On Saturday, two snowmobilers died in an avalanche near Rollins Pass, Colorado, bringing the total number of people killed in avalanches in the U.S. this season to five, according to the Colorado Avalanche Information Center.
The incident was listed among those caused by human activity.
Unlike most natural disasters, most fatal avalanches are caused by human activity, according to Ethan Greene, director of the Colorado Avalanche Information Center. He said that nearly 90% of avalanches are caused by humans.
Once an avalanche occurs, there is little a person can do to improve their chances of surviving the avalanche. He said there are generally three things that kill people in an avalanche: Asphyxiation from the snow, traumatic injury from the snow, and hypothermia.
“Those are things you don’t have a whole lot of control over and so if you want to not die in an avalanche, the thing to do is not get caught in an avalanche,” Greene said. “There are a lot of things you can do to make sure you don’t get caught in an avalanche, but once you do, there is not much you can do.”
Greene said knowing what kind of terrain is prone to an avalanche is one way to ensure you avoid the risk. He said avalanches generally happen when the steepness of a slope is between 30-50 degrees.
“When you’re in that range of being a snow-covered slope… you know you’re in a place where an avalanche can happen,” Greene said. “One way to deal with that is to avoid those kinds of slopes altogether.”
He said avalanches could happen at any time these types of slopes are snow-covered.
“Certainly, the more snow that we have and the deeper that avalanche breaks into the snowpack, the more mass you are going to have in the avalanche and the more dangerous and deadly it can be,” Greene said.
He said another facet is checking the avalanche forecast at avalanche.org. One caveat he noted is that many of the deaths don’t happen when there is an extreme risk of avalanches because people tend to avoid the slopes during those times.
He said there have been a handful of instances where avalanches happen when snow falls off a roof.
Although there is not much that can be done once an avalanche begins, Greene noted that doing whatever it takes to keep your nose and mouth above the snow gives a person a chance of surviving the event.
“If you can’t get out of the flow, keep your head out; that is gonna help you,” Greene said. “But you should never count on those actions to save your life. They are acts of desperation if you get in that situation.”