南海东北部海陆联测地震数据处理及初步结果

ONSHORE-OFFSHORE SEISMIC DATA PROCESSING AND PRELIMINARY RESULTS IN NE SOUTH CHINA SEA

为开展南海东北部海陆过渡带和滨海断裂带横向深部结构研究,利用陆上流动地震台记录与海上气枪放炮相结合的方法,首次在广东汕头沿海进行了海陆联合深地震探测。详细介绍了该次海陆联测地震数据处理的主要步骤与流程,并针对海陆联测地震数据和常用地震软件编写了3个格式转换程序。应用这3个程序和SAC、SU等地震软件得到了初步的数据处理结果。在南澳台和新塘台的单台地震记录剖面中可以清晰地识别出多种震相,得到许多有用的地震信息,证明海陆联测的野外工作和第1阶段的数据处理工作是成功的,为下一步地壳深部结构的研究打下了良好的基础。

In order to study the crustal structure across the Littoral Fault Belt and the transition zone of South China mainland and NE South China Sea, an onshore-offshore deep seismic experiment was carried out for the first time offshore Shantou, Guangdong Province. Air-gun arrays were used as seismic sources and five portable land stations were set up to record the seismic signals. The main flow steps for data processing were introduced in details. Three programs were written to convert the raw data to common data format. Preliminary results were obtained by using these three programs together with the seismic softwares of SAC and SU. Abundant crustal information and deep seismic phases were recognized in the seismic record sections. The apparent velocities of Pg and PmP are about 5.14 km·s^(-1) and 7.14—7.30 km·s^(-1) respectively. All these provide a strong base for the study of crustal structure for the next step.