The surficial and subglacial geomorphology of western Dronning Maud Land, Antarctica

Chang, Marc; Jamieson, Stewart S. R.; Bentley, Michael J.; Stokes, Chris R.

doi:10.1080/17445647.2015.1097289

Cited by 5 publications

(7 citation statements)

References 48 publications

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“…However, recognizing the presence and evolution of the periglacial environment in the nunataks' areas and linking it to the existence and evolution of permafrost is a pioneering proposition in the description and understanding of the glacier-permafrost interaction. There are very few papers dealing with the issue of nunataks' deglaciation at all [76,77].…”

Section: Discussionmentioning

confidence: 99%

Deglaciation Rate of Selected Nunataks in Spitsbergen, Svalbard—Potential for Permafrost Expansion above the Glacial Environment

Szafraniec

Dobiński

2020

Geosciences

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Spitsbergen has recently experienced a continuous deglaciation process, linked to both glacier front retreat and lowering of the glacier surface. This process is accompanied by permafrost aggradation from the top of the slopes down to the glacier. Here, the authors determine the rate of permafrost expansion in this type of vertical profile. To this end, seven nunataks across the island were analysed using Landsat satellite imagery, a high-resolution digital elevation model (ArcticDEM), and geoinformation software. Over the last 24–31 years, new nunataks gradually emerged from the ice cover at an average linear rate of 0.06 m a−1 per degree of increment of the slope of the terrain at an average altitude of approximately 640 m a.s.l. The analysis showed that the maximum rate of permafrost expansion down the slope was positively correlated with the average nunatak elevation, reaching a value of approximately 10,000 m2 a−1. In cold climates, with a mean annual air temperature (MAAT) below 0 °C, newly exposed land is occupied by active periglacial environments, causing permafrost aggradation. Therefore, both glacial and periglacial environments are changing over time concomitantly, with permafrost aggradation occurring along and around the glacier, wherever the MAAT is negative.

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Section: Discussionmentioning

confidence: 99%

Deglaciation Rate of Selected Nunataks in Spitsbergen, Svalbard—Potential for Permafrost Expansion above the Glacial Environment

Szafraniec

Dobiński

2020

Geosciences

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“…An approach to mapping subglacial landscapes with the potential to address this issue is the use of ice sheet surface morphology (Le Brocq et al, 2008;Ross et al, 2014;Chang et al, 2016), which records the fingerprint of subglacial topography due to its influence on ice flow (Rémy and Minster, 1997). Changes in slope, or curvature, of the ice surface can be extracted from radar-based satellite imagery (e.g.…”

Section: Background and Rationalementioning

confidence: 99%

Alpine topography of the Gamburtsev Subglacial Mountains, Antarctica, mapped from ice sheet surface morphology

Lea,

Jamieson,

Bentley

2024

The Cryosphere

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Abstract. Landscapes buried beneath the Antarctic Ice Sheet preserve information about the geologic and geomorphic evolution of the continent both before and during the wide-scale glaciation that began roughly 34×106 years ago. Since the inception of this ice sheet, some areas have remained cold-based and non-erosive, preserving ancient landscapes remarkably intact. The Gamburtsev Subglacial Mountains in central East Antarctica are one such landscape, maintaining evidence of tectonic, fluvial and glacial controls on their distinctly alpine morphology. The central Gamburtsev Mountains have previously been surveyed using airborne ice-penetrating radar; however, many questions remain as to their evolution and their influence on the East Antarctic Ice Sheet, including where in the region to drill for a 1.5×106 year-long “oldest-ice” core. Here, we derive new maps of the planform geometry of the Gamburtsev Subglacial Mountains from satellite remote sensing datasets of the ice sheet surface, based on the relationship between bed roughness and ice surface morphology. Automated and manual approaches to mapping were tested and validated against existing radar data and elevation models. Manual mapping was more effective than automated approaches at reproducing bed features observed in radar data, but a hybrid approach is suggested for future work. The maps produced here show the detail of mountain ridges and valleys on wavelengths significantly smaller than the spacing of existing radar flightlines, and mapping has extended well beyond the confines of existing radar surveys. Morphometric analysis of the mapped landscape reveals that it constitutes a preserved (>34 Ma) dendritic valley network, with some evidence for modification by topographically confined glaciation prior to ice sheet inception. The planform geometry of the landscape is a significant control on locations of basal melting, subglacial hydrological flows and the stability of the ice sheet over time, so the maps presented here may help to guide decisions about where to search for oldest ice.

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“…Assuming erosion is tied to glacial processes, the decreasing erosion with elevation can be explained by shorter duration of ice burial for higher-elevation sites or lower erosivity of the ice sheet at higher elevation where the ice is thinner and colder [47][48][49] . Several studies document low erosion rates beyond major troughs in DML: (i) in bedrock samples above the present-day ice-sheet surface using cosmogenic nuclides 10,33 and thermochronometry 50 , and (ii) below the present-day ice-sheet surface by ground-based 51,52 and airborne 20 radar surveys, or inversion of ice-surface imagery 53 revealing subglacially-preserved alpine and fluvial landscapes.…”

Section: Regional Variability Of Ice-sheet Burial Escarpment Hinge-zonementioning

confidence: 99%

A topographic hinge-zone divides coastal and inland ice dynamic regimes in East Antarctica

Andersen

Newall

Fredin

et al. 2023

Commun Earth Environ

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The impact of late Cenozoic climate on the East Antarctic Ice Sheet is uncertain. Poorly constrained patterns of relative ice thinning and thickening impair the reconstruction of past ice-sheet dynamics and global sea-level budgets. Here we quantify long-term ice cover of mountains protruding the ice-sheet surface in western Dronning Maud Land, using cosmogenic Chlorine-36, Aluminium-26, Beryllium-10, and Neon-21 from bedrock in an inverse modeling approach. We find that near-coastal sites experienced ice burial up to 75–97% of time since 1 Ma, while interior sites only experienced brief periods of ice burial, generally <20% of time since 1 Ma. Based on these results, we suggest that the escarpment in Dronning Maud Land acts as a hinge-zone, where ice-dynamic changes driven by grounding-line migration are attenuated inland from the coastal portions of the East Antarctic Ice Sheet, and where precipitation-controlled ice-thickness variations on the polar plateau taper off towards the coast.

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The surficial and subglacial geomorphology of western Dronning Maud Land, Antarctica

Cited by 5 publications

References 48 publications

Deglaciation Rate of Selected Nunataks in Spitsbergen, Svalbard—Potential for Permafrost Expansion above the Glacial Environment

Deglaciation Rate of Selected Nunataks in Spitsbergen, Svalbard—Potential for Permafrost Expansion above the Glacial Environment

Alpine topography of the Gamburtsev Subglacial Mountains, Antarctica, mapped from ice sheet surface morphology

A topographic hinge-zone divides coastal and inland ice dynamic regimes in East Antarctica

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