Analysis of Circum-Antarctic Ocean Basin Paleobathymetry and Structure

该奖项支持两项主要调查，利用最近完成的南极海洋地质和地球物理综合和相关的数字测深，沉积物厚度和地壳结构数据文件。 沿着使用的数字地壳年龄数据和环极地区的扩展速率数据将允许开发古地理重建，完成从白垩纪中期到现在的各种地质时期的古水深测量。地壳年龄和扩展速率数据文件既需要卸载沉积物，也需要重新定位深度，以说明由于冷却和等渗而产生的累积地壳沉降的影响。 确定最合理的古水深测量的一个重要好处将是手臂循环和气候建模与必要的限制，以完善他们的模型，并进一步评估这种模型的敏感性，海底形态障碍和不断变化的盆地大小。 数字年龄和扩展速率文件的第二个拟议应用是检验假设，即层速度和厚度以及小尺度海底粗糙度等选定海洋地壳参数取决于年龄和/或扩展速率。 建立这样的关系很可能导致对影响地壳演化的潜在偶然过程的新发现。 《南大洋海洋地质和地球物理图集》和其他数字数据提供了一个极好的机会，可以在世界海洋相当大的一部分地区检验这些假设。

Abstract This award supports two principal investigations that utilize the recently completed Antarctic Marine Geological and Geophysical synthesis and the associated digital bathymetric, sediment thickness, and crustal structure data files. These, used along with published digital crustal age data and spreading rate data for the circum-polar region will allow development of paleographic reconstructions, complete with paleobathymetry for a variety of geologic times from the mid-Cretaceous to the present. The crustal age and spreading rate data files are needed both to unload the sediments and reposition the depths to account for the effects of accrued crustal subsidence due to cooling and isostasy. An important benefit of determining the most plausible paleobathymetry will be to arm circulation and climate modellers with constraints necessary to refine their models and to further evaluate the sensitivity of such models to submarine morphological barriers and changing basin sizes. The second proposed application of the digital age and spreading rate files is to test hypotheses that selected oceanic crustal parameters of layer velocities and thicknesses, as well as small-scale seafloor roughness, are age and/or spreading rate dependent. Establishing such relationships is likely to lead to new discoveries about the underlying casual processes effecting crustal evolution. The Southern Ocean Marine Geological and Geophysical Atlas and other digital data provide an excellent opportunity to test such hypotheses for a significantly large fraction of the World Ocean.