Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate
It has been an underlying assumption in many studies that near-surface layers imaged by ground-penetrating radar (GPR) can be interpreted as depositional markers or isochrones. It has been shown that GPR layers can be approximately reproduced from the measured electrical properties of ice, but these...
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International Glaciological Society
2004
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Online Access: | http://nora.nerc.ac.uk/id/eprint/10145/ https://www.cambridge.org/core/journals/journal-of-glaciology/article/imaging-of-firn-isochrones-across-an-antarctic-ice-rise-and-implications-for-patterns-of-snow-accumulation-rate/8C2A56A25A1868C8E9E8EAFA5C40D4EB |
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ftnerc:oai:nora.nerc.ac.uk:10145 2023-05-15T13:45:10+02:00 Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate Vaughan, D.G. Anderson, P.S. King, J.C. Mann, G.W. Mobbs, S.D. Ladkin, R.S. 2004 http://nora.nerc.ac.uk/id/eprint/10145/ https://www.cambridge.org/core/journals/journal-of-glaciology/article/imaging-of-firn-isochrones-across-an-antarctic-ice-rise-and-implications-for-patterns-of-snow-accumulation-rate/8C2A56A25A1868C8E9E8EAFA5C40D4EB unknown International Glaciological Society Vaughan, D.G. orcid:0000-0002-9065-0570 Anderson, P.S.; King, J.C. orcid:0000-0003-3315-7568 Mann, G.W.; Mobbs, S.D.; Ladkin, R.S. 2004 Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate. Journal of Glaciology, 50 (170). 413-418. https://doi.org/10.3189/172756504781829882 <https://doi.org/10.3189/172756504781829882> Glaciology Data and Information Publication - Article PeerReviewed 2004 ftnerc https://doi.org/10.3189/172756504781829882 2023-02-04T19:26:32Z It has been an underlying assumption in many studies that near-surface layers imaged by ground-penetrating radar (GPR) can be interpreted as depositional markers or isochrones. It has been shown that GPR layers can be approximately reproduced from the measured electrical properties of ice, but these material layers are generally narrower and more closely spaced than can be resolved by typical GPR systems operating in the range 50-400 MHz. Thus GPR layers should be interpreted as interference patterns produced from closely spaced and potentially discontinuous material layers, and should not be assumed to be interpretable as precise markers of isochrones. We present 100 MHz GPR data from Lyddan Ice Rise, Antarctica, in which near-surface (< 50 m deep) layers are clearly imaged. The growth of the undulations in these layers with depth is approximately linear, implying that, rather than resulting from a pattern of vertical strain rate, they do correspond to some pattern of snowfall variation. Furthermore, comparison of the GPR layers with snow-stake measurements suggests that around 80% of the rms variability in mean annual accumulation is present in the GPR layers. The observations suggest that, at least in this case, the GPR layers do approximate isochrones, and that patterns of snow accumulation over Lyddan Ice Rise are dominated by extremely persistent spatial variations with only a small residual spatial variability. If this condition is shown to be widely applicable it may reduce the period required for measurements of surface elevation change to be taken as significant indications of mass imbalance. Article in Journal/Newspaper Antarc* Antarctic Antarctica Journal of Glaciology Natural Environment Research Council: NERC Open Research Archive Antarctic Lyddan Ice Rise ENVELOPE(-21.000,-21.000,-74.167,-74.167) Journal of Glaciology 50 170 413 418 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
topic |
Glaciology Data and Information |
spellingShingle |
Glaciology Data and Information Vaughan, D.G. Anderson, P.S. King, J.C. Mann, G.W. Mobbs, S.D. Ladkin, R.S. Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate |
topic_facet |
Glaciology Data and Information |
description |
It has been an underlying assumption in many studies that near-surface layers imaged by ground-penetrating radar (GPR) can be interpreted as depositional markers or isochrones. It has been shown that GPR layers can be approximately reproduced from the measured electrical properties of ice, but these material layers are generally narrower and more closely spaced than can be resolved by typical GPR systems operating in the range 50-400 MHz. Thus GPR layers should be interpreted as interference patterns produced from closely spaced and potentially discontinuous material layers, and should not be assumed to be interpretable as precise markers of isochrones. We present 100 MHz GPR data from Lyddan Ice Rise, Antarctica, in which near-surface (< 50 m deep) layers are clearly imaged. The growth of the undulations in these layers with depth is approximately linear, implying that, rather than resulting from a pattern of vertical strain rate, they do correspond to some pattern of snowfall variation. Furthermore, comparison of the GPR layers with snow-stake measurements suggests that around 80% of the rms variability in mean annual accumulation is present in the GPR layers. The observations suggest that, at least in this case, the GPR layers do approximate isochrones, and that patterns of snow accumulation over Lyddan Ice Rise are dominated by extremely persistent spatial variations with only a small residual spatial variability. If this condition is shown to be widely applicable it may reduce the period required for measurements of surface elevation change to be taken as significant indications of mass imbalance. |
format |
Article in Journal/Newspaper |
author |
Vaughan, D.G. Anderson, P.S. King, J.C. Mann, G.W. Mobbs, S.D. Ladkin, R.S. |
author_facet |
Vaughan, D.G. Anderson, P.S. King, J.C. Mann, G.W. Mobbs, S.D. Ladkin, R.S. |
author_sort |
Vaughan, D.G. |
title |
Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate |
title_short |
Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate |
title_full |
Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate |
title_fullStr |
Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate |
title_full_unstemmed |
Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate |
title_sort |
imaging of firn isochrones across an antarctic ice rise and implications for patterns of snow accumulation rate |
publisher |
International Glaciological Society |
publishDate |
2004 |
url |
http://nora.nerc.ac.uk/id/eprint/10145/ https://www.cambridge.org/core/journals/journal-of-glaciology/article/imaging-of-firn-isochrones-across-an-antarctic-ice-rise-and-implications-for-patterns-of-snow-accumulation-rate/8C2A56A25A1868C8E9E8EAFA5C40D4EB |
long_lat |
ENVELOPE(-21.000,-21.000,-74.167,-74.167) |
geographic |
Antarctic Lyddan Ice Rise |
geographic_facet |
Antarctic Lyddan Ice Rise |
genre |
Antarc* Antarctic Antarctica Journal of Glaciology |
genre_facet |
Antarc* Antarctic Antarctica Journal of Glaciology |
op_relation |
Vaughan, D.G. orcid:0000-0002-9065-0570 Anderson, P.S.; King, J.C. orcid:0000-0003-3315-7568 Mann, G.W.; Mobbs, S.D.; Ladkin, R.S. 2004 Imaging of firn isochrones across an Antarctic ice rise and implications for patterns of snow accumulation rate. Journal of Glaciology, 50 (170). 413-418. https://doi.org/10.3189/172756504781829882 <https://doi.org/10.3189/172756504781829882> |
op_doi |
https://doi.org/10.3189/172756504781829882 |
container_title |
Journal of Glaciology |
container_volume |
50 |
container_issue |
170 |
container_start_page |
413 |
op_container_end_page |
418 |
_version_ |
1766213992295956480 |