro Maeda, Teruhiro Yamaguchi, Masamitsu Takada, Makiko Iwakuni, Tadafumi Ochi, Irwan Meilano, Akira Hasegawa

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

An intermediate-strength earthquake of magnitude Mj 6.8 occurred on July 16, 2007, centered beneath the Japan Sea a few kilometers offshore of Niigata Prefecture in central Japan. We constructed a dense GPS network to investigate postseismic deformation after this event, choosing our GPS sites carefully so as to complement the nationwide GPS GEONET array. Coseismic displacements caused by the mainshock detected at some GEONET sites were used to estimate coseismic fault parameters. The results indicate that the geodetic data can be explained by a combination of two rectangular faults dipping northwest and southeast. Minor but definite postseismic deformation was detected largely in the southern part of the dense network. The time series of site coordinates can be characterized by a logarithmic decay function, and the estimated time constant seems to be almost similar in range to that of the 2004 Mid-Niigata Prefecture Earthquake. We also found a possible site instability at 960566 (Izumo-zaki, GEONET) caused by a small, local landslide associated with the mainshock and therefore concluded that the data obtained at this site should not be used for coseismic or postseismic analysis.)

Original languageEnglish
Pages (from-to)1081-1086
Number of pages6
Journalearth, planets and space
Volume60
Issue number11
DOIs
Publication statusPublished - 2008

Keywords

  • Coseismic slip
  • Crustal deformation
  • GPS
  • Niigata-Kobe Tectonic Zone
  • Postseismic deformation

ASJC Scopus subject areas

  • Geology
  • Space and Planetary Science

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