Project! Historic Photos, New Understanding

It can be a little overwhelming to think about something as massive as a glacier changing drastically over the course of a single generation. But that is happening, and we are using all kinds of tools, new and old, to help us understand what is happening and why. Our glaciology project as part of this summer school is to calculate the mass change in glaciers in the Svalbard valley in Norway over time, and we started by looking at aerial photographs taken in 1966, 1977, 1990, and 2005. We want to calculate changes in the glacier’s elevation by comparing observations from these photos, which were taken over time and across glaciers. Using this information from historic photographs, we can see the glacier levels decrease over time compared to stable features in the surrounding mountains. We are using geodetics (which refers to a grid used to locate places on the Earth) along with these observations to understand the mass balance of the glacier – that is, how much it increases or decreases over time – to allow us to track how the elevation of the glacier has changed over time and area. By combining our observations of how much the glacier elevation is decreasing, with data on the area over which the decrease is happening, we can find out the total volume of ice mass that the glacier has lost over time. By also considering meteorological variables, including temperature and precipitation data that were taken during the same time as the melting, we can also relate the glacier retreat to the climate conditions at the time. Glacier retreat is something that will directly or indirectly affect so many around the world through sea level rise and freshwater access, so it is vital that we understand how and why it is happening.

– Caitlyn and  Samiah

FIGURE_Sam&Caitlyn
Surface elevation in meters of Austre Broggerbreen valley glacier in Svalbard in 1966 (left) and 2005 (right). You can see the mass loss at the terminus of the glacier (~100-250 m elevation) in 2005.

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