CGRG Bibliography of Canadian Geomorphology
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Author : Grom, J.D.; and Pollard, W.H.
Date : 2008.
Title : A study of High Arctic retrogressive thaw slump dynamics, Eureka Sound Lowlands, Ellesmere Island.
Publication : 38th International Arctic Workshop. March 5-7, 2008. University of Colorado at Boulder, Colorado, USA.
Issue :
Page(s) :
Abstract
Polar regions are expected to exhibit a strong response to projected warming trends due to positive feedback systems inherent to the environment. A significant concern is the expansion of thermokarst and the resulting terrain instability and landscape alteration throughout the Arctic. Retrogressive thaw slumps-landforms resulting from slope failure of thawing ice-rich permafrost-are a prominent thermokarst feature in arctic landscapes (Fig. 1). Thaw slumps have reportedly been increasing in frequency and extent due to increased coastal erosion and ablation of massive ground ice. Rates of headwall retreat are expected to continue to increase under projected climate change scenarios. However, the interplay of climatic, geomorphic, and surficial controls influencing thaw slump activity makes it difficult to identify controlling processes in ice ablation and headwall retreat. Previous studies have noted net radiation as a significant contributing factor to retrogressive thaw slump activity. This study investigates thaw slump process in the Eureka area of the Canadian High Arctic and identifies microclimatic variation in and around a thaw slump. Morphologic data were gathered for the site, including headwall retreat, ice face and terrain angles, and ice profiles, in order to describe form-induced controls on the landform. In addition, automatic weather stations were strategically placed throughout the thaw slump area to capture weather conditions at the ice face, within the mudflow, and for the surrounding terrain. Meteorlogic data observations reveal the development of warmer air temperatures at the ice face under periods of high incoming solar radiation. Recorded air temperatures were up to 1.5°C warmer at the ice face as compared to the surrounding region (Fig. 2). Additional parameters, such as wind speed and direction, also interact with the landform’s morphology to induce these spatial temperature differences. These findings provide for a greater understanding of retrogressive thaw slump process and allow for greater prediction of ice ablation and headwall retreat under changing climate conditions.
Bibliography of Canadian Geomorphology