摘要
通过对乌恰、伽师地区GPS监测网进行的6期复测,结合周边地区的IGS站数据,计算得到了该区50多个GPS点位在ITRF2000下的最新运动速率及相对欧亚板块(在NNR-NUVEL1A地质模型下)的运动速率,由此得到了该区的现今地壳形变速率图。结果表明GPS站主要运动方向为北北西,基本上与天山褶皱带走向正交,形成对天山的正向挤压。同时对乌恰—伽师(20021225MS5.8)及伽师—巴楚(20030224MS6.8)地震前后的地壳运动进行了应变计算及分析,得出大震前震中及邻近地区会大面积产生高剪应变集中区的结论。
We have made 6 terms of GPS surveies in the Wuqia and Jiashi areas in Xinjiang since 1998. Combined with the data from neighbor IGS stations, we calculated and analyzed the deformation velocity of more than 50 GPS stations under ITRA200 and the relative ones to the Eurasia Plate (under NNR-NUVEL1A model), obtained present crustal deformation velocity map. The result shows that the principal motion is in NNW and generally orthogonal with the Tianshan fold belt, forming the squeeze to the Tianshan Mts. In addition, the changes of the stress field before and after the Wuqia-Jiashi M \-S 5.8 earthquake on Dec. 25, 2002 and the Jiashi-Bachu M \-S 6.8 earthquake on Feb. 24, 2003 show that it is possible to break out strong shock at the field of high shear strain accumulation.
出处
《内陆地震》
2004年第3期281-288,共8页
Inland Earthquake
基金
新疆自然科学基金(200321101)
自治区科技攻关项目(200333116)资助课题.
关键词
地壳运动
GPS
剪应变
GPS survey
Crustal motion
Shear strain
