Models of the 3-D Stratigraphy of Glaciated Continental Shelves

摘要冰川大陆架地层学的解释和从地层学中重建过去的冰盖波动需要理解地层几何、冰川和海洋沉积过程以及冰动力学之间的关系。以前的工作是用二维结构模拟模型研究南极大陆架的形态形成和广泛的地层几何形状。对形成南极冰架的过程提出了若干概括，并提出了若干解释地层特征的准则。该奖项支持在三个新方向上扩展建模工作的工作：1)构建三维模型，以解释跨大陆架槽和滩之间冰川形态和地层学的差异；2)完善仿结构模型，发展基于过程的模型。我们将把冰的前进和后退视为连续的、自回归的过程，而不是以前模型中的离散步骤。在基于过程的模式中，侵蚀和沉积将由基底冰的速度或基底剪应力决定。冰川侵蚀和沉积将与水沉积过程模型相结合。3)与南极和格陵兰东南冰架新收集的数据集进行详细比较，从而提高我们对冰川大陆架地层学的认识。这项工作对于了解北极和南极地区冰盖过去的行为非常重要。

Shen, Holbrook, and ten Brink OPP 9526930 Abstract The interpretation of the stratigraphy of the glaciated continental shelves and the reconstruction of past ice sheet fluctuations from the stratigraphy require understanding of the relationships among the stratal geometry, glacial and marine sedimentary processes, and ice dynamics. Previous work investigated the formation of the morphology and the broad stratal geometry of the Antarctic continental shelf with 2-D structure-imitating models. Several generalizations were proposed regarding processes that form the glaciated Antarctic shelves and several guidelines were proposed for the interpretation of stratigraphic features. This award supports work to expand the modeling efforts in three new directions: 1). constructing 3-D models to account for the differences in glacial morphology and stratigraphy between cross- shelf troughs and banks; 2). improving the structure-imitating models and developing process-based models. We will treat ice advance and retreat as continuous, autoregressive processes instead of discrete steps in our previous models. In the process- based models, erosion and deposition will be determined by the velocity of basal ice or the basal shear stress. Glacial erosion and deposition will be coupled with models of aqueous sedimentary processes. 3). making detailed comparison to newly compiled data sets from the Antarctic and the SE Greenland shelves, and in doing so improving our understanding of the stratigraphy of the glaciated continental shelf. This work is important to understanding the past behavior of ice sheets in both the northern and southern polar regions.