A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al
The distribution of moraines in the Transantarctic Mountains affords direct constraint of past ice-marginal positions of the East Antarctic Ice Sheet (EAIS). Here, we describe glacial geologic observations and cosmogenic-nuclide exposure ages from Roberts Massif, an ice-free area in the central Tran...
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ftdoajarticles:oai:doaj.org/article:71074f5134e24259830dea2403939088 2023-05-15T13:45:34+02:00 A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al A. Balter-Kennedy G. Bromley G. Balco H. Thomas M. S. Jackson 2020-08-01T00:00:00Z https://doi.org/10.5194/tc-14-2647-2020 https://doaj.org/article/71074f5134e24259830dea2403939088 EN eng Copernicus Publications https://tc.copernicus.org/articles/14/2647/2020/tc-14-2647-2020.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-14-2647-2020 1994-0416 1994-0424 https://doaj.org/article/71074f5134e24259830dea2403939088 The Cryosphere, Vol 14, Pp 2647-2672 (2020) Environmental sciences GE1-350 Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.5194/tc-14-2647-2020 2022-12-31T03:32:09Z The distribution of moraines in the Transantarctic Mountains affords direct constraint of past ice-marginal positions of the East Antarctic Ice Sheet (EAIS). Here, we describe glacial geologic observations and cosmogenic-nuclide exposure ages from Roberts Massif, an ice-free area in the central Transantarctic Mountains. We measured cosmogenic 3 He , 10 Be , 21 Ne , and 26 Al in 168 dolerite and sandstone boulders collected from 24 distinct deposits. Our data show that a cold-based EAIS was present, in a configuration similar to today, for many periods over the last ∼14.5 Myr, including the mid-Miocene, late Pliocene, and early to Middle Pleistocene. Moraine ages at Roberts Massif increase with distance from, and elevation above, the modern ice margin, which is consistent with a persistent EAIS extent during glacial maxima and slow, isostatic uplift of the massif itself in response to trough incision by outlet glaciers. We also employ the exceptionally high cosmogenic-nuclide concentrations in several boulders, along with multi-isotope measurements in sandstone boulders, to infer extremely low erosion rates ( ≪5 cm Myr −1 ) over the period covered by our record. Although our data are not a direct measure of ice volume, the Roberts Massif glacial record indicates that the EAIS was present and similar to its current configuration during at least some periods when the global temperature was believed to be warmer and/or atmospheric CO 2 concentrations were likely higher than today. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic East Antarctic Ice Sheet Transantarctic Mountains Roberts massif ENVELOPE(-177.083,-177.083,-85.533,-85.533) The Cryosphere 14 8 2647 2672 |
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 A. Balter-Kennedy G. Bromley G. Balco H. Thomas M. S. Jackson A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
The distribution of moraines in the Transantarctic Mountains affords direct constraint of past ice-marginal positions of the East Antarctic Ice Sheet (EAIS). Here, we describe glacial geologic observations and cosmogenic-nuclide exposure ages from Roberts Massif, an ice-free area in the central Transantarctic Mountains. We measured cosmogenic 3 He , 10 Be , 21 Ne , and 26 Al in 168 dolerite and sandstone boulders collected from 24 distinct deposits. Our data show that a cold-based EAIS was present, in a configuration similar to today, for many periods over the last ∼14.5 Myr, including the mid-Miocene, late Pliocene, and early to Middle Pleistocene. Moraine ages at Roberts Massif increase with distance from, and elevation above, the modern ice margin, which is consistent with a persistent EAIS extent during glacial maxima and slow, isostatic uplift of the massif itself in response to trough incision by outlet glaciers. We also employ the exceptionally high cosmogenic-nuclide concentrations in several boulders, along with multi-isotope measurements in sandstone boulders, to infer extremely low erosion rates ( ≪5 cm Myr −1 ) over the period covered by our record. Although our data are not a direct measure of ice volume, the Roberts Massif glacial record indicates that the EAIS was present and similar to its current configuration during at least some periods when the global temperature was believed to be warmer and/or atmospheric CO 2 concentrations were likely higher than today. |
format |
Article in Journal/Newspaper |
author |
A. Balter-Kennedy G. Bromley G. Balco H. Thomas M. S. Jackson |
author_facet |
A. Balter-Kennedy G. Bromley G. Balco H. Thomas M. S. Jackson |
author_sort |
A. Balter-Kennedy |
title |
A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al |
title_short |
A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al |
title_full |
A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al |
title_fullStr |
A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al |
title_full_unstemmed |
A 14.5-million-year record of East Antarctic Ice Sheet fluctuations from the central Transantarctic Mountains, constrained with cosmogenic 3 He, 10 Be, 21 Ne, and 26 Al |
title_sort |
14.5-million-year record of east antarctic ice sheet fluctuations from the central transantarctic mountains, constrained with cosmogenic 3 he, 10 be, 21 ne, and 26 al |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-2647-2020 https://doaj.org/article/71074f5134e24259830dea2403939088 |
long_lat |
ENVELOPE(-177.083,-177.083,-85.533,-85.533) |
geographic |
Antarctic East Antarctic Ice Sheet Transantarctic Mountains Roberts massif |
geographic_facet |
Antarctic East Antarctic Ice Sheet Transantarctic Mountains Roberts massif |
genre |
Antarc* Antarctic Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctic Ice Sheet The Cryosphere |
op_source |
The Cryosphere, Vol 14, Pp 2647-2672 (2020) |
op_relation |
https://tc.copernicus.org/articles/14/2647/2020/tc-14-2647-2020.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-14-2647-2020 1994-0416 1994-0424 https://doaj.org/article/71074f5134e24259830dea2403939088 |
op_doi |
https://doi.org/10.5194/tc-14-2647-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
8 |
container_start_page |
2647 |
op_container_end_page |
2672 |
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1766227497425305600 |