金沙江地震带强震动及其与现今弱震活动关系

Relationship Between Activity of Strong Earthquake And Current Activity of Weak Earthquake Along The Jinshajiang Zone

包括川滇菱块及马边－大关，宣威－弥勒地区在内的金沙江地震带记载（录）了川滇两省发生的绝大部分中、强以上地震，为我国西南一主要地震区。本文重点研究了该范围内强震的重复性及现今弱震密集区的强震危险性问题。金沙江地震带强震具有很高的原地重复性，７级以上强震原地重复率达６５．４％，平均复发时间１５７年；６级地震原地重复率达４１．８％，平均复发时间为２７．２年。川滇地区现今弱震活动密集区在活动期内本身发生６级以上强震的可能性很小。四川地区大多数情况下强震发生在距密集区４０－５０千米处，云南情况较复杂。但在作今后较长时间危险性分析预测时，现今弱震密集区本身仍有发生６级地震的危险，虽然发生７级以上地震可能性不大。

The many moderate-strong earthquakes which occurrred in Sichuan-Yunnan block,Mabian-Daguan and Xuanwei-Mile area distribute along The Jinshjiang zone.TheJinshajjang zone is one of major zones in southwest of China. Some key problems are mainlyresearched in this paper. They are the reproducibility and risk of strong earthquake in thecurrent dense area of weak earthquake, The strong earthquake along the zone is providedwith very high reproducibility at origial place, The repetition rate of M > 7. 0 earthquakesbae reached 65.4%, The mean recurrence period is 157 yeras, The rate and M > 6.0earthquakes has reached 41.8%. The period is 27.2%years. The probability is very smalland M>6. 0 earthquake is about to occur in the area in active period. Some strong earthquakecan occur in the region of 40-50 kilometres from the dense area in Sichuan under greatmajority situation, The situation in Yunnan is complex. Although the probability of M≥7.0earthquake is not big,the future risk of M>6.0 earthquake exists in the area.