南海西南次海盆广角地震探测  

Wide-angle seismic exploration in the southwest sub-basin of the South China Sea

作　　者：吴振利[1] 阮爱国 李家彪[1] 李昭兴[2] 丘学林[3] 丁巍伟[1] 

机构地区：[1]国家海洋局第二海洋研究所 国家海洋局海底科学重点实验室,浙江杭州310012 [2]台湾海洋大学应用地球物理研究所,中国台湾基隆20224 [3]中国科学院南海海洋研究所,广东广州510301

出　　处：《热带海洋学报》2012年第3期35-39,共5页Journal of Tropical Oceanography

基　　金：国家自然科学基金资助项目(91028006,41106053,41176046);中国科学院边缘海地质重点实验室资助项目(MSGL09-07);国家海洋局第二海洋研究所基本科研业务费专项资助项目(JT201101)

摘　　要：2010年12月—2011年3月在南海西南次海盆开展了海底地震仪(Ocean Bottom Seismometer,OBS)探测,采用Sedis IV型、I-4C型和MicrOBS3种不同型号的OBS,以4×24.5L的大容量气枪为震源,获得了覆盖西南次海盆残留扩张脊的3D人工地震数据。从处理的地震数据可知,此次试验是一次比较成功的地震实验,OBS地震记录清晰、震相丰富,所使用的气枪有足够的能量输出,显示了其良好的工作能力。选取剖面1中的7台OBS进行了2D剖面处理。初步建模结果表明,南海西南次海盆地壳结构为普通洋壳,海山顶部沉积层很薄,莫霍面埋深较浅。During December 2010 and March 2011,Ocean Bottom Seismometer（OBS） experiment was carried out in the southwest sub-basin of the South China Sea（SWSB）.Three types of OBS,Sedis IV type,I-4C type and MicrOBS type,were used in the experiment,and the energy source was supplied by 4×24.5L large volume air-gun.High quality seismic data that covered the extinct mid ocean ridge of the SWSB were acquired.The data could provide evidence for oceanic crust structure of the SWSB and seafloor spreading course,among others.The data of the seven stations of Profile 1 have been processed, which shows that the seismic records are clear and seismic phases are abundance and that the air-guns had enough energy supplies.Seismic phase analysis and first arrival tomography indicate that the crust of the SWSB is normal oceanic crust with a thin sedimentary layer on the seamount and shallow moho,which provides a good foundation for future research.

关 键 词：海底地震仪 广角地震 南海 西南次海盆 海底扩张 

分 类 号：P738.4[天文地球—海洋地质] P631.4[天文地球—海洋科学]