历史强震对渭河中游群发大型滑坡的诱发效应反演  

Inversion of the Inducing Effects of Historical Strong Earthquakes on Large-scale Landslides around the Middle Reaches of the Weihe River

作　　者：王涛[1] 吴树仁[1] 石菊松[1] 辛鹏[1] 梁昌玉[1] 

机构地区：[1]中国地质科学院地质力学研究所,国土资源部新构造运动与地质灾害重点实验室,北京100081

出　　处：《地球学报》2015年第3期353-361,共9页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目(编号:41102165);国家“十二五”科技支撑计划课题(编号:2012BAK10B02);中国地质调查局地质调查项目(编号:1212011140003;12120114035501)联合资助

摘　　要：以渭河中游地区为例,探索提出了开展历史地震对区域群发滑坡诱发效应反演研究的思路和方法。首先,基于汶川地震在渭河中游地区形成的高烈度异常和震害启示,通过区域活动构造和斜坡带断裂控滑分析,指出历史强震对区内群发大型滑坡的诱发效应不容忽视。然后,利用强震诱发滑坡的最远致灾震中距分析法,筛选出研究区周边300 km范围内需要重点考察其诱发效应的4次关键历史强震:公元前780年岐山MS7.0级地震、1654年天水南MS8.0级地震、1556年华县MS8.25级地震及1920年海原MS8.5级地震。随后,以岐山地震为例,具体阐述了基于Newmark位移模型的地震诱发滑坡位移及危险性反演评估方法;同时反演了其他3次历史强震诱发区内滑坡位移及危险性。最后,定量比较了反演历史强震诱发滑坡的位移与实际大型滑坡分布的空间匹配程度,结果显示天水南MS8.0级地震对渭河中游现存群发大型滑坡的诱发效应最强。Exemplified by the middle reaches of the Weihe River, the authors tentatively developed a new method for the study of the inducing effects of historical earthquakes on regional large-scale landslides. First, an analysis of regional active tectonics and fault-controlling slope sliding revealed that the inducing effects of historical strong earthquakes on regional large-scale landslides around the middle reaches of the Weihe River must not be neglected. Secondly, the farthest epicentral distance of seismic landslides distribution was calculated and analyzed. On such a basis, the authors hold that inducing effects of 4 key historical strong earthquakes within 300km around the middle reaches of the Weihe River should be studied with special attention, i.e., Qishan MS7.0 earthquake in 780 BC, Tianshui south MS8.0 earthquake in 1654 AD, Huaxian MS8.25 earthquake in 1556 AD and Haiyuan MS8.5 earthquake in 1920 AD. Then, taking Qishan earthquake as an example, the authors described the inversion method for seismic landslide displacement and hazard assessment based on Newmark displacement model. The other 3 historical earthquakes triggering landslide displacement were inversed, and the inversion results were quantitatively compared with the distribution of existing large-scale landslides to show the spatial matching degree. The result indicates that Tianshui south MS8.0 earthquake served as the strongest one among the earthquakes inducing regional large-scale landslides around the middle reaches of the Weihe River area.

关 键 词：历史地震 滑坡 Newmark位移模型 反演 渭河中游 黄土 

分 类 号：P315.01[天文地球—地震学] P315.725[天文地球—固体地球物理学]