KU researcher's data contribute to most detailed study of Greenland ice sheet

LAWRENCE -- Prasad Gogineni, Deane E. Ackers distinguished professor of electrical engineering and computer science at the University of Kansas, was one of five researchers whose work on the Greenland ice sheet appeared in the Dec. 14 issue of the prestigious journal Science. The article identified two fast-moving ice streams in the northeast section of the Greenland ice sheet.

Mark Fahnestock, from the Earth System Science Interdisciplinary Center at the University of Maryland, first identified the ice streams in 1992 using radar and weather satellite imagery, but previous models could not account for the rapid flow of ice. However, with NASA funding, Fahnestock used 1999 radar data and data processing from KU's Radar Systems and Remote Sensing Laboratory at the Information and Telecommunication Technology Center to create a new model that accounts for ice melting at the base, or bedrock, level.

"The identification of rapid basal melting is based on tracing the internal layering in the ice that is shown in Prasad's radar profiles, so his contribution is the fundamental observations that this work is based on," said Fahnestock, an assistant research scientist. "Prasad's group has produced the best operational radar and the most useful set of ice sounding observations available in Greenland."

The research team determined that geothermal heat under the ice caused the rapid basal melt. High magnetism and lower gravity suggest the heat source may have a volcanic origin, similar to the Yellowstone caldera in Wyoming.

Warm basal ice causes the ice streams and influences the flow and the present shape of the ice. So far, the ice sheet is still balanced, but its margins are changing fast. During the past 100 years, sea level rose about 6 inches, and climate change likely will accelerate the increase. Gogineni says it's too soon for researchers to determine whether the melt is only a short-term fluctuation or indeed a long-term change. Using airborne and surface radars, researchers will continue to study the conditions of the ice at the base in hopes of accurately predicting future behavior of the ice.

As part of a larger NASA project, Gogineni and researchers from Australia are developing a new three-frequency radar to measure where the ice meets the bedrock. The three-frequency approach will improve the ability to separate the variables in the radar data. The group plans to test the new radar in Greenland and Antarctica during summer 2003.