Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years
A 7000 year-long cirque glacier reconstruction from South Georgia, based on detailed analysis of fine-grained sediments deposited downstream in a bog and a lake, suggests continued presence during most of the Holocene. Glacier activity is inferred from various sedimentary properties including magnet...
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ftdoajarticles:oai:doaj.org/article:05560942f71e4b889a508a1bfd40419f 2023-05-15T18:33:04+02:00 Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years Lea T. Oppedal Jostein Bakke Øyvind Paasche Johannes P. Werner Willem G. M. van der Bilt 2018-02-01T00:00:00Z https://doi.org/10.3389/feart.2018.00002 https://doaj.org/article/05560942f71e4b889a508a1bfd40419f EN eng Frontiers Media S.A. http://journal.frontiersin.org/article/10.3389/feart.2018.00002/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2018.00002 https://doaj.org/article/05560942f71e4b889a508a1bfd40419f Frontiers in Earth Science, Vol 6 (2018) glacier distal glacier-fed lake distal glacier-fed bog glacial sediments holocene neoglacial Science Q article 2018 ftdoajarticles https://doi.org/10.3389/feart.2018.00002 2022-12-31T05:12:14Z A 7000 year-long cirque glacier reconstruction from South Georgia, based on detailed analysis of fine-grained sediments deposited downstream in a bog and a lake, suggests continued presence during most of the Holocene. Glacier activity is inferred from various sedimentary properties including magnetic susceptibility (MS), dry bulk density (DBD), loss-on-ignition (LOI) and geochemical elements (XRF), and tallied to a set of terminal moraines. The two independently dated sediment records document concurring events of enhanced glacigenic sediment influx to the bog and lake, whereas the upstream moraines afford the opportunity to calculate past Equilibrium Line Altitudes (ELA) which has varied in the order of 70 m altitude. Combined, the records provide new evidence of cirque glacier fluctuations on South Georgia. Based on the onset of peat formation, the study site was deglaciated prior to 9900 ± 250 years ago when Neumayer tidewater glacier retreated up-fjord. Changes in the lake and bog sediment properties indicate that the cirque glacier was close to its maximum Holocene extent between 7200 ± 400 and 4800 ± 200 cal BP, 2700 ± 150 and 2000 ± 200 cal BP, 500 ± 150–300 ± 100 cal BP, and in the Twentieth century (likely 1930s). The glacier fluctuations are largely in-phase with reconstructed Patagonian glaciers, implying that they respond to centennial climate variability possibly connected to corresponding modulations of the Southern Westerly Winds. Article in Journal/Newspaper Tidewater Directory of Open Access Journals: DOAJ Articles Neumayer Ela ENVELOPE(9.642,9.642,63.170,63.170) Frontiers in Earth Science 6 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
glacier distal glacier-fed lake distal glacier-fed bog glacial sediments holocene neoglacial Science Q |
spellingShingle |
glacier distal glacier-fed lake distal glacier-fed bog glacial sediments holocene neoglacial Science Q Lea T. Oppedal Jostein Bakke Øyvind Paasche Johannes P. Werner Willem G. M. van der Bilt Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years |
topic_facet |
glacier distal glacier-fed lake distal glacier-fed bog glacial sediments holocene neoglacial Science Q |
description |
A 7000 year-long cirque glacier reconstruction from South Georgia, based on detailed analysis of fine-grained sediments deposited downstream in a bog and a lake, suggests continued presence during most of the Holocene. Glacier activity is inferred from various sedimentary properties including magnetic susceptibility (MS), dry bulk density (DBD), loss-on-ignition (LOI) and geochemical elements (XRF), and tallied to a set of terminal moraines. The two independently dated sediment records document concurring events of enhanced glacigenic sediment influx to the bog and lake, whereas the upstream moraines afford the opportunity to calculate past Equilibrium Line Altitudes (ELA) which has varied in the order of 70 m altitude. Combined, the records provide new evidence of cirque glacier fluctuations on South Georgia. Based on the onset of peat formation, the study site was deglaciated prior to 9900 ± 250 years ago when Neumayer tidewater glacier retreated up-fjord. Changes in the lake and bog sediment properties indicate that the cirque glacier was close to its maximum Holocene extent between 7200 ± 400 and 4800 ± 200 cal BP, 2700 ± 150 and 2000 ± 200 cal BP, 500 ± 150–300 ± 100 cal BP, and in the Twentieth century (likely 1930s). The glacier fluctuations are largely in-phase with reconstructed Patagonian glaciers, implying that they respond to centennial climate variability possibly connected to corresponding modulations of the Southern Westerly Winds. |
format |
Article in Journal/Newspaper |
author |
Lea T. Oppedal Jostein Bakke Øyvind Paasche Johannes P. Werner Willem G. M. van der Bilt |
author_facet |
Lea T. Oppedal Jostein Bakke Øyvind Paasche Johannes P. Werner Willem G. M. van der Bilt |
author_sort |
Lea T. Oppedal |
title |
Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years |
title_short |
Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years |
title_full |
Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years |
title_fullStr |
Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years |
title_full_unstemmed |
Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years |
title_sort |
cirque glacier on south georgia shows centennial variability over the last 7000 years |
publisher |
Frontiers Media S.A. |
publishDate |
2018 |
url |
https://doi.org/10.3389/feart.2018.00002 https://doaj.org/article/05560942f71e4b889a508a1bfd40419f |
long_lat |
ENVELOPE(9.642,9.642,63.170,63.170) |
geographic |
Neumayer Ela |
geographic_facet |
Neumayer Ela |
genre |
Tidewater |
genre_facet |
Tidewater |
op_source |
Frontiers in Earth Science, Vol 6 (2018) |
op_relation |
http://journal.frontiersin.org/article/10.3389/feart.2018.00002/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2018.00002 https://doaj.org/article/05560942f71e4b889a508a1bfd40419f |
op_doi |
https://doi.org/10.3389/feart.2018.00002 |
container_title |
Frontiers in Earth Science |
container_volume |
6 |
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1766217350870204416 |