糸魚川-静岡構造線活断層系市之瀬断層群の最近の断層活動

• 三浦 大助

  (財) 電力中央研究所地圏環境部

• 幡谷 竜太

  (財) 電力中央研究所地圏環境部

• 阿部 信太郎

  (財) 電力中央研究所地圏環境部

• 宮腰 勝義

  (財) 電力中央研究所地圏環境部

• 井上 大榮

  (財) 電力中央研究所地圏環境部

• 二階堂 学

  (株) ダイヤコンサルタント中部支社

• 橘 徹

  (株) ダイヤコンサルタント中部支社 現所属: 岡山大学理学部地球科学教室内「瀬戸内環境地質研究会」

• 高瀬 信一

  (株) ダイヤコンサルタント中部支社 現所属: (株) ダイヤコンサルタント環境・防災事業部

書誌事項

タイトル別名

• Recent Faulting History at the Ichinose Fault Group, Southern Part of the Itoigawa-Shizuoka Tectonic Line, Central Japan
• 糸魚川-静岡構造線活断層系市之瀬断層群の最近の断層活動--中野地区トレンチ調査
• イトイガワ シズオカ コウゾウセンカツダンソウケイ イチノ セ ダンソウグン ノ サイキン ノ ダンソウ カツドウ ナカノ チク トレンチ チョウサ
• ―中野地区トレンチ調査―

抄録

Co-seismic faulting activity during the last three hundred thousands years of the Ichinose fault group, in the southern part of the 150km long Itoigawa-Shizuoka Tectonic Line active fault system, central Japan, was appraised. The Ichinose fault group consists of the mainly two distinct arcuate reverse fault traces bulged toward the east (frontal) and west (behind) directions. We conducted a trench excavation at the Nakano site across the behind fault, where the detailed geological and chronological information for the last ten thousands years was absent. The excavation resulted in evidences for the latest, at least two surface-rupturing events. The events were present sometimes between 665 and 1275 cal.y.B.P. and between 3355 and 4810 cal.y.B.P. The timing of the penultimate event is coincident with the previously estimated latest event on the frontal fault (3, 990-6, 270 cal.y.B.P.). The recurrence time and slip rate between these two events is approximately estimated as 3, 200 years and 0.9-1.8mm/yr in dip-slip, respectively. In comparison with a slip rate estimated from the geomorphological characteristics, the dip-slip rate from our excavation result is coincident well.<br>A reappraisal of geomorphological reference deposits and a result of the seismic investigation study suggest that the total deformation rate of the Ichinose fault group is 3.5-3.7mm/yr (possibly up to 5.0mm/yr) and it becomes to increase in recent several ten thousands years. While the deformation rate suggests that the co-seismic faulting activity at the Ichinose fault group as a whole is ranked as the one of most active faults in Japan, however, it is smaller than that of 6.3-8.3mm/yr estimated previously from the gravimetric and numerical analyses.

収録刊行物

• 地震　第２輯

  地震　第２輯 55 (1), 33-45, 2002

  公益社団法人 日本地震学会

キーワード

• Active fault
• Paleoseismology
• trench excavation
• Ichinose fault group
• Itoigawa-Shizuoka Tectonic Line

詳細情報

• CRID: 1390001204305745792
• NII論文ID: 10009481700
• NII書誌ID: AN00305741
• DOI: 10.4294/zisin1948.55.1_33
• ISSN: 18839029
• ISSN: 2186599X
• ISSN: 00371114
• NDL書誌ID: 6561920
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I6561920
• Web Site: https://www.jstage.jst.go.jp/article/zisin1948/55/1/55_1_33/_pdf
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  • NDL
  • Crossref
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