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Depth and temperature of permafrost on the Alaskan Arctic Slope; preliminary results

January 1, 1994

As permafrost is defined by its temperature, the only way to determine its depth is to monitor the return to equilibrium of temperatures in boreholes that penetrate permafrost. Such measurements are under way in 25 wells on the Alaskan Arctic Slope; 21 are in Naval Petroleum Reserve Alaska (NPRA), and 4 are in the foothills to the east. Near-equilibrium results indicate that permafrost thickness in NPRA generally ranges between 200 and 400 m (compared to 600+ m at Prudhoe Bay); there are large local variations and no conspicuous regional trends. By contrast the long-term mean temperature of the ground surface (one factor determining permafrost depth) varies systematically from north to south in a pattern modified by the regional topography. The observed variation in permafrost temperature and depth cannot result primarily from effects of surface bodies of water or regional variations in heat flow; they are consistent, however, with expectable variations in the thermal conductivity of the sediments. It remains to be determined (with conductivity measurements) whether certain sites with anomalously high local gradients have anomalously high heat flow; if they do, they might indicate upwelling of interstitial fluids in the underlying basin sediments.

Citation Information

Publication Year 1982
Title Depth and temperature of permafrost on the Alaskan Arctic Slope; preliminary results
DOI 10.3133/ofr821039
Authors Arthur H. Lachenbruch, J. H. Sass, L.A. Lawver, M.C. Brewer, T.H. Moses
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Open-File Report
Series Number 82-1039
Index ID ofr821039
Record Source USGS Publications Warehouse
USGS Organization