【摘要】 本文基于地震活动是现代地质构造运动之产物,以及对我国及邻区现代构造条件的认识,指出了构造类比中值得关注的7个问题,提出了发震构造识别方法的新建议,其主要结果如下:(1)发震构造宜定义为,"在现代构造条件下,曾发生或可能发生地震的地质构造"。(2)我国及邻区的现代地质构造同第四纪以来的新构造运动是一脉相承,密不可分的。其中,①现代构造应力场具有明显的区域特征,而且从中更新世以来是基本稳定的;②组成我国大陆不同新构造类型的活动地块(构造单元)之间,存在包括地壳和上地幔横向非均匀性的构造格架差异;③大陆内部各活动地块之间,也存在不同的现代构造形变特征;④宜将中更新世的构造形迹作为与地震活动有关的现代构造形迹看待。(3)在进行构造类比时值得关注的问题有:①宜按活动断裂当前所处的发育阶段来评价其潜在地震;②断裂活动时代并非识别发震构造的充分条件,只有符合现代构造条件的粘~滑断裂,才应识别为大地震的发震构造;③只有同现代构造应力场相适应的先存构造,才可能孕育和发生地震;④对于某些单一断层参数与震级关系的统计结果,未考虑各地震构造区之间现代构造条件和断裂发育阶段的差异,则难以用于构造类比;⑤凡有新生代玄武岩(β6)出露的地段,有可能只发生6.5级以下的地震;⑥地震同地表断裂形迹之间没有必然的联系,尤其仅有断层物质特性分析或测年结果可用时,宜慎重对待为妥;⑦构造类比方法仅适用于识别与先存构造继承性活动有关的发震构造,对于活动地块内部新生或隐伏的发震构造仍无能为力。(4)对于发震构造识别方法的建议是:①以新构造单元为基础划分地震构造区;②按历史重演原则识别曾发生过地震的构造,即凡有较可靠中强以上地震震中、有小地震成丛或呈带分布、或有可信古地震遗迹的地段,均宜识别出符合现代构造条件的发震构造;③根据地震构造区内曾发生过不同震级档地震的构造标志,再按类比原则推断可能的发震构造;④综合评定地震构造区的极限地震,并以此作为区内发震构造最大潜在地震的阀限。更多还原

【Abstract】 Based on the earthquake is the result of recent tectonic movement and the analysis on the recent geological structure in China and its adjacent regions,seven noticeable questions and several new suggestions about identifying seismogenic structure are listed in this paper.(1) The definition of seismogenic structure should be the geological structure that displays earthquake activity,or could generate earthquake in recent geological tectonic condition.(2) The recent geological tectonic in China and its adjacent areas succeeds to neotectonic movement of the Quaternary.From middle Pleistocene,the tectonic stress field is almost unchanged.So the geologic structure of middle Pleistocene should be identified as seismogenic structure.(3) Structure analog is frequently used to determine seismogenic structure.However there are several questions should be taken in.First,determining the maximum potential earthquake of seismogenic structure should consider the phase of the geologic evolution.Secondly,fault activity is not the only factor to identify seismogenic structure.We must consider several factors together,such as the nature of the fault,recent tectonic stress field and Cenozoic basalts.Last,structure analog can be only used in identifying those faults that show successive activity.(4) There are several suggestions on identifying seismogenic structure.Different seismic tectonic zones are corresponding to different neotectonic area.The principle that previous seismogenic structure can occur same earthquake again can be used to determine the structures that display seismic activity.Structure analog will be used to identify the possible seismogenic structures based on the structure characters in seismic tectonic zone.The upper limit of magnitude in seismic tectonic zone and seismogenic structure in zone can be the same.更多还原