The development of near-surface ground ice at Illisarvik, Richards Island, Northwest Territories

AbstractThis progress report classifies the different types of ground-ice bodies that occur in the Northern Foothills, northern Victoria Land, Antarctica. Oxygen isotope variations are presented, but interpretation is kept to a minimum pending further investigations. Surface ice, as distinct from moving glacier ice, occurs in the form of widespread buried (‘dead’) glacier ice lying beneath ablation (sublimation) till, together with perennial lake ice, snow banks and icing-blister ice.’Dry’ permafrost is uncommon, and interstitial ice is usually present at the base of the active layer and in the near-surface permafrost. This probably reflects the supply of moisture from the Ross Sea and limited sublimation under today’s climate. Intrusive ice occurs as layers within perennial lake-ice covers and gives rise to small icing blisters. Small ice wedges found beneath the furrows of high-centered polygons appear to agree with the model of sublimation-till development proposed by Marchant and others (2002).

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Permafrost, tectonics, and past and future regional climate change, Yukon and adjacent Northwest Territories

Canadian Journal of Earth Sciences ◽

10.1139/e94-015 ◽

1994 ◽

Vol 31 (1) ◽

pp. 182-191 ◽

Cited By ~ 39

Author(s):

C. R. Burn

Keyword(s):

Northwest Territories ◽

General Circulation ◽

Regional Climate ◽

Gulf Of Alaska ◽

General Circulation Models ◽

Yukon Territory ◽

Early Pleistocene ◽

Tectonic Activity ◽

Near Surface ◽

Late Tertiary

Late Tertiary changes in the general circulation of the atmosphere, regionally enhanced by uplift of the Wrangell – Saint: Elias and Coast mountains, were sufficient to promote permafrost development in the western Arctic. Permafrost developed in Yukon Territory and adjacent Northwest Territories during early Pleistocene glacial periods, after continued tectonic activity led to further modification of regional climate, but degraded in the interglacials. Permafrost has been present in northern parts of the region since the Illinoian glaciation, but most ground ice in central Yukon formed in the Late Wisconsinan. The present interglacial is the only one with widespread evidence of permafrost, which is maintained in the valleys of central and southern Yukon by the Saint Elias Mountains blocking continental penetration of maritime air from the Gulf of Alaska. This reduces snow depth in winter, while cold-air drainage in the dissected terrain of the Yukon Plateaus enhances the near-surface inversion, leading to continental minimum temperatures. General circulation models used to simulate climate represent the physiography of northwest Canada crudely. As a result, the simulations are unable to reproduce conditions responsible for the development and preservation of permafrost in the region.

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MASSIVE NEAR-SURFACE GROUND ICE IN ARCTIC ALASKA: DESCRIPTION AND MODELING ANALYSIS

Physical Geography ◽

10.1080/02723646.1982.10642222 ◽

1982 ◽

Vol 3 (2) ◽

pp. 123-147 ◽

Cited By ~ 2

Author(s):

S. I. Outcalt

Keyword(s):

Ground Ice ◽

Near Surface ◽

Arctic Alaska ◽

Modeling Analysis

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New ground ice maps for Canada using a paleogeographic modelling approach

The Cryosphere ◽

10.5194/tc-13-753-2019 ◽

2019 ◽

Vol 13 (3) ◽

pp. 753-773 ◽

Cited By ~ 13

Author(s):

H. Brendan O'Neill ◽

Stephen A. Wolfe ◽

Caroline Duchesne

Keyword(s):

Glacial Lake ◽

Significant Advance ◽

Small Scale ◽

Permafrost Degradation ◽

Field Observations ◽

Tree Line ◽

Ground Ice ◽

Near Surface ◽

Western Arctic ◽

Modelling Approach

Abstract. Ground ice melt caused by climate-induced permafrost degradation may trigger significant ecological change, damage infrastructure, and alter biogeochemical cycles. The fundamental ground ice mapping for Canada is now >20 years old and does not include significant new insights gained from recent field- and remote-sensing-based studies. New modelling incorporating paleogeography is presented in this paper to depict the distribution of three ground ice types (relict ice, segregated ice, and wedge ice) in northern Canada. The modelling uses an expert-system approach in a geographic information system (GIS), founded in conceptual principles gained from empirically based research, to predict ground ice abundance in near-surface permafrost. Datasets of surficial geology, deglaciation, paleovegetation, glacial lake and marine limits, and modern permafrost distribution allow representations in the models of paleoclimatic shifts, tree line migration, marine and glacial lake inundation, and terrestrial emergence, and their effect on ground ice abundance. The model outputs are generally consistent with field observations, indicating abundant relict ice in the western Arctic, where it has remained preserved since deglaciation in thick glacigenic sediments in continuous permafrost. Segregated ice is widely distributed in fine-grained deposits, occurring in the highest abundance in glacial lake and marine sediments. The modelled abundance of wedge ice largely reflects the exposure time of terrain to low air temperatures in tundra environments following deglaciation or marine/glacial lake inundation and is thus highest in the western Arctic. Holocene environmental changes result in reduced ice abundance where the tree line advanced during warmer periods. Published observations of thaw slumps and massive ice exposures, segregated ice and associated landforms, and ice wedges allow a favourable preliminary assessment of the models, and the results are generally comparable with the previous ground ice mapping for Canada. However, the model outputs are more spatially explicit and better reflect observed ground ice conditions in many regions. Synthetic modelling products that incorporated the previous ground ice information may therefore include inaccuracies. The presented modelling approach is a significant advance in permafrost mapping, but additional field observations and volumetric ice estimates from more areas in Canada are required to improve calibration and validation of small-scale ground ice modelling. The ground ice maps from this paper are available in the supplement in GeoTIFF format.

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