Numerical modelling of the Laurentide Ice Sheet in the Baffin Island region: the role of a Cumberland Sound ice stream

A numerical model reconstruction was made of the northeastern Laurentide Ic e Sheet in the Baffin Island - Foxe Basin region using geophysical, terrest rial, and marine geologic evidence for initial and boundary conditions. The simulated ice sheet consists of a Foxe Dome with additional smaller Hall a nd Amadjuak domes and a Penny Ice Divide. A specific objective was to deter mine boundary conditions that would allow advance of a marine-based low sur face slope ice stream into and out of Cumberland Sound, a major marine emba yment in the uplifted rim of the eastern Canadian Arctic (up to 1200 m deep ), while maintaining ice free or nonsliding (e.g., cold-based) thin ice on adjacent plateaus of Cumberland Peninsula; this scenario accommodates inter pretations based on terrestrial and marine studies in this region. After an initial ice-sheet configuration is placed on the eastern Arctic terrain, b asal sliding is allowed in specified regions. Basal sliding below sea level and between the Foxe Dome and Cumberland Sound and a reasonable but critic al initial ice sheet volume and dome surface elevation are needed to obtain advance along and out of Cumberland Sound. Rapid flow into Hudson Strait a nd along Cumberland Sound causes drawdown and a change in ice-sheet configu ration. Although more Foxe Dome ice flows into western Hudson Strait than C umberland Sound in the simulations, the latter may still have been an impor tant conduit connecting the interior of the northeastern Laurentide Ice She et to the Labrador Sea, thereby affecting regional ice sheet dynamics, spec ifically ice surface elevations and flow paths.