中亚地区地震序列特征

THE FEATURES OF THE EARTHQUAKE SEQUENCES IN CENTRAL ASIA

共搜集到１９７０～１９８４年中亚地区８ 个地震序列。通过分析这些板块内部地震序列的震源分布、震源机制，归纳出它们的特征是：震中分布的长轴都比较短，震中分布长轴和短轴的比值小；长轴的方向受当地地震带的走向控制，和碰撞带走向无关。地震序列中各地震的震源深度都比较浅。其中有震源机制资料的３ 个地震序列表明：主震的震源机制如果是逆冲滑动，倾角则比较低；主震的震源机制如果是走向滑动，倾角则比较高。不论主震的震源机制是倾滑，还是走滑。

The data of 8 earthquake sequences in Central Asia during the period of 1970~1984 are collected.By analyzing the hypocenter distribution and focal mechanisms of these intraplate earthquake sequences,their features have been drawn:the major axis of the epicenter area is shorter and the ratio of major axis to minor axis is less than those of the interplate earthquake;the direction of the major axis is controlled by the trend of local seismic zone and independent on the trend of collision zone;the hypocenters of all earthquake sequences are shallow;focal mechanism solutions are collected for only three earthquake sequences and they show lower dip for the reverse slip type mainshock,higher dip for the strik slip type mainshock;the consistency is bad between the focal mechanisms of mainshocks and aftershocks whether the focal mechanisms of mainshocks are reverse slip type or strike slip type.