Permafrost - The Periglacial Environment - page 95

Table 5. 3. Permafrost depths and mean annual air temperatures at selected locations in the
northern hemisphere.

Locality Latitude Permafrost Zone Mean Air Permafrost

Temperature Thickness (m)

(°C)

Canada
Resolute, NWT 74° N Continuous − 12 390-400

Inuvik, NWT 69° N Continuous − 9 100

Dawson City, YT 64° N Discontinuous − 5 60

Yellowknife, NWT 62° N Discontinuous − 6 60-100

Schefferville, PQ 54° N Discontinuous − 4 80

Thompson, Man 55° N Discontinuous − 4 15

Alaska
Barrow 71° N Continuous − 12 304-405

Umiat 69° N Continuous − 10 322

Fairbanks 64° N Discontinuous − 3 30-120

Bethel 60° N Discontinuous − 1 13-184

Nome 64° N Discontinuous − 4 37

Russia
Nord'vik 72° N Continuous − 12 610

Ust'Port 69° N Continuous − 10 455

Yakutsk 62° N Continuous − 10 195-250

Qinghai-Xizang (Tibet) Plateau
Fenghuo Shan 34° N Widespread − 6 110

Wudaoliang 35° N Widespread − 5 40

Sources: Brown (1970), Ferrians (1965), Brown and Péwé (1973), Washburn (1979), Wang and
French (1994).

Peninsula in Alaska and then south and east through Canada to the north of the Slave
Lakes. Continuous permafrost reaches its most southerly extent at latitude 55° N, where
it fringes the southern shore of Hudson Bay. East of Hudson Bay, continuous permafrost
reappears in the Ungava Peninsula at latitude 60° N. The reason for this latitudinal
jump is because the higher snow accumulations to the east of Hudson Bay keep ground
temperatures relatively high. The southern limit of discontinuous permafrost roughly
coincides with the 1 °C mean annual air temperature isotherm. Southwards of this iso-

therm, permafrost becomes restricted to peatlands, north-facing slopes, and shady river
banks.
The known thickness of permafrost in North America varies from 15-30 m at the
southern limit of the continuous zone to depths of over 500 m in the Canadian Arctic
Archipelago and northern Alaska.
As a generalization, permafrost in Russia is thicker than in North America. It increases
in thickness northwards from 300 m at the southern limit to over 600 m along the Siberian
coastal plain. A thickness in excess of 500 m also occurs in central Yakutia, while in
other areas, such as the Tamyr peninsula, permafrost reaches 400 m in thickness
(Baranov, 1959, pp. 15-19). The thickest known permafrost exists in northern Yakutia

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