海底地震仪数据丢失异常及内部时间校正  

Abnormal data missing and internal time correction of Ocean Bottom Seismometer

作　　者：李子正 丘学林 张佳政[1,2,3] 贺恩远 王强[6,7] 张浩宇 LI ZiZheng;QIU XueLin;ZHANG JiaZheng;HE EnYuan;WANG Qiang;ZHANG HaoYu(Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;Key Laboratory of Ocean and Marginal Sea Geology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou 510301,China;SINOPEC Geophysical Research Institute,Nanjing 211103,China;University of Chinese Academy of Sciences,Beijing 100049,China;Fujian Xiamen Institute of Geological Engineering,Institute of Marine Geological Survey,Xiamen Fujian 361008,China;Fujian Geological Engineering Survey Institute,Key Laboratory of Geohazard Prevention of Hilly Mountains of Ministry of Natural Resources,Fuzhou 350002,China)

机构地区：[1]南方海洋科学与工程广东省实验室(广州),广州511458 [2]中国科学院南海海洋研究所,边缘海与大洋地质重点实验室,广州510301 [3]中国科学院南海生态环境工程创新研究院,广州510301 [4]中国石油化工股份有限公司石油物探技术研究院,南京211103 [5]中国科学院大学,北京100049 [6]福建省厦门地质工程勘察院,海洋地质调查研究所,福建厦门361008 [7]福建省地质工程勘察院,自然资源部丘陵山地地质灾害防治重点实验室,福州350002

出　　处：《地球物理学报》2024年第7期2863-2873,共11页Chinese Journal of Geophysics

基　　金：南方海洋科学与工程广东省实验室(广州)人才团队引进重大专项(GML2019ZD0204);国家重点研发计划(2018YFC0309801);国家自然科学基金(41906061,42106082,U20A20100)联合资助。

摘　　要：TS03航次使用国产海底地震仪(Ocean Bottom Seismometer,OBS)在马里亚纳海沟南段进行了一系列主动源和被动源地震作业,旨在获取跨越海沟的壳幔结构和地震活动性.但在数据处理过程中,我们发现POBS04台站地震剖面的直达水波到时异常,给接下来的计算模拟工作带来困难.为此,本文计算了直达水波理论到时,对比SAC文件中气枪信号到时,以此进行异常数据的检查分析.结果表明,POBS04台站记录过程中发生了部分数据丢失,从而造成其内部时间存在错误,体现在SAC文件中气枪信号到时提前,以及相邻数据文件之间存在数十秒的时间间隔.因此,本文在SAC软件中将整段气枪信号进行延后,使其可以和直达水波理论到时准确对应;之后再进行裁截、分道排列和SEGY格式转换,最终得到了正常的单台地震剖面.这项研究发现了一种新型数据异常,为后续准确的OBS位置校正和地壳结构计算模拟提供了可靠的数据保障,也为国产仪器的改进及其异常数据修复提供了新的参考.During cruise TS03 in the Southern Mariana Trench,a series of active and passive seismic surveys were carried out using Ocean Bottom Seismometer(OBS)produced in China,aiming at cross-trench crustal structure and local seismicity.However,abnormal direct-water-wave events were found on the seismic section of POBS04,and a large GAP between data files was also noticeable during data processing.These abnormal data bring uncertainty to the following relocation of OBSs and seismic tomography.To analyze these abnormal data,arrival times of direct water wave were calculated and then compared with the air-gun signals in SAC file.Our results show that the internal time of POBS04 was incorrect because of data missing,which then resulted in early arrival of air-gun signals.Based on these findings,we delayed the arrival time of air-gun signals in SAC software to be identical to calculated arrival time of direct water wave.After that,correct SEGY file can be converted and plotted.This study reveals a new kind of abnormal data.This procedure assists in OBS relocation and seismic tomography,and provides new references for abnormal data correction and OBS upgrade.

关 键 词：海底地震仪(OBS) 数据丢失异常 内部时间校正 挑战者深渊 

分 类 号：P738[天文地球—海洋地质]