Seismogenic Structure of Lushan MW6.6 Earthquake, Sichuan, China
详细信息
- 责任者：Zhou Rongjun (Institute of Earthquake Engineering ; Seismological Bureau of Sichuan Province ; Chengdu 610041 ; China) ; Li Yong
- 刊名：Journal of Chengdu University of Technology
- 出版年：2013
- 卷期：40(4)
- 关键词：强震 ; strong earthquakes ; 孕震构造 ; seismogenic tectonics ; 龙门山断裂带 ; Longmenshan Fault Zone
- 页码：p.364-370
- 图表：8 illus., 31 refs.
- 分类号：0500
- issnNo：ISSN1671-9727
- isbnNo：CN51-1634/N
摘要
On April 20,2013,the Lushan Mw 6.6 earthquake occurred on the south segment of the Longmenshan fault zone and no significant coseismic ground rupture was observed.In this paper,the authors define the distribution of the intensity of this earthquake after redefining more than 400 macro-seismic damage survey points and referring to the near field ground acceleration(PGA) record of the Sichuan digital strong motion seismic network.The intensity of epicenter region reached Ⅸ degree on Chinese seismic intensity scale,slightly showing flat oval shape with the long axis to NE,without apparent direction.Furthermore,after consolidating the results of relocating 3 323 early aftershocks,petroleum seismic exploration profiles and focal mechanism solutions,the authors think that the Dayi fault controlling the east piedmont of Mengshan is the main causative structure of the Lushan earthquake,resulting from the thrusting of the Dayi fault induced by shortening of the Longmenshan fault zone in NW-SE direction.The Xinkaidian fault also produces coseismic ruptures in the depth,causing the phenomena that the earthquake damage on the hanging wall is significantly higher than that on the footwall.