Glacier Research by Iowa State Professor

Neal Iverson, whose glacial research has required him to live and work beneath a 700-foot thick river of ice in Norway for weeks, has published a research paper about glacier flow in the current issue of "Science" magazine.

Iverson is an associate professor of geology and atmospheric sciences at Iowa State, and is the first of eight authors of the paper, "Effects of Basal Debris on Glacial Flow." His research examines how glaciers move across rock and sediment and how they shape the landscape. Iverson's co-authors include Denis Cohen, a new affiliate faculty member at ISU; Peter Moore, a graduate student at Iowa State; and Thomas Hooyer, Wisconsin Geological Survey and a former Ph.D. student of Iverson's.

Current models of how glaciers slide may be off base, Iverson and his colleagues from the United States, Switzerland and Norway found. Fast sliding of glaciers and ice sheets can have substantial effects on sea level and climate, so accurate modeling of the process is important.

Iverson and his fellow researchers found that, for glaciers that rest directly on bedrock, friction between debris in the ice and underlying rock accounted for most of the resistance to sliding. Current models typically assume that resistance comes only from irregularities on the rock surface. For soft-bedded glaciers, which are separated from rock by a layer of wet sediment, high water pressure between the sediment particles allows the ice to slip along the surface of the sediment, rather than shearing it as expected. These experiments should prompt re-thinking of how glaciers move.

"Science" is the scholarly journal of the American Association for the Advancement of Science.

MEDIA:Images from the glacier are available at: http://www.iastate.edu/~nscentral/photos/03/jul/ice.html

Iverson's web site is:http://www.ge-at.iastate.edu/people/faculty/iverson/iverson.html