|Title||A decade of West Antarctic subglacial lake interactions from combined ICESat and CryoSat-2 altimetry|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Siegfried MR, Fricker HA, Roberts M, Scambos TA, Tulaczyk S|
|Journal||Geophysical Research Letters|
|Keywords||0746 Lakes; 0758 Remote sensing; 0774 Dynamics; 0776 Glaciology; 0794 Instruments and techniques; altimetry; CryoSat-2; glacier dynamics; ice stream; ICESat; subglacial lakes|
We use CryoSat-2 interferometric satellite radar altimetry over the Mercer and Whillans ice streams, West Antarctica, to derive surface elevation changes due to subglacial lake activity at monthly resolution for the period 2010 to 2013. We validate CryoSat-2 elevation measurements, trends, and spatial patterns of change using satellite image differencing and in situ vertical movement from Global Positioning System (GPS) data. Two subglacial lake discharge events occur in the same subglacial-hydrological catchment within a 9 month period. Using GPS measurements that are spanning the gap between the Ice, Cloud, and land Elevation Satellite and Cryosat-2 missions, we cross-calibrate the two missions to establish the efficacy of CryoSat-2 altimetry to measure dynamic changes on the ice sheets.
Our time series reveal two new large subglacial lake drainage events within the Whillans and Mercer Ice Streams northern basin in 2012 and 2013. This longer, ground-truthed time series is essential to building our mechanistic understanding of the evolution of the subglacial-hydrological system and its effect on ice dynamics. The relatively small footprint of CryoSat-2SARIn mode data combined with the spatial coverage due to nonrepeating ground tracks results in a powerful altimetry data set that can build upon the critical ice sheet-wide dynamic changes discovered through the ICESat mission.