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 (δD, δ18O and δ17O...
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Copernicus Publications
2016
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00012809 2023-05-15T13:34:49+02:00 Non-climatic signal in ice core records: lessons from Antarctic megadunes Ekaykin, Alexey Eberlein, Lutz Lipenkov, Vladimir Popov, Sergey Scheinert, Mirko Schröder, Ludwig Turkeev, Alexey 2016-06 electronic https://doi.org/10.5194/tc-10-1217-2016 https://noa.gwlb.de/receive/cop_mods_00012809 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00012765/tc-10-1217-2016.pdf https://tc.copernicus.org/articles/10/1217/2016/tc-10-1217-2016.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-10-1217-2016 https://noa.gwlb.de/receive/cop_mods_00012809 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00012765/tc-10-1217-2016.pdf https://tc.copernicus.org/articles/10/1217/2016/tc-10-1217-2016.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2016 ftnonlinearchiv https://doi.org/10.5194/tc-10-1217-2016 2022-02-08T22:55:54Z 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 (δD, δ18O and δ17O) 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 ∕ δD and 17O-excess ∕ δD slopes (where dxs = δD − 8 ⋅ δ18O and 17O-excess = ln(δ17O ∕ 1000 + 1) −0.528 ⋅ ln (δ18O ∕ 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 isotopic composition obtained from a core drilled in the megadune area. We note that the two profiles are very similar. The obtained results are discussed in terms of interpretation of data obtained from ice cores drilled beyond the megadune areas. Article in Journal/Newspaper Antarc* Antarctic Antarctica East Antarctica ice core The Cryosphere Niedersächsisches Online-Archiv NOA Antarctic East Antarctica Vostok Station ENVELOPE(106.837,106.837,-78.464,-78.464) The Cryosphere 10 3 1217 1227 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
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article Verlagsveröffentlichung Ekaykin, Alexey Eberlein, Lutz Lipenkov, Vladimir Popov, Sergey Scheinert, Mirko Schröder, Ludwig Turkeev, Alexey Non-climatic signal in ice core records: lessons from Antarctic megadunes |
topic_facet |
article Verlagsveröffentlichung |
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 (δD, δ18O and δ17O) 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 ∕ δD and 17O-excess ∕ δD slopes (where dxs = δD − 8 ⋅ δ18O and 17O-excess = ln(δ17O ∕ 1000 + 1) −0.528 ⋅ ln (δ18O ∕ 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 isotopic composition obtained from a core drilled in the megadune area. We note that the two profiles are very similar. The obtained results are discussed in terms of interpretation of data obtained from ice cores drilled beyond the megadune areas. |
format |
Article in Journal/Newspaper |
author |
Ekaykin, Alexey Eberlein, Lutz Lipenkov, Vladimir Popov, Sergey Scheinert, Mirko Schröder, Ludwig Turkeev, Alexey |
author_facet |
Ekaykin, Alexey Eberlein, Lutz Lipenkov, Vladimir Popov, Sergey Scheinert, Mirko Schröder, Ludwig Turkeev, Alexey |
author_sort |
Ekaykin, Alexey |
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://noa.gwlb.de/receive/cop_mods_00012809 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00012765/tc-10-1217-2016.pdf https://tc.copernicus.org/articles/10/1217/2016/tc-10-1217-2016.pdf |
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_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-10-1217-2016 https://noa.gwlb.de/receive/cop_mods_00012809 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00012765/tc-10-1217-2016.pdf https://tc.copernicus.org/articles/10/1217/2016/tc-10-1217-2016.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
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_ |
1766057781078523904 |