Models of the 3-D Stratigraphy of Glaciated Continental Shelves

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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.