【摘要】 根据东南沿海地震带去余后的4级以上地震目录，进行地震活动时间规律分析，发现1974年以来东南沿海地震带4级以上地震（去余）有成组活动的规律。给出了成组活动起止判定标准：上一组成组活动结束后，若发生1次4级以上地震，且震后275天内再次发震，则认为成组活动开始，第1次地震（首发地震）发震时间为成组活动开始时间。若震后417天（组内地震最长时间间隔）内未发生地震，则认为成组活动结束，组内最后一次地震发震时间为成组活动结束时间。同时总结出3条预测指标，指标1为首发地震后4.1年内东南沿海地震带有发生多次4级以上，甚至5级以上地震的可能。指标2为首发地震后25～275天内东南沿海地震带有再次发生4级以上地震的可能。指标3为首发地震后53～320天内东南沿海地震带有发生5级以上地震的可能。结合成组活动起止判定标准和3条预测指标，最终给出东南沿海地震带4级以上地震研判方案和清远4.3级地震对后续地震趋势研判的指示意义。更多还原

【Abstract】 The study analyzes the temporal patterns of M≥4 earthquakes(removing aftershocks)in the southeast coastal seismic zone since 1974. The results reveal that these earthquakes exhibit a pattern of grouped occurrence.Firstly,the paper establishes the criteria for identifying the onset and termination of such grouped episodes:If an M≥4 earthquake occurs within 0.75 years after the end of the previous group of seismic activities,the new group of seismic activities is considered to have started,and the occurrence time of the first earthquake(initial earthquake)is taken as the start time of the group of seismic activities. If no earthquake occurs within 417 days(the maximum time interval between earthquakes within the group) after an earthquake, the group of seismic activities is considered to have ended,and the occurrence time of the last earthquake within the group is taken as the end time of the group of seismic activities. At the same time,this paper summarizes three prediction indicators. Indicator 1∶Within 4.1 years following the first earthquake, multiple M≥4 earthquakes, potentially including M≥5 events,may occur in this seismic zone. Indicator 2:Between 25 and 275 days after the first earthquake,there is potential for another M≥4 earthquake in the zone. Indicator 3:An M≥5 earthquake may occur within 53 to 320 days after the first earthquake. Finally, by integrating the criteria for determining the onset and termination of such grouped activity with these three prediction indicators, this paper proposes an evaluation and prediction plan for M≥4earthquakes in the Southeastern Coastal Seismic Belt,along with implications of the Qingyuan M4.3 earthquake for evaluating subsequent seismic activity patterns.更多还原