地震学报2011，Vol.33Issue(1)：15-27,13.DOI:10.3969/j.issn.0253-3782.2011.01.002
乌鲁木齐地区现今构造应力场综合分析
Comprehensive analysis on present tectonic stress field in Urumqi region
摘要
Abstract
Urumqi city is located in central part of northern piedmont of Tianshah mountain. The mean direction of principal compressive stress in central section of northern Tianshan deduced from the focal mechanism solutions is around N10°E, with a clear feature of gradual change from west to east. In the region of Urumqi city, the direction derived from focal mechanism solutions of moderate-strong earthquakes is N15°-20°E. The principal stress direction found from fault striation inversion is N17°W-N2°E. The stress direction deduced from the above two data sets are basically in the variation range of the principal compressive stress in the central section of northern Tianshan. However, the stress direction inferred from composite fault-plane solutions of small earthquakes within 25 km of the Urumqi seismic station is N40°-46°E, which shows a deviation of 20°-30° from that of regional principal compressive stress. Nevertheless, the direction of maximum horizontal compressive stress measured in the boreholes in Urumqi city is around N55°E, which displays a further deviation of 10°-15°, and its deviation from that of regional stress field is up to 30°-40°. These phenomena indicate that a tension stress in the shallow layers in front part of the compressive fault-fold region has been superposed to the regional NNE-SSW trending compressive tectonic stress and makes the direction of local principal compressive stress turn to NEE-SWW. This is one of the causes why the normal faults, such as the Jiujiawan fault groups, were developed in Urumqi city.关键词
乌鲁木齐/构造应力场/震源机制解/综合断层面解/原地应力测量Key words
Urumqi/ tectonic stress field/ focal mechanism solution/ composite fault-plane solutions in-situ stress measurement分类
天文与地球科学引用本文复制引用
李莹甄,沈军,聂晓红,龙海英..乌鲁木齐地区现今构造应力场综合分析[J].地震学报,2011,33(1):15-27,13.基金项目
国家"973"项目(2008CB425703)和乌鲁木齐城市活断层探测项目(2004-1138)联合资助. （2008CB425703）
