PERMAFROST AND THE GEOTHERMAL REGIMES
GEOLOGICAL SURVEY RESTON VA
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Analysis of temperatures to a depth of 1200 ft beneath Ogotoruk Valley reveals that present earth temperatures at depth are strongly influenced by an extinct climate and by an ancient shoreline position. An active climatic change that has been in progress throughout the past century has increased the mean annual ground-surface temperature on the order of 2C. If the present climate persists, the inland permafrost thickness eventually will be reduced from about 1170 to about 850 ft. Earth-temperature anomalies near the shoreline indicate a rapid encroachment of the Chukchi Sea several thousand years ago and imply that permafrost extends under the margin of the sea to a maximum distance of about 100 yards at a depth of 200 or 300 ft. Preliminary results indicate that local heat flow from the interior of the earth is close to the world-wide average.
- Snow, Ice and Permafrost