TITLE:
Surface rupture and hazard characteristics of the Wenchuan Ms 8.0 earthquake, Sichuan, China
AUTHORS:
Rong-Jun Zhou, Yong Li, Liang Yan, Jian-Cheng Lei, Yi Zhang, Yu-Lin He, Long-Shen Chen, Xiao-Gang Li, Shi-Yuan Wang, You-Qing Ye, Yu-Fa Liu, Chuan-Chuan Kang, Tian-Yong Ge, Qiang He, Wei Huang
KEYWORDS:
Wenchuan earthquake; Longmen Shan; Surface rupture; Hazard; Sichuan; China
JOURNAL NAME:
Natural Science,
Vol.2 No.3,
April
12,
2010
ABSTRACT: Longmen Shan is located the special joint be-tween Tibetan Plateau inland in the west and Yangtze craton in the east. Consisting of a se-ries of parallel imbricated thrust, it develops, from the west to the east, the Maoxian-
Wenchuan, Beichuan-Yingxiu and Pengxian-
﹡This research was supported by China National Natural Science Foundation grant 40841010, 40972083 and China National Science and Technology supporting Plan Foundation grant 2006BAC13B02-07, 2006BAC13B01-604.
Guanxian faults. The Wenchuan earthquake is a thrust with strike-slip type, and thre surface ruptures are located on the Beichuan-Yingxiu fault zone and Pengxian-Guanxian fault zone. The surface rupture on the Beichuan-Yingxiu fault shows the thrust and dextral slip charac-teristic. The maximum vertical displacement of the surface rupture is about 10.3 m and the maxi-mum right-lateral displacement is about 5.85m. Though the vertical displacements and the hori-zontal displacements in the different segments have certain differences, as a whole, the ratio of the vertical displacement and the horizontal dis-placement is close to 1:1. The surface rupture on the Pengxian-Guanxian fault shows thrust and dextral characteristic. The rates of vertical dis-placements and the horizontal displacements ones on the most other segments are between 1:3 and 1:2. So the Beichuan- Yingxiu fault is a dextral-slip and thrust fault and the average ver-tical displacement is equal to the average hori-zontal displacement, while the Pengxian- Guan xian fault is thrust fault with a little dextral-slip component. The total intensity area above Ⅵ de-gree of the Wenchuan earthquake is about 333000 km2. The high earthquake intensity line stretches to N40-50°E along Longmen Shan tectonic belt. The rate of the long axis and the minor is betw- een 8:1 and 10:1. Three Ⅺ intensity regions are isolated in distribution. It presents a multipoint instantaneous characteristic of the rupture.