Non-climatic signal in ice core records: lessons from Antarctic megadunes
We present the results of glaciological investigations in the megadune area located 30 km to the east of Vostok Station (central East Antarctica) implemented during the 58th, 59th and 60th Russian Antarctic Expedition (January 2013–2015). Snow accumulation rate and isotope content ( δ D , δ 18 O and...
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Copernicus Publications
2016
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ftdoajarticles:oai:doaj.org/article:ca007c2177aa4d14926e5360963faae7 2023-05-15T13:58:20+02:00 Non-climatic signal in ice core records: lessons from Antarctic megadunes A. Ekaykin L. Eberlein V. Lipenkov S. Popov M. Scheinert L. Schröder A. Turkeev 2016-06-01T00:00:00Z https://doi.org/10.5194/tc-10-1217-2016 https://doaj.org/article/ca007c2177aa4d14926e5360963faae7 EN eng Copernicus Publications http://www.the-cryosphere.net/10/1217/2016/tc-10-1217-2016.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-10-1217-2016 https://doaj.org/article/ca007c2177aa4d14926e5360963faae7 The Cryosphere, Vol 10, Iss 3, Pp 1217-1227 (2016) Environmental sciences GE1-350 Geology QE1-996.5 article 2016 ftdoajarticles https://doi.org/10.5194/tc-10-1217-2016 2022-12-31T13:34:33Z We present the results of glaciological investigations in the megadune area located 30 km to the east of Vostok Station (central East Antarctica) implemented during the 58th, 59th and 60th Russian Antarctic Expedition (January 2013–2015). Snow accumulation rate and isotope content ( δ D , δ 18 O and δ 17 O) were measured along the 2 km profile across the megadune ridge accompanied by precise GPS altitude measurements and ground penetrating radar (GPR) survey. It is shown that the spatial variability of snow accumulation and isotope content covaries with the surface slope. The accumulation rate regularly changes by 1 order of magnitude within the distance < 1 km, with the reduced accumulation at the leeward slope of the dune and increased accumulation in the hollow between the dunes. At the same time, the accumulation rate averaged over the length of a dune wave (22 mm w.e.) corresponds well with the value obtained at Vostok Station, which suggests no additional wind-driven snow sublimation in the megadunes compared to the surrounding plateau. The snow isotopic composition is in negative correlation with the snow accumulation. Analysing dxs ∕ δ D and 17 O-excess ∕ δ D slopes (where dxs = δ D − 8 ⋅ δ 18 O and 17 O-excess = ln( δ 17 O ∕ 1000 + 1) −0.528 ⋅ ln ( δ 18 O ∕ 1000 + 1)), we conclude that the spatial variability of the snow isotopic composition in the megadune area could be explained by post-depositional snow modifications. Using the GPR data, we estimated the apparent dune drift velocity (4.6 ± 1.1 m yr −1 ). The full cycle of the dune drift is thus about 410 years. Since the spatial anomalies of snow accumulation and isotopic composition are supposed to drift with the dune, a core drilled in the megadune area would exhibit the non-climatic 410-year cycle of these two parameters. We simulated a vertical profile of snow isotopic composition with such a non-climatic variability, using the data on the dune size and velocity. This artificial profile is then compared with the real vertical profile of snow ... Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica ice core The Cryosphere Directory of Open Access Journals: DOAJ Articles Antarctic East Antarctica Vostok Station ENVELOPE(106.837,106.837,-78.464,-78.464) The Cryosphere 10 3 1217 1227 |
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. Ekaykin L. Eberlein V. Lipenkov S. Popov M. Scheinert L. Schröder A. Turkeev Non-climatic signal in ice core records: lessons from Antarctic megadunes |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
We present the results of glaciological investigations in the megadune area located 30 km to the east of Vostok Station (central East Antarctica) implemented during the 58th, 59th and 60th Russian Antarctic Expedition (January 2013–2015). Snow accumulation rate and isotope content ( δ D , δ 18 O and δ 17 O) were measured along the 2 km profile across the megadune ridge accompanied by precise GPS altitude measurements and ground penetrating radar (GPR) survey. It is shown that the spatial variability of snow accumulation and isotope content covaries with the surface slope. The accumulation rate regularly changes by 1 order of magnitude within the distance < 1 km, with the reduced accumulation at the leeward slope of the dune and increased accumulation in the hollow between the dunes. At the same time, the accumulation rate averaged over the length of a dune wave (22 mm w.e.) corresponds well with the value obtained at Vostok Station, which suggests no additional wind-driven snow sublimation in the megadunes compared to the surrounding plateau. The snow isotopic composition is in negative correlation with the snow accumulation. Analysing dxs ∕ δ D and 17 O-excess ∕ δ D slopes (where dxs = δ D − 8 ⋅ δ 18 O and 17 O-excess = ln( δ 17 O ∕ 1000 + 1) −0.528 ⋅ ln ( δ 18 O ∕ 1000 + 1)), we conclude that the spatial variability of the snow isotopic composition in the megadune area could be explained by post-depositional snow modifications. Using the GPR data, we estimated the apparent dune drift velocity (4.6 ± 1.1 m yr −1 ). The full cycle of the dune drift is thus about 410 years. Since the spatial anomalies of snow accumulation and isotopic composition are supposed to drift with the dune, a core drilled in the megadune area would exhibit the non-climatic 410-year cycle of these two parameters. We simulated a vertical profile of snow isotopic composition with such a non-climatic variability, using the data on the dune size and velocity. This artificial profile is then compared with the real vertical profile of snow ... |
format |
Article in Journal/Newspaper |
author |
A. Ekaykin L. Eberlein V. Lipenkov S. Popov M. Scheinert L. Schröder A. Turkeev |
author_facet |
A. Ekaykin L. Eberlein V. Lipenkov S. Popov M. Scheinert L. Schröder A. Turkeev |
author_sort |
A. Ekaykin |
title |
Non-climatic signal in ice core records: lessons from Antarctic megadunes |
title_short |
Non-climatic signal in ice core records: lessons from Antarctic megadunes |
title_full |
Non-climatic signal in ice core records: lessons from Antarctic megadunes |
title_fullStr |
Non-climatic signal in ice core records: lessons from Antarctic megadunes |
title_full_unstemmed |
Non-climatic signal in ice core records: lessons from Antarctic megadunes |
title_sort |
non-climatic signal in ice core records: lessons from antarctic megadunes |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/tc-10-1217-2016 https://doaj.org/article/ca007c2177aa4d14926e5360963faae7 |
long_lat |
ENVELOPE(106.837,106.837,-78.464,-78.464) |
geographic |
Antarctic East Antarctica Vostok Station |
geographic_facet |
Antarctic East Antarctica Vostok Station |
genre |
Antarc* Antarctic Antarctica East Antarctica ice core The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica ice core The Cryosphere |
op_source |
The Cryosphere, Vol 10, Iss 3, Pp 1217-1227 (2016) |
op_relation |
http://www.the-cryosphere.net/10/1217/2016/tc-10-1217-2016.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 1994-0416 1994-0424 doi:10.5194/tc-10-1217-2016 https://doaj.org/article/ca007c2177aa4d14926e5360963faae7 |
op_doi |
https://doi.org/10.5194/tc-10-1217-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
3 |
container_start_page |
1217 |
op_container_end_page |
1227 |
_version_ |
1766266578325733376 |