汶川大地震的深部构造特征

Characters of Deep Structure for Wenchuan Earthquak

利用卫星重力图来了解汶川地震的深部构造的特征。2-180低阶的卫星重力异常图可以反映场源深度为36km的密度分布特征;2-360高阶的卫星重力异常图可以反映场源深度为18km的深部构造特征。卫星重力异常显示了青藏高原板块深部的塑性物质向上流动。龙门山逆冲滑脱断裂带向四川盆地的逆冲推覆,由此引发了汶川地震。

Using the satellite gravity maps, the character of deep structures for Wenchuan earthquake s well explained. The 2--180 low--degree satellite gravity anomalies could reflect the characters of density distribution at the depth of 36 km. The 2--360 high--degree satellite gravity anomalies could reflect the feature of deep structures at the depth of 18 km, The upward movement of plastic material in Qinghai Xizang Plateau plate is expressed in the gravity maps. The active thrust faults with detachment of Longmen mountains thrust eastward over the Sichuan basin, which is believed to be the cause of the earthquake in Wenchuan area.