High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector
Understanding the past and future evolution of the Antarctic Ice Sheet is challenged by the availability and quality of observed paleo-boundary conditions. Numerical ice-sheet models often rely on these paleo-boundary conditions to guide and evaluate their models' predictions of sea-level rise,...
Published in: | The Cryosphere |
---|---|
Main Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2023
|
Subjects: | |
Online Access: | https://doi.org/10.5194/tc-17-1497-2023 https://doaj.org/article/900d0fa648fc4d84a628537ed61a88e4 |
id |
ftdoajarticles:oai:doaj.org/article:900d0fa648fc4d84a628537ed61a88e4 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:900d0fa648fc4d84a628537ed61a88e4 2023-05-15T13:36:30+02:00 High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector J. A. Bodart R. G. Bingham D. A. Young J. A. MacGregor D. W. Ashmore E. Quartini A. S. Hein D. G. Vaughan D. D. Blankenship 2023-04-01T00:00:00Z https://doi.org/10.5194/tc-17-1497-2023 https://doaj.org/article/900d0fa648fc4d84a628537ed61a88e4 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/1497/2023/tc-17-1497-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-1497-2023 1994-0416 1994-0424 https://doaj.org/article/900d0fa648fc4d84a628537ed61a88e4 The Cryosphere, Vol 17, Pp 1497-1512 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-1497-2023 2023-04-09T00:32:30Z Understanding the past and future evolution of the Antarctic Ice Sheet is challenged by the availability and quality of observed paleo-boundary conditions. Numerical ice-sheet models often rely on these paleo-boundary conditions to guide and evaluate their models' predictions of sea-level rise, with varying levels of confidence due to the sparsity of existing data across the ice sheet. A key data source for large-scale reconstruction of past ice-sheet processes are internal reflecting horizons (IRHs) detected by radio-echo sounding (RES). When IRHs are isochronal and dated at ice cores, they can be used to determine paleo-accumulation rates and patterns on large spatial scales. Using a spatially extensive IRH over the Pine Island Glacier (PIG), Thwaites Glacier (THW), and the Institute and Möller ice streams (IMIS, covering a total of 610 000 km 2 or 30 % of the West Antarctic Ice Sheet (WAIS)), and a local layer approximation model, we infer mid-Holocene accumulation rates over the slow-flowing parts of these catchments for the past ∼4700 years. By comparing our results with modern climate reanalysis models (1979–2019) and observational syntheses (1651–2010), we estimate that accumulation rates over the Amundsen–Weddell–Ross Divide were on average 18 % higher during the mid-Holocene than modern rates. However, no significant spatial changes in the accumulation pattern were observed. The higher mid-Holocene accumulation-rate estimates match previous paleo-accumulation estimates from ice-core records and targeted RES surveys over the ice divide, and they also coincide with periods of grounding-line readvance during the Holocene over the Weddell and Ross sea sectors. We find that our spatially extensive, mid-Holocene-to-present accumulation estimates are consistent with a sustained late-Holocene period of higher accumulation rates occurring over millennia reconstructed from the WAIS Divide ice core (WD14), thus indicating that this ice core is spatially representative of the wider West Antarctic region. We ... Article in Journal/Newspaper Antarc* Antarctic Antarctica ice core Ice Sheet Pine Island Pine Island Glacier Ross Sea The Cryosphere Thwaites Glacier West Antarctica Directory of Open Access Journals: DOAJ Articles Antarctic The Antarctic Ross Sea West Antarctica West Antarctic Ice Sheet Weddell Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) The Cryosphere 17 4 1497 1512 |
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 J. A. Bodart R. G. Bingham D. A. Young J. A. MacGregor D. W. Ashmore E. Quartini A. S. Hein D. G. Vaughan D. D. Blankenship High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Understanding the past and future evolution of the Antarctic Ice Sheet is challenged by the availability and quality of observed paleo-boundary conditions. Numerical ice-sheet models often rely on these paleo-boundary conditions to guide and evaluate their models' predictions of sea-level rise, with varying levels of confidence due to the sparsity of existing data across the ice sheet. A key data source for large-scale reconstruction of past ice-sheet processes are internal reflecting horizons (IRHs) detected by radio-echo sounding (RES). When IRHs are isochronal and dated at ice cores, they can be used to determine paleo-accumulation rates and patterns on large spatial scales. Using a spatially extensive IRH over the Pine Island Glacier (PIG), Thwaites Glacier (THW), and the Institute and Möller ice streams (IMIS, covering a total of 610 000 km 2 or 30 % of the West Antarctic Ice Sheet (WAIS)), and a local layer approximation model, we infer mid-Holocene accumulation rates over the slow-flowing parts of these catchments for the past ∼4700 years. By comparing our results with modern climate reanalysis models (1979–2019) and observational syntheses (1651–2010), we estimate that accumulation rates over the Amundsen–Weddell–Ross Divide were on average 18 % higher during the mid-Holocene than modern rates. However, no significant spatial changes in the accumulation pattern were observed. The higher mid-Holocene accumulation-rate estimates match previous paleo-accumulation estimates from ice-core records and targeted RES surveys over the ice divide, and they also coincide with periods of grounding-line readvance during the Holocene over the Weddell and Ross sea sectors. We find that our spatially extensive, mid-Holocene-to-present accumulation estimates are consistent with a sustained late-Holocene period of higher accumulation rates occurring over millennia reconstructed from the WAIS Divide ice core (WD14), thus indicating that this ice core is spatially representative of the wider West Antarctic region. We ... |
format |
Article in Journal/Newspaper |
author |
J. A. Bodart R. G. Bingham D. A. Young J. A. MacGregor D. W. Ashmore E. Quartini A. S. Hein D. G. Vaughan D. D. Blankenship |
author_facet |
J. A. Bodart R. G. Bingham D. A. Young J. A. MacGregor D. W. Ashmore E. Quartini A. S. Hein D. G. Vaughan D. D. Blankenship |
author_sort |
J. A. Bodart |
title |
High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector |
title_short |
High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector |
title_full |
High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector |
title_fullStr |
High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector |
title_full_unstemmed |
High mid-Holocene accumulation rates over West Antarctica inferred from a pervasive ice-penetrating radar reflector |
title_sort |
high mid-holocene accumulation rates over west antarctica inferred from a pervasive ice-penetrating radar reflector |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-1497-2023 https://doaj.org/article/900d0fa648fc4d84a628537ed61a88e4 |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic The Antarctic Ross Sea West Antarctica West Antarctic Ice Sheet Weddell Pine Island Glacier Thwaites Glacier |
geographic_facet |
Antarctic The Antarctic Ross Sea West Antarctica West Antarctic Ice Sheet Weddell Pine Island Glacier Thwaites Glacier |
genre |
Antarc* Antarctic Antarctica ice core Ice Sheet Pine Island Pine Island Glacier Ross Sea The Cryosphere Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica ice core Ice Sheet Pine Island Pine Island Glacier Ross Sea The Cryosphere Thwaites Glacier West Antarctica |
op_source |
The Cryosphere, Vol 17, Pp 1497-1512 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/1497/2023/tc-17-1497-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-1497-2023 1994-0416 1994-0424 https://doaj.org/article/900d0fa648fc4d84a628537ed61a88e4 |
op_doi |
https://doi.org/10.5194/tc-17-1497-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
4 |
container_start_page |
1497 |
op_container_end_page |
1512 |
_version_ |
1766079480143544320 |