Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures
Stable isotopes of water (δ18O and δ2H) were measured in the debris-laden ice underlying an Antarctic blue ice moraine, and in adjoining Law Glacier in the central Transantarctic Mountains. Air bubble content and morphology were assessed in shallow ice core samples. Stable isotope measurements plot...
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Cambridge University Press
2018
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Online Access: | https://doi.org/10.1017/jog.2018.4 https://doaj.org/article/620e5728db67491eaa29d3aba0c1bf23 |
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ftdoajarticles:oai:doaj.org/article:620e5728db67491eaa29d3aba0c1bf23 2023-05-15T13:45:45+02:00 Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures JOSEPH A. GRALY KATHY J. LICHT CHRISTINE M. KASSAB BROXTON W. BIRD MICHAEL R. KAPLAN 2018-04-01T00:00:00Z https://doi.org/10.1017/jog.2018.4 https://doaj.org/article/620e5728db67491eaa29d3aba0c1bf23 EN eng Cambridge University Press https://www.cambridge.org/core/product/identifier/S0022143018000047/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.4 0022-1430 1727-5652 https://doaj.org/article/620e5728db67491eaa29d3aba0c1bf23 Journal of Glaciology, Vol 64, Pp 185-196 (2018) blue ice ice core subglacial processes subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 article 2018 ftdoajarticles https://doi.org/10.1017/jog.2018.4 2023-03-12T01:30:59Z Stable isotopes of water (δ18O and δ2H) were measured in the debris-laden ice underlying an Antarctic blue ice moraine, and in adjoining Law Glacier in the central Transantarctic Mountains. Air bubble content and morphology were assessed in shallow ice core samples. Stable isotope measurements plot either on the meteoric waterline or are enriched from it. The data cluster in two groups: the ice underlying the moraine has a δ2H:δ18O slope of 5.35 ± 0.92; ice from adjoining portions of Law Glacier has a slope of 6.69 ± 1.39. This enrichment pattern suggests the moraine's underlying blue ice entrained sediment through refreezing processes acting in an open system. Glaciological conditions favorable to warm-based sediment entrainment occur 30–50 km upstream. Basal melting and refreezing are further evidenced by abundant vapor figures formed from internal melting of the ice crystals. Both the moraine ice and Law Glacier are sufficiently depleted of heavy isotopes that their ice cannot be sourced locally, but instead must be derived from far-field interior regions of the higher polar plateau. Modeled ice flow speeds suggest the ice must be at least 80 ka old, with Law Glacier's ice possibly dating to OIS 5 and moraine ice older still. Article in Journal/Newspaper Antarc* Antarctic ice core Journal of Glaciology Directory of Open Access Journals: DOAJ Articles Antarctic Transantarctic Mountains Polar Plateau ENVELOPE(0.000,0.000,-90.000,-90.000) Law Glacier ENVELOPE(162.000,162.000,-84.050,-84.050) Journal of Glaciology 64 244 185 196 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
blue ice ice core subglacial processes subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
spellingShingle |
blue ice ice core subglacial processes subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 JOSEPH A. GRALY KATHY J. LICHT CHRISTINE M. KASSAB BROXTON W. BIRD MICHAEL R. KAPLAN Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures |
topic_facet |
blue ice ice core subglacial processes subglacial sediments Environmental sciences GE1-350 Meteorology. Climatology QC851-999 |
description |
Stable isotopes of water (δ18O and δ2H) were measured in the debris-laden ice underlying an Antarctic blue ice moraine, and in adjoining Law Glacier in the central Transantarctic Mountains. Air bubble content and morphology were assessed in shallow ice core samples. Stable isotope measurements plot either on the meteoric waterline or are enriched from it. The data cluster in two groups: the ice underlying the moraine has a δ2H:δ18O slope of 5.35 ± 0.92; ice from adjoining portions of Law Glacier has a slope of 6.69 ± 1.39. This enrichment pattern suggests the moraine's underlying blue ice entrained sediment through refreezing processes acting in an open system. Glaciological conditions favorable to warm-based sediment entrainment occur 30–50 km upstream. Basal melting and refreezing are further evidenced by abundant vapor figures formed from internal melting of the ice crystals. Both the moraine ice and Law Glacier are sufficiently depleted of heavy isotopes that their ice cannot be sourced locally, but instead must be derived from far-field interior regions of the higher polar plateau. Modeled ice flow speeds suggest the ice must be at least 80 ka old, with Law Glacier's ice possibly dating to OIS 5 and moraine ice older still. |
format |
Article in Journal/Newspaper |
author |
JOSEPH A. GRALY KATHY J. LICHT CHRISTINE M. KASSAB BROXTON W. BIRD MICHAEL R. KAPLAN |
author_facet |
JOSEPH A. GRALY KATHY J. LICHT CHRISTINE M. KASSAB BROXTON W. BIRD MICHAEL R. KAPLAN |
author_sort |
JOSEPH A. GRALY |
title |
Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures |
title_short |
Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures |
title_full |
Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures |
title_fullStr |
Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures |
title_full_unstemmed |
Warm-based basal sediment entrainment and far-field Pleistocene origin evidenced in central Transantarctic blue ice through stable isotopes and internal structures |
title_sort |
warm-based basal sediment entrainment and far-field pleistocene origin evidenced in central transantarctic blue ice through stable isotopes and internal structures |
publisher |
Cambridge University Press |
publishDate |
2018 |
url |
https://doi.org/10.1017/jog.2018.4 https://doaj.org/article/620e5728db67491eaa29d3aba0c1bf23 |
long_lat |
ENVELOPE(0.000,0.000,-90.000,-90.000) ENVELOPE(162.000,162.000,-84.050,-84.050) |
geographic |
Antarctic Transantarctic Mountains Polar Plateau Law Glacier |
geographic_facet |
Antarctic Transantarctic Mountains Polar Plateau Law Glacier |
genre |
Antarc* Antarctic ice core Journal of Glaciology |
genre_facet |
Antarc* Antarctic ice core Journal of Glaciology |
op_source |
Journal of Glaciology, Vol 64, Pp 185-196 (2018) |
op_relation |
https://www.cambridge.org/core/product/identifier/S0022143018000047/type/journal_article https://doaj.org/toc/0022-1430 https://doaj.org/toc/1727-5652 doi:10.1017/jog.2018.4 0022-1430 1727-5652 https://doaj.org/article/620e5728db67491eaa29d3aba0c1bf23 |
op_doi |
https://doi.org/10.1017/jog.2018.4 |
container_title |
Journal of Glaciology |
container_volume |
64 |
container_issue |
244 |
container_start_page |
185 |
op_container_end_page |
196 |
_version_ |
1766230557340991488 |