Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing
The influence of surface melt on the flow of Greenland's largest outlet glaciers remains poorly known and in situ observations are few. We use field observations to link surface meltwater forcing to glacier-wide diurnal velocity variations on East Greenland's Helheim Glacier over two summe...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2022-02-01
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| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143021000745/type/journal_article |
| _version_ | 1811155752867332096 |
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| author | Laura A. Stevens Meredith Nettles James L. Davis Timothy T. Creyts Jonathan Kingslake Andreas P. Ahlstrøm Tine B. Larsen |
| author_facet | Laura A. Stevens Meredith Nettles James L. Davis Timothy T. Creyts Jonathan Kingslake Andreas P. Ahlstrøm Tine B. Larsen |
| author_sort | Laura A. Stevens |
| collection | DOAJ |
| description | The influence of surface melt on the flow of Greenland's largest outlet glaciers remains poorly known and in situ observations are few. We use field observations to link surface meltwater forcing to glacier-wide diurnal velocity variations on East Greenland's Helheim Glacier over two summer melt seasons. We observe diurnal variations in glacier speed that peak ~6.5 h after daily maximum insolation and extend from the terminus region to the equilibrium line. Both the amplitude of the diurnal speed variation and its sensitivity to daily melt are largest at the glacier terminus and decrease up-glacier, suggesting that the magnitude of the response is controlled not only by melt input volume and temporal variability, but also by background effective pressure, which approaches zero at the terminus. Our results provide evidence that basal lubrication by meltwater drives diurnal velocity variations at Greenland's marine-terminating glaciers in a similar manner to alpine glaciers and Greenland's land-terminating outlet glaciers. |
| first_indexed | 2024-04-10T04:39:51Z |
| format | Article |
| id | doaj.art-a88b8a0f67c54aa19f31f9e377e5cea8 |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:39:51Z |
| publishDate | 2022-02-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-a88b8a0f67c54aa19f31f9e377e5cea82023-03-09T12:41:12ZengCambridge University PressJournal of Glaciology0022-14301727-56522022-02-0168778910.1017/jog.2021.74Helheim Glacier diurnal velocity fluctuations driven by surface melt forcingLaura A. Stevens0https://orcid.org/0000-0003-0480-8018Meredith Nettles1https://orcid.org/0000-0003-4613-4162James L. Davis2https://orcid.org/0000-0003-3057-477XTimothy T. Creyts3https://orcid.org/0000-0003-1756-5211Jonathan Kingslake4Andreas P. Ahlstrøm5https://orcid.org/0000-0001-8235-8070Tine B. Larsen6Department of Earth Sciences, University of Oxford, Oxford, UK Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USALamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USALamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USALamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USALamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USAGeological Survey of Denmark and Greenland (GEUS), Copenhagen, DenmarkGeological Survey of Denmark and Greenland (GEUS), Copenhagen, DenmarkThe influence of surface melt on the flow of Greenland's largest outlet glaciers remains poorly known and in situ observations are few. We use field observations to link surface meltwater forcing to glacier-wide diurnal velocity variations on East Greenland's Helheim Glacier over two summer melt seasons. We observe diurnal variations in glacier speed that peak ~6.5 h after daily maximum insolation and extend from the terminus region to the equilibrium line. Both the amplitude of the diurnal speed variation and its sensitivity to daily melt are largest at the glacier terminus and decrease up-glacier, suggesting that the magnitude of the response is controlled not only by melt input volume and temporal variability, but also by background effective pressure, which approaches zero at the terminus. Our results provide evidence that basal lubrication by meltwater drives diurnal velocity variations at Greenland's marine-terminating glaciers in a similar manner to alpine glaciers and Greenland's land-terminating outlet glaciers.https://www.cambridge.org/core/product/identifier/S0022143021000745/type/journal_articleAtmosphere/ice/ocean interactionsglacier flowglacier hydrology |
| spellingShingle | Laura A. Stevens Meredith Nettles James L. Davis Timothy T. Creyts Jonathan Kingslake Andreas P. Ahlstrøm Tine B. Larsen Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing Journal of Glaciology Atmosphere/ice/ocean interactions glacier flow glacier hydrology |
| title | Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing |
| title_full | Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing |
| title_fullStr | Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing |
| title_full_unstemmed | Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing |
| title_short | Helheim Glacier diurnal velocity fluctuations driven by surface melt forcing |
| title_sort | helheim glacier diurnal velocity fluctuations driven by surface melt forcing |
| topic | Atmosphere/ice/ocean interactions glacier flow glacier hydrology |
| url | https://www.cambridge.org/core/product/identifier/S0022143021000745/type/journal_article |
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