Ice dynamics near Antarctic marginal mountain ranges: Implications for interpreting the glacial-geological evidence

Abstract

In the reconstruction of the glacial history of ice-covered areas, ice-sheet dynamics-translating the climatic signal to glacier variations-is often disregarded. In this paper an experimental framework, based on ice-sheet modeling, is presented to determine possible glacier transfer functions linking the climatic signal to the proxy record of glacial-geological observations. Applied to a flowline through a marginal mountain range in Dronning Maud Land, Antarctica, it provides a better insight into the glacial history of the last 200 000 years. With respect to the different combinations of boundary conditions, at least two scenarios were obtained for the glacial history in the vicinity of the mountain range. While inland of the mountains and near the coast the response to the climatic signal is more or less similar for both scenarios, within the mountain range a large difference was found, depending on the choice of boundary conditions. This aberrant behavior of the ice sheet near mountain ranges is an important element in the interpretation of the glacial-geological proxy record as a function of the climatic signal. The reason for the different response patterns encountered in the mountain area is primarily related to the sensitive interplay between surface mass balance and thermomechanical properties of the glacier.