Snowstruck: In the Grip of Avalanches

Natural History, Feb, 2006 by Laurence A. Marschall

Snowstruck: In the Grip of Avalanches by Jill Fredston Harcourt, Inc., 2005; $24.00

Snowstruck, a kind of sequel to Jill Fredston's book Rowing to Latitude, answers a question her earlier knuckle-biter may have left hanging. Why would any sane person spend her summers rowing a small boat through heavy seas along thousands of miles of desolate Arctic coastline? The answer: because, compared to what she does in the winter, a summer dodging icebergs and polar bears is pure relaxation.

Fredston and her husband, Doug Fesler, live in the mountains just outside Anchorage, Alaska. Their cabin is so exposed to the elements that when they aren't enjoying the view, they are battling hurricane winds and blinding snowstorms. For the past eighteen years the couple has run the Alaska Mountain Safety Center, an institution devoted to training alpinists, assessing avalanche threats, and helping out with rescues. They bring to their work a set of unique and complementary talents: Fredston must be one of the few people in the world with a master's degree in polar and ice studies from the University of Cambridge. Fesler seems to be a self-taught avalanche guru who can look at a snowdrift and immediately visualize the internal stresses and strains that hold it in place; "thinking like an avalanche" is what Fredston calls it. Both are skilled winter mountaineers, as comfortable in crampons and climbing harnesses as most people are in La-Z-Boy recliners.

Snowstruck tells the stories of the rescues they have taken part in and the avalanches they have analyzed. Much of what Fredston recounts is pretty grim--experienced skiers who push themselves a tad too close to the edge of an unstable slope, homesteaders buried by a collapsing mountainside. In eighteen years, Fredston confesses, she has "chiseled dozens of bodies from avalanche debris and never . . . dug a single person out alive."

Understanding these tragedies, however, is a way of predicting the avalanche perils of the future and, one hopes, of preventing prudent Alaskans from taking unexpectedly high risks. Avalanches, Fredston knows, start when slabs of dense snow detach from the layers beneath them, most often on slopes angled at between thirty and forty-five degrees. What happens next depends on the track taken by the detached slab as it accelerates. How much more snow does it pick up as it slides? Does it run out into a wide area or a narrow gulch? The leading edge of the avalanche can stir up a billowing powder blast so powerful that the few trees left standing after the snow passes will bear deep scars of pebbles that were blown, forty feet above the ground, like shrapnel in the snow-driven wind.

Fredston and Fesler can predict avalanches not only because they know the snow so well, but also because avalanches tend to recur in the same spot. The couple is often called in to create their own avalanches, removing dangerous snowpacks to make roads safe for traffic or to clear the backcountry for rescue parties or recreational activities. The author, who grew up in a placid suburb of New York City, now finds herself hanging out the open door of a helicopter, tossing sticks of dynamite into threatening snowdrifts while a blizzard rages below. "A colleague once lit a charge and threw it out the open door of a helicopter, only to have a blast of wind sling the bomb back in," she writes. A mad scramble to find the dynamite ensued, and the fuse had only seconds to burn when it was tossed back out into the storm.

Fredston doesn't hide her opinions about the forces of nature and the follies of humankind, but I wouldn't read her book for its uplifting thoughts. If you have loved ones, you don't have to live in avalanche country to know that life is fragile. Having a free winter evening, a warm fire, and a hot drink is reason enough to curl up with a rousing adventure book like Snowstruck.

LAURENCE A. MARSCHALL, author of The Supernova Story, is W. K. T. Sahm Professor of Physics at Gettysburg College in Pennsylvania, and director of Project CLEA, which produces widely used simulation software for education in astronomy. He is the 2005 winner of the Education Prize of the American Astronomical Society.