The Potential for Basal Melting Under Summit, Greenland

Abstract

AbstractThe deep-drilling projects at the Summit ice divide will require thermal models to help interpret the paleoclimatic signals in their cores. An analytic, steady-state model predicts basal temperatures within 1 °C of the ice melting-point and basal ice no older than 100–400 kyear should melting occur. A two-dimensional, time-dependent temperature model includes the effects of realistic two-dimensional ice flow and the temperature and mass-balance patterns of the last two glacial cycles. The model relaxes some assumptions made in one-dimensional studies and produces lower basal temperatures. The basal temperatures are most sensitive to the value of the geothermal heat flux and the mass-balance pattern. If the flux is less than 56 mW m−2, the bed has likely been frozen throughout the last glacial cycle. The decoupling of the energy and mass-conservation equations is a significant source of error which can be eliminated only by a fully coupled ice-flow/ heat-flow model.