Circum-Antarctic Stratigraphy and Paleobathymetry: Development of Grid-based Simulations

南大洋的古海洋学模型缺少边界条件，这些边界条件不能准确地描述海底表面在其地质时代的几何形状及其在长时间尺度上的动力学。这导致了对德雷克海峡和塔斯马尼亚门户深水开口的开始和古气候后果的不确定估计。主要的深海流系统，如南极环极流（ACC），通过诸如海洋高原和山脊等结构性障碍的发展和偏转的影响，由于缺乏对其水深增长的重建，也没有描述。由于沉积物覆盖变化的重建是精确古测深模型中最大的缺失部分，本项目将整合南极地震数据库系统（SDLS）的大型地震数据基础以及国际合作伙伴提供的数据和钻探信息，形成从大陆架到深海平原的统一环南极数字地层网格。该网格将用于计算一系列包含最新板块运动学模型、岩石圈沉降曲线和动态地幔地形模型的环南极古测深网格。最后，将利用古水深网格模拟古海洋学和古气候情景，特别强调德雷克海峡和塔斯马尼亚门户的开放以及沿大陆架、斜坡和隆起的古洋流动力学。

Paleoceanographic models of the Southern Ocean suffer from missing boundary conditions which describe accurately the geometries of the seafloor surfaces at their geological epoch and their dynamics over long time-scales. This results in uncertain estimates of the onset and paleoclimate consequences of the deep-water openings of the Drake Passage and the Tasmanian Gateway. The development and implications for deflections of major deep-sea current systems, e.g. the Antarctic Circum-Polar Current (ACC), through structural obstacles such as oceanic plateaus and ridges is also not described due to lacking reconstructions of their bathymetric growth. As the reconstruction of the changing sediment cover is the largest missing component for accurate paleobathymetric models, a unified circum-Antarctic digital stratigraphic grid from continental shelves to the abyssal plains will be generated in this project by integrating the large seismic data basis of the Antarctic Seismic Data Library System (SDLS) and data from international cooperation partners as well as drill information where available. This grid will then be used to calculate a series of circum-Antarctic paleobathymetric grids in which newest plate-kinematic models, lithospheric subsidence curves and models of dynamic mantle topography are incorporated. Finally, paleoceanographic and paleoclimate scenarios will be simulated using this paleobathymetric grid with particular emphasis on the opening of the Drake Passage and Tasmanian Gateway and the paleo-current dynamics along the continental shelves, slopes and rises.