The Missoulian

January 11, 2001

By DARYL GADBOW of the Missoulian

As increasing numbers of recreationists head into the backcountry each winter, persuing a variety of outdoor activities, the ability to predict avalanche danger becomes ever more crucial.

Avalanche probability is determined by snowpack, terrain, and weather conditions. Snowpack is composed of various layers of snow, some weaker and some stronger. The relationship between the layers - the stability of snowpack - determines the potential for avalanche.

The most reliable and widely used method for testing snowpack stability involves digging snow pits and examining the various layers. However, according to Karl Birkeland, a scientist for the Forest Service's National Avalanche Center, the snow-pit method is somewhat crude and relies heavily on the expertise of the person performing the test.

Now, as it has in so many other areas of our lives, new computer technology promises to replace the old method, making avalanche prediction much more precise.

The technology, called a snow penetrometer or SnowMicroPen, has been developed during the past six years by the U.S. Army Engineer Research and Development Center and the Swiss Federal Institute for Snow and Avalanche Research.

The device is a motorized probe with a tiny sensor at the tip that is driven through the snow, providing information about the strength and structure of the snow layers, which is analyzed on a portable computer.

"This instrument provides a remarkably detailed snow profile - something you could not get with any previous instrument," said Birkeland.

The technology used in the device has evolved over the past 40 years, he said.

The original "resistograph" was developed by Charles Bradley in the 1960s when he was a professor of earth sciences at Montana State University in Bozeman. In the mid-1980s, Bob Brown, a professor of civil engineering at MSU, and graduate student Tim Dowd enhanced the idea of the resistograph by adapting it to computer technology.

The resulting "digital resistograph" was further refined by Birkeland when he was doing research for his master's degree at MSU.

The National Avalanche Center, in cooperation with the U.S. Army, Swiss government and MSU, plans to test a prototype model of the SnowMicroPen this winter, Birkeland said. Some tests will be done at Park City, Utah, working with the community's snow safety department.

A private company from Wyoming will assess results of the tests to determine what it would cost to manufacture the snow penetrometer commercially, and if a market would exist for the device at the prospective cost.

The partnership of U.S. and Swiss agencies was arranged by TechLink, a Department of Defense and NASA contractor located at MSU, which helps companies throughout the Northwest with technology development and commercial partnerships with federal agencies.

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