title: An active subglacial water system in West Antarctica mapped from space.
abstract: Satellite laser altimeter elevation profiles from 2003 to 2006 collected over the lower parts of Whillans and Mercer ice streams, West Antarctica, reveal 14 regions of temporally varying elevation, which we interpret as the surface expression of subglacial water movement. Vertical motion and spatial extent of two of the largest regions are confirmed by satellite image differencing. A major, previously unknown subglacial lake near the grounding line of Whillans Ice Stream is observed to drain 2.0 cubic kilometers of water into the ocean over approximately 3 years, while elsewhere a similar volume of water is being stored subglacially. These observations reveal a wide spread, dynamic subglacial water system that may exert an important control on ice flow and mass balance.
authors.affiliation: Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA. hafricker@ucsd.edu
authors.forename: Helen Amanda
authors.initials: HA
authors.lastname: Fricker
authors.forename: Ted
authors.initials: T
authors.lastname: Scambos
authors.forename: Robert
authors.initials: R
authors.lastname: Bindschadler
authors.forename: Laurie
authors.initials: L
authors.lastname: Padman