Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core
An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near future, it is essential to judge how deep these records remain unaltered, since the proximity of the b...
Published in: | The Cryosphere |
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COPERNICUS GESELLSCHAFT MBH
2015
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Online Access: | https://epic.awi.de/id/eprint/38864/ https://epic.awi.de/id/eprint/38864/1/tc-9-1633-2015.pdf http://www.the-cryosphere.net/9/1633/2015/tc-9-1633-2015.html https://hdl.handle.net/10013/epic.46117 https://hdl.handle.net/10013/epic.46117.d001 |
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ftawi:oai:epic.awi.de:38864 2024-09-09T19:08:14+00:00 Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core Tison, Jean-Louis de Angelis, M. Littot, G. Wolff, Eric Ficher, Hubertus Hansson, M. Bigler, Matthias Udisti, Roberto Wegner, Anna Jouzel, Jean Stenni, Barbara Johnsen, Sigfus J. Masson-Delmotte, Valerie Landais, Amaelle Lipenkov, V. Loulergue, L. Barnola, J.-M. Petit, J. R. Delmonte, Barbara Dreyfus, G. Dahl-Jensen, Dorthe Durand, G. Bereiter, Bernhard Schilt, A. Spahni, Renato Pol, K. Lorrain, R. Souchez, R. Samyn, D. 2015-08-20 application/pdf https://epic.awi.de/id/eprint/38864/ https://epic.awi.de/id/eprint/38864/1/tc-9-1633-2015.pdf http://www.the-cryosphere.net/9/1633/2015/tc-9-1633-2015.html https://hdl.handle.net/10013/epic.46117 https://hdl.handle.net/10013/epic.46117.d001 unknown COPERNICUS GESELLSCHAFT MBH https://epic.awi.de/id/eprint/38864/1/tc-9-1633-2015.pdf https://hdl.handle.net/10013/epic.46117.d001 Tison, J. L. , de Angelis, M. , Littot, G. , Wolff, E. , Ficher, H. , Hansson, M. , Bigler, M. , Udisti, R. , Wegner, A. , Jouzel, J. , Stenni, B. , Johnsen, S. J. , Masson-Delmotte, V. , Landais, A. , Lipenkov, V. , Loulergue, L. , Barnola, J. M. , Petit, J. R. , Delmonte, B. , Dreyfus, G. , Dahl-Jensen, D. , Durand, G. , Bereiter, B. , Schilt, A. , Spahni, R. , Pol, K. , Lorrain, R. , Souchez, R. and Samyn, D. (2015) Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core , The Cryosphere, 9 , pp. 1633-1648 . doi:10.5194/tc-9-1633-2015 <https://doi.org/10.5194/tc-9-1633-2015> , hdl:10013/epic.46117 EPIC3The Cryosphere, COPERNICUS GESELLSCHAFT MBH, 9, pp. 1633-1648, ISSN: 1994-0416 Article isiRev 2015 ftawi https://doi.org/10.5194/tc-9-1633-2015 2024-06-24T04:12:21Z An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near future, it is essential to judge how deep these records remain unaltered, since the proximity of the bedrock is likely to interfere both with the recorded temporal sequence and the ice properties. In this paper, we present a multiparametric study (δD-δ18Oice, δ18Oatm, total air content, CO2, CH4, N2O, dust, high-resolution chemistry, ice texture) of the bottom 60 m of the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core from central Antarctica. These bottom layers were subdivided into two distinct facies: the lower 12 m showing visible solid inclusions (basal dispersed ice facies) and the upper 48 m, which we will refer to as the "basal clean ice facies". Some of the data are consistent with a pristine paleoclimatic signal, others show clear anomalies. It is demonstrated that neither large-scale bottom refreezing of subglacial water, nor mixing (be it internal or with a local basal end term from a previous/initial ice sheet configuration) can explain the observed bottom-ice properties. We focus on the high-resolution chemical profiles and on the available remote sensing data on the subglacial topography of the site to propose a mechanism by which relative stretching of the bottom-ice sheet layers is made possible, due to the progressively confining effect of subglacial valley sides. This stress field change, combined with bottom-ice temperature close to the pressure melting point, induces accelerated migration recrystallization, which results in spatial chemical sorting of the impurities, depending on their state (dissolved vs. solid) and if they are involved or not in salt formation. This chemical sorting effect is responsible for the progressive build-up of the visible solid aggregates that therefore mainly originate "from within", and not from incorporation processes of debris from the ice ... Article in Journal/Newspaper Antarc* Antarctica EPICA ice core Ice Sheet The Cryosphere Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) The Cryosphere 9 4 1633 1648 |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
An important share of paleoclimatic information is buried within the lowermost layers of deep ice cores. Because improving our records further back in time is one of the main challenges in the near future, it is essential to judge how deep these records remain unaltered, since the proximity of the bedrock is likely to interfere both with the recorded temporal sequence and the ice properties. In this paper, we present a multiparametric study (δD-δ18Oice, δ18Oatm, total air content, CO2, CH4, N2O, dust, high-resolution chemistry, ice texture) of the bottom 60 m of the EPICA (European Project for Ice Coring in Antarctica) Dome C ice core from central Antarctica. These bottom layers were subdivided into two distinct facies: the lower 12 m showing visible solid inclusions (basal dispersed ice facies) and the upper 48 m, which we will refer to as the "basal clean ice facies". Some of the data are consistent with a pristine paleoclimatic signal, others show clear anomalies. It is demonstrated that neither large-scale bottom refreezing of subglacial water, nor mixing (be it internal or with a local basal end term from a previous/initial ice sheet configuration) can explain the observed bottom-ice properties. We focus on the high-resolution chemical profiles and on the available remote sensing data on the subglacial topography of the site to propose a mechanism by which relative stretching of the bottom-ice sheet layers is made possible, due to the progressively confining effect of subglacial valley sides. This stress field change, combined with bottom-ice temperature close to the pressure melting point, induces accelerated migration recrystallization, which results in spatial chemical sorting of the impurities, depending on their state (dissolved vs. solid) and if they are involved or not in salt formation. This chemical sorting effect is responsible for the progressive build-up of the visible solid aggregates that therefore mainly originate "from within", and not from incorporation processes of debris from the ice ... |
format |
Article in Journal/Newspaper |
author |
Tison, Jean-Louis de Angelis, M. Littot, G. Wolff, Eric Ficher, Hubertus Hansson, M. Bigler, Matthias Udisti, Roberto Wegner, Anna Jouzel, Jean Stenni, Barbara Johnsen, Sigfus J. Masson-Delmotte, Valerie Landais, Amaelle Lipenkov, V. Loulergue, L. Barnola, J.-M. Petit, J. R. Delmonte, Barbara Dreyfus, G. Dahl-Jensen, Dorthe Durand, G. Bereiter, Bernhard Schilt, A. Spahni, Renato Pol, K. Lorrain, R. Souchez, R. Samyn, D. |
spellingShingle |
Tison, Jean-Louis de Angelis, M. Littot, G. Wolff, Eric Ficher, Hubertus Hansson, M. Bigler, Matthias Udisti, Roberto Wegner, Anna Jouzel, Jean Stenni, Barbara Johnsen, Sigfus J. Masson-Delmotte, Valerie Landais, Amaelle Lipenkov, V. Loulergue, L. Barnola, J.-M. Petit, J. R. Delmonte, Barbara Dreyfus, G. Dahl-Jensen, Dorthe Durand, G. Bereiter, Bernhard Schilt, A. Spahni, Renato Pol, K. Lorrain, R. Souchez, R. Samyn, D. Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core |
author_facet |
Tison, Jean-Louis de Angelis, M. Littot, G. Wolff, Eric Ficher, Hubertus Hansson, M. Bigler, Matthias Udisti, Roberto Wegner, Anna Jouzel, Jean Stenni, Barbara Johnsen, Sigfus J. Masson-Delmotte, Valerie Landais, Amaelle Lipenkov, V. Loulergue, L. Barnola, J.-M. Petit, J. R. Delmonte, Barbara Dreyfus, G. Dahl-Jensen, Dorthe Durand, G. Bereiter, Bernhard Schilt, A. Spahni, Renato Pol, K. Lorrain, R. Souchez, R. Samyn, D. |
author_sort |
Tison, Jean-Louis |
title |
Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core |
title_short |
Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core |
title_full |
Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core |
title_fullStr |
Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core |
title_full_unstemmed |
Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core |
title_sort |
retrieving the paleoclimatic signal from the deeper part of the epica dome c ice core |
publisher |
COPERNICUS GESELLSCHAFT MBH |
publishDate |
2015 |
url |
https://epic.awi.de/id/eprint/38864/ https://epic.awi.de/id/eprint/38864/1/tc-9-1633-2015.pdf http://www.the-cryosphere.net/9/1633/2015/tc-9-1633-2015.html https://hdl.handle.net/10013/epic.46117 https://hdl.handle.net/10013/epic.46117.d001 |
genre |
Antarc* Antarctica EPICA ice core Ice Sheet The Cryosphere |
genre_facet |
Antarc* Antarctica EPICA ice core Ice Sheet The Cryosphere |
op_source |
EPIC3The Cryosphere, COPERNICUS GESELLSCHAFT MBH, 9, pp. 1633-1648, ISSN: 1994-0416 |
op_relation |
https://epic.awi.de/id/eprint/38864/1/tc-9-1633-2015.pdf https://hdl.handle.net/10013/epic.46117.d001 Tison, J. L. , de Angelis, M. , Littot, G. , Wolff, E. , Ficher, H. , Hansson, M. , Bigler, M. , Udisti, R. , Wegner, A. , Jouzel, J. , Stenni, B. , Johnsen, S. J. , Masson-Delmotte, V. , Landais, A. , Lipenkov, V. , Loulergue, L. , Barnola, J. M. , Petit, J. R. , Delmonte, B. , Dreyfus, G. , Dahl-Jensen, D. , Durand, G. , Bereiter, B. , Schilt, A. , Spahni, R. , Pol, K. , Lorrain, R. , Souchez, R. and Samyn, D. (2015) Retrieving the paleoclimatic signal from the deeper part of the EPICA Dome C ice core , The Cryosphere, 9 , pp. 1633-1648 . doi:10.5194/tc-9-1633-2015 <https://doi.org/10.5194/tc-9-1633-2015> , hdl:10013/epic.46117 |
op_doi |
https://doi.org/10.5194/tc-9-1633-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
4 |
container_start_page |
1633 |
op_container_end_page |
1648 |
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1809822438527074304 |