平原M5.5地震土壤气地球化学特征及成因  

GEOCHEMICAL CHARACTERISTICS AND GENESIS OF SOIL GAS IN THE PINGYUAN M5.5 EARTHQUAKE

作　　者：苏淑娟 陈其峰[1] 孙豪[1] 刘军 冯梁乐 徐继龙 杨彦明[3,4] 雒昆利 SU Shu-juan;CHEN Qi-feng;SUN Hao;LIU Jun;FENG Liang-le;XU Ji-long;YANG Yan-ming;LUO Kun-li(Shandong Earthquake Agency,Jinan 250000,China;Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Earthquake Agency of Inner Mongolia Autonomous Region,Hohhot 010010,China;State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China)

机构地区：[1]山东省地震局,济南250000 [2]中国科学院地理科学与资源研究所,北京100101 [3]内蒙古自治区地震局,呼和浩特010010 [4]中国地震局地质研究所,地震动力学国家重点实验室,北京100029

出　　处：《地震地质》2024年第2期433-448,共16页Seismology and Geology

基　　金：山东省地震局一般科研项目(YB2416,YB2313);中国地震局震情跟踪定向工作任务(2024020302);国家自然科学基金(42277196,41877299);内蒙古自治区自然科学基金(2023MS04012)共同资助。

摘　　要：2023年8月6日2时33分,山东省德州市平原县发生M5.5地震。文中跨震中布设4条长30km的勘测线,现场测量了土壤气Rn、CO_(2)和Hg浓度。结果表明:1)土壤气浓度表现出明显的空间差异,震中区与4条测线的东、西两端气体浓度相对较高。2)土壤气浓度的空间分布特征在震中及其东部地区相似,但在震中西部差异较大,在西部旧城断裂(F_(3))附近,Rn和CO_(2)的浓度高于震中区,推测应与地震活动和F_(3)控制的鼻状构造有关。3)Rn、CO_(2)和Hg的浓度在陵县-冠县断裂(F_(1))和F_(3)附近出现高值异常,余震自F_(1)向F_(3)发展,结合地质与地球物理研究资料推断,平原M5.5地震应与F_(1)和F_(3)共同作用有关。以上结果表明,气体地球化学方法能较好地指示隐伏断层的位置与展布方向。At 2:33 am on August 6,2023,a M5.5 earthquake occurred in Pingyuan county,Dezhou city,Shandong Province.The faults within the epicenter and adjacent areas are deeply buried by the thick Quaternary sediment cover on which human activity is intensive,which makes it difficult to determine the location of the buried active faults from the surface based on geological and geomorphological evidences.It is necessary to detect the location of the buried active faults around earthquake areas and estimate their seismic risk.In this study,based on the epicenter distribution direction of major earthquake and aftershocks,seismic and geological data of earthquake areas,and damage degree of local buildings,4 survey lines with a length of 30km were arranged across the epicenters and adjacent areas,and the concentrations of Rn,CO_(2) and Hg in soil gas were measured on site,and the results are as follows:(1)There are obvious spatial differences in the concentrations of soil gas near the epicenter and its vicinities within the distance of 30km.Gas concentrations are relatively high near the epicenter areas and the east and west ends of 4 arranged survey lines,in contrast to those which are relatively low in other non-structural control regions.The spatial distribution pattern of Rn concentration in soil gas is basically consistent with that of CO_(2),which may be due to CO_(2) used as a carrier gas of Rn to migrate to the surface.At the southern end of the Lingxian-Guanxian Fault(F_(1)),the spatial concentration patterns of Rn and CO_(2) gases exhibit multiple peaks or wide anomalous zones.It is speculated that the deformation zone of the fault rupture at this location is relatively wide,and there may be secondary permeable fracture zones in the west of the F_(1).The escape form of Rn and CO_(2) gas indicates that there may indeed be multiple small fault branches near the F_(1),and the fault structure is relatively complex.(2)The spatial concentration distributions of Hg,Rn and CO_(2) in the epicenter areas are similar to that in i

关 键 词：平原M5.5地震 断层土壤气浓度 陵县-冠县断裂 旧城断裂 构造地球化学 

分 类 号：P315.724[天文地球—地震学]