Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone
We document the density and hydrologic properties of bare, ablating ice in a mid-elevation (1215 m a.s.l.) supraglacial internally drained catchment in the Kangerlussuaq sector of the western Greenland ice sheet. We find low-density (0.43–0.91 g cm −3 , μ = 0.69 g cm −3 ) ice to at least 1.1 m depth...
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2018
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ftdoajarticles:oai:doaj.org/article:6644dfc240bf4b8ba4b45789e6b4a0e4 2023-05-15T16:26:56+02:00 Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone M. G. Cooper L. C. Smith A. K. Rennermalm C. Miège L. H. Pitcher J. C. Ryan K. Yang S. W. Cooley 2018-03-01T00:00:00Z https://doi.org/10.5194/tc-12-955-2018 https://doaj.org/article/6644dfc240bf4b8ba4b45789e6b4a0e4 EN eng Copernicus Publications https://www.the-cryosphere.net/12/955/2018/tc-12-955-2018.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-12-955-2018 1994-0416 1994-0424 https://doaj.org/article/6644dfc240bf4b8ba4b45789e6b4a0e4 The Cryosphere, Vol 12, Pp 955-970 (2018) Environmental sciences GE1-350 Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/tc-12-955-2018 2022-12-31T02:27:34Z We document the density and hydrologic properties of bare, ablating ice in a mid-elevation (1215 m a.s.l.) supraglacial internally drained catchment in the Kangerlussuaq sector of the western Greenland ice sheet. We find low-density (0.43–0.91 g cm −3 , μ = 0.69 g cm −3 ) ice to at least 1.1 m depth below the ice sheet surface. This near-surface, low-density ice consists of alternating layers of water-saturated, porous ice and clear solid ice lenses, overlain by a thin (< 0.5 m), even lower density (0.33–0.56 g cm −3 , μ = 0.45 g cm −3 ) unsaturated weathering crust. Ice density data from 10 shallow (0.9–1.1 m) ice cores along an 800 m transect suggest an average 14–18 cm of specific meltwater storage within this low-density ice. Water saturation of this ice is confirmed through measurable water levels (1–29 cm above hole bottoms, μ = 10 cm) in 84 % of cryoconite holes and rapid refilling of 83 % of 1 m drilled holes sampled along the transect. These findings are consistent with descriptions of shallow, depth-limited aquifers on the weathered surface of glaciers worldwide and confirm the potential for substantial transient meltwater storage within porous low-density ice on the Greenland ice sheet ablation zone surface. A conservative estimate for the ∼ 63 km 2 supraglacial catchment yields 0.009–0.012 km 3 of liquid meltwater storage in near-surface, porous ice. Further work is required to determine if these findings are representative of broader areas of the Greenland ice sheet ablation zone, and to assess the implications for sub-seasonal mass balance processes, surface lowering observations from airborne and satellite altimetry, and supraglacial runoff processes. Article in Journal/Newspaper Greenland Ice Sheet Kangerlussuaq The Cryosphere Directory of Open Access Journals: DOAJ Articles Greenland Kangerlussuaq ENVELOPE(-55.633,-55.633,72.633,72.633) The Cryosphere 12 3 955 970 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 M. G. Cooper L. C. Smith A. K. Rennermalm C. Miège L. H. Pitcher J. C. Ryan K. Yang S. W. Cooley Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
We document the density and hydrologic properties of bare, ablating ice in a mid-elevation (1215 m a.s.l.) supraglacial internally drained catchment in the Kangerlussuaq sector of the western Greenland ice sheet. We find low-density (0.43–0.91 g cm −3 , μ = 0.69 g cm −3 ) ice to at least 1.1 m depth below the ice sheet surface. This near-surface, low-density ice consists of alternating layers of water-saturated, porous ice and clear solid ice lenses, overlain by a thin (< 0.5 m), even lower density (0.33–0.56 g cm −3 , μ = 0.45 g cm −3 ) unsaturated weathering crust. Ice density data from 10 shallow (0.9–1.1 m) ice cores along an 800 m transect suggest an average 14–18 cm of specific meltwater storage within this low-density ice. Water saturation of this ice is confirmed through measurable water levels (1–29 cm above hole bottoms, μ = 10 cm) in 84 % of cryoconite holes and rapid refilling of 83 % of 1 m drilled holes sampled along the transect. These findings are consistent with descriptions of shallow, depth-limited aquifers on the weathered surface of glaciers worldwide and confirm the potential for substantial transient meltwater storage within porous low-density ice on the Greenland ice sheet ablation zone surface. A conservative estimate for the ∼ 63 km 2 supraglacial catchment yields 0.009–0.012 km 3 of liquid meltwater storage in near-surface, porous ice. Further work is required to determine if these findings are representative of broader areas of the Greenland ice sheet ablation zone, and to assess the implications for sub-seasonal mass balance processes, surface lowering observations from airborne and satellite altimetry, and supraglacial runoff processes. |
format |
Article in Journal/Newspaper |
author |
M. G. Cooper L. C. Smith A. K. Rennermalm C. Miège L. H. Pitcher J. C. Ryan K. Yang S. W. Cooley |
author_facet |
M. G. Cooper L. C. Smith A. K. Rennermalm C. Miège L. H. Pitcher J. C. Ryan K. Yang S. W. Cooley |
author_sort |
M. G. Cooper |
title |
Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone |
title_short |
Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone |
title_full |
Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone |
title_fullStr |
Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone |
title_full_unstemmed |
Meltwater storage in low-density near-surface bare ice in the Greenland ice sheet ablation zone |
title_sort |
meltwater storage in low-density near-surface bare ice in the greenland ice sheet ablation zone |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-12-955-2018 https://doaj.org/article/6644dfc240bf4b8ba4b45789e6b4a0e4 |
long_lat |
ENVELOPE(-55.633,-55.633,72.633,72.633) |
geographic |
Greenland Kangerlussuaq |
geographic_facet |
Greenland Kangerlussuaq |
genre |
Greenland Ice Sheet Kangerlussuaq The Cryosphere |
genre_facet |
Greenland Ice Sheet Kangerlussuaq The Cryosphere |
op_source |
The Cryosphere, Vol 12, Pp 955-970 (2018) |
op_relation |
https://www.the-cryosphere.net/12/955/2018/tc-12-955-2018.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-12-955-2018 1994-0416 1994-0424 https://doaj.org/article/6644dfc240bf4b8ba4b45789e6b4a0e4 |
op_doi |
https://doi.org/10.5194/tc-12-955-2018 |
container_title |
The Cryosphere |
container_volume |
12 |
container_issue |
3 |
container_start_page |
955 |
op_container_end_page |
970 |
_version_ |
1766015943243202560 |