近期新疆震源机制解与地震活动特征研究

Research on the Characteristics of Recent Focal Mechanism Solution and Seismic Activity in Xinjiang Area

分析了2003-2009年新疆及其周边88次中强震震源机制解及其分布特征,并结合同期地震活动特点与区域应力场进行了讨论。认为:这一期间新疆主要受NNW向水平挤压应力制约,与1990-2002年新疆主压应力P轴NNE向分布有一定差异;中强震震源断层具有多样性,显示出新疆构造运动的复杂性;主压应力P轴仰角的变化与新疆地震活动的强弱交替相关;研究时段内不同强度的地震空间分布具有较明显的层次性特征。

The focal mechanism solutions and the distribution characteristic of 88 moderate-strong earthquakes in Xinjiang and its adjacent area from 2003 to 2009 are analyzed.The related discussion is given combining with the seismic activity characteristics and the region stress field in the same period.The result shows that stress field in Xinjiang area is mainly controlled by level pressure stress in NNW direction in this period,with certain difference from the principal compress stress P axis distribution in NNE from 1990 to 2002.The seismogenic faults of moderate-strong earthquakes exist certain multiplicity,it demonstrates the complexity of tectonic movement in Xinjiang area.The elevation angle′s change of principal compression stress P axis is related with alternation of strong and the weak of seismic activity.In the research time,the spatial distribution with different magnitude earthquakes have obvious level characteristic.