Antarctica Bed (below the surface)
Antarctica Surface
Glacier modelers attempt to combine both topological and climate data to construct a computer-generated "picture," or model, that is able to change over time, just as the ice sheets have. This time dependence is known as dynamic modeling.
Dynamic models allow us to reconstruct the shape, as well as the outline, of ice sheets of the past. After glacial geological indicators have identified an outline or margin of the ice sheet, the interior thickness can be calculated from various conservation laws and constitutive relationships that make up parts of the model.
In trying to understand the behavior of ice sheets, one cannot design controlled experiments as one does in a laboratory. Numerical models provide the only arena for doing "experiments" on ice sheets. What happens to the shape of an ice sheet as the amount of snowfall increases or decreases? How rapidly does it respond to a change in external conditions? If the climate warms, does the ice sheet get bigger (more snow available from the more moist air) or smaller (more melting by the warmer atmosphere)? How does the warming of the surface due to climatic change penetrate to the bed?
Faculty
Fei Chai, Jim Fastook, Kirk Maasch
Click image above for an animation showing
growth/ decline of the Northern Hemisphere Glaciation
View larger version (1.3mb)
Research
Studying Byrd Glacier as a rock-floored ice stream ending as a calvng ice shelfTerence Hughes, Roger LeB. Hooke, James Fastook
Did the Laurentide Ice Sheet Control Abrupt Climate Change?
Terence Hughes, James Fastook