青海龙羊峡超低频电磁辐射在中强震前的短期(短临)异常特征及单台预报效能

根据青海龙羊峡电磁台自1991年9月以来的资料，对电磁波辐射在震前的异常特征进行了分析总结。地震往往发生在电磁波异常结束后，电磁波在一组异常中出现显著异常是地震进入短期(短临)异常的主要特征。显著异常判断指标是一次地震中异常幅度(产生的场强)最大的或异常持续时间最长的异常。通过对有震异常、无震异常和漏报的统计，龙羊峡电磁波辐射的预报效能并不高。

THE CHARACTERISTICS OF SHORT-TERM ANOMALY OF ULTRA-LOW FREQUENCY ELECTROMAGNETIC RADIATION IN LONGYANG GORGE OF QINGHAI PROVINCE BEFORE A MID-STRONG EARTHQUAKE AND ITS PREDICTION EFFICACY ABOUT MONO-STATION

According to data of the electromagnetic station in Longyang gorge of Qinghai since Sep. 1991, we analysed and summarized some anomaly characteristics of electromagnetic wave radiation before earthquakes. After the anomaly of electromagnetic wave ended, the earthquake often occurred in. The marked anomaly which electromagnetic wave appears in a set anomaly is mainly characteristics which the earthquake will get into short-term. The determined index of obvious anomaly is the most amplitude of anomaly (being into field intensity) or the longest of anomaly duration in a case. By statistics of anomalies which having earthquakes, not having earthquakes, and leaky predictions, we thought the prediction efficacy wasn't high in electromagnetic wave radiation of Longyang gorge.