论文部分内容阅读
利用１９７０～１９９３年华北地区ＭＬ≥２０的微震资料，根据其地震活动特点，从中挑选了一些有代表性的区域，做其ＧＲ关系曲线。由该曲线可得到每个震级的年频次。同时，由该区域的历史地震（１３００～１９９３年）可得到较大震级的实际年频次。两者对比，发现具有很好的一致性。因此，当选取合适的区域时，利用近代微震资料完全可以推测出该区域较大地震的活动情况。但同时有两点需注意：（１）利用微震资料进行统计时，得到的是一个地震活动体系（或断层体系）中各种震级的地震年频次，是对一个体系整体活动情况的估计；（２）在所用微震资料时间段内及其附近发生大地震时，在包括该地震的地震活动体系中，利用微震资料进行统计得不到该体系的地震活动情况
Using the microseismic data of ML≥20 in North China from 1970 to 1993, some representative regions were selected according to the characteristics of their seismic activity, and their GR curves were obtained. The annual frequency of each magnitude can be obtained from this curve. At the same time, the actual annual frequency of larger magnitude can be obtained from the historical earthquakes in the region (from 1300 to 1993). The two contrast, found to have good consistency. Therefore, when choosing the appropriate area, the use of modern microseismic data can completely predict the activity of larger earthquakes in this area. However, there are two points to be noticed at the same time: (1) The frequency of annual earthquakes of various magnitudes in a seismic system (or fault system) when using microseismic data is an estimate of the overall activity of a system; 2) In the event of a large earthquake within and near the period of microseismic data used, the seismic activity of the system can not be obtained from the statistics of microseismic data in the seismic activity system including the earthquake