西天山地区重力场变化与地震研究

基于2013~2015年西天山地区流动重力观测资料，结合区域地震目录，分析研究区域重力场时空变化与地震的关系。结果表明：1）重力场变化反映出西天山地区是构造运动活跃的地区，重力场变化的“增强-减弱-增强”过程与区域地震活动趋势的“活跃-平静-活跃”相对应，西天山区域重力场变化与塔里木板块北漂旋转相关。2）西天山地区震中多出现在重力变化接近为零的断层附近，震中附近重力变化较为剧烈，震中区水平梯度方向接近该区域断层走向。3）西天山区域地震前，跨断层测段剖面出现转折图像。

Variation of Gravity Field and Earthquake in the West Tianshan Area

Based on gravity observations from 2013 to 2015 of west Tianshan area, and considering regional earthquake catalogue,we analyze the relationship between variation of gravity field and earthquakes in the west Tianshan mountains. The results show that: (1) The west Tianshan area is one of the most active areas in the gravity field. Gravity field change “enhance-weakened-enhance” correspond with seismic trend activity “active-quiet-active”. The change of regional gravity field is related to the north drift rotation of Tarim plate.(2)The epicenter is located in the high gradient zone of gravity variation and is close to the “0” equivalent line. (3) Before the earthquake in the west Tianshan area, the cross-fault section shows a turning image.