【摘要】 根据马尼拉海沟及邻区地震、火山活动的分析,并结合地震震源机制和地球物理资料分析,发现马尼拉海沟在深度200多公里仍为俯冲的性质,深地震主要集中在12°N～14°N之间,地震密集区出现明显的分段特征,从北到南深度逐渐变深.震源机制解所反映的最大主压应力轴(P轴)以菲律宾大断层为界,北部主要为NW向;南部较为复杂,为NW,NE和近NS向.显示了北部以挤压逆冲为特征,南部以顺时针旋转为特征.菲律宾板块向西仰冲所产生的构造应力,被马尼拉海沟的斜向俯冲,菲律宾大断层的左旋走滑,以及民都洛断层的左旋走滑所调节.更多还原

【Abstract】 According to the activity of earthquakes and volcanoes along the Manila trench and its adjacent region, combined with analysis of focal mechanism solutions and geophysics data, the Manila trench is still being downward subduction in the depth of 200 km. Deep earthquakes mainly concentrate between 12°N and 14°N, the concentrated region is divided into different sections, and the focal depth is gradually deep from the north to the south. From the focal mechanism solution data, the maximum principal stress direction (P axis) varies from the northern region of Philippine fault to the southern region of the fault. In the north P axes directions are mainly NW, however in the south there is the complex displaying and P axes have NW, NE and approximately NS directions. These results show the characteristic of press-thrust in the northern region of the Philippine fault and the clockwise rotation in the southern region of the fault. The stress caused by the Philippine plate, which moved upon the South China Sea sub-plate, is adjusted by the oblique subduction of the Manila trench, the sinistral strike-slip of the Philippine fault and the sinistral strike-slip of the Mindoro fault.更多还原