南沙地块OBS2019-2测线数据处理与震相识别  

Data processing and phase identification of OBS2019-2 in Nansha Block

作　　者：郭建 丘学林[1,2,3,4] 李子正[1,2,3,4] 黄海波 GUO Jian;QIU Xuelin;LI Zizheng;HUANG Haibo(Key Laboratory of Ocean and Marginal Sea Geology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China;Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou 510301,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院边缘海与大洋地质重点实验室,中国科学院南海海洋研究所,广东广州510301 [2]南方海洋科学与工程广东省实验室(广州),广东广州511458 [3]中国科学院南海生态环境工程创新研究院,广东广州510301 [4]中国科学院大学,北京100049

出　　处：《热带海洋学报》2022年第5期43-56,共14页Journal of Tropical Oceanography

基　　金：国家自然科学基金(42174110、42176081、41674092);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)。

摘　　要：为揭示南海南部陆缘的地壳结构,研究其张裂-破裂机制,开展共轭陆缘对比,我们在南沙地块礼乐西海槽附近的洋陆转换带上完成了OBS2019-2测线的探测工作。相较于北部陆缘,南部陆缘已有的海底地震仪(ocean bottom seismometer,OBS)测线较少,对深部地壳结构的研究也较少,因此OBS2019-2测线就尤为重要。文章重点阐述了OBS2019-2测线的数据处理工作,包括UKOOA文件制作、数据格式转换、位置校正、单个台站综合地震记录剖面的生成等,然后在剖面图中对各类深部震相(Pg、PcP、PmP、Pn)进行识别追踪,并建立初步的模型;使用Rayinvr软件进行走时试算工作,验证了震相识别的准确性。处理结果显示OBS2019-2测线的深部震相清晰,最远震相可以连续追踪到120km以外,数据整体质量良好,能为后续速度建模和构造解释等工作提供坚实基础。The survey of OBS2019-2 line was carried out across the continent-ocean transition zone(COT)near the Liyuexi Trough of the Nansha Block.This work is critical as it is able to reveal the crustal structure and study rifting-breakup mechanism of the southern continental margin of the South China Sea(SCS).The data of OBS2019-2 is also important to make a comparative study of conjugate continental margin of SCS.Compared with the northern continental margin,there is fewer Ocean Bottom Seismometer(OBS)survey lines and deep crustal structure study in the southern continental margin of SCS.Therefore,more work needs to be done on OBS2019-2.This paper focuses on the data processing workflow of OBS2019-2,including UKOOA file preparation,data format conversion,position relocation,single station seismic record section drawing,etc.Then different kinds of deep seismic phases(e.g.Pg,PcP,PmP,Pn)are identified and traced.These seismic phases are subsequently verified by the travel-time calculation using Rayinvr software.The results of data processing show that deep seismic phases in the seismic record profiles are distinct.The farthest seismic phase could be continuously traced up to 120 km away.Seismic data of OBS2019-2 are of high quality,which can provide a solid foundation for subsequent velocity modeling and structural interpretation.

关 键 词：南沙地块 海底地震仪 地壳结构 数据处理 震相识别 

分 类 号：P712.83[天文地球—海洋科学]