Using a GIS to Facilitate the Reconstruction of the Scandinavian Ice Sheet

Major limitations in the successful use of ice sheet models for climate research arise from limited field data for model verification and the end result may be unrealistic simulations of ice sheet inception, growth, and decay. If a numerical ice sheet model is to be considered an accurate reconstruction of a previous glacial cycle, then the estimated ice marginal positions, subglacial regime, and ice flow charateristics must reasonably agree with field observations. A high resolution, three-dimensional, thermomechanical model was used to simulate the Fennoscandian Ice Sheet (FIS) through the last glacial maximum. Field observations from Denmark, Kola Peninsula, and the Kiruana and Stockholm regions have been digitized and are used for model verification. A Geographic Information System (GIS) was used to integrate model output and field observations (i.e., moraines, eskers, lineations) into one database. A technique that utilizes a system of buffering and overlay was used to determine the proximity and parallel conformity between model and empirical data. Through an iterative process, numerous model runs were tested to find which modeled ice margins best agree with field data. Once the "best fit" model runs were selected, field observations were then used to verify ice flow direction. The end result is a method that links a numerical ice sheet model with field evidence that constrains the marginal extent and general ice flow patterns. Results from this project can improve contemporary knowledge on the evolution of the subglacial thermal regime, as well as the inception and growth of the Scandinavian Ice Sheet during the LGM.