祁连山断裂带中东段断层土壤气氡浓度强度时空分布特征及其地震危险性分析  

Spatial and temporal distribution characteristics of soil gas radon concentration intensity in the mid-eastern segment of the Qilianshan fault zone and its seismic hazard analysis

作　　者：万悦 苏鹤军[1,2,3] 李晨桦 周慧玲[1,2,3] WAN Yue;SU Hejun;LI Chenhua;ZHOU Huiling(Lanzhou Institute of Seismology,CEA,Lanzhou 730000,Gansu,China;Gansu Lanzhou Geophysics National Observation and Research Station,Lanzhou 730000,Gansu,China;Gansu Earthquake Agency,Lanzhou 730000,Gansu,China)

机构地区：[1]中国地震局兰州地震研究所,甘肃兰州730000 [2]甘肃兰州地球物理国家野外科学观测野外研究站,甘肃兰州730000 [3]甘肃省地震局,甘肃兰州730000

出　　处：《地震工程学报》2023年第2期491-500,共10页China Earthquake Engineering Journal

基　　金：甘肃省地震局地震科技野外站基金(2021Y11,2021Y16);地震科技星火计划项目(XH21033)。

摘　　要：基于祁连山断裂带中东段9个观测点2016—2021年的土壤气体氡浓度观测数据,深入分析其浓度强度时空分布特征。同时结合历史大震背景、现今地震活动与断裂带滑动速率的对比分析,从地球化学的角度对祁连山断裂带中东段进行地震危险区段判定。研究表明:祁连山断裂中东段土壤气体氡浓度强度的空间分布特征为东强西弱,其时间序列变化特征总体呈下降趋势;断层土壤气氡浓度强度的空间分布特征、历史及现今地震活动和断裂滑动速率具有较好的耦合性。研究结论可以提供研究区深部地下流体活动的证据,对进一步研究追踪未来可能发生地震的断层和活动段具有重要意义。Based on the observation data of soil gas radon concentration from nine measurement points from 2016 to 2021,the spatial and temporal distribution characteristics of radon concentration intensity in the mid-eastern segment of the Qilianshan fault zone were analyzed.Combining this analysis with strong historical earthquakes,present seismic activities,and fault zone sliding rate,the seismic hazard zones of the mid-eastern segment of the Qilianshan fault zone were determined from a geochemical perspective.The study results show that the study area has stronger soil gas radon concentration intensity in the eastern segment than in the western segment,and the change characteristics of the time series show a decreasing trend.The spatial distribution characteristics of soil gas radon concentration intensity,historical and present seismic activities,and fracture sliding rate are well coupled.This study provides evidence of deep underground fluid activity in the study area,which is vital in tracing the faults and active segments with seismic risk.

关 键 词：祁连山断裂带中东段 土壤气氡 时空演化特征 

分 类 号：P315.724[天文地球—地震学]