More people are surviving avalanches than decades ago — here's why

People buried in avalanches are more likely to be rescued quickly and survive the experience today than they were four decades ago, a new study suggests.

Avalanches can kill in a number of ways. Most people caught in these snow flows die of injuries sustained during the avalanche, suffocation after being buried by snow, or hypothermia that sets in as they await rescue. Time is critical — most people who live to tell the tale are rescued within the first few minutes after burial.

The first in-depth studies of avalanche survival were published only 30 years ago and focused on incidents in the Swiss Alps. At that time, fewer than half of the people buried in avalanches survived, and almost all of those who did survive had been rescued within 15 minutes of burial.

Since the 1990s, though, we've developed more reliable ways to predict avalanches, as well as new technologies to improve people's chances of being found and rescued quickly. The new research shows that these advancements have improved avalanche survival.

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The study, published Sept. 25 in the journal JAMA Network Open, examined records of avalanche survival in Switzerland that were published between 1981 and 2020. Within those four decades, more than 7,000 people were caught in avalanches, including 1,643 people who were "critically buried," meaning snow covered their head and chest.

"If a person caught in an avalanche remains on the surface or is only partially buried, with the head and chest exposed, the survival rate exceeds 90%," said Dr. Hermann Brugger, co-author of the study and founder of the Institute for Mountain Emergency Medicine in Bolzano, Italy. That percentage is based on all reports from 1981 to 1998.