Meet the Expert: Permafrost
On August 14, 2012 from 10-11am (2pm Eastern) NPS terrestrial ecologist Dave Swanson will host a live chat about permafrost in Alaska and how the National Park Service is monitoring land features related to permafrost thaw. The chat will happen via Twitter and Facebook as well as through email.
Dave uses repeat aerial photography and ground surveys to develop 3D models of dramatic land features caused by permafrost thaw. The 3D models are developed each year and then compared to models from previous years to determine total area, rates of expansion, volume of material displaced, and rates of revegetation.
Permafrost underlies ~80% of Alaska and is found in 10 of the 16 Alaska National Park Service units. The term permafrost refers to ground that remains frozen for two or more consecutive years. Increased permafrost melt is expected to continue as a result of climate change. Thawing permafrost has been identified as one of the major threats facing northern ecosystems.
"The result of thawing ice-rich permafrost in a boreal forest ecosystem is not just a slight shift in the nature of the ecosystem, but rather partial or total destruction of the ecosystem and replacement with a new ecosystem" (Osterkamp and Jorgenson, 2009)