Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique
Ice cores are a fantastic tool to study the past climate of our planet. Recently, the European Project for Ice Coring in Antarctica (EPICA) allowed to extract the Dome Concordia ice core (75◦06′ S; 123◦21′ E). The first studies show that the last 740000 years of our climatic history are recorded. In...
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Other Authors: | , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
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HAL CCSD
2004
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Online Access: | https://theses.hal.science/tel-00701364 https://theses.hal.science/tel-00701364/document https://theses.hal.science/tel-00701364/file/These-Durand-2004-1.pdf |
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ftunigrenoble:oai:HAL:tel-00701364v1 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Université Grenoble Alpes: HAL |
op_collection_id |
ftunigrenoble |
language |
French |
topic |
carottes de glace European Project for Ice Coring in Antarctica Dôme Concordia microstructure grain [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
spellingShingle |
carottes de glace European Project for Ice Coring in Antarctica Dôme Concordia microstructure grain [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology Durand, Gaël Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique |
topic_facet |
carottes de glace European Project for Ice Coring in Antarctica Dôme Concordia microstructure grain [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology |
description |
Ice cores are a fantastic tool to study the past climate of our planet. Recently, the European Project for Ice Coring in Antarctica (EPICA) allowed to extract the Dome Concordia ice core (75◦06′ S; 123◦21′ E). The first studies show that the last 740000 years of our climatic history are recorded. In this manuscript, a study on the microstructure (grain boundaries network) evolution along the Dome concordia ice core is presented. In a first part, we study the mean grain size evolution along the core which is showing sharp variations during climatic transitions. The analysis of the grain size distribution parameters as well as correlations between mean grain size and impurities content show that the dust particles decrease the normal grain growth rate during Glacial period. This can explain the observed grain size variations. The development of a mean field approximation model, which is able to calculate the mean grain size evolution, confirms quantitatively this result. It allows also to study the role of bubbles, clathrates and rotation recrystallization on the mean grain size. The geometry of the microstructure can also reveal the deformation of the ice layers. From a procedure developed initially to measure the deformation field of foams and which has been adapted to ice, we show that our measurements contradict two classical assumptions used to describe the ice deformation at a dome: (i) shearing is present and its value increases with depth, (ii) the vertical deformation is not homogeneous (some layers are more deformed than their neighbours). Classical glaciological dating models use these assumptions, therefore opening some questions on their validity. Then, we examine the impact of the vertical deformation heterogeneities on the dating. Particularely, we focus on the determination of the duration of brief events. Les carottes de glace sont un fantastique outil d'étude du climat de notre planète. Récemment, le projet européen EPICA (European Project for Ice Coring in Antarctica) a permis d'extraire une ... |
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) Université Joseph-Fourier - Grenoble I Jérome Weiss |
format |
Doctoral or Postdoctoral Thesis |
author |
Durand, Gaël |
author_facet |
Durand, Gaël |
author_sort |
Durand, Gaël |
title |
Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique |
title_short |
Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique |
title_full |
Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique |
title_fullStr |
Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique |
title_full_unstemmed |
Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique |
title_sort |
microstructure, recristallisation et déformation des glaces polaires de la carotte epica, dôme concordia, antarctique |
publisher |
HAL CCSD |
publishDate |
2004 |
url |
https://theses.hal.science/tel-00701364 https://theses.hal.science/tel-00701364/document https://theses.hal.science/tel-00701364/file/These-Durand-2004-1.pdf |
genre |
Antarc* Antarctica Antarctique* EPICA ice core |
genre_facet |
Antarc* Antarctica Antarctique* EPICA ice core |
op_source |
https://theses.hal.science/tel-00701364 Glaciologie. Université Joseph-Fourier - Grenoble I, 2004. Français. ⟨NNT : ⟩ |
op_relation |
tel-00701364 https://theses.hal.science/tel-00701364 https://theses.hal.science/tel-00701364/document https://theses.hal.science/tel-00701364/file/These-Durand-2004-1.pdf |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1798845417682632704 |
spelling |
ftunigrenoble:oai:HAL:tel-00701364v1 2024-05-12T07:53:54+00:00 Microstructure, recristallisation et déformation des glaces polaires de la carotte EPICA, Dôme Concordia, Antarctique Durand, Gaël 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) Université Joseph-Fourier - Grenoble I Jérome Weiss 2004-10-27 https://theses.hal.science/tel-00701364 https://theses.hal.science/tel-00701364/document https://theses.hal.science/tel-00701364/file/These-Durand-2004-1.pdf fr fre HAL CCSD tel-00701364 https://theses.hal.science/tel-00701364 https://theses.hal.science/tel-00701364/document https://theses.hal.science/tel-00701364/file/These-Durand-2004-1.pdf info:eu-repo/semantics/OpenAccess https://theses.hal.science/tel-00701364 Glaciologie. Université Joseph-Fourier - Grenoble I, 2004. Français. ⟨NNT : ⟩ carottes de glace European Project for Ice Coring in Antarctica Dôme Concordia microstructure grain [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology info:eu-repo/semantics/doctoralThesis Theses 2004 ftunigrenoble 2024-04-18T02:22:47Z Ice cores are a fantastic tool to study the past climate of our planet. Recently, the European Project for Ice Coring in Antarctica (EPICA) allowed to extract the Dome Concordia ice core (75◦06′ S; 123◦21′ E). The first studies show that the last 740000 years of our climatic history are recorded. In this manuscript, a study on the microstructure (grain boundaries network) evolution along the Dome concordia ice core is presented. In a first part, we study the mean grain size evolution along the core which is showing sharp variations during climatic transitions. The analysis of the grain size distribution parameters as well as correlations between mean grain size and impurities content show that the dust particles decrease the normal grain growth rate during Glacial period. This can explain the observed grain size variations. The development of a mean field approximation model, which is able to calculate the mean grain size evolution, confirms quantitatively this result. It allows also to study the role of bubbles, clathrates and rotation recrystallization on the mean grain size. The geometry of the microstructure can also reveal the deformation of the ice layers. From a procedure developed initially to measure the deformation field of foams and which has been adapted to ice, we show that our measurements contradict two classical assumptions used to describe the ice deformation at a dome: (i) shearing is present and its value increases with depth, (ii) the vertical deformation is not homogeneous (some layers are more deformed than their neighbours). Classical glaciological dating models use these assumptions, therefore opening some questions on their validity. Then, we examine the impact of the vertical deformation heterogeneities on the dating. Particularely, we focus on the determination of the duration of brief events. Les carottes de glace sont un fantastique outil d'étude du climat de notre planète. Récemment, le projet européen EPICA (European Project for Ice Coring in Antarctica) a permis d'extraire une ... Doctoral or Postdoctoral Thesis Antarc* Antarctica Antarctique* EPICA ice core Université Grenoble Alpes: HAL |