Viscoelastic simulation of deep tectonic deformation of the Longmenshan fault zone and its implication for strong earthquakes

doi:10.6038/cjg20151120

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院地球与行星物理重点实验室

	Viscoelastic simulation of deep tectonic deformation of the Longmenshan fault zone and its implication for strong earthquakes
	Chen Qi-Fu 1; Hua Cheng 2; Li Le 3; Cheng Jin 4
刊名	CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
	2015-11-01
卷号	58 期号:11 页码:4129-4137
关键词	Longmenshan fault zone Deep slip rate Repeating earthquake Viscoelasticity
DOI	10.6038/cjg20151120
文献子类	Article
英文摘要	The 2008 M(w)7. 9 Wenchuari earthquake ruptured the middle and northern segments of the Longmenshan faults zone (LMSFZ) at the eastern margin of the Tibetan Plateau. Prior to this earthquake, the LMSFZ had been seismically quiet for several centuries, where no hints suggest such a M similar to 8. 0 earthquake might strike the area. The long-term geological investigations and short-term geodetic measurements before the Wenchuan earthquake generally agree that the horizontal slip rate along the LMSFZ is very limited. The low deformation rate observed at the surface around the LMSFZ may not reflect the true deep deformation where the devastating Wenchuan earthquake nucleated. The slip rates at depth derived from seismological investigation of repeating microearthquakes were found to be systematically larger than those observed on the surface. In order to validate the depth-related slip rate pattern, based on regional tectonic characteristics of the LMSFZ, a two-dimensional viscoelastic finite-element model with contact algorithm is established to simulate the evolution process of the crust and upper mantle during an earthquake cycle. The viscoelastic creep and discontinuity contact relationships in the crust and upper mantle are taking into account. Our primary results confirm the depth-related lateral slip rate pattern around the LMSFZ revealed by the seismological observations of repeating earthquakes. Furthermore, the LMSFZ and its surrounding regions are prone to accumulation of strain and strain rate potential with the highest stress concentration area of 5 similar to 19 km depth, suggesting that this area may essentially nucleate strong earthquakes over time, depending on the bilateral rheology structure of the lower crust and upper mantle. At the same time, the large strain rate accommodated at depth can explain the occurrence of the unanticipated Wenchuan M(w)7. 9 earthquake in 2008.
WOS关键词	2008 WENCHUAN EARTHQUAKE ; TIBETAN PLATEAU ; REPEATING EARTHQUAKES ; SEISMIC HAZARD ; FRICTION LAWS ; ASEISMIC SLIP ; CHINA ; SICHUAN ; RUPTURE ; STRAIN
WOS研究方向	Geochemistry & Geophysics
语种	英语
WOS记录号	WOS:000365695200020
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/62161]
专题	地质与地球物理研究所_中国科学院地球与行星物理重点实验室
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing 100029, Peoples R China 2.Fudan Univ, Dept Mech & Engn Sci, Shanghai 200433, Peoples R China 3.China Earthquake Adm, Inst Earthquake Sci, Key Lab Earthquake Predict, Beijing 100036, Peoples R China 4.Fudan Univ, Sch Math Sci, Shanghai 200433, Peoples R China
推荐引用方式 GB/T 7714	Chen Qi-Fu,Hua Cheng,Li Le,et al. Viscoelastic simulation of deep tectonic deformation of the Longmenshan fault zone and its implication for strong earthquakes[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2015,58(11):4129-4137.
APA	Chen Qi-Fu,Hua Cheng,Li Le,&Cheng Jin.(2015).Viscoelastic simulation of deep tectonic deformation of the Longmenshan fault zone and its implication for strong earthquakes.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,58(11),4129-4137.
MLA	Chen Qi-Fu,et al."Viscoelastic simulation of deep tectonic deformation of the Longmenshan fault zone and its implication for strong earthquakes".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 58.11(2015):4129-4137.