Evidence of glacial flour in the deepest 89 m of the Vostok ice core
International audience The 3623 m long Vostok ice core is divided into two main parts: (1) from the surface to a depth of 3310m, the ice layers are undisturbed and may be used to reconstruct the climatic record over the past 420 kyr; (2) from 3538 m to the bottom, the core is made up of accreted ice...
Published in: | Annals of Glaciology |
---|---|
Main Authors: | , , , , , , , |
Other Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2002
|
Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/hal-03127326 https://doi.org/10.3189/172756402781816816 |
id |
ftccsdartic:oai:HAL:hal-03127326v1 |
---|---|
record_format |
openpolar |
institution |
Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
spellingShingle |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment Simões, Jefferson Petit, Jean Robert Souchez, Roland Lipenkov, Vladimir Ya. De Angelis, Martine Leibao, Liu Jouzel, Jean Duval, Paul Evidence of glacial flour in the deepest 89 m of the Vostok ice core |
topic_facet |
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment |
description |
International audience The 3623 m long Vostok ice core is divided into two main parts: (1) from the surface to a depth of 3310m, the ice layers are undisturbed and may be used to reconstruct the climatic record over the past 420 kyr; (2) from 3538 m to the bottom, the core is made up of accreted ice formed by freezing of the lake. In between, the glacier ice is disturbed by ice dynamics, as shown, for example, by inclined volcanic-ash layers. Microparticle concentrations and distributions as well as ionic and isotopic content were used to subdivide this third section. The identification of layers with bedrock material provides clues as to the entrainment processes at sub-freezing temperatures. Dust concentration and size distribution as well as ionic content are comparable with values found in ice of glacial and interglacial periods. Below 3450 m depth, however, the mode of the volume size distribution clearly shifts from 2.1 µm to 3.4 µm in diameter. Particles as large as 30 µm in diameter are observed and cannot have an aeolian origin. From microscopic observations, we suggest that they originate from the bedrock and represent glacial flour entrained in a shear layer up to 89 m from the glacier sole. This process most likely occurred when the ice sheet was grounded before flowing over the lake. |
author2 |
Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-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 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 libre de Bruxelles (ULB) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) Glaces et Continents, Climats et Isotopes Stables (GLACCIOS) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) |
format |
Article in Journal/Newspaper |
author |
Simões, Jefferson Petit, Jean Robert Souchez, Roland Lipenkov, Vladimir Ya. De Angelis, Martine Leibao, Liu Jouzel, Jean Duval, Paul |
author_facet |
Simões, Jefferson Petit, Jean Robert Souchez, Roland Lipenkov, Vladimir Ya. De Angelis, Martine Leibao, Liu Jouzel, Jean Duval, Paul |
author_sort |
Simões, Jefferson |
title |
Evidence of glacial flour in the deepest 89 m of the Vostok ice core |
title_short |
Evidence of glacial flour in the deepest 89 m of the Vostok ice core |
title_full |
Evidence of glacial flour in the deepest 89 m of the Vostok ice core |
title_fullStr |
Evidence of glacial flour in the deepest 89 m of the Vostok ice core |
title_full_unstemmed |
Evidence of glacial flour in the deepest 89 m of the Vostok ice core |
title_sort |
evidence of glacial flour in the deepest 89 m of the vostok ice core |
publisher |
HAL CCSD |
publishDate |
2002 |
url |
https://hal.archives-ouvertes.fr/hal-03127326 https://doi.org/10.3189/172756402781816816 |
genre |
Annals of Glaciology ice core Ice Sheet |
genre_facet |
Annals of Glaciology ice core Ice Sheet |
op_source |
ISSN: 0260-3055 Annals of Glaciology https://hal.archives-ouvertes.fr/hal-03127326 Annals of Glaciology, International Glaciological Society, 2002, 35 (1), pp.340-346. ⟨10.3189/172756402781816816⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.3189/172756402781816816 hal-03127326 https://hal.archives-ouvertes.fr/hal-03127326 doi:10.3189/172756402781816816 |
op_doi |
https://doi.org/10.3189/172756402781816816 |
container_title |
Annals of Glaciology |
container_volume |
35 |
container_issue |
1 |
container_start_page |
340 |
op_container_end_page |
346 |
_version_ |
1765999291089813504 |
spelling |
ftccsdartic:oai:HAL:hal-03127326v1 2023-05-15T13:29:12+02:00 Evidence of glacial flour in the deepest 89 m of the Vostok ice core Simões, Jefferson Petit, Jean Robert Souchez, Roland Lipenkov, Vladimir Ya. De Angelis, Martine Leibao, Liu Jouzel, Jean Duval, Paul Laboratoire de glaciologie et géophysique de l'environnement (LGGE) Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-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 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 libre de Bruxelles (ULB) Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) Glaces et Continents, Climats et Isotopes Stables (GLACCIOS) Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ) 2002-01-01 https://hal.archives-ouvertes.fr/hal-03127326 https://doi.org/10.3189/172756402781816816 en eng HAL CCSD International Glaciological Society info:eu-repo/semantics/altIdentifier/doi/10.3189/172756402781816816 hal-03127326 https://hal.archives-ouvertes.fr/hal-03127326 doi:10.3189/172756402781816816 ISSN: 0260-3055 Annals of Glaciology https://hal.archives-ouvertes.fr/hal-03127326 Annals of Glaciology, International Glaciological Society, 2002, 35 (1), pp.340-346. ⟨10.3189/172756402781816816⟩ [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces environment info:eu-repo/semantics/article Journal articles 2002 ftccsdartic https://doi.org/10.3189/172756402781816816 2021-12-19T00:32:01Z International audience The 3623 m long Vostok ice core is divided into two main parts: (1) from the surface to a depth of 3310m, the ice layers are undisturbed and may be used to reconstruct the climatic record over the past 420 kyr; (2) from 3538 m to the bottom, the core is made up of accreted ice formed by freezing of the lake. In between, the glacier ice is disturbed by ice dynamics, as shown, for example, by inclined volcanic-ash layers. Microparticle concentrations and distributions as well as ionic and isotopic content were used to subdivide this third section. The identification of layers with bedrock material provides clues as to the entrainment processes at sub-freezing temperatures. Dust concentration and size distribution as well as ionic content are comparable with values found in ice of glacial and interglacial periods. Below 3450 m depth, however, the mode of the volume size distribution clearly shifts from 2.1 µm to 3.4 µm in diameter. Particles as large as 30 µm in diameter are observed and cannot have an aeolian origin. From microscopic observations, we suggest that they originate from the bedrock and represent glacial flour entrained in a shear layer up to 89 m from the glacier sole. This process most likely occurred when the ice sheet was grounded before flowing over the lake. Article in Journal/Newspaper Annals of Glaciology ice core Ice Sheet Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Annals of Glaciology 35 1 340 346 |