Permafrost Terrain Stability and Thermokarst Monitoring: - Arctic LCC

52. Hinkel, K.M., and Hurd, J.K., 2006, Permafrost destabilization and thermokarst
following snow fence installation, Barrow, Alaska, USA: Arctic, Antarctic, and Alpine
Research, v. 38, no. 4, p. 530–539.
This paper describes the effect of a snow fence on permafrost temperature and land
subsidence in Barrow, Alaska, from 1999 to 2005. Data loggers were installed at depths of
5, 30, and 50 cm in the ground on the downwind side of the snow fence and in tundra sites
not affected by the snow drifts that formed as a result of the snow fence. Active layer
thickness and snow depth were measured annually in August and April, respectively. As a
result of the snow fence, the ground temperature in the downwind strip has warmed by 2–
14°C in the winter, and has cooled by 2–3°C in the summer because of the time it takes to
melt the drifted snow (3–4 m in thickness). The net effect has been a warming of the ground
surface, a thawing of the permafrost, subsidence of about 10–20 cm, and development of
thermokarst ponds. This study highlights the importance of snow accumulation and
thickness on the ground thermal regime and potential to form thermokarst in areas where air
temperatures are thought to be too cold for the formation of thermokarst.
53. Hinkel, K.M., Jones, B.M., Eisner, W.R., Cuomo, C.J., Beck, R.A., and Frohn, R.,
2007, Methods to assess natural and anthropogenic thaw lake drainage on the western
Arctic coastal plain of northern Alaska: Journal of Geophysical Research, v. 112,
no. F2, F02S16.
This paper describes three methods for assessing the natural and anthropogenic drainage of
thermokarst lakes on the western Arctic Coastal Plain of northern Alaska: (1) comparison of
Landsat imagery between about 1970 and about 2000 for a 35,000-km 2 area, (2) comparison
of historical aerial photography from 1949 to 1955 with recent high-resolution orthorectified
radar derived imagery from 2002 for the Barrow Peninsula, and (3) interviews with local
and traditional knowledge holders. About 50 lakes larger than 10 ha drained in the 25-year
period were analyzed with an automated classification of the Landsat imagery. This analysis
showed that only 0.027 percent of the extant lakes in the region had catastrophic drainage
during this time period. The authors also attempted to classify the lake drainage events by a
mechanism that included lake coalescence (19), coastal erosion (1), stream meandering (8),
headward erosion (13), and unresolvable (9). By extending the analysis back to 1950 with
the automated classification of the aerial photography for the Barrow study region the
authors showed that human activity was responsible for about 40 percent of the lake
drainage events on the Barrow Peninsula. The timing and mechanism of select lake drainage
events were further refined through the interviews with the traditional and local knowledge
holders.
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