Characteristics of block strain and fault movement in the Sichuan-Yunnan region before and after Wenchuan earthquake

• Main Authors: Zhao Jing, Jiang Zaisen, Wu Yanqiang, Liu Xiaoxia, Wei Wenxin
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2012-05-01
• Series: Geodesy and Geodynamics
• Subjects: GPS; velocity field; Wenchuan earthquake; strain status of blocks; faults deformation characteristics
• Online Access: http://www.sciencedirect.com/science/article/pii/S1674984715301154

Deformation characteristics of the Sichuan-Yunnan region during the two periods 1999—2007 and 2007—2009 are analyzed with a block deformation model and GPS velocity profiles. The results show that the direction of the principal compressive strain rate of the Northwest-Sichuan block - the Mid-Yunnan block - the Southwest-Yunnan block was characterized by a clockwise rotation from north to south. The Anninghe and the Zemuhe faults had some shear-strain accumulation. The southern segment of the Xiaojiang fault had mainly strike-slip movement, while the northern segment was mainly accumulating strain. The 2008 Ms8. 0 Wenchuan earthquake had some influence on the mid-southern segment of the Lijiang-Xiaojinhe fault, the Anninghe fault and the Jinshajiang fault, but not the Zemuhe fault, the Xiaojiang fault and the Red River fault as much.