In situ measurements of Antarctic snow compaction compared with predictions of models
We describe in situ measurements of the compaction of Antarctic snow. At three different sites in Antarctica, the rate of compaction was measured hourly, over various depth intervals, for up to two years. These measurements show that compaction at each of the sites occurs through slow, viscous defor...
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American Geophysical Union
2010
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ftnerc:oai:nora.nerc.ac.uk:13759 2023-05-15T13:45:11+02:00 In situ measurements of Antarctic snow compaction compared with predictions of models Arthern, Robert J. Vaughan, David G. Rankin, Andrew M. Mulvaney, Robert Thomas, Elizabeth R. 2010-09 text http://nora.nerc.ac.uk/id/eprint/13759/ https://nora.nerc.ac.uk/id/eprint/13759/1/jgrf643.pdf https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009JF001306 en eng American Geophysical Union https://nora.nerc.ac.uk/id/eprint/13759/1/jgrf643.pdf Arthern, Robert J. orcid:0000-0002-3762-8219 Vaughan, David G. orcid:0000-0002-9065-0570 Rankin, Andrew M.; Mulvaney, Robert orcid:0000-0002-5372-8148 Thomas, Elizabeth R. orcid:0000-0002-3010-6493 . 2010 In situ measurements of Antarctic snow compaction compared with predictions of models. Journal of Geophysical Research, 115 (F3), F03011. 12, pp. https://doi.org/10.1029/2009JF001306 <https://doi.org/10.1029/2009JF001306> Glaciology Publication - Article PeerReviewed 2010 ftnerc https://doi.org/10.1029/2009JF001306 2023-02-04T19:28:47Z We describe in situ measurements of the compaction of Antarctic snow. At three different sites in Antarctica, the rate of compaction was measured hourly, over various depth intervals, for up to two years. These measurements show that compaction at each of the sites occurs through slow, viscous deformation of the snowpack, with no significant contribution from sudden collapse of weak layers. The measured rates of compaction at the coldest site exhibit a strong seasonality, consistent with a temperature-dependent sintering mechanism having activation energy of 70 kJ mol(-1). At the two warmer sites, activation energies of 80 and 120 kJ mol(-1) provide slightly better agreement with the observations. Published models of snow compaction underestimate the temperature sensitivity. A good match to our observations is provided by a semi-empirical model, based on rate equations for lattice-diffusion (Nabarro-Herring) creep of material around pores, combined with normal grain growth. This model also provides a theoretical basis for a widely used empirical model of snow compaction. The rate coefficient for lattice-diffusion inferred from our measurements is considerably higher than published values, however, and other creep mechanisms cannot be ruled out. Article in Journal/Newspaper Antarc* Antarctic Antarctica Natural Environment Research Council: NERC Open Research Archive Antarctic Journal of Geophysical Research 115 F3 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
topic |
Glaciology |
spellingShingle |
Glaciology Arthern, Robert J. Vaughan, David G. Rankin, Andrew M. Mulvaney, Robert Thomas, Elizabeth R. In situ measurements of Antarctic snow compaction compared with predictions of models |
topic_facet |
Glaciology |
description |
We describe in situ measurements of the compaction of Antarctic snow. At three different sites in Antarctica, the rate of compaction was measured hourly, over various depth intervals, for up to two years. These measurements show that compaction at each of the sites occurs through slow, viscous deformation of the snowpack, with no significant contribution from sudden collapse of weak layers. The measured rates of compaction at the coldest site exhibit a strong seasonality, consistent with a temperature-dependent sintering mechanism having activation energy of 70 kJ mol(-1). At the two warmer sites, activation energies of 80 and 120 kJ mol(-1) provide slightly better agreement with the observations. Published models of snow compaction underestimate the temperature sensitivity. A good match to our observations is provided by a semi-empirical model, based on rate equations for lattice-diffusion (Nabarro-Herring) creep of material around pores, combined with normal grain growth. This model also provides a theoretical basis for a widely used empirical model of snow compaction. The rate coefficient for lattice-diffusion inferred from our measurements is considerably higher than published values, however, and other creep mechanisms cannot be ruled out. |
format |
Article in Journal/Newspaper |
author |
Arthern, Robert J. Vaughan, David G. Rankin, Andrew M. Mulvaney, Robert Thomas, Elizabeth R. |
author_facet |
Arthern, Robert J. Vaughan, David G. Rankin, Andrew M. Mulvaney, Robert Thomas, Elizabeth R. |
author_sort |
Arthern, Robert J. |
title |
In situ measurements of Antarctic snow compaction compared with predictions of models |
title_short |
In situ measurements of Antarctic snow compaction compared with predictions of models |
title_full |
In situ measurements of Antarctic snow compaction compared with predictions of models |
title_fullStr |
In situ measurements of Antarctic snow compaction compared with predictions of models |
title_full_unstemmed |
In situ measurements of Antarctic snow compaction compared with predictions of models |
title_sort |
in situ measurements of antarctic snow compaction compared with predictions of models |
publisher |
American Geophysical Union |
publishDate |
2010 |
url |
http://nora.nerc.ac.uk/id/eprint/13759/ https://nora.nerc.ac.uk/id/eprint/13759/1/jgrf643.pdf https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009JF001306 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_relation |
https://nora.nerc.ac.uk/id/eprint/13759/1/jgrf643.pdf Arthern, Robert J. orcid:0000-0002-3762-8219 Vaughan, David G. orcid:0000-0002-9065-0570 Rankin, Andrew M.; Mulvaney, Robert orcid:0000-0002-5372-8148 Thomas, Elizabeth R. orcid:0000-0002-3010-6493 . 2010 In situ measurements of Antarctic snow compaction compared with predictions of models. Journal of Geophysical Research, 115 (F3), F03011. 12, pp. https://doi.org/10.1029/2009JF001306 <https://doi.org/10.1029/2009JF001306> |
op_doi |
https://doi.org/10.1029/2009JF001306 |
container_title |
Journal of Geophysical Research |
container_volume |
115 |
container_issue |
F3 |
_version_ |
1766215619481436160 |