The importance of meltwater to the peripheral thinning of Greenland
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.
