断層間の力学的相互作用を考慮した地震活動のシミュレーション Simulation of Seismic Activity with an Interacting Fault System Model

この論文にアクセスする

この論文をさがす

抄録

We attempt to simulate the activity of earthquakes of moderate to large sizes in and around the Japanese islands using a block and fault model, in which slip deficit rates were derived from triangulation and trilateration data covering one-hundred years. The original block and fault model has 104 faults. However, the original fault size is too large to simulate moderate earthquakes. Therefore, we divide each modeled fault into 5 × 5 elements to generate earthquakes as small as <I>M</I>5. In total there are 2600 elements. We assume stress accumulates according to the estimated slip deficit rates. Interaction between fault elements is represented by changes in Coulomb Failure Function (hereafter Δ CFF) induced by the movement of other faults that are determined by the geometrical relationship and the direction of slip deficit rates. When stress reaches the threshold level, accumulated CFF is released by a forward slip and redistributed to surrounding faults according to the CFF changes calculated above. If the redistribution of CFF induces the next rupture, the same process is repeated until there are no more rupturing elements. We assume rupture thresholds to be 2.5 MPa for interplate boundaries and 10 MPa for inland faults, respectively. We simulate seismicity for 10000 years with a time step of 1 year.<BR>In this simulation large events that rupture almost all elements of a fault rarely occur. This suggests that strain rates derived from geological data or historical earthquake catalog might be underestimated. Simulated seismicity does not satisfactorily fit the GutenbergRichter's law, because moderate events occur more frequently than small or large events. This suggests that we have to incorporate heterogeneity in the rupture threshold or the size of elements on a fault plane. The correlation between interplate earthquakes along the Nankai trough and inland events in southwest Japan is not clear, but there seems to be a complementary relationship in activities between both regions. Migration of large events along the Nankai trough is occasionally seen in this simulation, but its direction is different from time to time.

収録刊行物

  • 地學雜誌

    地學雜誌 111(2), 298-307, 2002

    学術雑誌目次速報データベース由来

参考文献:  20件中 1-20件 を表示

各種コード

  • NII論文ID(NAID)
    10008209818
  • NII書誌ID(NCID)
    AN00322536
  • 本文言語コード
    JPN
  • 資料種別
    REV
  • ISSN
    0022135X
  • NDL 記事登録ID
    6147844
  • NDL 雑誌分類
    ZM41(科学技術--地球科学)
  • NDL 請求記号
    Z15-169
  • データ提供元
    CJP書誌  NDL  NII-ELS  J-STAGE 
ページトップへ