Transcript
Terminus mapping is a great way to map a small portion of the icefield. We come out twice a year, and we use a GPS to walk the edge of the terminus and map the farthest extent of Exit Glacier, and that allows us to see what type of changes are occuring over the winter accumulation period and the summer ablation period. With that data, that can help us—as we witness these changes within the ice field, we can hopefully be able to correlate that with the weather data that we have. At Exit Glacier, we have a time-lapse camera set up on the glacier that allows us to take a couple photos every single day and then to put that sequence of photos into a video where we can see changes of the glacier and the vegetation phenology throughout an entire year.
In a lot of parts of the country, climate change issues are a little more subtle, and we can point here and say, look how fast this is changing, this is what the future holds for perhaps a lot of us, and a lot of the planet, as climate continues to change.
Transcript
The state of a glacier is determined by its surface mass balance, the difference between the amount of snow and ice accumulation, and the amount of snow and ice loss, called ablation. Determining the annual mass balance of a glacier is like balancing your checkbook where the accumulation is the deposit and the ablation is the withdrawal. Climate change can lead to variations in temperature and snowfall, which will affect the mass balance of a glacier, and ultimately the long-term behavior of a glacier. A glacier that experiences several years of a negative balance, or more ablation than accumulation, will thin and retreat. A glacier that experiences several years of a positive balance will thicken and advance. In the spring, we dig snow pits and measure the depth and density of snow to determine total winter accumulation. In the fall, we return to these sites and measure how much snow and ice melted.
Glaciers in Alaska and Canada are experiencing some of the highest rates of mass loss in the world, and are one of the largest contributors to sea level rise. Changes in glacial melt affect surrounding ecosystems, including changes in water quantity and chemistry in both freshwater and marine environments, changes to land cover and surface albedo, and changes to our view—the landscape that we live in and recreate in, the landscape that makes Alaska and Kenai Fjords such a unique environment.
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Kenai Fjords Mass Balance |
Last updated: July 15, 2019