对汶川8.0级地震前四川地区地电地磁观测异常的分析与思考

研究了汶川8.0级地震前四川地区模拟和数字地电、地磁类观测资料。四川地区地电6台站的26测项模拟观测,在汶川8.0级地震前仅出现1项中期异常,异常台站比1/6=0.17;异常测项比为1/26=0.04。对"九五"到"十五"期间四川地区数字化改造或数字地电观测资料,没有分析检测出异常项。四川地区6个台的地磁垂直分量整点值的日变形态在震前2天出现波谷分裂的异常现象,由于平时出现此类异常频繁,若用于预测无统计学的显著意义。可见汶川8.0级地震前四川地区地电和地磁类观测资料结果出现的异常现象比例是极低的。同时对疑似或有争议的异常测项进行分析说明,对汶川8.0级地震前电磁类异常少的原因进行了讨论。

Analyzing the anomalies of geo-electrical and geo-magnetic observation data in Sichuan Province before the 2008 Wenchuan M8.0 Earthquake

Among the geo-electrical data from seismic station in Sichuan Province,an item of middle-term anomaly before the 2008 Wenchuan M8.0 earthquake is identified.With the terms of anomaly ration,the anomaly ratio of seismic station is 0.17 and the anomaly ration of observation items is 0.04.For the items of the geo-electrical observation data included in the digitalized projects of the ninth Five-year Plane and the Tenth Five-year Plan in Sichuan Province,any anomaly changes were not found clearly.But 2 days bef...