|Title||Significant groundwater contribution to Antarctic ice streams hydrologic budget|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Christoffersen P., Bougamont M., Carter S.P, Fricker H.A, Tulaczyk S.|
|Journal||Geophysical Research Letters|
|Type of Article||Article|
|Keywords||basal mechanics; bed; beneath; Groundwater; Hydrology; Ice sheet; ice stream; model; radar interferometry; sea-level; sheet; subglacial processes; till; variability; west antarctica|
Satellite observations have revealed active hydrologic systems beneath Antarctic ice streams, but sources and sinks of water within these systems are uncertain. Here we use numerical simulations of ice streams to estimate the generation, flux, and budget of water beneath five ice streams on the Siple Coast. We estimate that 47% of the total hydrologic input (0.98km(3)yr(-1)) to Whillans (WIS), Mercer (MIS), and Kamb (KIS) ice streams comes from the ice sheet interior and that only 8% forms by local basal melting. The remaining 45% comes from a groundwater reservoir, an overlooked source in which depletion significantly exceeds recharge. Of the total input to Bindschadler (BIS) and MacAyeal (MacIS) ice streams (0.56km(3)yr(-1)), 72% comes from the interior, 19% from groundwater, and 9% from local melting. This contrasting hydrologic setting modulates the ice streams flow and has important implications for the search for life in subglacial lakes.