伊東沖と岩手山における火山性力源による地震のトリガリング  [in Japanese] Earthquake Triggering Due to Volcanic Deformation Sources in Areas East off Ito and around the Mt. Iwate Volcano  [in Japanese]

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Abstract

A change of Coulomb Failure Stress (CFS) is commonly used to explain a mechanism of earthquake triggering due to both earthquake faulting and volcanic sources. First, we introduced crustal deformation and source model for five episodes of volcanic activities off Ito, central Japan and around the Mt. Iwate volcano, northern Japan based on dense geodetic measurements. And then, we calculated spatial distribution of a CFS change due to the estimated source models and compared the observed seismic activities.<BR>In the case of the 1998 earthquake swarm off Ito, the region where opening of dike and the largest earthquake (<I>M</I>5.7) increase CFS was concordant with the hypocenter distribution observed after the largest earthquake. However, the largest earthquake occurred in the area where CFS decreased.<BR>In the case of the Iwate volcano, a volcanic inflation source increased CFS by 0.33 MPa at the hypocenter of the <I>M</I>6.1 earthquake that occurred on September 3, 1998. The calculated CFS change is 7 % of the coseismic stress drop. The M6.1 earthquake occurred at the northern edge of the Nishine Fault found by geographical and geological studies. It suggests that the inflation promoted the rupture of a known Quaternary fault. Stress shadow caused by the <I>M</I>6.1 earthquake explains the observed quiescence of the seismic swarm activity west of E140.95° after the occurrence of the earthquake.

Journal

  • Journal of geography

    Journal of geography 111(2), 166-174, 2002

    Tokyo Geographical Society

References:  26

Cited by:  4

Codes

  • NII Article ID (NAID)
    10008209473
  • NII NACSIS-CAT ID (NCID)
    AN00322536
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    0022135X
  • NDL Article ID
    6147568
  • NDL Source Classification
    ZM41(科学技術--地球科学)
  • NDL Call No.
    Z15-169
  • Data Source
    CJP  CJPref  NDL  NII-ELS  J-STAGE 
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