GIS ANALYSIS OF ANTARCTICA BENEATH THE ICE AND EFFECTS OF ICE REMOVAL AND ISOSTATIC REBOUND

Capturing students’ imagination and desire to explore the unknown is an effective way to integrate GIS and geology into undergraduate education. For example, an exercise using Antarctic elevation and ice thickness raster data sets uses tools available in the ArcGIS Spatial Analyst and 3D Analyst extensions to answer questions and produce maps that display Antarctic topography, sub-ice topography, the effect of higher sea level and the effects of isostatic adjustment from ice removal. But the motivation for the student is: What does Antarctica look like beneath the ice? A continent of mountain ranges, deep valleys, plains, inland seas, offshore islands and the like exists there, for the most part invisible but for a few features that protrude above the ice. Wouldn't it be nice to have a topographic map in shaded relief of Antarctica without the ice and with oceans filling areas that are below sea level? Wouldn't it be even nicer to have such a map that accounted for the isostatic rise of the land surface that would occur after the weight of the ice was removed? What would the continent look like if sea level rose by an amount equal to the volume of the water locked up as ice? How much ice is there? In this activity, students use 1:5,000,000 scale BEDMAP continent-wide Antarctic data sets of surface elevation, ice thickness, bedrock topography, rock outcroppings, and coast lines to examine the effects of ice removal and sea level rise on the physiography of the continent. Through this exercise, students learn valuable geologic concepts as well as answer critical questions relevant to the effects of changing climate.