【摘要】 采用累计频度方法,对华北活动地块Ms≥5.5地震前中等地震聚集活动区的地震做了时空扫描,并对平静现象进行了定量分析,结果表明:对各Ⅱ级活动地块采用不同的扫描方法,在强震前都表现出明显的增强、平静过程,平静的时间长短与所给定的构造区域有关。本文给出了华北3个Ⅱ级活动地块的发震模式。对各活动地块分别进行了R值检验,表明3个活动地块采用不同的发震模式均具有较高的预报效能。更多还原

【Abstract】 The time-space distribution of earthquakes of moderate earthquake in concentrated activity area before earthquakes of Ms≥5.5 in North China active block has been calculated and its quiescence phenomenon has been analyzed by use of the method of accumulative frequency. The results of different scanning methods in all second-order active blocks have reflected the process of enhancement and quiescence before strong earthquakes, which revealed that the length of seismic quiescence time was related to tectonic area. Seismogenic patterns of three second - order active blocks in North China have been put forward. Tests by R- value in three active blocks with different seismogenic patterns indicated high seismic prediction effectiveness.更多还原