Ancient pre-glacial erosion surfaces preserved beneath the West Antarctic Ice Sheet

Kathryn Rose; Neil Ross; Tom Jordan; Robert Bingham; Hugh F. J. Corr; F  Ferraccioli; Anne Le Brocq; David Rippin; Martin J. Siegert

doi:10.5194/esurf-3-139-2015

Ancient pre-glacial erosion surfaces preserved beneath the West Antarctic Ice Sheet

Kathryn Rose, Neil Ross, Tom Jordan, Robert Bingham, Hugh F. J. Corr, F Ferraccioli, Anne Le Brocq, David Rippin, Martin J. Siegert

Environment and Geography

Research output: Contribution to journal › Article › peer-review

Abstract

We present ice-penetrating radar evidence for ancient (pre-glacial) and extensive erosion surfaces preserved beneath the upstream Institute and Möller ice streams, West Antarctica. Radar data reveal a smooth, laterally continuous, gently sloping topographic block, comprising two surfaces separated by a distinct break in slope. The erosion surfaces are preserved in this location due to the collective action of the Pirrit and Martin– Nash hills on ice sheet flow, resulting in a region of slow flowing, cold-based ice downstream of these major topographic barriers. Our analysis reveals that smooth, flat subglacial topography does not always correspond to regions of either present or former fast ice flow, as has previously been assumed. We discuss the potential origins of the erosion surfaces. Erosion rates across the surfaces are currently low, precluding formation via present-day glacial erosion. We suggest that fluvial or marine processes are most likely to have resulted in the formation of these surfaces, but we acknowledge that distinguishing between these processes with certainty requires further data.

Original language	English
Pages (from-to)	139-152
Number of pages	14
Journal	Earth Surface Dynamics
Volume	3
Issue number	1
DOIs	https://doi.org/10.5194/esurf-3-139-2015
Publication status	Published - Feb 2015

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10.5194/esurf-3-139-2015

Cite this

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title = "Ancient pre-glacial erosion surfaces preserved beneath the West Antarctic Ice Sheet",

abstract = "We present ice-penetrating radar evidence for ancient (pre-glacial) and extensive erosion surfaces preserved beneath the upstream Institute and M{\"o}ller ice streams, West Antarctica. Radar data reveal a smooth, laterally continuous, gently sloping topographic block, comprising two surfaces separated by a distinct break in slope. The erosion surfaces are preserved in this location due to the collective action of the Pirrit and Martin– Nash hills on ice sheet flow, resulting in a region of slow flowing, cold-based ice downstream of these major topographic barriers. Our analysis reveals that smooth, flat subglacial topography does not always correspond to regions of either present or former fast ice flow, as has previously been assumed. We discuss the potential origins of the erosion surfaces. Erosion rates across the surfaces are currently low, precluding formation via present-day glacial erosion. We suggest that fluvial or marine processes are most likely to have resulted in the formation of these surfaces, but we acknowledge that distinguishing between these processes with certainty requires further data.",

author = "Kathryn Rose and Neil Ross and Tom Jordan and Robert Bingham and Corr, {Hugh F. J.} and F Ferraccioli and {Le Brocq}, Anne and David Rippin and Siegert, {Martin J.}",

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T1 - Ancient pre-glacial erosion surfaces preserved beneath the West Antarctic Ice Sheet

AU - Rose, Kathryn

AU - Ross, Neil

AU - Jordan, Tom

AU - Bingham, Robert

AU - Corr, Hugh F. J.

AU - Ferraccioli, F

AU - Le Brocq, Anne

AU - Rippin, David

AU - Siegert, Martin J.

PY - 2015/2

Y1 - 2015/2

N2 - We present ice-penetrating radar evidence for ancient (pre-glacial) and extensive erosion surfaces preserved beneath the upstream Institute and Möller ice streams, West Antarctica. Radar data reveal a smooth, laterally continuous, gently sloping topographic block, comprising two surfaces separated by a distinct break in slope. The erosion surfaces are preserved in this location due to the collective action of the Pirrit and Martin– Nash hills on ice sheet flow, resulting in a region of slow flowing, cold-based ice downstream of these major topographic barriers. Our analysis reveals that smooth, flat subglacial topography does not always correspond to regions of either present or former fast ice flow, as has previously been assumed. We discuss the potential origins of the erosion surfaces. Erosion rates across the surfaces are currently low, precluding formation via present-day glacial erosion. We suggest that fluvial or marine processes are most likely to have resulted in the formation of these surfaces, but we acknowledge that distinguishing between these processes with certainty requires further data.

AB - We present ice-penetrating radar evidence for ancient (pre-glacial) and extensive erosion surfaces preserved beneath the upstream Institute and Möller ice streams, West Antarctica. Radar data reveal a smooth, laterally continuous, gently sloping topographic block, comprising two surfaces separated by a distinct break in slope. The erosion surfaces are preserved in this location due to the collective action of the Pirrit and Martin– Nash hills on ice sheet flow, resulting in a region of slow flowing, cold-based ice downstream of these major topographic barriers. Our analysis reveals that smooth, flat subglacial topography does not always correspond to regions of either present or former fast ice flow, as has previously been assumed. We discuss the potential origins of the erosion surfaces. Erosion rates across the surfaces are currently low, precluding formation via present-day glacial erosion. We suggest that fluvial or marine processes are most likely to have resulted in the formation of these surfaces, but we acknowledge that distinguishing between these processes with certainty requires further data.

U2 - 10.5194/esurf-3-139-2015

DO - 10.5194/esurf-3-139-2015

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JO - Earth Surface Dynamics

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