Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica
<p>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...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-01-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/15/247/2021/tc-15-247-2021.pdf |
| _version_ | 1830133689420349440 |
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| author | C. Haas C. Haas C. Haas C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers J. F. Beckers A. J. Gough |
| author_facet | C. Haas C. Haas C. Haas C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers J. F. Beckers A. J. Gough |
| author_sort | C. Haas |
| collection | DOAJ |
| description | <p>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 <span class="inline-formula">m</span>. EM forward modelling suggests that this corresponds to SIPL
conductivities between 900 and 1800 <span class="inline-formula">mS m<sup>−1</sup></span>, 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 <span class="inline-formula">m</span> near the ice shelf front. They indicate interannual SIPL thickness
variability of up to 2 <span class="inline-formula">m</span>. 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.</p> |
| first_indexed | 2024-12-17T06:57:51Z |
| format | Article |
| id | doaj.art-6d8e88cc3a8a487983c3d3f5cf750314 |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-17T06:57:51Z |
| publishDate | 2021-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-6d8e88cc3a8a487983c3d3f5cf7503142022-12-21T21:59:21ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242021-01-011524726410.5194/tc-15-247-2021Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, AntarcticaC. Haas0C. Haas1C. Haas2C. Haas3P. J. Langhorne4W. Rack5G. H. Leonard6G. M. Brett7D. Price8J. F. Beckers9J. F. Beckers10A. J. Gough11Department of Earth and Atmospheric Science, University of Alberta, Edmonton, CanadaDepartment of Earth and Space Science and Engineering, York University, Toronto, CanadaAlfred Wegener Institute for Polar and Marine Research, Bremerhaven, GermanyDepartment of Environmental Physics, University of Bremen, Bremen, GermanyDepartment of Physics, University of Otago, Dunedin, New ZealandGateway Antarctica, University of Canterbury, Christchurch, New ZealandSchool of Surveying, University of Otago, Dunedin, New ZealandGateway Antarctica, University of Canterbury, Christchurch, New ZealandGateway Antarctica, University of Canterbury, Christchurch, New ZealandDepartment of Earth and Atmospheric Science, University of Alberta, Edmonton, CanadaCanadian Forest Service, Natural Resources Canada, Edmonton, CanadaDepartment of Physics, University of Otago, Dunedin, New Zealand<p>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 <span class="inline-formula">m</span>. EM forward modelling suggests that this corresponds to SIPL conductivities between 900 and 1800 <span class="inline-formula">mS m<sup>−1</sup></span>, 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 <span class="inline-formula">m</span> near the ice shelf front. They indicate interannual SIPL thickness variability of up to 2 <span class="inline-formula">m</span>. 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.</p>https://tc.copernicus.org/articles/15/247/2021/tc-15-247-2021.pdf |
| spellingShingle | C. Haas C. Haas C. Haas C. Haas P. J. Langhorne W. Rack G. H. Leonard G. M. Brett D. Price J. F. Beckers J. F. Beckers A. J. Gough Airborne mapping of the sub-ice platelet layer under fast ice in McMurdo Sound, Antarctica The Cryosphere |
| title | 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_short | 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 |
| url | https://tc.copernicus.org/articles/15/247/2021/tc-15-247-2021.pdf |
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