[关键词]
[摘要]
利用1999~2007期GPS速度场数据,通过块体模型择优得到了南北地震带中南段主要块体边界带变形的适用模型,并给出了块体边界主要断层的滑动速率。结果表明,龙门山断裂带宝兴-汶川段张压速率较小,为0.5~1.8mm·a-1;汶川-茂县压性相对显著,速率达1.8~3.8mm·a-1;鲜水河断裂带张压及走滑速率存在一定的空间差异性特征,即炉霍以北张性滑动速率(8.1mm·a-1)比左旋走滑速率(4.8mm·a-1)大,炉霍-道孚段张压速率与走滑速率基本相同,道孚-康定段呈现出左旋走滑速率减小、张性速率增大的变化趋势,康定-石棉段表现出较明显的左旋走滑性质;小江断裂带走滑速率明显大于张压速率;红河断裂带空间分段性较为明显,北西段滑动量较小,但存在一定的张压分量(景东段速率4.7mm·a-1),南东段(个旧以西)以走滑为主(速率4.5mm·a-1)。
[Key word]
[Abstract]
In this paper, using the 1999 -2007 GPS velocity field data and choosing the block model, we researched the applicability of each block and gave the slip rate of each block boundary. The results show that the Baoxing-Wenchuan compression rate in the Longmenshan fault zone is smaller, about O. 5 1 8mm·a-1 ; the Wenchuan-Maoxian pressure rate is relatively obvious, at 1.8 3.8mm· a-1 ; the Xianshuihe fault belt tension pressure rate and slip rate has some spatial difference characteristics : the slip rate of north of Luhuo region (8.1 mm·a-1 ) is bigger than the sinistral strike-slip rate (4.8mm·a-1 ); Luhuo-Dawu paragraph pressure characteristics and slip rate is basically the same; Dawu-Kangding section presents a decrease of the strike-slip rate, but there is a trend of rate increase; the Kangding-Shimian segment showed strike-slip nature; the Xiaojiang fault slip rate is significantly greater than pressure rate; the Red River fault zone spatial segmentation is more obvious: north west slip amount is smaller, but there are some tension pressure components (4.7mm.a-1 at Jingdong). The rate at south-east paragraph (west to Gejiu) is basically of strike-slip type (g. 5mm·a-1 ).
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[基金项目]
国家“十二五”科技支撑计划(2012BAK19802)、地震行业专项(201108009)、震情跟踪青年课题(2012020212)共同资助