Differentiating bubble-free layers from melt layers in ice cores using noble gases
Melt layers are clear indicators of extreme summer warmth on polar ice caps. The visual identification of refrozen meltwater as clear bubble-free layers cannot be used to study some past warm periods, because, in deeper ice, bubbles are lost to clathrate formation. We present here a reliable method...
Published in: | Journal of Glaciology |
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Language: | English |
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International Glaciological Society
2015
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Online Access: | https://oskar-bordeaux.fr/handle/20.500.12278/31132 https://doi.org/10.3189/2015JoG14J237 |
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ftoskarbordeaux:oai:oskar-bordeaux.fr:20.500.12278/31132 2023-05-15T16:29:36+02:00 Differentiating bubble-free layers from melt layers in ice cores using noble gases ORSI, Anais KAWAMURA, Kenji FEGYVERESI, John HEADLY, Melissa ALLEY, Richard SEVERINGHAUS, Jeffrey 2015 https://oskar-bordeaux.fr/handle/20.500.12278/31132 https://doi.org/10.3189/2015JoG14J237 en eng International Glaciological Society 0022-1430 https://oskar-bordeaux.fr/handle/20.500.12278/31132 doi:10.3189/2015JoG14J237 ice and climate ice core meltwater chemistry polar firn surface melt Planète et Univers [physics]/Sciences de la Terre/Glaciologie Planète et Univers [physics]/Sciences de la Terre/Climatologie Article de revue 2015 ftoskarbordeaux https://doi.org/10.3189/2015JoG14J237 2021-05-11T22:30:49Z Melt layers are clear indicators of extreme summer warmth on polar ice caps. The visual identification of refrozen meltwater as clear bubble-free layers cannot be used to study some past warm periods, because, in deeper ice, bubbles are lost to clathrate formation. We present here a reliable method to detect melt events, based on the analysis of Kr/Ar and Xe/Ar ratios in ice cores, and apply it to the detection of melt in clathrate ice from the Eemian at NEEM, Greenland. Additionally, melt layers in ice cores can compromise the integrity of the gas record by dissolving soluble gases, or by altering gas transport in the firn, which affects the gas chronology. We find that the easily visible 1 mm thick bubble-free layers in the WAIS Divide ice core do not contain sufficient melt to alter the gas composition in the core, and do not cause artifacts or discontinuities in the gas chronology. The presence of these layers during winter, and the absence of anomalies in soluble gases, suggests that these layers can be formed by processes other than refreezing of meltwater. Consequently, the absence of bubbles in thin crusts is not in itself proof of a melt event Other/Unknown Material Greenland ice core OSKAR Bordeaux (Open Science Knowledge ARchive) Greenland Journal of Glaciology 61 227 585 594 |
institution |
Open Polar |
collection |
OSKAR Bordeaux (Open Science Knowledge ARchive) |
op_collection_id |
ftoskarbordeaux |
language |
English |
topic |
ice and climate ice core meltwater chemistry polar firn surface melt Planète et Univers [physics]/Sciences de la Terre/Glaciologie Planète et Univers [physics]/Sciences de la Terre/Climatologie |
spellingShingle |
ice and climate ice core meltwater chemistry polar firn surface melt Planète et Univers [physics]/Sciences de la Terre/Glaciologie Planète et Univers [physics]/Sciences de la Terre/Climatologie ORSI, Anais KAWAMURA, Kenji FEGYVERESI, John HEADLY, Melissa ALLEY, Richard SEVERINGHAUS, Jeffrey Differentiating bubble-free layers from melt layers in ice cores using noble gases |
topic_facet |
ice and climate ice core meltwater chemistry polar firn surface melt Planète et Univers [physics]/Sciences de la Terre/Glaciologie Planète et Univers [physics]/Sciences de la Terre/Climatologie |
description |
Melt layers are clear indicators of extreme summer warmth on polar ice caps. The visual identification of refrozen meltwater as clear bubble-free layers cannot be used to study some past warm periods, because, in deeper ice, bubbles are lost to clathrate formation. We present here a reliable method to detect melt events, based on the analysis of Kr/Ar and Xe/Ar ratios in ice cores, and apply it to the detection of melt in clathrate ice from the Eemian at NEEM, Greenland. Additionally, melt layers in ice cores can compromise the integrity of the gas record by dissolving soluble gases, or by altering gas transport in the firn, which affects the gas chronology. We find that the easily visible 1 mm thick bubble-free layers in the WAIS Divide ice core do not contain sufficient melt to alter the gas composition in the core, and do not cause artifacts or discontinuities in the gas chronology. The presence of these layers during winter, and the absence of anomalies in soluble gases, suggests that these layers can be formed by processes other than refreezing of meltwater. Consequently, the absence of bubbles in thin crusts is not in itself proof of a melt event |
format |
Other/Unknown Material |
author |
ORSI, Anais KAWAMURA, Kenji FEGYVERESI, John HEADLY, Melissa ALLEY, Richard SEVERINGHAUS, Jeffrey |
author_facet |
ORSI, Anais KAWAMURA, Kenji FEGYVERESI, John HEADLY, Melissa ALLEY, Richard SEVERINGHAUS, Jeffrey |
author_sort |
ORSI, Anais |
title |
Differentiating bubble-free layers from melt layers in ice cores using noble gases |
title_short |
Differentiating bubble-free layers from melt layers in ice cores using noble gases |
title_full |
Differentiating bubble-free layers from melt layers in ice cores using noble gases |
title_fullStr |
Differentiating bubble-free layers from melt layers in ice cores using noble gases |
title_full_unstemmed |
Differentiating bubble-free layers from melt layers in ice cores using noble gases |
title_sort |
differentiating bubble-free layers from melt layers in ice cores using noble gases |
publisher |
International Glaciological Society |
publishDate |
2015 |
url |
https://oskar-bordeaux.fr/handle/20.500.12278/31132 https://doi.org/10.3189/2015JoG14J237 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland ice core |
genre_facet |
Greenland ice core |
op_relation |
0022-1430 https://oskar-bordeaux.fr/handle/20.500.12278/31132 doi:10.3189/2015JoG14J237 |
op_doi |
https://doi.org/10.3189/2015JoG14J237 |
container_title |
Journal of Glaciology |
container_volume |
61 |
container_issue |
227 |
container_start_page |
585 |
op_container_end_page |
594 |
_version_ |
1766019302521044992 |