Steady-state characteristics of the Greenland ice sheet under different climates

The Greenland ice sheet is modelled to simulate its extent and volume in warmer climates, and also to find out whether the ice sheet would re-form on theice-free bedrock under present climatic conditions. The ice sheet model is a three-dimensional thermo-mechanical model with a fine resolution grid. Thebedrock surface beneath the ice sheet was mapped using radio-echo-sounding measurements by the Electromagnetic Institute, Copenhagen. The modelexperiments show that increased temperature will result in ice-margin retreat, but the ice sheet is relatively stable; it takes a rather high temperature rise of atleast 6iC for the ice sheet to disappear completely, which indicates that the ice sheet probably survived the last interglacial. Also, it appears that the Greenlandice sheet is not a mere relict ice mass from a previously colder climate but that the ice sheet will still re-form on the bare bedrock under the present, or evenslightly warmer, climatic conditions.