Mapping of erosion features related to thaw of permafrost in Bering Land Bridge National Preserve, Cape Krusenstern National Monument, and Kobuk Valley National Park
Dates
Year
2010
Citation
Swanson, David K., 2010, Mapping of erosion features related to thaw of permafrost in Bering Land Bridge National Preserve, Cape Krusenstern National Monument, and Kobuk Valley National Park: National Park Service Natural Resource Program Center National Park Service: Fort Collins, Colorado, v. NPS/ARCN/NRDS—2010/122.
Summary
A systematic survey was made of three National Park Service units in northern Alaska for active-layer detachments (ALDs) and retrogressive thaw slumps (RTS) using high-resolution satellite imagery from 2006 and 2008. ALDs and RTS develop by localized thaw of permafrost, and have the potential to expose significant areas of soil to erosion. I identified 22 ALDs in Bering Land Bridge National Preserve, 22 in Cape Krusenstern National Monument, and 14 in Kobuk Valley National Park. These ALDs are typically 10 to 30 m wide and up to 300 m long, and on the average expose about 1000 sq m of bare soil each, amounting to a total area of about 6 ha in the 3 NPS units. The ALDs occur on long, well vegetated slopes of moderate steepness and are [...]
Summary
A systematic survey was made of three National Park Service units in northern Alaska for active-layer detachments (ALDs) and retrogressive thaw slumps (RTS) using high-resolution satellite imagery from 2006 and 2008. ALDs and RTS develop by localized thaw of permafrost, and have the potential to expose significant areas of soil to erosion. I identified 22 ALDs in Bering Land Bridge National Preserve, 22 in Cape Krusenstern National Monument, and 14 in Kobuk Valley National Park. These ALDs are typically 10 to 30 m wide and up to 300 m long, and on the average expose about 1000 sq m of bare soil each, amounting to a total area of about 6 ha in the 3 NPS units. The ALDs occur on long, well vegetated slopes of moderate steepness and are restricted to specific physiographic areas. These ALDs probably formed by deep thaw during the exceptionally warm summer of 2004. No true retrogressive thaw slumps were found in the study area.
