Hydrostatic‐system palsas at Toolik lake, Alaska: Field observations and simulation

Abstract Stratigraphic and chemical data from the ice core of an ‘anthropogenic palsa’ at Toolik Lake, Alaska, indicate that the mound formed as a consequence of hydrostatic pressure developed in an isolated hydrologic system within the active layer. Survey data for five palsas over a three‐year per...

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Bibliographic Details
Published in:Earth Surface Processes and Landforms
Main Authors: Outcalt, S. I., Nelson, F. E., Hinkel, K. M., Martin, G. D.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1986
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Online Access:http://dx.doi.org/10.1002/esp.3290110109
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.3290110109
https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.3290110109
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Summary:Abstract Stratigraphic and chemical data from the ice core of an ‘anthropogenic palsa’ at Toolik Lake, Alaska, indicate that the mound formed as a consequence of hydrostatic pressure developed in an isolated hydrologic system within the active layer. Survey data for five palsas over a three‐year period suggest that growth was essentially complete at the time of the initial survey; a net decrease of summit elevation is apparent in all five mounds, but complete degradation of the palsas would require several decades at observed rates. Because accurate field measurements of thermal and hydrologic evolution in such features are extremely difficult, simulation of the environmental conditions and events involved in palsa growth is an important supplement to field observation. Both analytic and finite‐element models yield results that are in substantial agreement with inferences drawn from observational data.