基于接收函数的廊坊北三县地区地壳结构研究及其动力学意义  

Crustal Structure in the Beisan County area of Langfang City Using P-wave Receiver Functions and Its Dynamic Implications

作　　者：谭萍 邓淼 万永革[1] TAN Ping;DENG Miao;WAN Yongge(Hebei Key Laboratory of Earthquake Dynamics,Institute of Disaster Prevention,Sanhe 065201,China)

机构地区：[1]防灾科技学院河北省地震动力学重点实验室,河北三河065201

出　　处：《防灾科技学院学报》2025年第1期59-67,共9页Journal of Institute of Disaster Prevention

基　　金：廊坊市科学技术研究与发展计划自筹经费项目(2022011062);河北省高等学校科学技术研究项目(BJ2025123);河北省自然科学基金项目(D2020512005)。

摘　　要：针对防灾科技学院地震遥测台网固定地震台站所记录的波形资料提取P波接收函数,采用谐波分析方法和网格搜索法求得廊坊北三县地区地壳各向异性快波偏振方向和分裂时差,并基于H-κ-c叠加方法得到研究区地壳厚度和泊松比。研究结果显示:(1)廊坊北三县地区台站下方地壳快慢波分裂时差为0.46~0.56 s,平均值为0.49 s,指示该地区地壳存在明显的方位各向异性;(2)地壳各向异性的快波偏振方向呈现为NNE-SSW向,与邻近的断裂走向一致,指示该地区地壳各向异性主要受到断裂带的影响;(3)研究区地壳厚度呈现西高东低的特征,与张渤地震带整体地壳厚度变化特征相符,且地壳厚度变化较大,反映了华北克拉通的伸展构造特征;(4)廊坊北三县地区地壳平均泊松比变化较大,研究区北部和东北部泊松比相对低,指示该地区脆性矿物含量高,更容易发生应力积累,而西南部地区泊松比较高,很可能受到上地幔熔融物质底侵的影响。Using the seismic wave forms recorded by the permanent seismic stations in the Earthquake Remote Sensing Network of Institute of Disaster Prevention,we calculated the P wave receiver functions.Then,on the basis of it,the fast wave polarization direction and the delay time of crustal anisotropy in the Beisan County of Langfang City are determined by harmonic analysis and grid search methods.Moreover,the crustal thickness and Poisson's ratio of the study area were obtained by the new H-κ-c stacking method.As the research results show that:(1)The time difference between the fast and slow wave splitting of the crust below the stations in the study area is 0.46-0.56 s,with an average value of 0.49 s,indicating significant directional anisotropy in the crust of the region.(2)The fast wave polarization direction of crustal anisotropy consistently shows a NNE-SSW orientation,which is consistent with the strike of faults in the nearby,indicating that the crustal anisotropy in the region is primarily influenced by the fault zones.(3)The crustal thickness decreases from west to east in the study area,being consistent with the overall crustal thickness variation of the Zhangjiakou-Bohai seismic belt.The significant variation of crustal thickness reflects the extensional tectonic characteristics of the North China Craton.(4)The average Poisson's ratio varies considerably in the study area.It is relatively low in the northern and northeastern parts of the study area,indicating a higher content of brittle minerals,which are more prone to stress accumulation.It is relatively high in southwestern part of the study area,likely influenced by the underplating of mantle-derived magma.

关 键 词：廊坊北三县 接收函数 地壳各向异性 地壳厚度 泊松比 

分 类 号：P315.23[天文地球—地震学]