An Estimate of Ice Wedge  Volume for a High Arctic Polar Desert Environment, Fosheim Peninsula, Ellesmere Island

Bernard-Grand'Maison, Claire; Pollard, W. H.

doi:10.5194/tc-2018-29

Cited by 6 publications

(21 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As satellite and geographic information system products achieve greater pixel resolution, incorporating finer detail of surface cover, including IWs, will be possible. Furthermore, there has been a growing effort to develop automatic mapping of IW polygons (Bernard‐Grand'Maison & Pollard, ; Lousada et al, 2018; Ulrich et al, ; Zhang et al, ) that will facilitate incorporating the impacts of degraded IW troughs into models. The use of drones to create high‐resolution digital elevation models shows great promise, particularly in change detection over time; however, their spatial coverage is limited.…”

Section: Discussionmentioning

confidence: 99%

“…Mean IW width and height is 1.46 m and 3.23 m, respectively (Couture & Pollard, 1998) and is younger than the tabular massive ice but the exact age is unknown. IWs are estimated to occur in 50% of the Fosheim Peninsula (roughly 3,000 km 2 ) occupying 3.81% of the upper 5.9 m of permafrost (Bernard‐Grand'Maison & Pollard, ) and are epigenetic, forming within permafrost that is older than the IW and grows progressively wider to form a “V” shape (Mackay, 1990). IWs in the region currently form mostly high‐centered polygons with no rims present (Bernard‐Grand'Maison & Pollard, ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Impacts of Degrading Ice‐Wedges on Ground Temperatures in a High Arctic Polar Desert System

2020

View full text Add to dashboard Cite

Ice‐wedge ice is the most widespread type of massive ice found in the continuous permafrost zone. Polygonal networks of ice‐wedges drive environmental changes and feedback that will likely be exacerbated with future climate change. Recent decadal‐scale observations have shown that ice‐wedges are degrading rapidly within the entire Circum‐Arctic Region but observations of feedback associated with ground temperature regimes are still lacking in many areas. We present over a year's worth of field observations from an area with cold (−16.5°C), thick (>500 m) continuous permafrost and a mean annual air temperature of −19.7°C in the Canadian high Arctic. Topographic surveys, thaw depths, vegetation cover, soil moisture, and annual shallow (12 cm) ground temperature measurements were collected for seven ice‐wedge troughs and two polygon centers in a high‐centered polygon system. We show that geomorphic changes caused by ice‐wedge degradation generate new responses in soil moisture, vegetation cover, and snow distribution that create a mosaic of ground temperatures that range by 5.1°C for mean annual, 2.5°C in summer, and 15.2°C in winter between polygon‐centers and ice‐wedge troughs. Our results show that snow redistribution due to wind induces the cooling of polygon centers, thus promoting new thermal contraction cracking and ice‐wedge formation. We provide an example based on high‐resolution remote sensing data on how these ice‐wedge trough densities vary spatially in our study area. Capturing these fine scale geomorphic differences and resulting ground temperatures will be critical to accurately assess future changes of these common Arctic landscapes.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Impacts of Degrading Ice‐Wedges on Ground Temperatures in a High Arctic Polar Desert System

2020

View full text Add to dashboard Cite

show abstract

“…Recent estimates on Fosheim Peninsula indicate that ice-wedge polygons cover about 50% of the terrain, and that wedge ice occupies between 1.4 to 5.9% volume of the upper 5.9 m of permafrost (Bernard-Grand'Maison and Pollard, 2018). In this region, wedge ice abundance is modelled mostly as low, with some small areas of medium abundance (Fig.…”

Section: Wedge Icementioning

confidence: 96%

“…Calibration includes the adjustment of model parameters to improve agreement between model outputs and observations. The Pollard, 2018;Couture and Pollard, 1998;French, 1974;Pollard and French, 1980). Therefore, there is insufficient field data to meaningfully calibrate model parameters and quantitatively validate the outputs.…”

Section: Input Value Calibrationmentioning

confidence: 99%

“…Complementary geophysical techniques may allow differentiation and mapping of massive ice, wedge ice, and icy sediments (De Pascale et al, 2008), but accurate volumetric determinations are not yet possible. Because of their distinct polygonal surface expression, volume estimates of ice wedges can be derived using high-resolution imagery (Bernard-Grand'Maison and Pollard, 2018;Ulrich et al, 2014), but their accuracy ultimately depends on field measurements of ice wedge widths and depths. Air-and spaceborne optical, LiDAR, and D-InSAR techniques allow characterization of thermokarst terrain and processes, offering indirect insights into ground ice conditions (Kääb, 2008;Kokelj and Jorgenson, 2013).…”

Section: Directions For Ground Ice Modelling and Mappingmentioning

confidence: 99%

See 1 more Smart Citation

New ground ice maps for Canada using a paleogeographic modelling approach

O'Neill¹,

Wolfe²,

Duchesne³

2018

Preprint

View full text Add to dashboard Cite

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 (massive ice and icy sediments, 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 massive ice and icy sediments 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 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 tree line advanced during warmer periods. Published observations of thaw slumps and 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 some 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.

show abstract

Distribution, morphometry, and ice content of ice‐wedge polygons in Tombstone Territorial Park, central Yukon, Canada

Frappier

Lacelle

2021

Permafrost & Periglacial

View full text Add to dashboard Cite

Investigations of the regional distribution of ice‐wedge polygons and wedge‐ice volume allow for the assessment of the vulnerability of permafrost landscapes to thaw‐induced disturbances and related ecological feedbacks. Ice‐wedge polygons have been described in multiple studies in flat terrain and low‐gradient hillslopes, but few studies have examined ice‐wedge polygons in mountainous terrain. This study investigates the distribution, morphometry, and wedge‐ice content of ice‐wedge polygons in Tombstone Territorial Park, a mountainous permafrost region in central Yukon. Results show that ice‐wedge polygons occupy 2.6% of the park and preferentially develop in woody sedge peat, glaciofluvial, and alluvial deposits along the lower reaches of the Blackstone and East Blackstone rivers on hillslopes ≤1°. The morphometry of five of six polygonal sites studied showed statistically similar polygon sizes and trough angles, while showing different development stages based on vegetation type, surface wetness, and spatial pattern. The estimation of wedge‐ice volumes in the ice‐wedge polygons is 8–22% and is comparable to that of other Arctic regions. However, the estimated wedge‐ice volume represents a minimum value because older generations of ice wedges are truncated 3–4 m below the surface with no evidence of surface polygons, and the polygonal network can be obscured by slope processes, vegetation, and ice‐wedge inactivity. This study provides insights into the application of morphometric and soil parameters for the assessment of ice‐wedge polygon distribution and development stages.

show abstract

An Estimate of Ice Wedge Volume for a High Arctic Polar Desert Environment, Fosheim Peninsula, Ellesmere Island

Cited by 6 publications

References 26 publications

Impacts of Degrading Ice‐Wedges on Ground Temperatures in a High Arctic Polar Desert System

Impacts of Degrading Ice‐Wedges on Ground Temperatures in a High Arctic Polar Desert System

New ground ice maps for Canada using a paleogeographic modelling approach

Distribution, morphometry, and ice content of ice‐wedge polygons in Tombstone Territorial Park, central Yukon, Canada

Contact Info

Product

Resources

About