伽师及周围地区现代构造应力场特征研究  

CHARACTERISTICS OF RECENT TECTONIC STRESS FIELD IN JIASHI, XINJIANG AND ADJACENT REGIONS

作　　者：崔效锋[1] 

机构地区：[1]中国地震局地壳应力研究所,中国北京100085

出　　处：《地震学报》2006年第4期347-356,共10页Acta Seismologica Sinica

基　　金：国家财政部巴楚伽师地震专项资助

摘　　要：对伽师及周围地区内震源机制解、钻孔崩落、断层滑动资料等地应力数据进行统计,分析了区域构造应力场的总体方向特征.3类地应力数据给出的水平最大主应力方向差异不大,表明该地区构造应力场在水平向上总体呈南北向挤压.利用137个地震震源机制解数据,对伽师及周围地区现代构造应力场的时空变化特征进行了反演分析.反演计算结果表明,伽师周围地区区域现代构造应力场最大主应力σ1为北北西-南南东向,方位角为162°.在1997—2003年的伽师巴楚地震前,伽师震源区最大主应力σ1和最小主应力σ3的方向,相对于周围区域构造应力场发生了顺时针偏转,最大主应力σ1变为北北东—南南西向,方位角为25°.在这一构造应力场的控制下,发生了包括1997年伽师强震群在内的一系列地震.其后,伽师震源区构造应力场可能又一次发生了调整,控制2003年伽师巴楚地震的构造应力场与周围地区区域现代构造应力场相一致.In this paper, we analyze the general directional features of regional tectonic stress field in Jiashi, Xinjiang and adjacent regions from the data of focal mechanism solutions, borehole breakouts and fault slip. The direction of maximum horizontal principal stress given by these three sorts of stress data differs slightly, which indicates there is a NS-trending horizontal compression in the tectonic stress field in the region of interest. We also invert and analyze the temporal and spatial changes of recent tectonic stress field in the research region by using 137 focal mechanism solutions. The inverted results show that the maximum principal stress σ1 in Jiashi and adjacent regions is NNW-SSE with an azimuth of 162°. In the period from 1997 to 2003 before the occurrence of Jiashi-Bachu earthquake, the directions of the maximum principal stress σ1 and the minimum principal stress σ3 in Jiashi seismic source zone changed clockwise with respect to the tectonic stress field in the regions around. The maximum principal stress σ1 adjusted to the direction of NNE-SSW with an azimuth of 25°. Under the control of this tectonic stress field, a series of earthquakes happened, including the Jiashi strong earthquake swarm in 1997. Then, the tectonic stress field in the Jiashi seismic source zone might adjust again. And the tectonic stress field controlling the Jiashi-Bachu earthquake in 2003 was in accordance with the regions around.

关 键 词：新疆伽师 应力场 反演分析 

分 类 号：P315.727[天文地球—地震学]