基于浅地层剖面振幅属性的海底沉积物类型反演——以舟山群岛为例

Using amplitude properties of shallow seismic profiles to reveal the seabed sediment types:A case study in Zhoushan Islands

应用声学方法反演海底沉积物类型对于研究海洋和开发海洋具有重要意义。基于有限的海底取样或原位测试获取海底沉积物类型,其成本高、效率低、连续性差,而声学反演方法由于其迅速、连续、方便、经济等优点受到普遍重视。本文基于在舟山群岛海域获取的高密度高分辨率浅地层剖面数据,利用前处理、振幅属性提取等技术进行海底表层沉积物类型反演,通过与侧扫声呐数据解释的地貌类型和实测海底表层沉积物类型对比,发现浅地层剖面振幅均方根RMS属性值可较准确地反演海底表层沉积物类型。利用最近获得的1100 km浅地层剖面振幅RMS属性值反演出舟山群岛的沉积物类型主要有黏土、黏土质粉砂、粉砂、砂和基岩5种类型,通过与实测数据对比,初步估算准确率在72%以上,表明作为一种新的利用浅地层剖面振幅属性反演海底表层沉积物类型的方法在该区是可行的。

Using acoustic parameters to reveal sediment types is of great significance for ocean research and development.Obtaining sediment types based on limited seabed sampling or in situ testing has often high cost,low efficiency,and poor continuity,to which acoustic profiling provides an advantageous tool that is rapid,continuous,convenient,and economical.Based on the high density and high resolution shallow stratigraphic profile data obtained in Zhoushan Islands periphery,East Chia Sea,technologies of pre-processing,amplitude attribute extraction,and so on were used to decipher the submarine surface sediment types.By comparing the geomorphic types interpreted from side scan sonar data and measured submarine surface sediment types,we found that the RMS(root mean square)attribute of the amplitude on shallow strata profile could accurately reflect the types of seafloor surface sediments.According to the amplitude RMS attribute of 1100 km shallow stratum profile obtained recently,the sediment types of Zhoushan Islands were interpretated,including mainly clay,clay silt,silt,sand,and bedrock.Compared to the measured data,the rate of successful match reached over 72%.This study provided a feasible way using the amplitude attribute of shallow seismic profiling to determine the surface sediment type in the study area and beyond.