东昆仑断裂带玛沁段周围小震震源机制解系统聚类分析

摘要

By using the maximum amplitude ratio of P and S wave, the focal mechanisms of 57 small earthquakes since 2008 in Maqin region of the east Kunlun active fault were calculated, and the systematic cluster analysis was also carried out. The results indicated that the dislocation mode of small earthquakes was domina- ted by strike-slip fault activities in the region, the azimuth and the dip of mean principal compressional stress axis was 50°and 5°, the azimuth and the dip of mean principal tensil stress axis was 140°and 4° ,which were in consonance with the geodynamic regime of Maqin region.%利用P、S波最大振幅比计算得到东昆仑断裂带玛沁段周围2008年以来57个小地震震源机制解，并进行系统聚类分析。结果表明，该区小震错动方式以走滑型活动为主，平均主压应力P轴方位角为50°，倾角为5°，主张应力T轴方位角为140°，倾角为4°，与该区所受的地球动力学背景基本一致。