汶川地震前后青藏高原东北缘重力场动态变化研究

Gavity Changes before and after the Wenchuan M_S8.0 Earthquake in The Northeastern Edge of Qinghai-Tibet Block

通过对青藏高原东北缘重力观测资料进行整体平差计算,系统分析了该区重力场在汶川8.0级地震前后重力场的时空动态演化特征。研究结果表明,汶川地震的发生使青藏高原深部物质向北东运移,且部分通道受鄂尔多斯陆块的阻隔,青藏高原东北缘区域重力场出现大空间尺度的趋势性显著重力变化;汶川地震后,甘、宁、陕交界的六盘山断裂带与西秦岭北缘断裂带以及之间地区重力场出现显著的非均匀变化,该地区受汶川大地震的影响显著。

Temporal-spatial evolution of gravity field before the Wenchun Ms8. 0 earth- quake has been analyzed systematically by integrally adjusting the gravity observation data from the northeastern edge of the Tibetan Plateau. The results show that deep material of Tibetan Plateau moved northeastward after Wenchun Ms8.0 earthquake, and some chan- nels have been blocked by the Ordos block. Regional gravity field has changed significantly on a large spatial scale. After the Wenchun earthquake, gravity field changed non-uni- formly between Liupanshan fault zone which borders land of Gan-Ning-Shan and the fault zone along the north edge of west Qinling mountains. This area has been affected by the Wenchun earthquake significantly.