地震危险性分析中确定潜在震源的反思

在区域稳定性评价中,其主要内容之一就是地震稳定性评价。近年来,国内外多采用地震危险性分析的概率方法作为区域地震稳定性评价的主要方法。 在地震危险性分析中,首要问题是确定区域潜在震源,但至今尚缺乏完整、科学的理论和实践。作者认为有必要从地震地质角度进行一次深刻的地质反思。 本文从构造变形的动力源、区域及局部应力场、地震断裂活动带的地震重复周期,地震断裂的活动特征及区域地震强度衰减规律等几个方面提出了若干看法,作为地震危险性分析的基础地震地质工作加以考虑。至于常见的非发震断裂在区域地震稳定性评为中所起的作用,则需对这些断裂的地质特征与周围地质体的介质特征进行具体的对比分析,才能判定其对地震波传播的影响,不能一概而论。

SOME RETROSPECTIONS OF DETERMINATION OF POTENTIAL EARTHQUAKE SOURCE IN SEISMIC RiSK ANALYSIS

Abstract One of the main contents on regional stability evaluation is the appraisement of regional seismic stability. In recent years, the method of seismic risk analysis through probability consideration of earthquake becomes a dominant technique in the appraisement of regional seismic stability.In seismic risk analysis, first of all is to determine the regional potential earthquake sources. But the comprehensive scientific theory and practice are still wanting. The author holds that it is necessary to make a profound retrospection from the point of view of seismo-eology. In this paper, several points of view about the following aspects as the dynamic source of tectonic deformation, regional or local stress field, repetition periods of earthquakes of active tectonic belt, active characteristics of seismic faults and the atteuation regularity of regional earthquake intencity etc., are put forward. All of these factors mentioned above should be considered as basic work in seismic rick analysis. As to what function the nonseismic faults will serve in the appraisement of regional seismic stability, we must make a concrete correlation and snalysis with geological features of the faults and surrounding medium of geological body, ft can not be lumped together when we make any judgement of the effects on seismic wave propagation.