2003年民乐Ms6.1级地震前的重力变化研究

The Study of Gravity Variation before Minle Ms6.1 Earthquake in 2003

以河西地区的流动重力监测资料为基础 ,分析了 2 0 0 3年 1 0月 2 5日民乐MS6 1级地震前的重力场变化 ,认为在空间分布上 ,地震发生前观测区出现了区域性的重力异常变化及与构造活动断裂走向基本一致的重力变化高梯度带 ,并在震中或邻区产生局部重力变化异常区。在时间序列上 ,地震发生前 ,重力段差和重力测点先是增强 ,然后反向减弱 ,并在反向过程中发震。

Based on the mobile gravity data of Hexi area, the variation characteristics of gravity field before Minle M S6.1 earthquake on Oct. 25, 2003 are analyzed. The analysis shows that in the spatial distribution, the gravity field has anomalous changes before the earthquake, and there is a gravity change belt along the active tectonic fault in the earthquake spot before the earthquake, and a regional anomaly area of gravity variation will be grown in the epicenter or its neighborhood; in the time sequence, the gravity field strengthens first, then weakens backward, the earthquake comes about during the inverse process.