龙门山地震带地震活动特征的研究

Research on the Seismicity Features along the Longmenshan Seismic BeIt

本文剖析和研究了龙门山地震带强震活动的时空状态及中等地震活动特征，取得了一些有益的认识。该带强震频度不高，中等地震相对活跃。强震活动的盛衰变化没有明显规律，其主体活动地段为汶川－一茂县一北川段和天全一宝兴段，二者的强震具有交替发生的特点。自然节律显示有规律起伏，可以推测地震的强、弱趋势。本文仔细剖析了中等地震活动情况，提出的若干特征对于监视本带有一定社会影响的４～５级地震有实际意义。

Intbis paper,the time- space state of strong earthquakeactivity along theLongmenshanseismic belt and the features of seismicity were analysed and researched.Some of profitablerecognition were obtained.The seismic frequency of strong earthquake along the belt is nothigh but the medium earthquakes are active relatively.The rise and fall variation of strongearthquake activity has no clear regular patten, and main active segments are the Wenchuan- Maowen- Beichuan segment and the Tianquan-Baoxing segment.The strong earthquakes oc- curred on the two segments are provided with the feature of alternate occurrence。The natu-ral rhythm shows regular rise and fall.As may be inferred from this,the strong and weaktendency of seismicity can be predicted。The active case of medium earthquake was carefully analysed in this paper,The severalfeatures given are useful to prodiction of 4一5magnitude earthquakes which exercise a cer-tain social influence