南海南部海域海底沉积物弹性性质及其分布

ELASTIC PROPERTIES OF SEAFLOOR SEDIMENTS IN SOUTHERN SOUTH CHINA SEA AND THEIR DISTRIBUTIONS

报道和分析了12°N以南的南海南部海域海底沉积物弹性参数纵波速Vp、横波速Vs、弹性模量E、体积弹性模量K、压缩系数β、剪切模量μ、泊松比ν和拉梅常数λ,并对大陆架和大陆坡、深海盆的结果进行比较分析。结果表明,海底浅层沉积物声速(纵波速)以低声速为主,高声速沉积物主要在大陆架和个别岛礁区域,低声速沉积物连成一片,高声速沉积物不是连成一片。大陆架海底沉积物弹性模量、体积弹性模量、泊松比和拉梅常数等4项参数比大陆坡海底沉积物要高,大陆坡海底沉积物压缩系数比大陆架海底沉积物要高,剪切模量在大陆架和大陆坡海底上相差不大。讨论了它们之间的关系、平面分布特征及其普遍意义。

The elastic behaviors of seafloor sediments in the southern South China Sea to the south of 12°N were reported and analyzed, including compressive wave velocity V_ p , shear wave velocity V_ s , Young's modulus E, bulk modulus K, constrained modulus β, rigidity modulus μ, Poisson's ratio ν, and Lames constant λ, and were compared with the elastic parameters of sediments collected from the continental shelf and continental slope. The study results show that the seafloor surface is mainly composed of sediments with lower compressive wave velocity, while sediments with higher velocity mainly distribute in the continental shelf and some island reef areas. Sediments with lower sound velocity have the distribution feature of continuity, while those with higher sound velocity are dispersed. The values of Young's modulus, elastic modulus, Poisson's ratio and Lames constant of seafloor sediments in the continental shelf are higher than those in the continental slope, while the constrained modulus is just the opposite, and the values of rigidity modulus are similar. In addition, the relations, distribution features and universal significances of the elastic parameters were also discussed.