汶川8.0级地震前地下流体长趋势变化特征讨论
|
摘要
通过对汶川MS8.0地震震中周围地区震前地下流体长期观测资料的分析表明,震前地下流体出现了长趋势变化,其特征是时间早、范围广,具有协调性以及向未来震中迁移等特征,形态主要为趋势转折、破年变、加速等,其中大多数为趋势转折变化。进一步对比研究地壳形变、地下流体长趋势变化发现,地壳形变和地下流体长趋势变化迁移特征一致,地壳形变长趋势时间较早于地下流体长趋势变化时间,形变出现张压变化与水位变化有比较密切的关系,即形变大部分出现缓慢压性变化或张性减缓变化,水位大部分出现缓慢上升或下降减缓变化。最后讨论了地下流体长趋势变化机理。
Long-time observed data of Subsurface fluid from a wide circumferential region of the Wenchuan MS8.0 epicenter is analyzed before the earthquake.The result show that the subsurface fluids have long-time trend changes before the Wenchuan MS8.0 earthquake.The changes are characterized by earlier emerging time,wider range,compatibility and migration toward the epicenter etc.The shape of subsurface fluid long-time trend change is characterized by trend turn,annual variation damage and accelerating variation etc,mostly trend turns.Further comparative study with crustal deformation shows that the long-time trend change migration of subsurface fluid and crustal deformation is identical,and the long-time trend change time of crustal deformation is earlier than that of subsurface fluid.The tensor-pressure variation of crustal deformation is more closely related with the level variation of underground water,namely if the long-time trend change of crustal deformation is the majority variation shape of slow pressure or tensor diminution,then the long-time trend change shape of of underground water level is the majority variation shape of slow elevation or descending diminution.Finally,the productive mechanism on long-time trend change of subsurface fluid is discussed before Wenchuan MS8.0 earthquake.
Long-time observed data of Subsurface fluid from a wide circumferential region of the Wenchuan MS8.0 epicenter is analyzed before the earthquake.The result show that the subsurface fluids have long-time trend changes before the Wenchuan MS8.0 earthquake.The changes are characterized by earlier emerging time,wider range,compatibility and migration toward the epicenter etc.The shape of subsurface fluid long-time trend change is characterized by trend turn,annual variation damage and accelerating variation etc,mostly trend turns.Further comparative study with crustal deformation shows that the long-time trend change migration of subsurface fluid and crustal deformation is identical,and the long-time trend change time of crustal deformation is earlier than that of subsurface fluid.The tensor-pressure variation of crustal deformation is more closely related with the level variation of underground water,namely if the long-time trend change of crustal deformation is the majority variation shape of slow pressure or tensor diminution,then the long-time trend change shape of of underground water level is the majority variation shape of slow elevation or descending diminution.Finally,the productive mechanism on long-time trend change of subsurface fluid is discussed before Wenchuan MS8.0 earthquake.
引文
[1]薄万举,杨国华,张风霜.汶川8.0地震孕震机理的形变证据与模型推演[J].地震,2009,29(1):85-92.
[2]梅世蓉,冯德益,张国民,等.中国地震预报概论[M].北京:地震出版社,1993.
[3]国家地震局预测预防司.地下流体地震预报方法[M].北京:地震出版社,1997.
[4]车用太,鱼金子,刘五洲.水氡异常的水动力学机制[J].地震地质,1997,19(4):353-357.
[5]陆明勇,范雪芳,等.强震前地下流体长趋势变化特征及其产生机理的研究[J].西北地震学报,2009,31(3):265-271.
[6]范雪芳,王吉易,陆明勇.汶川8.0级地震前典型流体中期前兆异常的初步研究[J].地震,2009,29(1):133-140.
[7]刘耀炜,施锦.强震地下流体前兆信息特征[J].地震学报,2000,22(1):59-64.
[8]刘耀炜,张元生.共和7.0级地震前地下流体前兆的动态演化特征[J].西北地震学报,1998,20(1):59-64.
[9]陆明勇,黄辅琼,刘善华,等.地壳变形与地下水相互作用及其异常关系初探[J].地震,2005,25(1):67-73.
[10]张培震.中国地震灾害与防震减灾[J].地震地质,2008,30(4):577-583.
①张培震,5.12汶川大地震的破裂特征与成因机制,2009年。
②中国地质调查局,汶川地震及其诱发的次生地质灾害情况分析会,2008年。
①中国地震局地壳应力研究所,2007—2009年中国大陆地震趋势预测研究(地下流体学科),2006年。
①刘耀炜等,1~3年我国大陆地震大形势研究(地下流体学科),2005年。
②中国地震局地壳应力研究所,2007—2009年中国大陆地震趋势预测研究(地下流体学科),2006年。
①刘耀炜等,1~3年我国大陆地震大形势研究(地下流体学科),2005年。
②刘杰,我国大陆近期7级地震形势讨论,2005年。
[2]梅世蓉,冯德益,张国民,等.中国地震预报概论[M].北京:地震出版社,1993.
[3]国家地震局预测预防司.地下流体地震预报方法[M].北京:地震出版社,1997.
[4]车用太,鱼金子,刘五洲.水氡异常的水动力学机制[J].地震地质,1997,19(4):353-357.
[5]陆明勇,范雪芳,等.强震前地下流体长趋势变化特征及其产生机理的研究[J].西北地震学报,2009,31(3):265-271.
[6]范雪芳,王吉易,陆明勇.汶川8.0级地震前典型流体中期前兆异常的初步研究[J].地震,2009,29(1):133-140.
[7]刘耀炜,施锦.强震地下流体前兆信息特征[J].地震学报,2000,22(1):59-64.
[8]刘耀炜,张元生.共和7.0级地震前地下流体前兆的动态演化特征[J].西北地震学报,1998,20(1):59-64.
[9]陆明勇,黄辅琼,刘善华,等.地壳变形与地下水相互作用及其异常关系初探[J].地震,2005,25(1):67-73.
[10]张培震.中国地震灾害与防震减灾[J].地震地质,2008,30(4):577-583.
①张培震,5.12汶川大地震的破裂特征与成因机制,2009年。
②中国地质调查局,汶川地震及其诱发的次生地质灾害情况分析会,2008年。
①中国地震局地壳应力研究所,2007—2009年中国大陆地震趋势预测研究(地下流体学科),2006年。
①刘耀炜等,1~3年我国大陆地震大形势研究(地下流体学科),2005年。
②中国地震局地壳应力研究所,2007—2009年中国大陆地震趋势预测研究(地下流体学科),2006年。
①刘耀炜等,1~3年我国大陆地震大形势研究(地下流体学科),2005年。
②刘杰,我国大陆近期7级地震形势讨论,2005年。
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心