Study on temporal change of attenuation structure in the the inland earthquake's source region

2013 Fiscal Year Final Research Report

• Project/Area Number: 23540488
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Solid earth and planetary physics
• Research Institution: Chiba University
• Principal Investigator: TSUMURA Noriko 千葉大学, 理学(系)研究科(研究院), 助教 (00272302)
• Co-Investigator(Kenkyū-buntansha): HIRAMATSU Yoshihiro 金沢大学, 理工研究域, 准教授 (80283092)
• Project Period (FY): 2011 – 2013
• Keywords: Q値 / 能登半島地震 / 地震波減衰

Research Abstract

Tsumura et al.(2012) mapped a seismic attenuation (Qp) structure in the source region of the 2007 Noto Hanto earthquake. The results show low Qp zone is seen at the main shock fault, where aftershocks' activity is high. Next we made Qp/Qs estimation for several ray paths by using spectral ratio method. Obtained Qp/Qs for the low Qp zone in the main shock fault is higher than that of the surrounding area. In conjunction with other geophysical data, these attenuation features might be caused by the rupture of the main shock.
To detect the temporal change of seismic structure near the source region, we made the other temporary seismic observations in 2011 and in 2012. In these observations, we set seismic stations, whose locations were same as those of 2007 observation. The result for 2011 and 2012 observation data shows that ray paths having high Qp/Qs concentrated on the west coast area of Noto Peninsula where high Qp/Qs was observed in 2007, and temporal change of Qp/Qs was not clear.

Research Products

• [Journal Article] 東海地域下の三次元地震波減衰構造-微小地震スペクトルを用いた推定- (2012)
  • Author(s): 高岡宏之, 津村紀子, 高橋福助, 野崎謙二, 加藤愛太郎, 飯高隆, 岩崎貴哉, 酒井慎一, 平田直, 生田領野, 國友孝洋, 吉田康弘, 勝俣啓, 山岡耕春, 渡辺俊樹, 山崎文人, 大久保慎人, 鈴木貞臣
  • Journal Title: 地震 2 Volume: 65 Pages: 175-187
  • Peer Reviewed
• [Presentation] The attenuation structure in the source region of 2007 Noto-Hanto Earthquake, northern part of central Japan (2013)
  • Author(s): N. Tsumura, T. Emoto, G. Takahashi, Y. Kazato, K. Miyagaki, Y. Hiramatsu, S. Ueno, Y. Hara, R. Koizumi, K. Hirano, H. Takaoka, M.Totani, A. Kato
  • Organizer: American Geophysical Union Fall Meeting
  • Place of Presentation: サンフランシスコ
  • Year and Date: 20131209-13
• [Presentation] 能登半島地震震源域における地震波減衰構造(2) (2013)
  • Author(s): 津村紀子・高岡宏之・江元智子・高橋豪・戸谷真亜久・風戸良仁・宮垣敬一郎・平松良浩・浦野駿・原雄斗・小泉亮・堀野一樹・加藤愛太郎・能登半島地震合同観測グループ
  • Organizer: 日本地震学会秋季大会
  • Place of Presentation: 横浜
  • Year and Date: 20131007-09
• [Presentation] 能登半島地震震源域における地震波減衰構造 (2012)
  • Author(s): 津村紀子・吉住武倫・小林理紗・能登半島地震合同観測グループ
  • Organizer: 地震学会秋季大会
  • Place of Presentation: 函館
  • Year and Date: 20121016-19
• [Presentation] 3D-Q structure in the source region of 2007 Noto Hanto Earthquake, central Japan (2012)
  • Author(s): N. Tsumura, T. Yoshizumi, R. Kobayashi, Group for aftershock observation of the 2007 Noto Hanto Earthquake
  • Organizer: AOGS-AGU Joint assembly
  • Place of Presentation: シンガポール
  • Year and Date: 20120813-17
• [Presentation] 濃尾地震震源域周辺の3 次元地震波減衰構造 (2011)
  • Author(s): 津村紀子・加藤愛太郎・中島淳一・濃尾合同観測グループ
  • Organizer: 地震学会秋季大会
  • Place of Presentation: 静岡
  • Year and Date: 20111012-14