山西断陷带水平形变分析
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摘要
对汶川地震前后山西断陷带及邻区的观测资料进行了处理,获得了2007—2008年的运动速率。此外,又以2003—2007年的运动速率为参照获得了汶川地震之后的偏离位移场,结果表明:1)运动似乎显得杂乱无章,观测误差也相对较大,这可能与观测时间段分别包含了地震前后有关;尽管如此,其运动分布仍有其特征,较明显的为该带北段有向南的运动趋势,该段南部有向北的运动趋势,它们大致交汇于太原以南地区;2)震后的偏离位移场显现,汶川地震对山西断陷带有一定的影响,主要体现在断陷带的南部,这种影响以该段向北位移为主,量级为数毫米;而北段向西的偏移可能反映了来自于东侧的应力有所加强。总之,从危险性的角度来看,当前需密切关注的地域可能是该带的北端。
Based on processing of observation data of Shanxi rift zone and its adjacent region,the movement rate during 2007-2008 is obtained.In addition,deviated displacement field after Wenchuan earthquake is got,referring to the movement rate of 2003-2007.The results show that 1)The movement seems to be in disorder,with rather large inaccuracy,which may be related to observation time that covers periods before and after the earthquake.However,the movement still shows distinguishing characteristics,which is that northern zone moves towards south,while southern zone moves towards north,intersecting around south of Taiyuan region.2)Deviated displacement field comes out after the earthquake,effected by Wenchuan earthquake on Shanxi rift zone.The influence is mainly on the southern part,showing movement towards north with millimeter unit.Meanwhile,the offset of northern part towards west probably reflects the increasing stress from the east.Anyway,the dangerous region needing to be paid more attention should be the northern part of Shanxi rift zone.
Based on processing of observation data of Shanxi rift zone and its adjacent region,the movement rate during 2007-2008 is obtained.In addition,deviated displacement field after Wenchuan earthquake is got,referring to the movement rate of 2003-2007.The results show that 1)The movement seems to be in disorder,with rather large inaccuracy,which may be related to observation time that covers periods before and after the earthquake.However,the movement still shows distinguishing characteristics,which is that northern zone moves towards south,while southern zone moves towards north,intersecting around south of Taiyuan region.2)Deviated displacement field comes out after the earthquake,effected by Wenchuan earthquake on Shanxi rift zone.The influence is mainly on the southern part,showing movement towards north with millimeter unit.Meanwhile,the offset of northern part towards west probably reflects the increasing stress from the east.Anyway,the dangerous region needing to be paid more attention should be the northern part of Shanxi rift zone.
引文
[1]杨国华,王秀文,等.山西地震带近期水平运动状态及活动性.地壳形变与地震.1999,19(4):50-55.
[2]杨国华,赵承坤,韩月萍,等.应用GPS技术监测山西断裂带的水平运动[J].地震学报.2000,22(5):465-471.
[3]杨国华,王敏.山西断裂带活动趋势与动态特征[J].中国地震.2002,18(2):148-156.
[2]杨国华,赵承坤,韩月萍,等.应用GPS技术监测山西断裂带的水平运动[J].地震学报.2000,22(5):465-471.
[3]杨国华,王敏.山西断裂带活动趋势与动态特征[J].中国地震.2002,18(2):148-156.
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