Thermal refraction: implications for subglacial heat flux
Abstract In this study, we explore small-scale (~1 to 20 km) thermal-refractive effects on basal geothermal heat flux (BGHF) at subglacial boundaries resulting from lateral thermal conductivity contrasts associated with subglacial topography and geologic contacts. We construct a series of two-dimens...
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crcambridgeupr:10.1017/jog.2021.38 2024-05-19T07:42:11+00:00 Thermal refraction: implications for subglacial heat flux Willcocks, Simon Hasterok, Derrick Jennings, Samuel 2021 http://dx.doi.org/10.1017/jog.2021.38 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143021000381 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/4.0/ Journal of Glaciology volume 67, issue 265, page 875-884 ISSN 0022-1430 1727-5652 journal-article 2021 crcambridgeupr https://doi.org/10.1017/jog.2021.38 2024-05-02T06:51:11Z Abstract In this study, we explore small-scale (~1 to 20 km) thermal-refractive effects on basal geothermal heat flux (BGHF) at subglacial boundaries resulting from lateral thermal conductivity contrasts associated with subglacial topography and geologic contacts. We construct a series of two-dimensional, conductive, steady-state models that exclude many of the complexities of ice sheets in order to demonstrate the effect of thermal refraction. We show that heat can preferentially flow into or around a subglacial valley depending on the thermal conductivity contrast with underlying bedrock, with anomalies of local BGHF at the ice–bedrock interface between 80 and 120% of regional BGHF and temperature anomalies on the order of ±15% for the typical range of bedrock conductivities. In the absence of bed topography, subglacial contacts can produce significant heat flux and temperature anomalies that are locally extensive (>10 km). Thermal refraction can result in either an increase or decrease in the likelihood of melting and ice-sheet stability depending on the conductivity contrast and bed topography. While our models exclude many of the physical complexities of ice behavior, they illustrate the need to include refractive effects created by realistic geology into future glacial models to improve the prediction of subglacial melting and ice viscosity. Article in Journal/Newspaper Ice Sheet Journal of Glaciology Cambridge University Press Journal of Glaciology 1 10 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract In this study, we explore small-scale (~1 to 20 km) thermal-refractive effects on basal geothermal heat flux (BGHF) at subglacial boundaries resulting from lateral thermal conductivity contrasts associated with subglacial topography and geologic contacts. We construct a series of two-dimensional, conductive, steady-state models that exclude many of the complexities of ice sheets in order to demonstrate the effect of thermal refraction. We show that heat can preferentially flow into or around a subglacial valley depending on the thermal conductivity contrast with underlying bedrock, with anomalies of local BGHF at the ice–bedrock interface between 80 and 120% of regional BGHF and temperature anomalies on the order of ±15% for the typical range of bedrock conductivities. In the absence of bed topography, subglacial contacts can produce significant heat flux and temperature anomalies that are locally extensive (>10 km). Thermal refraction can result in either an increase or decrease in the likelihood of melting and ice-sheet stability depending on the conductivity contrast and bed topography. While our models exclude many of the physical complexities of ice behavior, they illustrate the need to include refractive effects created by realistic geology into future glacial models to improve the prediction of subglacial melting and ice viscosity. |
format |
Article in Journal/Newspaper |
author |
Willcocks, Simon Hasterok, Derrick Jennings, Samuel |
spellingShingle |
Willcocks, Simon Hasterok, Derrick Jennings, Samuel Thermal refraction: implications for subglacial heat flux |
author_facet |
Willcocks, Simon Hasterok, Derrick Jennings, Samuel |
author_sort |
Willcocks, Simon |
title |
Thermal refraction: implications for subglacial heat flux |
title_short |
Thermal refraction: implications for subglacial heat flux |
title_full |
Thermal refraction: implications for subglacial heat flux |
title_fullStr |
Thermal refraction: implications for subglacial heat flux |
title_full_unstemmed |
Thermal refraction: implications for subglacial heat flux |
title_sort |
thermal refraction: implications for subglacial heat flux |
publisher |
Cambridge University Press (CUP) |
publishDate |
2021 |
url |
http://dx.doi.org/10.1017/jog.2021.38 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143021000381 |
genre |
Ice Sheet Journal of Glaciology |
genre_facet |
Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 67, issue 265, page 875-884 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2021.38 |
container_title |
Journal of Glaciology |
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1 |
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10 |
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1799481833616834560 |