Permafrost Terrain Stability and Thermokarst Monitoring: - Arctic LCC

20. Burn, C.R., and Smith, M.W., 2006, Development of thermokarst lakes during the
Holocene at sites near Mayo, Yukon Territory: Permafrost and Periglacial Processes,
v. 1, no. 2, p. 161–175.
This paper describes the formation of thermokarst lakes in the boreal forest region of the
Yukon Territory using ground surveys, remote sensing, and dendrochronology. The paper
describes the growth of thermokarst lakes through analysis of aerial photography and treering
series obtained from submerged trees in the expanding lake margins. The mean axial
growth rate of 16 thermokarst lakes is presented in table 1. The mean growth of lakes was
0.7 m/yr along their long axis and 0.5 m/yr along their short axis. The maximum observed
expansion rate was 1.2 m/yr. The expansion rate of lakes likely is not constant from year to
year and, during particularly warm summers, stable banks may be reactivated and lake
expansion may accelerate. Tree-ring analysis and measurements of lake talik thickness
indicate that the lakes likely formed in the mid-1800s. Estimates of talik formation indicated
vertical degradation of permafrost of about 0.5 to 1 m/yr. The authors provided a context in
which to interpret the formation of thermokarst lakes in the region throughout the Holocene
and suggested that these lakes likely were formed following a forest fire.
21. Cabot, E.C., 1947, The northern Alaskan coastal plain interpreted from aerial
photographs: Geographical Review, v. 37, no. 4, p. 639–648.
This paper describes the utility of black and white, vertical and oblique aerial photography
for describing permafrost-related landforms in northern Alaska. There is a brief discussion
on the formation of lakes and ponds in the region, elongation of lakes, drainage of lakes, and
a lake cycle. The author noted the role of floating lake ice pans and mechanical erosion of
shorelines in the expansion of lakes and the role of bank overflow during breakup as a key
process for lake drainage.
22. Chen, W., Chen, W., Li, J., Zhang, Y., Fraser, R., Olthof, I., .and Chen, Z., 2012,
Mapping Aboveground and Foliage Biomass Over the Porcupine Caribou Habitat in
Northern Yukon and Alaska Using Landsat and JERS-1/SAR Data, Remote Sensing of
Biomass - Principles and Applications, Dr. Lola Fatoyinbo (Ed.), ISBN: 978-953-51-
0313-4, InTech, DOI: 10.5772/19219.
This article used Landsat imagery and remote sensing techniques to map the aboveground
biomass and foliage biomass of the range of the Porcupine caribou herd. The area includes
part of the Arctic Wildlife Refuge on the Arctic Coastal Plain, Alaska, and western Yukon
and Northwest Territories, Canada. Field studies were done to ground-truth satellite images
in the middle of the growing season. Habitat characteristics were measured and those
characteristics were related to satellite images of the same area to predict biomass across the
entire range. Measured aboveground biomass ranged from 10 to 100 t/ha for sparsely
forested woodlands, 1 to 100 t/ha for low-high shrub sites, and 0.5 to 10 t/ha for mixed
graminoids-dwarf shrub-herb sites. Biomass was similar on the calving and breeding
grounds for the Porcupine caribou herd, which was greater than what is available to the
Bathurst caribou herd. This may explain partially why the Bathurst herd leaves their calving
grounds soon after giving birth, while the Porcupine herd stays at their calving grounds
much longer, and Porcupine herd calves grow faster and weigh more than Bathurst herd
calves.
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