Geophysical constraints on the properties of a subglacial lake in northwest Greenland
In this study, we report the results of an active-source seismology and ground-penetrating radar survey performed in northwestern Greenland at a site where the presence of a subglacial lake beneath the accumulation area has previously been proposed. Both seismic and radar results show a flat reflect...
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Copernicus Publications
2021
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Online Access: | https://doi.org/10.5194/tc-15-3279-2021 https://tc.copernicus.org/articles/15/3279/2021/tc-15-3279-2021.pdf https://doaj.org/article/7adbe5c35e01492c9c07462c06db981a |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:7adbe5c35e01492c9c07462c06db981a 2023-05-15T16:27:10+02:00 Geophysical constraints on the properties of a subglacial lake in northwest Greenland R. Maguire N. Schmerr E. Pettit K. Riverman C. Gardner D. N. DellaGiustina B. Avenson N. Wagner A. G. Marusiak N. Habib J. I. Broadbeck V. J. Bray S. H. Bailey 2021-07-01 https://doi.org/10.5194/tc-15-3279-2021 https://tc.copernicus.org/articles/15/3279/2021/tc-15-3279-2021.pdf https://doaj.org/article/7adbe5c35e01492c9c07462c06db981a en eng Copernicus Publications doi:10.5194/tc-15-3279-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/3279/2021/tc-15-3279-2021.pdf https://doaj.org/article/7adbe5c35e01492c9c07462c06db981a undefined The Cryosphere, Vol 15, Pp 3279-3291 (2021) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2021 fttriple https://doi.org/10.5194/tc-15-3279-2021 2023-01-22T19:11:37Z In this study, we report the results of an active-source seismology and ground-penetrating radar survey performed in northwestern Greenland at a site where the presence of a subglacial lake beneath the accumulation area has previously been proposed. Both seismic and radar results show a flat reflector approximately 830–845 m below the surface, with a seismic reflection coefficient of −0.43 ± 0.17, which is consistent with the acoustic impedance contrast between a layer of water and glacial ice. Additionally, in the seismic data we observe an intermittent lake bottom reflection arriving between 14–20 ms after the lake top reflection, corresponding to a lake depth of approximately 10–15 m. A strong coda following the lake top and lake bottom reflections is consistent with a package of lake bottom sediments although its thickness and material properties are uncertain. Finally, we use these results to conduct a first-order assessment of the lake origins using a one-dimensional thermal model and hydropotential modeling based on published surface and bed topography. Using these analyses, we narrow the lake origin hypotheses to either anomalously high geothermal flux or hypersalinity due to local ancient evaporite. Because the origins are still unclear, this site provides an intriguing opportunity for the first in situ sampling of a subglacial lake in Greenland, which could better constrain mechanisms of subglacial lake formation, evolution, and relative importance to glacial hydrology. Article in Journal/Newspaper Greenland The Cryosphere Unknown Greenland The Cryosphere 15 7 3279 3291 |
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geo envir |
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geo envir R. Maguire N. Schmerr E. Pettit K. Riverman C. Gardner D. N. DellaGiustina B. Avenson N. Wagner A. G. Marusiak N. Habib J. I. Broadbeck V. J. Bray S. H. Bailey Geophysical constraints on the properties of a subglacial lake in northwest Greenland |
topic_facet |
geo envir |
description |
In this study, we report the results of an active-source seismology and ground-penetrating radar survey performed in northwestern Greenland at a site where the presence of a subglacial lake beneath the accumulation area has previously been proposed. Both seismic and radar results show a flat reflector approximately 830–845 m below the surface, with a seismic reflection coefficient of −0.43 ± 0.17, which is consistent with the acoustic impedance contrast between a layer of water and glacial ice. Additionally, in the seismic data we observe an intermittent lake bottom reflection arriving between 14–20 ms after the lake top reflection, corresponding to a lake depth of approximately 10–15 m. A strong coda following the lake top and lake bottom reflections is consistent with a package of lake bottom sediments although its thickness and material properties are uncertain. Finally, we use these results to conduct a first-order assessment of the lake origins using a one-dimensional thermal model and hydropotential modeling based on published surface and bed topography. Using these analyses, we narrow the lake origin hypotheses to either anomalously high geothermal flux or hypersalinity due to local ancient evaporite. Because the origins are still unclear, this site provides an intriguing opportunity for the first in situ sampling of a subglacial lake in Greenland, which could better constrain mechanisms of subglacial lake formation, evolution, and relative importance to glacial hydrology. |
format |
Article in Journal/Newspaper |
author |
R. Maguire N. Schmerr E. Pettit K. Riverman C. Gardner D. N. DellaGiustina B. Avenson N. Wagner A. G. Marusiak N. Habib J. I. Broadbeck V. J. Bray S. H. Bailey |
author_facet |
R. Maguire N. Schmerr E. Pettit K. Riverman C. Gardner D. N. DellaGiustina B. Avenson N. Wagner A. G. Marusiak N. Habib J. I. Broadbeck V. J. Bray S. H. Bailey |
author_sort |
R. Maguire |
title |
Geophysical constraints on the properties of a subglacial lake in northwest Greenland |
title_short |
Geophysical constraints on the properties of a subglacial lake in northwest Greenland |
title_full |
Geophysical constraints on the properties of a subglacial lake in northwest Greenland |
title_fullStr |
Geophysical constraints on the properties of a subglacial lake in northwest Greenland |
title_full_unstemmed |
Geophysical constraints on the properties of a subglacial lake in northwest Greenland |
title_sort |
geophysical constraints on the properties of a subglacial lake in northwest greenland |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-3279-2021 https://tc.copernicus.org/articles/15/3279/2021/tc-15-3279-2021.pdf https://doaj.org/article/7adbe5c35e01492c9c07462c06db981a |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland The Cryosphere |
genre_facet |
Greenland The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 3279-3291 (2021) |
op_relation |
doi:10.5194/tc-15-3279-2021 1994-0416 1994-0424 https://tc.copernicus.org/articles/15/3279/2021/tc-15-3279-2021.pdf https://doaj.org/article/7adbe5c35e01492c9c07462c06db981a |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/tc-15-3279-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
7 |
container_start_page |
3279 |
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3291 |
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