Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica
We collected ~1300 km of ground-penetrating radar profiles over McMurdo Ice Shelf, Antarctica, using frequencies between 40 and 400 MHz to determine extent, continuity and depth to the brine. We also used profiles to determine meteoric ice thickness and locate englacial features, which may suggest i...
Published in: | Annals of Glaciology |
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Cambridge University Press
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ftdoajarticles:oai:doaj.org/article:b73eb71b27754353b9082ea3884e1156 2023-05-15T13:29:31+02:00 Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica S. Campbell Z. Courville S. Sinclair J. Wilner 2017-04-01T00:00:00Z https://doi.org/10.1017/aog.2017.26 https://doaj.org/article/b73eb71b27754353b9082ea3884e1156 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S026030551700026X/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2017.26 0260-3055 1727-5644 https://doaj.org/article/b73eb71b27754353b9082ea3884e1156 Annals of Glaciology, Vol 58, Pp 1-11 (2017) glacier geophysics glacier mapping ground-penetrating radar ice/ocean interactions ice shelves Meteorology. Climatology QC851-999 article 2017 ftdoajarticles https://doi.org/10.1017/aog.2017.26 2023-03-12T01:31:57Z We collected ~1300 km of ground-penetrating radar profiles over McMurdo Ice Shelf, Antarctica, using frequencies between 40 and 400 MHz to determine extent, continuity and depth to the brine. We also used profiles to determine meteoric ice thickness and locate englacial features, which may suggest ice shelf instability. The brine extends 9–13 km inland from the ice shelf terminus and covers the entire region between Ross, White and Black Islands. Jump unconformities and basal fractures exist in the brine and ice shelf, respectively, suggesting prior fracturing and re-suturing. One 100 MHz profile, the most distal from the ice shelf edge while still being situated over the brine, simultaneously imaged the brine and bottom of meteoric ice. This suggests a negative brine salinity gradient moving away from the terminus. The meteoric ice bottom was also imaged in a few select locations through blue ice in the ablation zone near Black Island. We suggest that brine, sediment-rich ice and poor antenna coupling on rough ice attenuates the signal in this area. When combined with other recent mass-balance and structural glaciology studies of MIS, our results could contribute to one of the most high-resolution physical models of an ice shelf in Antarctica. Article in Journal/Newspaper Annals of Glaciology Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf Black Island Directory of Open Access Journals: DOAJ Articles Black Island ENVELOPE(70.100,70.100,-49.440,-49.440) McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) Annals of Glaciology 58 74 1 11 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
glacier geophysics glacier mapping ground-penetrating radar ice/ocean interactions ice shelves Meteorology. Climatology QC851-999 |
spellingShingle |
glacier geophysics glacier mapping ground-penetrating radar ice/ocean interactions ice shelves Meteorology. Climatology QC851-999 S. Campbell Z. Courville S. Sinclair J. Wilner Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica |
topic_facet |
glacier geophysics glacier mapping ground-penetrating radar ice/ocean interactions ice shelves Meteorology. Climatology QC851-999 |
description |
We collected ~1300 km of ground-penetrating radar profiles over McMurdo Ice Shelf, Antarctica, using frequencies between 40 and 400 MHz to determine extent, continuity and depth to the brine. We also used profiles to determine meteoric ice thickness and locate englacial features, which may suggest ice shelf instability. The brine extends 9–13 km inland from the ice shelf terminus and covers the entire region between Ross, White and Black Islands. Jump unconformities and basal fractures exist in the brine and ice shelf, respectively, suggesting prior fracturing and re-suturing. One 100 MHz profile, the most distal from the ice shelf edge while still being situated over the brine, simultaneously imaged the brine and bottom of meteoric ice. This suggests a negative brine salinity gradient moving away from the terminus. The meteoric ice bottom was also imaged in a few select locations through blue ice in the ablation zone near Black Island. We suggest that brine, sediment-rich ice and poor antenna coupling on rough ice attenuates the signal in this area. When combined with other recent mass-balance and structural glaciology studies of MIS, our results could contribute to one of the most high-resolution physical models of an ice shelf in Antarctica. |
format |
Article in Journal/Newspaper |
author |
S. Campbell Z. Courville S. Sinclair J. Wilner |
author_facet |
S. Campbell Z. Courville S. Sinclair J. Wilner |
author_sort |
S. Campbell |
title |
Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica |
title_short |
Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica |
title_full |
Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica |
title_fullStr |
Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica |
title_full_unstemmed |
Brine, englacial structure and basal properties near the terminus of McMurdo Ice Shelf, Antarctica |
title_sort |
brine, englacial structure and basal properties near the terminus of mcmurdo ice shelf, antarctica |
publisher |
Cambridge University Press |
publishDate |
2017 |
url |
https://doi.org/10.1017/aog.2017.26 https://doaj.org/article/b73eb71b27754353b9082ea3884e1156 |
long_lat |
ENVELOPE(70.100,70.100,-49.440,-49.440) ENVELOPE(166.500,166.500,-78.000,-78.000) |
geographic |
Black Island McMurdo Ice Shelf |
geographic_facet |
Black Island McMurdo Ice Shelf |
genre |
Annals of Glaciology Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf Black Island |
genre_facet |
Annals of Glaciology Antarc* Antarctica Ice Shelf Ice Shelves McMurdo Ice Shelf Black Island |
op_source |
Annals of Glaciology, Vol 58, Pp 1-11 (2017) |
op_relation |
https://www.cambridge.org/core/product/identifier/S026030551700026X/type/journal_article https://doaj.org/toc/0260-3055 https://doaj.org/toc/1727-5644 doi:10.1017/aog.2017.26 0260-3055 1727-5644 https://doaj.org/article/b73eb71b27754353b9082ea3884e1156 |
op_doi |
https://doi.org/10.1017/aog.2017.26 |
container_title |
Annals of Glaciology |
container_volume |
58 |
container_issue |
74 |
container_start_page |
1 |
op_container_end_page |
11 |
_version_ |
1766001051028160512 |