Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica
Basal melting of ice shelves can result in the outflow of supercooled ice shelf water, which can lead to the formation of a sub-ice platelet layer (SIPL) below adjacent sea ice. McMurdo Sound, located in the southern Ross Sea, Antarctica, is well known for the occurrence of a SIPL linked to ice shel...
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Copernicus Publications
2021
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ftdoajarticles:oai:doaj.org/article:6d8e88cc3a8a487983c3d3f5cf750314 2023-05-15T14:00:54+02:00 Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers A. J. Gough 2021-01-01T00:00:00Z https://doi.org/10.5194/tc-15-247-2021 https://doaj.org/article/6d8e88cc3a8a487983c3d3f5cf750314 EN eng Copernicus Publications https://tc.copernicus.org/articles/15/247/2021/tc-15-247-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-247-2021 1994-0416 1994-0424 https://doaj.org/article/6d8e88cc3a8a487983c3d3f5cf750314 The Cryosphere, Vol 15, Pp 247-264 (2021) Environmental sciences GE1-350 Geology QE1-996.5 article 2021 ftdoajarticles https://doi.org/10.5194/tc-15-247-2021 2022-12-31T07:00:26Z Basal melting of ice shelves can result in the outflow of supercooled ice shelf water, which can lead to the formation of a sub-ice platelet layer (SIPL) below adjacent sea ice. McMurdo Sound, located in the southern Ross Sea, Antarctica, is well known for the occurrence of a SIPL linked to ice shelf water outflow from under the McMurdo Ice Shelf. Airborne, single-frequency, frequency-domain electromagnetic induction (AEM) surveys were performed in November of 2009, 2011, 2013, 2016, and 2017 to map the thickness and spatial distribution of the landfast sea ice and underlying porous SIPL. We developed a simple method to retrieve the thickness of the consolidated ice and SIPL from the EM in-phase and quadrature components, supported by EM forward modelling and calibrated and validated by drill-hole measurements. Linear regression of EM in-phase measurements of apparent SIPL thickness and drill-hole measurements of “true” SIPL thickness yields a scaling factor of 0.3 to 0.4 and rms error of 0.47 m . EM forward modelling suggests that this corresponds to SIPL conductivities between 900 and 1800 mS m −1 , with associated SIPL solid fractions between 0.09 and 0.47. The AEM surveys showed the spatial distribution and thickness of the SIPL well, with SIPL thicknesses of up to 8 m near the ice shelf front. They indicate interannual SIPL thickness variability of up to 2 m . In addition, they reveal high-resolution spatial information about the small-scale SIPL thickness variability and indicate the presence of persistent peaks in SIPL thickness that may be linked to the geometry of the outflow from under the ice shelf. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice The Cryosphere Directory of Open Access Journals: DOAJ Articles McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) McMurdo Sound Ross Sea The Cryosphere 15 1 247 264 |
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 C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers A. J. Gough Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Basal melting of ice shelves can result in the outflow of supercooled ice shelf water, which can lead to the formation of a sub-ice platelet layer (SIPL) below adjacent sea ice. McMurdo Sound, located in the southern Ross Sea, Antarctica, is well known for the occurrence of a SIPL linked to ice shelf water outflow from under the McMurdo Ice Shelf. Airborne, single-frequency, frequency-domain electromagnetic induction (AEM) surveys were performed in November of 2009, 2011, 2013, 2016, and 2017 to map the thickness and spatial distribution of the landfast sea ice and underlying porous SIPL. We developed a simple method to retrieve the thickness of the consolidated ice and SIPL from the EM in-phase and quadrature components, supported by EM forward modelling and calibrated and validated by drill-hole measurements. Linear regression of EM in-phase measurements of apparent SIPL thickness and drill-hole measurements of “true” SIPL thickness yields a scaling factor of 0.3 to 0.4 and rms error of 0.47 m . EM forward modelling suggests that this corresponds to SIPL conductivities between 900 and 1800 mS m −1 , with associated SIPL solid fractions between 0.09 and 0.47. The AEM surveys showed the spatial distribution and thickness of the SIPL well, with SIPL thicknesses of up to 8 m near the ice shelf front. They indicate interannual SIPL thickness variability of up to 2 m . In addition, they reveal high-resolution spatial information about the small-scale SIPL thickness variability and indicate the presence of persistent peaks in SIPL thickness that may be linked to the geometry of the outflow from under the ice shelf. |
format |
Article in Journal/Newspaper |
author |
C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers A. J. Gough |
author_facet |
C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers A. J. Gough |
author_sort |
C. Haas |
title |
Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
title_short |
Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
title_full |
Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
title_fullStr |
Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
title_full_unstemmed |
Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
title_sort |
airborne mapping of the sub-ice platelet layer under fast ice in mcmurdo sound, antarctica |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/tc-15-247-2021 https://doaj.org/article/6d8e88cc3a8a487983c3d3f5cf750314 |
long_lat |
ENVELOPE(166.500,166.500,-78.000,-78.000) |
geographic |
McMurdo Ice Shelf McMurdo Sound Ross Sea |
geographic_facet |
McMurdo Ice Shelf McMurdo Sound Ross Sea |
genre |
Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice The Cryosphere |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice The Cryosphere |
op_source |
The Cryosphere, Vol 15, Pp 247-264 (2021) |
op_relation |
https://tc.copernicus.org/articles/15/247/2021/tc-15-247-2021.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-15-247-2021 1994-0416 1994-0424 https://doaj.org/article/6d8e88cc3a8a487983c3d3f5cf750314 |
op_doi |
https://doi.org/10.5194/tc-15-247-2021 |
container_title |
The Cryosphere |
container_volume |
15 |
container_issue |
1 |
container_start_page |
247 |
op_container_end_page |
264 |
_version_ |
1766270295861100544 |