The Role of Lakes and Streams in Permafrost Degradation in Northern Alaska

October 26, 2013 • Filed under: News — Peter.Prokein

The continuous permafrost landscape of the Beaufort Coastal Plain in northern Alaska is dotted with lakes and dissected by streams and rivers. These lentic and lotic waterbodies are hotspots on the landscape relative to cold permafrost with thermal offsets often exceeding 10 degrees C and thus a primary mechanism of permafrost degradation.

Friday Seminar Series

  • What: The Role of Lakes and Streams in Permafrost Degradation in Northern Alaska
  • Who: Chris Arp
  • When: 3:30-4:30 p.m., Friday, Oct. 25
  • Where: Duckering 531

The changes in coastlines and lakeshores are often driven by thermal erosion of ice-rich permafrost, beaded streams evolve from thawpits that collect and route warm water, and warm water thaws sediment (taliks) below lakes. Talik development and expansion is particularly tied to whether bedfast ice or floating ice develops over the winter and how this changes bed temperatures. Changing ice thickness or water balance can cause the ice regimes of lakes and streams to shift over time and potentially increase permafrost degradation. In this talk Chris will describe two evolving research programs that are helping to understand, in part, the interaction of lakes and streams across the permafrost landscape.