Active Projects: The Importance of Meltwater to the Peripheral Thinning of Greenland (Dec. 2006 - Dec. 2009)
Participants:
Tom Neumann, University of Vermont
Julie Rumrill, University of Vermont
Ginny Catania, University of Texas at Austin
Jamin Greenbaum, University of Texas at Austin
With collaboration from:
Mark Fahnestock, University of New Hampshire
Sarah Das, Woods Hole Oceanographic Institute
Jay Zwally, NASA Oceans and Ice Branch
Koni Steffen, University of Colorado
Funding agency: NASA Jan 06 - Jan 09
Project Goals: Our goal in this proposal is to study the importance of short-term ice velocity changes near Swiss Camp, Greenland to the stability of the ice sheet interior. Several areas in Greenland are thinning (particularly those below 2000 m elevation). While this observed thinning coincides with increased surface melt, in the past decade thinning is more rapid than expected from increased surface melting alone, suggesting an ice dynamical cause. Our work will focus on the connection between increased surface melt and increased ice velocity in the vicinity of Swiss Camp first measured in the mid 1990s.
We propose to: (1) measure the spatial and temporal extent of seasonal changes in ice velocity on a network of poles using global positioning system (GPS) measurements, (2) use surface-based radio-echo sounding (RES) to determine the characteristics and water content of the glacier bed and measure how the water content changes during the melt season, (3) use RES to study the englacial drainage system and changes to the system during the melt season, (4) use our measurements in an ice-flow model to determine the effect of seasonal changes in ice velocity on the stability of the interior ice near Swiss Camp, (5) correlate these data to melt proxy data available at NSIDC, and (6) use these results to assess the importance of seasonal melt water in other areas of Greenland, and determine to what extent increased melt is responsible for the observed thinning in Greenland.
Project Highlights:
We had a successful first season in Greenland. Check out the pictures. Data coming soon....
Published/Presented Results:
- Rumrill, J., T. Neumann, and G. Catania, 2006, Assessing the Spatial and Temporal Extent of Velocity Variations near Swiss Camp, Greenland, Fall AGU, C11A-1136.
- Catania, G., T. Neuumann, and L. Koenig, 2007, Radar Across the Equilibrium Line of the Greenland Ice Sheet: Evidence for surface water drainage, NASA-PARCA meeting, JPL
This is a satellite image of our GPS locations. Jacobshavn Glacier is at the bottom of the image.
Check out these great pictures from inside the ice sheet.
