A 2D subglacial groundwater model of a Scandinavian
Ice Sheet flow line
Moeller, Carolyn A.
moeller@geology.wisc.edu
University of Wisconsin-Madison,
Department of Geology and Geophysics, 1215 W. Dayton Street, Madison, WI 53706
Mickelson, David M.
davem@geology.wisc.edu
University of Wisconsin-Madison, Department
of Geology and Geophysics, 1215 W. Dayton Street, Madison, WI 53706
Anderson, Mary P.
andy@geology.wisc.edu
University of Wisconsin-Madison,
Department of Geology and Geophysics, 1215 W. Dayton Street, Madison, WI 53706
Winguth, Cornelia
cwinguth@facstaff.wisc.edu
Univeristy of Wisconsin-Madison,
Department of Atmospheric & Oceanic Sciences, 1225 W. Dayton Street,
Madison, WI 53706
The behavior of the subglacial groundwater
system is one of several aspects of the Scandinavian Ice Sheet that are still
poorly understood, yet is also a critical glaciological constraint. It
influences the stability of the ice sheet, ice sheet thickness, and extent, and
is therefore an important component for the reconstruction of climate during
the last glacial period. We examine the subglacial hydrology of a flow line of
the Scandinavian Ice Sheet using a two-dimensional MODFLOW-based profile model
assuming that groundwater flow is parallel to the ice flow line. A
two-dimensional, time dependent, thermomechanically coupled ice flow model
provides the meltwater input from basal melting along the flow line. This is
used to simulate recharge to the subglacial groundwater system. The model results
indicate that the bed sediments alone would not have been capable of
transmitting all of the basal meltwater out of the fjord during times of
advance and retreat, as well as at the maximum position at the edge of the
continental shelf. Surface meltwater contributes additional recharge and would
also greatly impact the underlying aquifer. Such conditions could explain
non-climatically driven margin readvances during the overall retreat phase.
Additionally, a drainage network would aid in keeping basal water pressures at
reasonable levels, and serve to evacuate excess meltwater from the system.