Analysis of Circum-Antarctic Ocean Basin Paleobathymetry and Structure

该奖项支持两项主要研究，这些研究利用了最近完成的南极海洋地质和地球物理合成以及相关的数字测深、沉积物厚度和地壳结构数据文件。这些数据与已公布的数字地壳年龄数据和环极地区的扩展速率数据一起使用，将使古地理重建得以发展，并完成从白垩纪中期到现在的各种地质时代的古水深测量。为了卸载沉积物和重新定位深度，以解释由于冷却和均衡作用引起的地壳沉降的影响，需要地壳年龄和扩展速率数据文件。确定最合理的古水深测量的一个重要好处是，为环流和气候建模者提供必要的约束条件，以完善他们的模型，并进一步评估这些模型对海底形态障碍和不断变化的盆地大小的敏感性。数字时代和扩展速率文件的第二个建议应用是检验假设，即选定的海洋地壳参数，如层速度和厚度，以及小尺度海底粗糙度，与年龄和/或扩展速率有关。建立这样的关系可能会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地图集和其他数字数据提供了一个极好的机会，可以在世界海洋的很大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.