Crossover scaling phenomena for glaciers and ice caps
ABSTRACT While the terms ‘glacier’ and ‘ice cap’ have distinct morphological meanings, no easily defined boundary or transition distinguishes one from the other. Despite this, the exponent of the power law function relating volume to surface area differs sharply for glaciers and ice caps, suggesting...
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/jog.2016.6 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214301600006X |
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crcambridgeupr:10.1017/jog.2016.6 2024-03-03T08:45:19+00:00 Crossover scaling phenomena for glaciers and ice caps BAHR, DAVID B. PFEFFER, W. TAD 2016 http://dx.doi.org/10.1017/jog.2016.6 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214301600006X en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 62, issue 232, page 299-309 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.6 2024-02-08T08:33:09Z ABSTRACT While the terms ‘glacier’ and ‘ice cap’ have distinct morphological meanings, no easily defined boundary or transition distinguishes one from the other. Despite this, the exponent of the power law function relating volume to surface area differs sharply for glaciers and ice caps, suggesting a fundamental distinction beyond a smoothly transitioning morphology. A standard percolation technique from statistical physics is used to show that valley glaciers are in fact differentiated from ice caps by an abrupt geometric transition. The crossover is a function of increasing glacier thickness, but it owes its existence more to the nature of the underlying bedrock topography than to specifics of glacier mechanics: the crossover is caused by a switch from directed flow that is constrained by surrounding bedrock topography to unconstrained radial flow of thicker ice that has subsumed the topography. The crossover phenomenon is nonlinear and rapid so that few if any glaciers will have geometries or dynamics that blend the two extremes. The exponents of scaling relationships change abruptly at the crossover from one regime to another; in particular, the volume/area scaling exponent will switch from γ = 1.375 for glaciers to γ = 1.25 for ice caps, with few, if any, ice bodies having exponents that fall between these values. Article in Journal/Newspaper Ice cap Journal of Glaciology Cambridge University Press Journal of Glaciology 62 232 299 309 |
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Open Polar |
collection |
Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes BAHR, DAVID B. PFEFFER, W. TAD Crossover scaling phenomena for glaciers and ice caps |
topic_facet |
Earth-Surface Processes |
description |
ABSTRACT While the terms ‘glacier’ and ‘ice cap’ have distinct morphological meanings, no easily defined boundary or transition distinguishes one from the other. Despite this, the exponent of the power law function relating volume to surface area differs sharply for glaciers and ice caps, suggesting a fundamental distinction beyond a smoothly transitioning morphology. A standard percolation technique from statistical physics is used to show that valley glaciers are in fact differentiated from ice caps by an abrupt geometric transition. The crossover is a function of increasing glacier thickness, but it owes its existence more to the nature of the underlying bedrock topography than to specifics of glacier mechanics: the crossover is caused by a switch from directed flow that is constrained by surrounding bedrock topography to unconstrained radial flow of thicker ice that has subsumed the topography. The crossover phenomenon is nonlinear and rapid so that few if any glaciers will have geometries or dynamics that blend the two extremes. The exponents of scaling relationships change abruptly at the crossover from one regime to another; in particular, the volume/area scaling exponent will switch from γ = 1.375 for glaciers to γ = 1.25 for ice caps, with few, if any, ice bodies having exponents that fall between these values. |
format |
Article in Journal/Newspaper |
author |
BAHR, DAVID B. PFEFFER, W. TAD |
author_facet |
BAHR, DAVID B. PFEFFER, W. TAD |
author_sort |
BAHR, DAVID B. |
title |
Crossover scaling phenomena for glaciers and ice caps |
title_short |
Crossover scaling phenomena for glaciers and ice caps |
title_full |
Crossover scaling phenomena for glaciers and ice caps |
title_fullStr |
Crossover scaling phenomena for glaciers and ice caps |
title_full_unstemmed |
Crossover scaling phenomena for glaciers and ice caps |
title_sort |
crossover scaling phenomena for glaciers and ice caps |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/jog.2016.6 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S002214301600006X |
genre |
Ice cap Journal of Glaciology |
genre_facet |
Ice cap Journal of Glaciology |
op_source |
Journal of Glaciology volume 62, issue 232, page 299-309 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2016.6 |
container_title |
Journal of Glaciology |
container_volume |
62 |
container_issue |
232 |
container_start_page |
299 |
op_container_end_page |
309 |
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1792500852650409984 |