Perennial frost blisters of the outer Mackenzie Delta, western Arctic coast, Canada

Auteur(s) et Affiliation(s)



Description :
Saturated floodplains in Arctic deltas provide conditions favourable for frost mound growth. A case study is presented on low mounds in low-centred syngenetic ice-wedge polygons of Big Lake Delta Plain, outer Mackenzie Delta. In 2008 and 2009, 12 mounds were examined by drilling to describe their morphologic variations and to investigate their growth processes. Organic inclusions in the ice, bubble densities, electrical conductivity profiles, and ice-crystal structure indicated that the mounds were hydrostatic frost blisters. Up to 6 frost blisters were found within individual polygons due to the relatively small volume of water needed to create each mound. The frost blisters were perennial, with individuals remaining identifiable on aerial photographs and satellite images for up to 10 years. Frost blisters collapsed along dilation cracks opened by hydrostatic uplift and by thawing from their sides caused by snow drifting and water ponding. Cyclical growth and decay of the mounds may degrade the visible polygonal network over time.


Type de document :
Article de périodique

Source :
Earth surface processes and landforms, issn : 0197-9337, 2014, vol. 39, n°. 2, p. 200-213, nombre de pages : 14, Références bibliographiques : 1 p.

Date :
2014

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley