Trilobites: Searching for the Human Factor in Deadly Avalanches
Every year, about 30 Americans die in avalanches, with an additional 110 deaths in Canada and Europe. Skiers and snowmobilers account for the vast majority of these deaths.
Jordy Hendrikx has lost friends and a student to such disasters. An earth sciences professor and director of the Snow and Avalanche Laboratory at Montana State University, Dr. Hendrikx studied the geophysics of snow for a decade before he decided that, to prevent avalanche accidents, human behavior in the backcountry needed to be better understood.
Scientists have a good grasp on how weather and terrain contribute to avalanches. Research suggests avalanche forecasts have about an 80 percent accuracy rate. But human activity is a huge — and unpredictable — factor in avalanches.
“Avalanches aren’t just acts of God,” Dr. Hendrikx said. “About 90 percent of avalanche victims trigger the avalanche themselves.”
These accidents are rarely a result of ignorance. People traveling in the backcountry usually understand avalanche forecasts and know how to read the terrain. What they are unaware of, Dr. Hendrikx believes, “is how they make decisions in a group, under different settings and different pressures.”
To untangle these decision-making processes, Dr. Hendrikx teamed up with Jerry Johnson, a professor of political science at Montana State University, to start their Tracks Project in 2013.
The project relies on backcountry skiers and snowmobilers who record their slope movements and answer survey questions using their smartphones. The researchers have collected reports from more than 800 people around the world.
Among their preliminary findings, some are intuitive. Older people, especially those with children, make more conservative decisions. Young, all-male groups take more risks. Those firmly set on a goal, like conquering a new slope, make riskier choices.
Other findings are more surprising. Though going out alone in the backcountry tends to be seen as risky, project respondents who were solo travelers tended to make safer choices than those who traveled in larger groups.
Some evidence suggests larger groups make riskier decisions. Part of that may be peer pressure or a desire to show off. Part of it may be the so-called expert halo, which causes people to blindly defer to the perceived authority in the group instead of communicating about perceived dangers.
Faced with the same avalanche conditions, experts chose steeper terrain, where avalanches are more likely to be triggered, than others.
The Tracks Project follows work from an avalanche researcher named Ian McCammon, who, in the early 2000s, analyzed 715 recreational avalanche fatalities in the United States across three decades. Among other findings, he suggested that skiers took more risks when they were familiar with a route or when competing for “first tracks” on fresh powder.
Unlike Dr. McCammon, Dr. Johnson explained, “we’re also looking at the good side of the story, which is that 99 percent of people are using the terrain appropriately.” Though the number of people engaging in backcountry sports has surged in the last decade, the accident rate has remained steady.
From survey responses, Dr. Johnson and Dr. Hendrikx have found that groups that preplanned routes and made communication a priority made better decisions. People who dug pits to assess snow characteristics or looked for recent avalanche activity before going down a slope sometimes changed routes to avoid danger.
The researchers hope their findings can help improve avalanche education. They also believe their research can help others who traverse tricky terrain in their work, such as wildland firefighters and military personnel.
These wider implications drive Dr. Hendrikx.
“At some point, I realized I could spend the next 10 years looking at the minute details of how snow surface crystals form, and maybe save one or two lives,” he said. “But really understanding the decision-making matrix, and how group dynamics affect it — I felt this is where I could make the biggest impact, and ultimately, save more lives.”
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