Three-Dimensional Velocity Structure of the Upper Crust in the Hida Region, Central Honshu, Japan, and Its Relation to Local Seismicity, Quaternary Active Volcanoes and Faults.

• Mikumo Takeshi

  Research Center for Earthquake Prediction, Disaster Prevention Research Institute, Kyoto University

• Hirahara Kazuro

  Research Center for Earthquake Prediction, Disaster Prevention Research Institute, Kyoto University

• Takeuchi Fumiaki

  Research Center for Earthquake Prediction, Disaster Prevention Research Institute, Kyoto University

• Wada Hiroo

  Kamitakara Geophysical Observatory, Disaster Prevention Research Institute, Kyoto University

• Tsukuda Tameshige

  Shin'etsu Seismological Observatory, Earthquake Research Institute, The University of Tokyo

• Fujii Iwao

  Takayama Seismological Observatory, Faculty of Sciences, Nagoya University

• Nishigami Kin'ya

  Research Center for Earthquake Prediction, Disaster Prevention Research Institute, Kyoto University

抄録

The three-dimensional (3-D) velocity structure of the upper crust in the central part of the Hida region, central Honshu, Japan, has been investigated by simultaneous inversion of travel time data for velocity and hypocentral parameters using Thurber's method (1983). The data used for this purpose were 2, 231 P-wave arrival times from 204 local earthquakes observed at 16 high-sensitivity seismograph stations. The iterative damped least-squares inversion used here provided reliable results with the diagonal elements of resolution matrix well exceeding 0.90 and standard errors less than 3% for the central area. The central part of the Hida region covering an extremely low seismicity area has high velocities probably extending down to a mid-crust. The high-velocity area composed of hard metamorphic and granitic complex extends from the western flank of the Hida mountains to the western section of the seismically active Atotsugawa-Ushikubi faults. The axial part of the Hida mountains and its southwestward area, on the other hand, is covered by remarkable low-velocities. The low velocities may be associated with a high thermal state due to active volcanism beneath the mountains involving volcanoes Mts. Tateyama, Yake, Norikura, and Ontake. The southwestern part of the Hida region is also partially covered by low-velocities beneath the Ryohaku mountains, which may also be related to volcanism of Mt. Hakusan. The obtained 3-D velocity structure appears to be qualitatively consistent with the Bouguer gravity anomalies and also with the large-scale 3-D structure so far obtained.

収録刊行物

• Ｊｏｕｒｎａｌ　ｏｆ　Ｐｈｙｓｉｃｓ　ｏｆ　ｔｈｅ　Ｅａｒｔｈ

  Ｊｏｕｒｎａｌ　ｏｆ　Ｐｈｙｓｉｃｓ　ｏｆ　ｔｈｅ　Ｅａｒｔｈ 43 (1), 59-78, 1995

  公益社団法人 日本地震学会、特定非営利活動法人 日本火山学会、日本測地学会

キーワード

• General Earth and Planetary Sciences

詳細情報

• CRID: 1390001206510057984
• NII論文ID: 10006235231
• NII書誌ID: AA00704960
• DOI: 10.4294/jpe1952.43.59
• ISSN: 18842305
• ISSN: 00223743
• ISSN: http://id.crossref.org/issn/00223743
• HANDLE: 2433/193402
• 本文言語コード: en
• データソース種別:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可