重复地震研究综述

THE REVIEWS OF RESEARCH IN THE RECURRENCE EARTHQUAKES

一个地区在某一时期内多次发生强震称为重复地震,按空间位置的分布,重复地震可分为原地重复、带内重复和构造重复三种。两次地震的震源区相连,极震区重迭称为强震的原地重复,如1303年山西洪洞地震和1695年的临汾地震。四川鲜水河地震带曾发生一连串强震,如1923年(7)1/4级地震和1973年7.6级地震等可称为带内重复。至于公元前70年山东诸城7级地震和1668年郯城-莒县(8)1/2级地震均发生在郯庐活动构造带内则称为构造重复。强震往往重复发生在某些特殊地质构造部位。如郯庐断裂、怀来-新活动断陷盆地带和在中国的中西部由三个地质孤状带构成的南北地震带等。强震重复在时间上多发生于不同的地震活动期中,如华北第三活跃期内的1679年三河-平谷地震和第四活跃期中的1976年唐山地震即为明显震例。大地震在某些条件下具有原地重演的现象已成为众所瞩目的事实。通过强震重复性研究,可以了解产生重复地震的原因和条件。深入对重复地震发展过程的认识并掌握它的活动规律,不仅可提高中长期地震预报水平,为工程建设提供可靠的科学依据,合理减少抗震设计投资;提出合适的措施避免地震造成的损失。还可以及时较准确地划出中短期的地震危险区,减轻地震灾害,为短临预报提供有发生强震的危险地点或较小的地区。本文综合评述了国内外有关重复地震研究的最新成果及发展动态,全文分三个部分。

We have reviewed the lately achievement and recent development in the re-search of the recurrence earthquakes in this paper. It is introduced that the typical castes of recurrence earth-quakes, calcilation methods of recur-rence intervals up to now in China and the world and the cases of recurren-ce earthquakes etc. The recurrence earthquakes means the strong earthquak-es occur in a certain area during a period of time, According to the spatial distribution of the earthquakes, the recurrence earthquakes can be divided nito three types, which are recurrence in same region, recurrence in a fault zone and tectonic recurrence. A lot of examples of earthquakes show that the recurrence intervals of interplate earthquake is shorter, it generally equal to several decades. The interplate earthquakes chime in with the ch-aracteristic earthquake model. But the recurrence intevals of introplate ea-rthquake is much longer, which are hundreds or even thousands of years. The recurrence causes of introplate earthquakes is much more complicated than in-terplate earthquakes.