State researchers are nearly finished with an innovative avalanche mapping project that will help assess risks to Chilkat Valley infrastructure and residents.
Scientists at the Alaska Department of Natural Resource’s Climate and Cryosphere Hazards Program (CCHP) are using recent climatological data and evolving a technique developed by Swiss researchers to create a baseline model of avalanche potential across Southeast Alaska. The project, which the Haines Avalanche Center is supporting with field monitoring, will be useful for planning infrastructure projects and for establishing baseline knowledge of avalanche dynamics in Southeast, said CCHP program manager Gabe Wolken.
“The state is really far behind on having an awareness or an understanding of where avalanches occur, to what extent and how regularly they occur. So we’re really trying to improve on that,” Wolken said, adding that avalanches are Alaska’s deadliest natural hazard, having caused 90 deaths in the last 22 years.
In 2000, an avalanche hit a subdivision in Cordova, killing one resident, severely injuring another, who was fully buried for six hours, and destroyed five homes and two warehouses. A tragedy similar to that one isn’t unthinkable in Haines, where private property and major borough infrastructure, like Haines Highway and Lutak Road, are located in avalanche zones. In 2019, slides killed three local snowboarders—two in Haines Pass and one on the backside of Mt. Ripinsky. And from 2011 to 2014, four heliskiers died in avalanches near Haines.
“Haines is a really important place for snow avalanches because of the proximity of this really abrupt terrain and snow in the high country and the impact on some of the infrastructure in the area,” Wolken said. “This is one area that we’re keenly interested in—what the implications might be for future snow avalanches and how these changes might be impacting people, property, infrastructure and natural resources as well, everything from hunting to firewood.”
The state’s mapping won’t show daily avalanche risk (like the low-to-high scale that the Haines Avalanche Center uses to inform local winter recreationists), but instead will project the maximum slide run-out in avalanche zones regionwide.
Still, while the state is mapping terrain on a regional scale, Wolken and his team plan to work with the Haines Avalanche Center on field monitoring. Collecting data from one or two avalanche paths in the borough will provide “ground-truthing,” helping to verify the performance of the state’s regional-scale model, Wolken said.
“Haines is a really important part of this work because it’s one of those places we can interact with people on the ground…and try to get a better idea of how we can more specifically model some of the avalanche paths locally,” Wolken said.
Erik Stevens, director of the Haines Avalanche Center, said that the center has played and will continue to play a support role for CCHP’s project. “I do think (the study) is really important. We have a lot of unstudied avalanche paths in Haines, and some of them are adjacent to private property,” Stevens said.
The state researchers are building on a modeling technique developed by the Institute for Snow and Avalanche Research in Switzerland. But the difference, Wolken said, “is that in Switzerland, there are many weather stations that well represent the climatological conditions in Swiss Alps whereas these assets are largely absent in Alaska where avalanches start.”
CCHP is using climatological data from 1981 to 2010 to project avalanche flow and frequency based on snow volume and weather conditions. With a similar method — but using climate forecasts instead of historical data — CCHP will start next year to model future avalanche dynamics in Southeast. (The climate forecasts were done by scientists at the University of Alaska, Fairbanks.)
The impacts of climate change will be “extremely variable” in Southeast, Wolken said, given the region’s range of microclimates. Generally speaking, precipitation events will be more intense. But while changes are expected, “they’re not going to be the same everywhere,” Wolken said. For example, some places might see less snow and more rain due to warmer temperatures, while other, cooler parts of the region, especially high elevations, might see more snow. Areas near Haines could become more vulnerable to avalanches.
Wolken said CCHP will publish its baseline map by the end of the year. There will be an interactive online mapping tool available to the public.
The Haines Avalanche Center recently announced its 2021-22 avalanche safety course schedule, which can be found at https://alaskasnow.org/learn/.