龙门山及邻区断裂分布及地震前后断裂形态差异

利用欧拉方程(欧拉反褶积法)对龙门山地区重力数据进行反演,得到了地震前龙门山及邻区断裂的分布特征及参考深度。汶川地震波及范围广、破坏性大,地震前后发震断裂及周围断裂的形态必然会存在一定差异。笔者布设了一条实测重力剖面来对比地震前后断裂的形态。对比发现,地震后龙门山断裂带的逆冲趋势减弱,映秀—北川断裂与都江堰—江油断裂之间产生了多个破碎带。通过断裂形态的变化探究本次地震的成因,提出了应力面(第二地震面)和多震源的观点。

Fault Distribution of Longmenshan and Adjacent Regions and Fault Morphological Differences Before and After the Earthquake

The fault distributions and reference depths in Longmenshan and adjacent areas before earthquake has been obtained by Euler equation(Euler deconvolution) inversion method about gravity data of Wenchuan area.Wenchuan earthquake spreads widely and causes seriously destructions,which will results in morphology differences in seismogenic fault and peripheral faults.A gravity profile was designed in this area to compare the fault morphology before and after the earthquake.The thrust nature of Longmenshan belt diminished,and a number of fracture zone between Yingxiu-Beichuan fault and Dujiangyan-Jiangyou fault were produced.The viewpoints of stress plane(second earthquake plane) and multi-sources were proposed according to the genesis research about Wenchuan earthquake through fault morphology differences.