1997年玛尼7.5级地震前兆特征分析
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摘要
分析了 1 997年玛尼 7.5级地震的前兆特征 ,认为玛尼地震的发生具有一定的构造背景 ,它发生在中国大陆西部及邻区第 5个活跃幕 7级以上强震所构成的“大三角”分布的特定节点上。地震前存在着低 b值、缺震、频度、GL值等测震学异常以及水位、水温、地应力等水化学和地形变学异常。通过该地震前兆特征的追溯性分析 ,必将对地震预报带来有益的思考
The characteristics of temporal and spatial distribution of the precursory anomaly before Mani earthquake with Ms7.5 have been analyzed.And the spatial distribution of the strong earthquakes with Ms≥7.0 in China western continent and its neighboring area in the fifth strong earthquake episode has discussed in detail.Mani earthquake was occurred at a big background of equally spaced net,and this epicenter was just in Ms≥7.0 earthquake risk net.The obvious earthquake precursors were found:regional seismic swarm activity increased,b value became lower than before,GL≥1,etc..Several days to several months before Mani earthquake,some mediumshort precursors were found:water level in Urumqi,water temperature in Ge'ermu,stress in Delingha.Now,to rethink the precursory anomaly phenomona before Mani earthquake will be great significance for the earthquake prediction in the future.
The characteristics of temporal and spatial distribution of the precursory anomaly before Mani earthquake with Ms7.5 have been analyzed.And the spatial distribution of the strong earthquakes with Ms≥7.0 in China western continent and its neighboring area in the fifth strong earthquake episode has discussed in detail.Mani earthquake was occurred at a big background of equally spaced net,and this epicenter was just in Ms≥7.0 earthquake risk net.The obvious earthquake precursors were found:regional seismic swarm activity increased,b value became lower than before,GL≥1,etc..Several days to several months before Mani earthquake,some mediumshort precursors were found:water level in Urumqi,water temperature in Ge'ermu,stress in Delingha.Now,to rethink the precursory anomaly phenomona before Mani earthquake will be great significance for the earthquake prediction in the future.
引文
1 中国地震局分析预报中心 .中国地震趋势预测研究 ( 1 997年度 ) .北京 :地震出版社 ,1 996,1～ 2 0
2 马宗晋 ,汪良谋 ,等 .中国及邻区特大地震地质与地球物理环境和危险区划分 .中国大陆 2 0 0 5年前强震危险性预测研究 .北京 :地震出版社 ,1 997,1 72～ 1 82
3 王道 ,卢静芳 ,等 .西藏 7.5级地震在乌鲁木齐地区地下水中的远场效应 .内陆地震 ,1 999,1 3( 1 ) :93～ 95
4 汪成民 ,张洪波 .地震前地下水位的短期及临震变化异常 .地震学报 ,1 982 ,4( 4 ) :1 2 0～ 1 25
2 马宗晋 ,汪良谋 ,等 .中国及邻区特大地震地质与地球物理环境和危险区划分 .中国大陆 2 0 0 5年前强震危险性预测研究 .北京 :地震出版社 ,1 997,1 72～ 1 82
3 王道 ,卢静芳 ,等 .西藏 7.5级地震在乌鲁木齐地区地下水中的远场效应 .内陆地震 ,1 999,1 3( 1 ) :93～ 95
4 汪成民 ,张洪波 .地震前地下水位的短期及临震变化异常 .地震学报 ,1 982 ,4( 4 ) :1 2 0～ 1 25
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