汶川8.0级地震前龙门山断裂带的垂直变化特征
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摘要
根据龙门山构造带上的跨断层水准测量资料,计算了龙门山断裂带1986年至2008年1月的垂直活动速率、断层形变异常强度及测线的月变化率,研究了龙门山断裂带1986至2008年初的异常变化。结果表明,龙门山断裂带的垂直活动速率不大,在1 mm/a以下。但是在大震发生前的1～3 a,断层活动加速,在形变异常强度图上变化显著,在月变率统计图上,也有明显的异常。龙门山断裂带的断层形变异常对于南北地震带上600余公里以内的3次7级以上大震均有反映,对本区的地震反映更明显。
Based on the cross-fault leveling data in Longmenshan tectonic belt,we calculated the vertical activity rates of Longmenshan fault zone within 1986-2008,anomaly intensities of fault deformation and monthly variation rates of the survey line and studied the anomalies of Longmenshan fault zone within 1986-2008.The result shows that the vertical activity rates of Longmenshan fault zone are not high and below 1mm/a,however,during one to three years before the large MS8.0 earthquake,the fault activity was increasing,which exhibited remarkable changes on the anomaly intensities of deformation and monthly variation rates.Three big earthquakes with magnitude larger than MS7 which occurred within 600km of the North-South seismic belt are reflected by the anomalies of fault deformations of Longmenshan fault zone,and the reflection is more noticeable when earthquakes occurred locally.
Based on the cross-fault leveling data in Longmenshan tectonic belt,we calculated the vertical activity rates of Longmenshan fault zone within 1986-2008,anomaly intensities of fault deformation and monthly variation rates of the survey line and studied the anomalies of Longmenshan fault zone within 1986-2008.The result shows that the vertical activity rates of Longmenshan fault zone are not high and below 1mm/a,however,during one to three years before the large MS8.0 earthquake,the fault activity was increasing,which exhibited remarkable changes on the anomaly intensities of deformation and monthly variation rates.Three big earthquakes with magnitude larger than MS7 which occurred within 600km of the North-South seismic belt are reflected by the anomalies of fault deformations of Longmenshan fault zone,and the reflection is more noticeable when earthquakes occurred locally.
引文
[1]徐锡伟,于贵华,马文涛,等.中国大陆中轴构造带地壳最新构造变动样式及其动力学内涵[J].地学前缘,2003,10(特刊):160-167.
[2]薄万举,杨国华,郭良迁,等.地壳形变与地震预测研究[M].北京:地震出版社,2001.
[3]郭良迁,薄万举,杨国华.华北地区断裂带的现代形变特征[J].大地测量与地球动力学,2003,23(2)29-36.
[4]赖锡安,黄立人,徐菊生,等.中国大陆现今地壳运动[M].北京:地震出版社,2004.
[5]马廷著,黄佩玉.京津唐活动断裂带现代运动特征[A].中国地震学会地震地质专业委员会.中国活动断裂[C].北京:地震出版社,1982.
[6]郭良迁,谢觉民.张北6.2级地震的断层形变速率异常[J].地壳形变与地震,2001,21(1):79-84.
[7]郭良迁,薄万举,杨国华.中国大陆的垂直形变速率梯度及地震活动[J].地震地质,2001,23(3):347-356.
[8]郭良迁,李延兴,胡新康,等.中国大陆地壳运动与汶川MS8.0级地震孕育的关系[J].地球物理学报,2009,52(2):531-537.
[2]薄万举,杨国华,郭良迁,等.地壳形变与地震预测研究[M].北京:地震出版社,2001.
[3]郭良迁,薄万举,杨国华.华北地区断裂带的现代形变特征[J].大地测量与地球动力学,2003,23(2)29-36.
[4]赖锡安,黄立人,徐菊生,等.中国大陆现今地壳运动[M].北京:地震出版社,2004.
[5]马廷著,黄佩玉.京津唐活动断裂带现代运动特征[A].中国地震学会地震地质专业委员会.中国活动断裂[C].北京:地震出版社,1982.
[6]郭良迁,谢觉民.张北6.2级地震的断层形变速率异常[J].地壳形变与地震,2001,21(1):79-84.
[7]郭良迁,薄万举,杨国华.中国大陆的垂直形变速率梯度及地震活动[J].地震地质,2001,23(3):347-356.
[8]郭良迁,李延兴,胡新康,等.中国大陆地壳运动与汶川MS8.0级地震孕育的关系[J].地球物理学报,2009,52(2):531-537.
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