【摘要】 则木河断裂带是四川西部一条重要的北西向地震断裂带,近代构造活动强烈,具左旋错动性质。该断裂北段在西昌北侧于西宁附近与南北向的安宁河断裂带似交非交,构成特殊的发震构造部位,历史上一系列强震在这里重复发生。而断裂南段,由于多组断裂的交汇,岩石极度破碎,不利于大量应变能的储存,常以中、小地震的形式释放应变能。研究资料表明,该断裂北段系属发展中的断裂,同时又是构造的交汇区,有利于应变能的积累,因此对其北段的地震危险性应给予足够的重视。更多还原

【Abstract】 The Zcmuhe fault is a major notthwest-trending seismic zone in the western part of Sichuan province.It is recently undergone extensive tectonic activities and characterized as left-lateral offset.The northern segment of the fault that lies to the north of Xichang is somewhat intersected with the north-south trending An-ninghe fault zone near Xichang,forming an unique scismogenic locus for the recurrences of a series of large earthquakes in history.The southern segment,however,due to the convergence of several faults and the severely fractured rocks is not capable to store a grat amount of strain energy which has been usually released in moderate and small earthquakes.Research data indicate that the northern segment fo the fault is a developing fault and a structurally convergent area at the same time,capable to accumulate strain energy.Therefore,great attention should be paid to the seismic risk on this segment.更多还原