基于三分量宽频带台阵数据的福建地区地震背景噪声源分析  

Microseism sources estimated with three-component broadband seismometer array in Fujian and its adjacent areas

作　　者：张丽娜 刘祥龙 董培育[1] 陈智勇[4] 宋政宏 ZHANG LiNa;LIU XiangLong;DONG PeiYu;CHEN ZhiYong;SONG ZhengHong(Institute of Seismology,China Earthquake Administration,Wuhan 430071,China;State Key Laboratory of Geodesy and Earth’s Dynamics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China;Department of Earth and Space Sciences,Southern University of Science and Technology,Guangdong Shenzhen 518055,China;Fujian Earthquake Agency,Fujian Marine Seismic Observation Center,Fujian Xiamen 361000,China)

机构地区：[1]中国地震局地震研究所,武汉430071 [2]中国科学院精密测量科学与技术创新研究院,大地测量与地球动力学国家重点实验室,武汉430077 [3]南方科技大学地球与空间科学系,广东深圳518055 [4]福建省地震局,福建省海洋地震观测中心,福建厦门361000

出　　处：《地球物理学报》2025年第2期531-546,共16页Chinese Journal of Geophysics

基　　金：国家自然科学基金(41904064)资助.

摘　　要：背景噪声成像已经在地震学研究中得到广泛应用,但其精度会受到噪声源分布的严重影响,亟待开展相关研究.本文选取2016年福建及其邻区的94个宽频带地震台的三分量连续记录,采用频率域偏振分析的方法分析了该地区0.085~0.2Hz和0.2~0.5Hz两个频段内噪声的主要来源方向,并对其季节变化进行分析,发现0.085~0.2Hz频段的噪声来源随季节变化较大,冬季噪声主要来源于阿拉斯加海域;夏秋两季噪声主要来源于印度洋南部以及南极洲附近的区域.0.2~0.5Hz频段噪声来源方向的季节变化较小,主要来自东南方向,表明其主要来源可能是我国东南沿海海域.部分台站方向估计存在较大偏差,分析表明是由偏振分析方法的180°模糊问题引起的.最后,本文结合噪声互相关函数的非对称性,以及莫兰蒂台风期间的台阵聚束分析结果,对偏振分析结果进行了验证.Ambient noise tomography has been widely applied in seismology studies.Its accuracy is seriously affected by the distribution of noise sources,so it is urgent to conduct relevant research.In this study,three-component continuous records from 94 broadband seismic stations in Fujian and its adjacent areas in 2016 were used,and the frequency domain polarization analysis method was used to obtain back-azimuth of microseism in the frequency ranges of 0.085~0.2 Hz and 0.2~0.5 Hz,and its seasonal variation was analyzed.It was found that the seasonal variation of 0.085~0.2 Hz noise source is significant,with noise mainly from Alaska in winter,and mainly from the southern Indian Ocean and the area near Antarctica in summer and autumn.The seasonal variation of 0.2~0.5 Hz noise source was small,mainly from the southeast,indicating that its main source may be the coastal waters of Southeast China.It was found that there were significant deviations at some stations,which were caused by the 180°ambiguity problem of polarization analysis.Finally,we also cross-checked with result of the asymmetry of the noise cross-correlation function,and the result of array beamforming during typhoon Meranti's passage,to verify the polarization analysis results.

关 键 词：噪声源 偏振分析 噪声互相关函数非对称性 聚束分析 

分 类 号：P315[天文地球—地震学]