ICE-SHEET-DERIVED SUBMARINE GROUNDWATER DISCHARGE ON GREENLAND'S CONTINENTAL SHELF

Isotopically depleted, relatively fresh pore fluids were reported in continental shelf sediments 40 to 100 km off shore, southeastern Greenland during ODP drilling campaign Leg 152 in 1994. This suggests that significant quantities of glacial meltwater may be sequestered in volcanic and/or sedimentary formations on Greenland’s continental shelf. We present a paleohydrologic reconstruction of the late Pleistocene hydrogeology of southeastern Greenland using a finite element model that incorporates fluctuating sea level and ice sheet geometry. We varied permeabilities, δ¹⁸O and salinity boundary conditions as well as ice-sheet extent in order to constrain infiltration rates. Our model shows that the emplacement of isotopically depleted freshwater into offshore aquifers was greatest during the last glacial maximum when the ice sheet extended to near the shelf-slope break. Model results further suggest that significant temporal variations in submarine groundwater discharge occurred during the Pleistocene.