Detailed Mapping of Focal Mechanisms in/around the 1995 Hyogo-ken Nanbu Earthquake Rupture Zone.

• Katao Hiroshi

  Research Center for Earthquake Prediction, Disaster Prevention Research Institute

• Maeda Naoki

  Kanto Gakuin University

• Hiramatsu Yoshihiro

  Research Center for Earthquake Prediction, Disaster Prevention Research Institute

• Iio Yoshihisa

  National Research Institute of Earth Science and Disaster Prevention

• Nakao Setsuro

  Tottori Observatory, Disaster Prevention Research Institute

Bibliographic Information

Other Title

• Detailed Mapping of Focal Mechanisms in
• Detailed mapping of focal mechanisms in and around the 1995 Hyogo-Ken Nanbu earthquake rupture zone

Abstract

Earthquake focal mechanisms before and after the 1995 Hyogo-ken Nanbu earthquake have been investigated using seismic records from regional seismic networks. Before the mainshock, seismicity was very active at the Tamba Plateau, a neighboring area of the Hyogo-ken Nanbu earthquake rupture zone. In contrast, the seismicity along the Hyogo-ken Nanbu earthquake rupture zone was not so active. Most earthquakes in these regions had source mechanisms of E-W compression and were of the strike-slip or reverse-fault type. Most aftershocks along the Hyogo-ken Nanbu earthquake rupture zone have strike-slip solutions with P-axis in the E-W or ESE-WNW direction, which is compatible with the trend of aftershock distribution and the strike of active faults the same as the mainshock mechanism. Simultaneously, many other aftershocks were of the reverse-fault type with E-W compression. This area is still controlled by the regional stress field of E-W compression observed before the mainshock. Although, we could find various types of mechanisms in the aftershock sequence, some normal fault-type events were also observed in the mainshock rupture zone. We could find events of SE-NW compression, and this direction is nearly perpendicular to the trend of the mainshock rupture zone. Some aftershocks that occurred near the epicenter of the mainshock had solutions of N-S compression. The geometry of the active fault systems and/or local stress change induced by the mainshock may cause these complex features of focal mechanisms. After the mainshock, the focal mechanisms of earthquakes in the Tamba Plateau were approximately E-W compressional; the same as that before the mainshock.

Journal

• Journal of Physics of the Earth

  Journal of Physics of the Earth 45 (2), 105-119, 1997

  The Seismological Society of Japan, The Volcanological Society of Japan, The Geodetic Society of Japan

Keywords

• General Earth and Planetary Sciences

Details

• CRID: 1390001206509749504
• NII Article ID: 10002428777
• NII Book ID: AA00704960
• DOI: 10.4294/jpe1952.45.105
• ISSN: 18842305
• ISSN: 00223743
• NDL BIB ID: 4317043
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I4317043
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed