中文摘要：

利用芦山地震科学考察流动重力观测成果及科考区域内其他流动重力观测资料,系统分析芦山地震前后重力场变化特征。结果表明：1）地震前,重力场变化显著异常特征主要表现为龙门山断裂带两侧正、负高值异常以及与龙门山、鲜水河、大凉山断裂平行或垂直的较大规模重力变化梯度带,与汶川地震前重力变化特征一致;2）地震后,重力场变化沿龙门山发生反向调整;3）中下地壳物质的生热、膨胀可能是松潘-甘孜块体震前重力变化的场源,并可能成为芦山地震及汶川地震的重要触发因素。

英文摘要：

By using gravity data in the area of the scientific expedition of the Lushan earthquake,we have systematically obtained the gravity variation before and after earthquake.The results show that：1）before the earthquake,the area beside the Longmenshan fault shows an obvious anomaly,and some high gradient zones are parallel or vertical with the Longmenshan,Xianshuihe and Daliangshan faults;2）after the earthquake,gravity variation was opposite in the area beside the Longmenshan fault;3）heat and bulge of the material of middle and bottom crust probably cause the gravity variation and may be one important trigger factor of the Lushan earthquake.