The Origin of the 2008 Wenchuan Earthquake Determined by the Analysis on the Active Longmenshan Nappe in Terms of Rockmass Mechanics

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所 > Journal of Mountain Science > Journal of Mountain Science-2012 > Vol9 No.3

	The Origin of the 2008 Wenchuan Earthquake Determined by the Analysis on the Active Longmenshan Nappe in Terms of Rockmass Mechanics
	YAN Zhixin ; MA Guozhe ; YUAN Binxiang ; NIU Fujun
刊名	Journal of Mountain Science
	2012-06
卷号	9 期号:3 页码:395-402
关键词	Active nappe Rockmass structure cybernetics Shear-slip failure Wenchuan earthquake Seismicorigin
通讯作者	MA Guozhe
英文摘要	On 12 May 2008, the magnitude 8.0 Wenchuan Earthquake occurred along the Longmen Shan nappe, Sichuan, China. This devastating earthquake led to a heavy death toll of greater than 80,000. The seismic origin of this earthquake is currently hotly debated. We suppose that it is a special type of intraplate earthquake called an active-nappe-type earthquake. Using a holistic methodology, incorporating rockmass structure cybernetics and Byerlee’s law, we present a comprehensive study on the geological origin of macroseisms in the Longmen Shan area and the seismic origin of the 2008 Wenchuan earthquake. Previous studies of neotectonic activity indicate that the Longmen Shan nappe moves at a rate of 1~3 mm/yr, due to horizontal compressive stress from the Tibetan Plateau. The difference between movement rates in the Bayankala block, Longmen Shan nappe and Sichuan Basin cause slow shear stress and strain accumulation in the Longmen Shan nappe. It is exhibited a relatively simple linear relations for the shear strength and the buried depth of the structural planes, and the detachment layer of the nappe has a higher shearing-sliding strength compared to the overlying fault planes and the underlying ductile shear belts, thus making it more prone to stick-slip deformation. Therefore, the detachment layer was the main section responsible for the Wenchuan earthquake. The initial rupture burst in the detachment layer under the Yingxiu－Beichuan fault, the rupture area nearly 1.4454 × 10⁴km²，encompassed the cross point of the Yingxiu and the Anxian–Guanxian faults with the detachment layer, then caused the Yingxiu－Beichuan and Anxian–Guanxian faults took an active part in this earthquake, so this earthquake might consist of three chain-like earthquake stages, totally increasing the duration of this earthquake an unusually large amount, to 120 s. The focal depth spanned range of 10–20km，consistent with the observed result of this focal depth by several agencies.
收录类别	SCI
语种	英语
公开日期	2013-04-16
内容类型	期刊论文
源URL	[http://192.168.143.20:8080/handle/131551/5108]
专题	成都山地灾害与环境研究所_Journal of Mountain Science _Journal of Mountain Science-2012_Vol9 No.3
推荐引用方式 GB/T 7714	YAN Zhixin,MA Guozhe,YUAN Binxiang,et al. The Origin of the 2008 Wenchuan Earthquake Determined by the Analysis on the Active Longmenshan Nappe in Terms of Rockmass Mechanics[J]. Journal of Mountain Science,2012,9(3):395-402.
APA	YAN Zhixin,MA Guozhe,YUAN Binxiang,&NIU Fujun.(2012).The Origin of the 2008 Wenchuan Earthquake Determined by the Analysis on the Active Longmenshan Nappe in Terms of Rockmass Mechanics.Journal of Mountain Science,9(3),395-402.
MLA	YAN Zhixin,et al."The Origin of the 2008 Wenchuan Earthquake Determined by the Analysis on the Active Longmenshan Nappe in Terms of Rockmass Mechanics".Journal of Mountain Science 9.3(2012):395-402.