Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records
International audience Atmospheric methane (CH4) records reconstructed from polar ice cores represent an integrated view on processes predominantly taking place in the terrestrial biogeosphere. Here, we present dual stable isotopic methane records [δ13CH4 and δD(CH4)] from four Antarctic ice cores,...
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Online Access: | https://insu.hal.science/insu-03706522 https://doi.org/10.1073/pnas.1613883114 |
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ftunigrenoble:oai:HAL:insu-03706522v1 2024-05-12T07:54:32+00:00 Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records Bock, Michael Schmitt, Jochen Beck, Jonas Seth, Barbara Chappellaz, Jérôme Fischer, Hubertus Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) 2017 https://insu.hal.science/insu-03706522 https://doi.org/10.1073/pnas.1613883114 en eng HAL CCSD National Academy of Sciences info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.1613883114 insu-03706522 https://insu.hal.science/insu-03706522 BIBCODE: 2017PNAS.114E5778B doi:10.1073/pnas.1613883114 PUBMEDCENTRAL: PMC5530640 ISSN: 0027-8424 EISSN: 1091-6490 Proceedings of the National Academy of Sciences of the United States of America https://insu.hal.science/insu-03706522 Proceedings of the National Academy of Sciences of the United States of America, 2017, 114, pp.E5778-E5786. ⟨10.1073/pnas.1613883114⟩ atmosphere methane megafauna ice core stable isotopes [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2017 ftunigrenoble https://doi.org/10.1073/pnas.1613883114 2024-04-18T03:04:26Z International audience Atmospheric methane (CH4) records reconstructed from polar ice cores represent an integrated view on processes predominantly taking place in the terrestrial biogeosphere. Here, we present dual stable isotopic methane records [δ13CH4 and δD(CH4)] from four Antarctic ice cores, which provide improved constraints on past changes in natural methane sources. Our isotope data show that tropical wetlands and seasonally inundated floodplains are most likely the controlling sources of atmospheric methane variations for the current and two older interglacials and their preceding glacial maxima. The changes in these sources are steered by variations in temperature, precipitation, and the water table as modulated by insolation, (local) sea level, and monsoon intensity. Based on our δD(CH4) constraint, it seems that geologic emissions of methane may play a steady but only minor role in atmospheric CH4 changes and that the glacial budget is not dominated by these sources. Superimposed on the glacial/interglacial variations is a marked difference in both isotope records, with systematically higher values during the last 25,000 y compared with older time periods. This shift cannot be explained by climatic changes. Rather, our isotopic methane budget points to a marked increase in fire activity, possibly caused by biome changes and accumulation of fuel related to the late Pleistocene megafauna extinction, which took place in the course of the last glacial. Article in Journal/Newspaper Antarc* Antarctic ice core Université Grenoble Alpes: HAL Antarctic Proceedings of the National Academy of Sciences 114 29 |
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Open Polar |
collection |
Université Grenoble Alpes: HAL |
op_collection_id |
ftunigrenoble |
language |
English |
topic |
atmosphere methane megafauna ice core stable isotopes [SDU]Sciences of the Universe [physics] |
spellingShingle |
atmosphere methane megafauna ice core stable isotopes [SDU]Sciences of the Universe [physics] Bock, Michael Schmitt, Jochen Beck, Jonas Seth, Barbara Chappellaz, Jérôme Fischer, Hubertus Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records |
topic_facet |
atmosphere methane megafauna ice core stable isotopes [SDU]Sciences of the Universe [physics] |
description |
International audience Atmospheric methane (CH4) records reconstructed from polar ice cores represent an integrated view on processes predominantly taking place in the terrestrial biogeosphere. Here, we present dual stable isotopic methane records [δ13CH4 and δD(CH4)] from four Antarctic ice cores, which provide improved constraints on past changes in natural methane sources. Our isotope data show that tropical wetlands and seasonally inundated floodplains are most likely the controlling sources of atmospheric methane variations for the current and two older interglacials and their preceding glacial maxima. The changes in these sources are steered by variations in temperature, precipitation, and the water table as modulated by insolation, (local) sea level, and monsoon intensity. Based on our δD(CH4) constraint, it seems that geologic emissions of methane may play a steady but only minor role in atmospheric CH4 changes and that the glacial budget is not dominated by these sources. Superimposed on the glacial/interglacial variations is a marked difference in both isotope records, with systematically higher values during the last 25,000 y compared with older time periods. This shift cannot be explained by climatic changes. Rather, our isotopic methane budget points to a marked increase in fire activity, possibly caused by biome changes and accumulation of fuel related to the late Pleistocene megafauna extinction, which took place in the course of the last glacial. |
author2 |
Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ) Institut des Géosciences de l’Environnement (IGE) Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ) |
format |
Article in Journal/Newspaper |
author |
Bock, Michael Schmitt, Jochen Beck, Jonas Seth, Barbara Chappellaz, Jérôme Fischer, Hubertus |
author_facet |
Bock, Michael Schmitt, Jochen Beck, Jonas Seth, Barbara Chappellaz, Jérôme Fischer, Hubertus |
author_sort |
Bock, Michael |
title |
Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records |
title_short |
Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records |
title_full |
Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records |
title_fullStr |
Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records |
title_full_unstemmed |
Glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic CH4 ice core records |
title_sort |
glacial/interglacial wetland, biomass burning, and geologic methane emissions constrained by dual stable isotopic ch4 ice core records |
publisher |
HAL CCSD |
publishDate |
2017 |
url |
https://insu.hal.science/insu-03706522 https://doi.org/10.1073/pnas.1613883114 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic ice core |
genre_facet |
Antarc* Antarctic ice core |
op_source |
ISSN: 0027-8424 EISSN: 1091-6490 Proceedings of the National Academy of Sciences of the United States of America https://insu.hal.science/insu-03706522 Proceedings of the National Academy of Sciences of the United States of America, 2017, 114, pp.E5778-E5786. ⟨10.1073/pnas.1613883114⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1073/pnas.1613883114 insu-03706522 https://insu.hal.science/insu-03706522 BIBCODE: 2017PNAS.114E5778B doi:10.1073/pnas.1613883114 PUBMEDCENTRAL: PMC5530640 |
op_doi |
https://doi.org/10.1073/pnas.1613883114 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
114 |
container_issue |
29 |
_version_ |
1798850100245561344 |