New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr
International audience Gas is trapped in polar ice sheets at ~50–120 m below the surface and is therefore younger than the surrounding ice. Firn densification models are used to evaluate this ice age-gas age difference (?age) in the past. However, such models need to be validated by data, in particu...
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Format: | Article in Journal/Newspaper |
Language: | English |
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HAL CCSD
2007
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Online Access: | https://hal.science/hal-00330764 https://hal.science/hal-00330764/document https://hal.science/hal-00330764/file/cp-3-527-2007.pdf |
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ftunigrenoble:oai:HAL:hal-00330764v1 |
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openpolar |
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Open Polar |
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Université Grenoble Alpes: HAL |
op_collection_id |
ftunigrenoble |
language |
English |
topic |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
spellingShingle |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences Loulergue, L. Parrenin, F. Blunier, T. Barnola, J.-M. Spahni, R. Schilt, A. Raisbeck, G. Chappellaz, J. New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr |
topic_facet |
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
description |
International audience Gas is trapped in polar ice sheets at ~50–120 m below the surface and is therefore younger than the surrounding ice. Firn densification models are used to evaluate this ice age-gas age difference (?age) in the past. However, such models need to be validated by data, in particular for periods colder than present day on the East Antarctic plateau. Here we bring new constraints to test a firn densification model applied to the EPICA Dome C (EDC) site for the last 50 kyr, by linking the EDC ice core to the EPICA Dronning Maud Land (EDML) ice core, both in the ice phase (using volcanic horizons) and in the gas phase (using rapid methane variations). We also use the structured 10 Be peak, occurring 41 kyr before present (BP) and due to the low geomagnetic field associated with the Laschamp event, to experimentally estimate the ?age during this event. Our results seem to reveal an overestimate of the ?age by the firn densification model during the last glacial period at EDC. Tests with different accumulation rates and temperature scenarios do not entirely resolve this discrepancy. Although the exact reasons for the ?age overestimate at the two EPICA sites remain unknown at this stage, we conclude that current densification model simulations have deficits under glacial climatic conditions. Whatever the cause of the ?age overestimate, our finding suggests that the phase relationship between CO 2 and EDC temperature previously inferred for the start of the last deglaciation (lag of CO 2 by 800±600 yr) seems to be overestimated. |
author2 |
Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Climate and Environmental Physics Bern (CEP) Physikalisches Institut Bern Universität Bern / University of Bern (UNIBE)-Universität Bern / University of Bern (UNIBE) Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM) Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Loulergue, L. Parrenin, F. Blunier, T. Barnola, J.-M. Spahni, R. Schilt, A. Raisbeck, G. Chappellaz, J. |
author_facet |
Loulergue, L. Parrenin, F. Blunier, T. Barnola, J.-M. Spahni, R. Schilt, A. Raisbeck, G. Chappellaz, J. |
author_sort |
Loulergue, L. |
title |
New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr |
title_short |
New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr |
title_full |
New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr |
title_fullStr |
New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr |
title_full_unstemmed |
New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr |
title_sort |
new constraints on the gas age-ice age difference along the epica ice cores, 0–50 kyr |
publisher |
HAL CCSD |
publishDate |
2007 |
url |
https://hal.science/hal-00330764 https://hal.science/hal-00330764/document https://hal.science/hal-00330764/file/cp-3-527-2007.pdf |
geographic |
Antarctic Dronning Maud Land |
geographic_facet |
Antarctic Dronning Maud Land |
genre |
Antarc* Antarctic Dronning Maud Land EPICA ice core |
genre_facet |
Antarc* Antarctic Dronning Maud Land EPICA ice core |
op_source |
ISSN: 1814-9324 EISSN: 1814-9332 Climate of the Past https://hal.science/hal-00330764 Climate of the Past, 2007, 3 (3), pp.527-540 |
op_relation |
hal-00330764 https://hal.science/hal-00330764 https://hal.science/hal-00330764/document https://hal.science/hal-00330764/file/cp-3-527-2007.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1798836309651881984 |
spelling |
ftunigrenoble:oai:HAL:hal-00330764v1 2024-05-12T07:56:18+00:00 New constraints on the gas age-ice age difference along the EPICA ice cores, 0–50 kyr Loulergue, L. Parrenin, F. Blunier, T. Barnola, J.-M. Spahni, R. Schilt, A. Raisbeck, G. Chappellaz, J. Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Observatoire des Sciences de l'Univers de Grenoble (OSUG) Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS) Climate and Environmental Physics Bern (CEP) Physikalisches Institut Bern Universität Bern / University of Bern (UNIBE)-Universität Bern / University of Bern (UNIBE) Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM) Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS) 2007-08-28 https://hal.science/hal-00330764 https://hal.science/hal-00330764/document https://hal.science/hal-00330764/file/cp-3-527-2007.pdf en eng HAL CCSD European Geosciences Union (EGU) hal-00330764 https://hal.science/hal-00330764 https://hal.science/hal-00330764/document https://hal.science/hal-00330764/file/cp-3-527-2007.pdf info:eu-repo/semantics/OpenAccess ISSN: 1814-9324 EISSN: 1814-9332 Climate of the Past https://hal.science/hal-00330764 Climate of the Past, 2007, 3 (3), pp.527-540 [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment [SDU.STU]Sciences of the Universe [physics]/Earth Sciences info:eu-repo/semantics/article Journal articles 2007 ftunigrenoble 2024-04-18T03:16:11Z International audience Gas is trapped in polar ice sheets at ~50–120 m below the surface and is therefore younger than the surrounding ice. Firn densification models are used to evaluate this ice age-gas age difference (?age) in the past. However, such models need to be validated by data, in particular for periods colder than present day on the East Antarctic plateau. Here we bring new constraints to test a firn densification model applied to the EPICA Dome C (EDC) site for the last 50 kyr, by linking the EDC ice core to the EPICA Dronning Maud Land (EDML) ice core, both in the ice phase (using volcanic horizons) and in the gas phase (using rapid methane variations). We also use the structured 10 Be peak, occurring 41 kyr before present (BP) and due to the low geomagnetic field associated with the Laschamp event, to experimentally estimate the ?age during this event. Our results seem to reveal an overestimate of the ?age by the firn densification model during the last glacial period at EDC. Tests with different accumulation rates and temperature scenarios do not entirely resolve this discrepancy. Although the exact reasons for the ?age overestimate at the two EPICA sites remain unknown at this stage, we conclude that current densification model simulations have deficits under glacial climatic conditions. Whatever the cause of the ?age overestimate, our finding suggests that the phase relationship between CO 2 and EDC temperature previously inferred for the start of the last deglaciation (lag of CO 2 by 800±600 yr) seems to be overestimated. Article in Journal/Newspaper Antarc* Antarctic Dronning Maud Land EPICA ice core Université Grenoble Alpes: HAL Antarctic Dronning Maud Land |