Research into the Regional Characteristics of the Tectonic Stress Field in Jiashi, Xinjiang and Its
Surrounding Areas
作者：Gao Guoying;Wang Haitao;Nie Xiaohong;Long Haiying 作者机构：Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China;Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China;Earthquake
Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China;Earthquake Administration of Xinjiang Uygur Autonomous Region, Urumqi 830011, China 来源：中国地震研究（英文版） ISSN：0891-4176 年：2007 卷：021 期：004 页码：397-408 页数：12 中图分类：P3 正文语种：chi
关键词：Focal mechanism solution; Tectonic stress field; Region characteristic; Jiashi and its surrounding area
摘要：Jiashi and its surrounding areas are composed of many structural zones. Using the focal mechanism solutions of 59 moderately strong earthquakes in Jiashi and its surrounding areas,and combining these with the calculation results of system cluster and stress field inversion,
we analyzed the evolvement characteristics of the stress field for different times and different regions. The results were as follows: The earthquakes in Jiashi are mainly strike-slip.However, those of the Kalpin block are mainly reverse events, showing an obvious thrusting.The regional characteristics are different from other areas. The direction of the regional principal stress field is near NS. However, under different tectonic backgrounds, the directions of the stress fields are different. The direction of the principal compress stress is near NS in the Kashi-Wuqia area. But before and after the 3 earthquakes with M7.0, dynamic evolution from NW to NS and then to NE with time process was observed. The Kalpin block has been dominated by a consistent stress field in the NW direction for a long time. However, the direction of the stress field of the Jiashi region is NE. Since 1996, the direction of the regional stress field has changed obviously. The direction of the P axis was deflected towards the NE,and the plunge angle increased. The result shows clearly the regional characteristics and variation of the distribution pattern of the stress field in different tectonic environments.
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