声学特性参数定量反演海底沉积物粒度类型的理论与实验研究

项目名称： 声学特性参数定量反演海底沉积物粒度类型的理论与实验研究

项目编号： No.41476028

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 李赶先

作者单位： 中国科学院南海海洋研究所

项目金额： 88万元

中文摘要： 对采自南海海底沉积物样品，进行实验室中的海底温压条件下沉积物各项参数测量，获得纵波声速、声阻抗和声衰减等海上声学反演可以得到的声学特性参数数据；获得沉积物剪切模量、固结剪切模量、固结体积压缩模量等弹性参数，以及获得沉积物粒度分析数据。利用声学基础理论建立的声速-复合参数模型、弹性基础理论公式，以及沉积物弹性模量与各成分体积分数理论关系等，建立声学特性参数定量反演海底沉积物孔隙度、固结剪切模量、固结体积压缩模量等理论公式与经验公式，建立声学特性参数定量反演海底沉积物的砂、粉砂、粘土三组分体积分数的理论公式与经验公式方程组，进而求解和计算出沉积物的砂、粉砂、粘土三组分质量百分含量，以便对沉积物进行粒度类型定名。由此实现本项目研究目标：建立声学特性参数定量反演海底沉积物粒度类型的基础理论与实验技术。这对于海洋物理学、海洋地质学和海底声学物理等交叉渗透与融合发展，具有重要理论意义和应用价值。

中文关键词： 海底沉积物；声学参数；定量反演；弹性模量；粒度类型

英文摘要： By measurement of the parameters of the sediments, which were collected from the South China Sea, under laboratory conditions of temperature and pressure in situ, the data of acoustic properties, such as the longitudinal wave velocity, the acoustic impedance and acoustic attenuation, were inversed in light of the hydroacoustic data obtained on survey ship, mentioned above. Then elastic parameters, such as shear modulus of saturated sediments, shear modulus and bulk compressibility modulus of consolidation sediments, were inversed according to the data of acoustic properties above. At the same time, analysis results of sediment particle size can be accessed. So with the help of sound-complex variable model deduced by means of the basic acoustic theory, the basic formula of elastic modulus and the theoretical relationship between the elastic modulus and the volume fraction of each component of sediments, we can establish theoretical and empirical formula which may quantitatively inverse marine sediments porosity, consolidation shear modulus and bulk compressional modulus of consolidated sediments by acoustic parameters, and then establish theoretical and empirical formula which may quantitatively inverse the volume fractions in percentages of the three components that are sand, silt and clay of seafloor sediments by these acoustic parameters above. Furthermore we can identify the mass percentages of the sand, silt and clay, three components of the sediments, so the type of the sediment grain size can be denominated. Thereby we achieve the project target that establishes the system theory and experimental techniques by which inversion of type of grain size of seafloor sediment with the acoustic properties of seafloor sediment can be accomplished. This will have important theoretical significance and application value in cross-infiltration and integrated development of hydroacousticphysics, marine geology and oceanography military.

英文关键词： seafloor sediment;acoustic parameter;quantification inversion;elastic mudulus;grain size type