著者
奥村 晃史 井村 隆介 今泉 俊文 東郷 正美 澤 祥 水野 清秀 苅谷 愛彦 斉藤 英二
出版者
公益社団法人 日本地震学会
雑誌
地震 第2輯 (ISSN:00371114)
巻号頁・発行日
vol.50, no.appendix, pp.35-51, 1998-03-31 (Released:2010-11-17)

The Itoigawa?Shizuoka tectonic line active fault system (ISTL) is one of the longest and the most complex active fault systems on land in Japan with very high activity. The system comprises the northern (55 km long east dipping reverse faults), the middle (60 km long left-lateral strike-slip faults), and the southern (35 km long west-dipping reverse faults) sections. The estimates of the average slip rate range 2 to over 10 m/103 yr in the system. This high slip rate and probable quiescense of the system exceeding 1150 years indicate the possibility of a surface faulting event in the near future. Since historic and instrumental records of seismicity along the ISTL is very poor, geological study on the paleoseismology of the ISTL has an important clue to evaluate the long-term seismic risks of the fault zone. In 1995 and 1996 the Geological Survey of Japan opened six exploratory trenches in the fault system and the results from the three in the northern section are reported in this paper. The Hakuba trench on the Kamishiro fault brought four earthquake events since 6738 BP (dendrocorrected radiocarbon age in calendar year) with the average recurrence interval to be between 1108 and 2430 years. The last event here postdates 1538 BP. The Omachi trench exposed the last event after 6th to 7th century AD and before 12th century at the latest, Only one event after 3rd to 4th century AD was identified in the Ikeda trench. The timing of the last event from each trench is between 500 and 1500 BP, which interval coincides with the timing of the last event in the middle section as well as the 841 AD or 762 AD earthquake reported in historical documents. The dating of the upper age limit of the last event is not precise enough to correlate the event with any of known earthquake. The recurrence interval of the northern section, however, is significantly longer than that of the Gofukuji fault. The difference in the recurrence time from one section to another is concordant with the difference in the apparent slip rate.

言及状況

Yahoo!知恵袋 (1 users, 1 posts)

神城断層を含む糸魚川‐静岡構造線に沿った断層帯の断層はすべて横ずれ成分を含む逆断層です。 プレートによる東西圧縮を受ける東北日本弧の断層は、ほとんどが逆断層で、被害地震を起こす規模の断層はすべて逆断層だと言い切ってもいいかもしれません。たとえ横ずれ断層でも、逆断層の成分を持っています。 リンクは論文ですが、今回の震源の近くで断層をトレンチ調査した時のものです。中の断面図で逆断層であることが ...

Twitter (32 users, 32 posts, 15 favorites)

おお、旧知の奥村くんの報告だったのか@usa_hakase: 白馬トレンチの本論文あった。奥村ほか1998 https://t.co/OnfMhOP7V8
見てる: 糸魚川-静岡構造線活断層系北部の最近の断層活動 -神城断層・松本盆地東縁断層トレンチ発掘調査- https://t.co/pl3W44psRp
さきほどの震源(36.7,137.9)は,神城断層のトレンチ調査のすぐ近くだ。糸魚川-静岡構造線活断層系北部の最近の断層活動 http://t.co/4A3VOxwenY
あら、いむらさんのお名前が。 RT @haruyagi: 活断層トレンチ調査の論文 https://t.co/QkLRY9QeKa
活断層トレンチ調査の論文 https://t.co/vMVO4XOCqb

収集済み URL リスト

https://www.jstage.jst.go.jp/article/zisin1948/50/appendix/50_appendix_35/_pdf (31)

https://www.jstage.jst.go.jp/article/zisin1948/50/appendix/50_appendix_35/_article/references/-char/ja/ (2)