"As populations increase in and around mountainous regions, recreational activities are more concentrated. Hazards exist not only in terms of individual risks, but also to property, as more people choose to live in remote areas," says Tom Baerwald, NSF's Geography and Regional Science Program director in the Division of Behavioral and Cognitive Sciences. "This fundamental research by Hansen and her colleagues will give us valuable new information that will save lives in the future."

The Federal Emergency Management Agency (FEMA) has estimated there are more than 10,000 reported snow avalanches each year, but Birkeland, in his Forest Service role, estimates that the number of unreported avalanches, to include remote, inaccessible areas, could be up to a hundred times more numerous. He also says that over the past decade, the average number of deaths in the U.S. has nearly doubled due to avalanches. In 1991, FEMA estimated the annual death toll to be about 17. The death rate is now about 30 per year, according to Birkeland. Population increases in mountainous areas, and a general increase in skiing, snowboarding and snowmobiling in undeveloped backcountry areas are among the reasons for rising avalanche-caused deaths.

Much of the previous research on snow stability has looked at individual slopes at a single moment in time, but snowpacks, as researchers have discovered, are dynamic systems. Using a new snow stability test, and a sensitive instrument co-developed by Switzerland's Federal Institute for Snow and Avalanche Research and by the U.S. Army Cold Regions Engineering Lab, Hansen and Birkeland will sample, over limited periods, how snow stability changes over adjacent 900-square-meter plots across a variety of field sites. The researchers will collect data on how spatial patterns of snow change through time, looking at patterns of weak layer thickness, strength and microstructural
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Contact: Bill Noxon
wnoxon@aol.com
703-292-8070
National Science Foundation
20-Feb-2003