Ground-ice stratigraphy and formation at North Head, Tuktoyaktuk Coastlands, western Arctic Canada: a product of glacier-permafrost interactions

This chapter focuses on the development and advance of the arctic fur trade to the year 1914: the decline of the shore whaling industry and the rise of the market for white fox furs; the beginning of the dispersal of trapping families along the coast; the importance of the Cape Smythe Whaling and Trading Company at Barrow, Alaska; and the activities of H. Liebes and Company, furriers of San Francisco.

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Ground ice, organic carbon and soluble cations in tundra permafrost soils and sediments near a Laurentide ice divide in the Slave Geological Province, Northwest Territories, Canada

The Cryosphere ◽

10.5194/tc-14-4341-2020 ◽

2020 ◽

Vol 14 (12) ◽

pp. 4341-4364

Author(s):

Rupesh Subedi ◽

Steven V. Kokelj ◽

Stephan Gruber

Keyword(s):

Organic Carbon ◽

Landscape Change ◽

Ice Sheet ◽

Canadian Arctic ◽

Landscape Changes ◽

Ground Ice ◽

Basal Ice ◽

Permafrost Soils ◽

Western Arctic ◽

Mineral Soils

Abstract. The central Slave Geological Province is situated 450–650 km from the presumed spreading centre of the Keewatin Dome of the Laurentide Ice Sheet, and it differs from the western Canadian Arctic, where recent thaw-induced landscape changes in Laurentide ice-marginal environments are already abundant. Although much of the terrain in the central Slave Geological Province is mapped as predominantly bedrock and ice-poor, glacial deposits of varying thickness occupy significant portions of the landscape in some areas, creating a mosaic of permafrost conditions. Limited evidence of ice-rich ground, a key determinant of thaw-induced landscape change, exists. Carbon and soluble cation contents in permafrost are largely unknown in the area. Twenty-four boreholes with depths up to 10 m were drilled in tundra north of Lac de Gras to address these regional gaps in knowledge and to better inform projections and generalizations at a coarser scale. Excess-ice contents of 20 %–60 %, likely remnant Laurentide basal ice, are found in upland till, suggesting that thaw subsidence of metres to more than 10 m is possible if permafrost were to thaw completely. Beneath organic terrain and in fluvially reworked sediment, aggradational ice is found. The variability in abundance of ground ice poses long-term challenges for engineering, and it makes the area susceptible to thaw-induced landscape change and mobilization of sediment, solutes and carbon several metres deep. The nature and spatial patterns of landscape changes, however, are expected to differ from ice-marginal landscapes of western Arctic Canada, for example, based on greater spatial and stratigraphic heterogeneity. Mean organic-carbon densities in the top 3 m of soil profiles near Lac de Gras are about half of those reported in circumpolar statistics; deeper deposits have densities ranging from 1.3–10.1 kg C m−3, representing a significant additional carbon pool. The concentration of total soluble cations in mineral soils is lower than at previously studied locations in the western Canadian Arctic. This study can inform permafrost investigations in other parts of the Slave Geological Province, and its data can support scenario simulations of future trajectories of permafrost thaw. Preserved Laurentide basal ice can support new ways of studying processes and phenomena at the base of an ice sheet.

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Expansion of the Trade in Northern Alaska and Western Arctic Canada

White Fox and Icy Seas in the Western Arctic ◽

10.2307/j.ctt21668sx.9 ◽

2018 ◽

pp. 77-108

Keyword(s):

Arctic Canada ◽

Western Arctic ◽

Northern Alaska

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Toward Monopoly Control in Western Arctic Canada

White Fox and Icy Seas in the Western Arctic ◽

10.2307/j.ctt21668sx.17 ◽

2018 ◽

pp. 228-244

Keyword(s):

Arctic Canada ◽

Western Arctic

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Competition among Traders in Western Arctic Canada

White Fox and Icy Seas in the Western Arctic ◽

10.2307/j.ctt21668sx.13 ◽

2018 ◽

pp. 159-204

Keyword(s):

Arctic Canada ◽

Western Arctic

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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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