論文

査読有り
2018年2月1日

Dissipative Intraplate Faulting During the 2016 Mw 6.2 Tottori, Japan Earthquake

Journal of Geophysical Research: Solid Earth
  • Zachary E. Ross
  • ,
  • Hiroo Kanamori
  • ,
  • Egill Hauksson
  • ,
  • Naofumi Aso

123
2
開始ページ
1631
終了ページ
1642
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1002/2017JB015077
出版者・発行元
Blackwell Publishing Ltd

The 2016 Mw 6.2 Tottori earthquake occurred on 21 October 2016 and produced thousands of aftershocks. Here we analyze high-resolution-relocated seismicity together with source properties of the mainshock to better understand the rupture process and energy budget. We use a matched-filter algorithm to detect and precisely locate &gt
10,000 previously unidentified aftershocks, which delineate a network of sharp subparallel lineations exhibiting significant branching and segmentation. Seismicity below 8 km depth forms highly localized fault structures subparallel to the mainshock strike. Shallow seismicity near the main rupture plane forms more diffuse clusters and lineations that often are at a high angle (in map view) to the mainshock strike. An empirical Green's function technique is used to derive apparent source time functions for the mainshock, which show a large amplitude pulse 2–4 s long. We invert the apparent source time functions for a slip distribution and observe a ~16 km2 patch with average slip ~3.2 m. 93% of the seismic moment is below 8 km depth, which is approximately the depth below which the seismicity becomes very localized. These observations suggest that the mainshock rupture area was entirely within the lower half of the seismogenic zone. The radiated seismic energy is estimated to be 5.7 × 1013 J, while the static stress drop is estimated to be 18–27 MPa. These values yield a radiation efficiency of 5–7%, which indicates that the Tottori mainshock was extremely dissipative. We conclude that this inefficiency in energy radiation is likely a product of the immature intraplate environment and the underlying geometric complexity.

Web of Science ® 被引用回数 : 15

リンク情報
DOI
https://doi.org/10.1002/2017JB015077
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000428437500040&DestApp=WOS_CPL
ID情報
  • DOI : 10.1002/2017JB015077
  • ISSN : 2169-9356
  • ISSN : 2169-9313
  • SCOPUS ID : 85042117895
  • Web of Science ID : WOS:000428437500040

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