【摘要】 经过几十年地震预报探索实践,已发现了很多地震前兆异常,其中部分前兆还通过了优秀地震前兆标准的检验,并分析总结了前兆异常的群体特征.但用这些前兆异常,通过经验性统计方法进行地震预报成功率很低,其根本原因是地震孕育、发生的空间尺度较大,前兆异常的挑选较为困难;地震复发周期较长,已积累的震例资料不足于研究地震孕育发生的规律;地震的孕震环境复杂,与周边的动力、构造环境密切相关,不同地震之间前兆异常差异较大;前兆观测分布在地球表面,只是地下应力、应变的间接反映,所获取的异常与地震前兆关系有待深入研究.在目前情况下,下一次地震完全按统计得到的共性特征演化明显是不可能的.地震前兆观测应从单点观测向直接观测地下应力、应变场过渡,地震预报从经验性统计预报向基于地球物理场动态观测的物理预报过渡.更多还原

【Abstract】 In the past tens of years, many earthquake precursors were detected in the earthquake prediction exploration. And some of the precursors have passed the evaluation criterion of proposed earthquake precursors. Also the group characteristics for these proposed precursors were summarized. However, the earthquake prediction based on these precursors together with empirical statistical methods is not very successful. We consider that the reasons are as follows:(1) precursors are hard to select for each specific earthquake because of the large scale of the seismogenic zone;(2) the precursor observations on the existed earthquake cases are too short compared to the long recurrence time;(3) the seismogenic environment is complex and closely related to the dynamics and tectonic backgrounds, which caused the large differences of the precursory anomalies for each earthquake;(4) the precursory anomalies are observed on the surface of the earth. And they give only indirect reflection of the stress or strain changes in the deep area. The relationship between the observed anomalies and the precursors of earthquakes still needs be investigated in detail. Therefore, it is clear that the earthquake does not exactly follow the statistical behaviors summarized so far. We need direct measurements of underground stress/strain state for capturing earthquake precursors, instead of the measurements at individual sites. Earthquake prediction also need rely on physical models based on spatial-/temporal- dependent physical field, instead of empirical and statistical approaches.更多还原