西天山地区重力场变化与地震研究

Variation of Gravity Field and Earthquake in the West Tianshan Area

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。

Based on gravity observations from 2013 to 2015 of west Tianshan area, and considering re- gional earthquake catalogue, we analyze the relationship between variation of gravity field and earth- quakes 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＂ corre spond 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 grav- ity variation and is close to the ＂0＂ equivalent line. （3） Before the earthquake in the west Tianshan ar- ea, the cross-fault section shows a turning image.