A comparison of different ways of dealing with isostasy: examples from modeling the Antarctic ice sheet during the last glacial cycle

• Main Authors: Le Meur, E., Huybrechts, Philippe
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1996
• Subjects: Antarctic; The Antarctic; Annals of Glaciology; Antarc*; Antarctica; Ice Sheet
• Online Access: https://epic.awi.de/id/eprint/2128/; https://epic.awi.de/id/eprint/2128/1/Meu1995a.pdf; https://hdl.handle.net/10013/epic.12717; https://hdl.handle.net/10013/epic.12717.d001

The bedrock isostatic response exerts a strong control on ice sheet dynamics and is therefore always taken into account in ice sheet models. This paperreviews the various methods normally used in the ice-sheet modeling community to deal with the bedrock response and compares these with a moresophisticated full Earth model. Each of these bedrock treatments, five in total, are coupled with a three-dimensional thermomechanical ice sheet model underthe same forcing conditions to simulate the Antarctic ice sheet during the last glacial cycle. The outputs of the simulations are compared on the basis of thetime-dependent behavior for the total ice volume and the mean bedrock elevation during the cycle, and of the present rate of uplift over Antarctica. Thiscomparison confirms the necessity of accounting for the elastic bending of the lithosphere in order to yield realistic bedrock patterns. It furthermoredemonstrates the deficiencies inherent to the diffusion equation in modeling the complex deformation within the mantle. Nevertheless, when characteristicparameters are varied within their range of uncertainty, differences within one single method are often of the same order as those between the variousmethods. This overview finally tries to point out the main advantages and drawbacks of each of these methods and to determine which one is mostappropriate depending on the specific modeling requirements.