Influence of fault geometry and fault interaction

Authors: Hui Wang Jie Liu XuHui Shen Mian Liu QingSong Li YaoLin Shi GuoMin Zhang

Publish Date: 2010/05/15

Volume: 53, Issue: 7, Pages: 1056-1070

PDF Link

Abstract

There are several major active fault zones in the western Sichuan and its vicinity Slip rates and seismicity vary on different fault zones For example slip rates on the Xianshuihe fault zone are higher than 10 mm/a Its seismicity is also intense Slip rates on the Longmenshan fault zone are low However Wenchuan M s80 earthquake occurred on this fault zone in 2008 Here we study the impact of fault geometry on strain partitioning in the western Sichuan region using a threedimensional viscoelastoplastic model We conclude that the slip partitioning on the XianshuiheXiaojiang fault presents as segmented and it is related to fault geometry and fault structure Slip rate is high on fault segment with simple geometry and structure and vice versa Strain rate outside the fault is localized around the fault segment with complex geometry and fault structure Strain partitioning on the central section of the XianshuiheXiaojiang fault zone is influenced by the interaction between the AnningheZemuhe fault and the Daliangshan fault zone Striking of the Longmenshan fault zone is nearly orthogonal to the direction of eastward extrusion in the Tibetan Plateau It leads to low slip rate on the fault zone

Keywords: