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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ftcopernicus:oai:publications.copernicus.org:tcd89722 2023-05-15T13:31:39+02:00 Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica Haas, Christian Langhorne, Patricia J. Rack, Wolfgang Leonard, Greg H. Brett, Gemma M. Price, Daniel Beckers, Justin F. Gough, Alex J. 2020-09-24 application/pdf https://doi.org/10.5194/tc-2020-268 https://tc.copernicus.org/preprints/tc-2020-268/ eng eng doi:10.5194/tc-2020-268 https://tc.copernicus.org/preprints/tc-2020-268/ eISSN: 1994-0424 Text 2020 ftcopernicus https://doi.org/10.5194/tc-2020-268 2020-09-28T16:22:13Z 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 inphase and quadrature components, supported by EM forward modeling, and calibrated and validated by drill-hole measurements. Linear regression of EM inphase measurements of apparent SIPL thickness and drill-hole measurements of <q>true</q> SIPL thickness yields a scaling factor of 0.3 to 0.4, and rms error of 0.47 m. EM forward modeling suggests that this corresponds to SIPL conductivities between 900 and 1800 mS/m, 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. Text Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice Copernicus Publications: E-Journals McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) McMurdo Sound Ross Sea |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
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 inphase and quadrature components, supported by EM forward modeling, and calibrated and validated by drill-hole measurements. Linear regression of EM inphase measurements of apparent SIPL thickness and drill-hole measurements of <q>true</q> SIPL thickness yields a scaling factor of 0.3 to 0.4, and rms error of 0.47 m. EM forward modeling suggests that this corresponds to SIPL conductivities between 900 and 1800 mS/m, 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 |
Text |
author |
Haas, Christian Langhorne, Patricia J. Rack, Wolfgang Leonard, Greg H. Brett, Gemma M. Price, Daniel Beckers, Justin F. Gough, Alex J. |
spellingShingle |
Haas, Christian Langhorne, Patricia J. Rack, Wolfgang Leonard, Greg H. Brett, Gemma M. Price, Daniel Beckers, Justin F. Gough, Alex J. Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica |
author_facet |
Haas, Christian Langhorne, Patricia J. Rack, Wolfgang Leonard, Greg H. Brett, Gemma M. Price, Daniel Beckers, Justin F. Gough, Alex J. |
author_sort |
Haas, Christian |
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 |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-2020-268 https://tc.copernicus.org/preprints/tc-2020-268/ |
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 |
genre_facet |
Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf McMurdo Sound Ross Sea Sea ice |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-2020-268 https://tc.copernicus.org/preprints/tc-2020-268/ |
op_doi |
https://doi.org/10.5194/tc-2020-268 |
_version_ |
1766019718214320128 |