Studying the rising tide
Prof. Evans wins grant to study Greenland’s melting glaciers and their influence on sea level rise
A new $139,104 grant from the National Science Foundation will support Professor Matthew Evans' research into the forces driving the melting of Greenland's glaciers.
The research aims to improve understanding of a critical question over which there is wide disagreement. Estimates of the Greenland ice sheet's contribution to sea level rise over the next century range from a few centimeters to a meter.
"The big question is how the Disko Bay system has responded to temperature changes in the recent past," said Professor Evans. "The hope is that we can better predict how warming will impact the system in the future. It's an important system, with one of the fastest advancing and iceberg-producing glaciers on Earth."
The three-year NSF grant will allow Professor Evans, four Wheaton students and collaborators from several other institutions to conduct field research in the Disko Bay region of western Greenland.
In particular, the team will focus on the role of sea surface temperature and sea ice variability in influencing outlet glacier behavior and ice sheet/cap mass balance (snowfall and melt) over the past two centuries. Outlet glaciers are fingers of the ice sheets that extend from the main ice cap to the sea.
"The speed at which outlet glaciers flow is a function of three linked processes," Evans said. "Ocean temperature melts the glaciers from below where they enter the ocean. Air temperatures drive surface melting on the glaciers themselves and this surface water often flows to the base of these glaciers through moulins (vertical shafts in the glacier). This water is thought to lubricate and accelerate the glaciers. Finally, sea ice acts as a buttress, slowing the glaciers by providing the cork on the bottle so-to-speak."
In the first year, the research team plans to conduct site reconnaissance on ice caps on Disko Island and the Nuussuaq Peninsula and collection of shallow cores at both ice cap sites and on the western Greenland margin to overlap with the last 10 to 30 years of satellite imagery. Deep ice-coring activity will take place in 2014; the team intends to collect ice cores extending approximately 100 meters deep.
Following the field work, Evans and the Wheaton undergraduates who will serve as research assistants will conduct extensive lab and computational work to derive climate reconstructions from these cores. The work will be conducted at the National Ice Core Lab in Denver, Colo., where the 100-meter samples can be stored safely, at the Woods Hole Oceanographic Institution (WHOI) and at Wheaton. Their results will complement recent glaciological studies of regional ice dynamic behavior, as well as recent paleoceanographic and glacial geologic reconstructions of conditions from this area and era.
Evans and the Wheaton team will be collaborating with principal investigators and doctoral students from WHOI, Clark University; and the University of Washington
The Greenland outlet flow glaciers continues Evans' research interest as well as his commitment to involving undergraduates in fieldwork and laboratory study. In the past, he has received awards to pursue related projects, such as a NASA grant to study glaciers in Antartica and and an NSF award to study Himalayan hot springs role in the global carbon cycle.