Geophysical constraints on the properties of a subglacial lake in northwest Greenland
Author
Maguire, R.Schmerr, N.
Pettit, E.
Riverman, K.
Gardner, C.
Dellagiustina, D.N.
Avenson, B.
Wagner, N.
Marusiak, A.G.
Habib, N.
Broadbeck, J.I.
Bray, V.J.
Bailey, S.H.
Affiliation
Lunar and Planetary Laboratory, University of ArizonaIssue Date
2021
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Copernicus GmbHCitation
Maguire, R., Schmerr, N., Pettit, E., Riverman, K., Gardner, C., Dellagiustina, D. N., Avenson, B., Wagner, N., Marusiak, A. G., Habib, N., Broadbeck, J. I., Bray, V. J., & Bailey, S. H. (2021). Geophysical constraints on the properties of a subglacial lake in northwest Greenland. Cryosphere, 15(7), 3279–3291.Journal
CryosphereRights
Copyright © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.Collection Information
This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.Abstract
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 830-845ĝ€¯m below the surface, with a seismic reflection coefficient of -0.43ĝ€¯±ĝ€¯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 14-20ĝ€¯ms after the lake top reflection, corresponding to a lake depth of approximately 10-15ĝ€¯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. © Author(s) 2021.Note
Open access journalISSN
1994-0416Version
Final published versionae974a485f413a2113503eed53cd6c53
10.5194/tc-15-3279-2021
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Except where otherwise noted, this item's license is described as Copyright © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.