7级大震和中强震的前兆异常有本质区别吗?

Are there essential differences for precursory anomalies between strong earthquakes with M≥7 and moderate earthquakes?

据震前次一等地震活动增强、空区和条带等地震活动图像 ,以及各学科前兆异常持续时间和空间分布等方面 ,比较了 7级强震和中强震的前兆异常特征。结论是没有质的区别 ,但在量上有明显的差异。文中分别对 7级强震前 5级、 6级地震活动增强 ,和 6级地震前 4级、 5级地震活动增强 ,选择了时空阈值和预报规则 ,进行了预报评分检验 ,得到了肯定的结论。

In this paper, the differences of precursory anomalies between strong earthquakes with M ≥7 and moderate earthquakes with M =5~6 were compared and analyzed. The results indicate that there are not any essential differences, but obvious quantitative differences between them. Prediction efficacies for increase of seismicity with M 5～6 before an earthquake with M ≥7 and increase of seismicity with M 4~5 before and earthquake with m =5~6 were also statistically examined and were passed, respectively.