利用远震P波和瑞雷面波偏振评估ChinArray一期地震计方位偏差  

Evaluating seismometer orientation of ChinArray-Ⅰusing teleseismic P-wave and Rayleigh-wave polarization

作　　者：徐桂灵 王伟涛[1,2] 许卫卫 吉敏[1,2] 袁松湧 Xu Guiling;Wang Weitao;Xu Weiwei;Ji Min;Yuan Songyong(Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Key Laboratory of Earthquake Source Physics,China Earthquake Administration,Beijing 100081,China)

机构地区：[1]中国地震局地球物理研究所,北京100081 [2]中国地震局震源物理重点实验室,中国北京100081

出　　处：《地震学报》2024年第5期844-864,共21页Acta Seismologica Sinica

基　　金：中国地震局地球物理研究所中央级公益性科研院所基本科研业务费(DQJB19B36,DQJB23R18)资助.

摘　　要：利用远震P波和瑞雷面波偏振特征的两种独立分析方法,对2011—2013年间在南北地震带南段布设的中国地震科学探测台阵一期台站的方位偏差进行了评估。研究使用了震中距30°-90°范围内696次远震的P波数据和震中距10°-170°范围内1928次地震的瑞雷面波数据。结果显示:两种偏振分析方法所得台站的水平方位角偏差具有较好的一致性。在全部352个台站中,除4个台站由于可用数据较少而未进行评估外,281个台站的南北向分量与地理北向偏差小于10°,21个台站的方位偏差在10°-20°之间,其余台站则出现故障或偏差较大。所获结果与前人基于远震P波的结果类似,但存在7个台站的方位偏差与其结果差异超过5°,进一步的分析表明这些台站在不同时段水平方位角偏差发生过改变,需要分时段进行评估。同时,研究发现仪器不同分量的增益故障会影响仪器水平方位角的偏差估计,可与噪声功率谱结合开展协同评估。The accurate estimation of seismometer orientation is considered essential for seismological studies that depend on three-component seismic records.It is necessary to align the north-south horizontal component with the geographic north during station deployment to achieve accurate recording and analysis of seismic waveforms.Orientation deviation is influenced by a variety of factors.Ocean-bottom seismometers cannot achieve alignment with geographic directions due to limitations of the deployment method.Local magnetic anomalies or incorrect corrections for magnetic declination corrections can cause the magnetic compass fail to align to geographic north when seismometers are deployed on land.Ground subsidence and instrument movement during the operation stage can additionally cause orientation deviations.It is therefore considered an important step in enhancing the accuracy of subsequent research to employ seismological methods to estimate the orientation deviation during instrument deployment.Because of the large surface deformation and high seismicity in Yunnan Province,many seismic studies have been carried out in this area using data recorded by China Earthquake Administration(CEA)permanent stations.However,the large distances between the stations of the permanent seismic stations can lead to the phenomenon of low resolution of the research results on a small scale.In order to conduct an in-deep study of the seismicity and deep structure of the region,350 broadband transportable array were deployed in Yunnan and the surrounding areas of the southern section of the North-South Seismic Belt during 2011 to 2013,known as the ChinArray phaseⅠ.Due to changes in the observation environment,the positions of two stations were shifted by a few kilometers in the middle of the deployment period during the observation period,so that a total of 352 stations were observed in the study area.We estimate the seismometer orientations of ChinArray phaseⅠ.Two independent polarization analysis methods,teleseismic P-wave and Rayl

关 键 词：中国地震科学探测台阵 地震计方位 远震P波 瑞雷面波 偏振分析 

分 类 号：P315.78[天文地球—地震学]