Determining Transient Physical Conditions under the Southern Laurentide Ice Sheet Using Geologic Information and Numerical Modeling by David M. Mickelson and Paul Cutler (Department of Geology and Geophysics, University of Wisconsin, Douglas R. MacAyeal (Department of Geophysical Sciences, University of Chicago) and Patrick M. Colgan (Department of Geology, Northeastern University). We will reconstruct the dynamics and subglacial environment of the southern Laurentide Ice Sheet (SLIS) during the late Wisconsin by integrating the glacial geologic record with numerical ice-sheet modeling. We focus on the SLIS because there are striking contrasts in landform assemblages from north to south, and the record of ice sheets is well documented in time and space. Data will be organized and analyzed in a geographic information system. Our ice-sheet model is two-dimensional, time-dependent, and incorporates the upper 1-km of the subsurface in addition to overlying ice. The model will be adapted to handle basal/subsurface processes by adding a 'geologic package'. This will include treatment of permafrost, hydrology, basal motion and till dynamics. This modeling will help us understand the conditions of formation of the glacial landscape of the Great Lakes area.
