High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site
International audience Methane (CH 4) in marine sediments has the potential to contribute to changes in the ocean and climate system. Physical and biochemical processes that are difficult to quantify with current standard methods such as acoustic surveys and discrete sampling govern the distribution...
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Online Access: | https://hal.science/hal-02366680 https://hal.science/hal-02366680/document https://hal.science/hal-02366680/file/os-15-1055-2019.pdf https://doi.org/10.5194/os-15-1055-2019 |
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ftunigrenoble:oai:HAL:hal-02366680v1 2024-05-12T07:59:48+00:00 High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site Jansson, Pär Triest, Jack Grilli, Roberto Ferré, Benedicte Silyakova, Anna Mienert, Jurgen Chappellaz, Jérôme Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) The Arctic University of Norway Tromsø, Norway (UiT) 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 ) 2019 https://hal.science/hal-02366680 https://hal.science/hal-02366680/document https://hal.science/hal-02366680/file/os-15-1055-2019.pdf https://doi.org/10.5194/os-15-1055-2019 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/os-15-1055-2019 hal-02366680 https://hal.science/hal-02366680 https://hal.science/hal-02366680/document https://hal.science/hal-02366680/file/os-15-1055-2019.pdf doi:10.5194/os-15-1055-2019 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 1812-0784 EISSN: 1812-0792 Ocean Science https://hal.science/hal-02366680 Ocean Science, 2019, 15 (4), pp.1055-1069. ⟨10.5194/os-15-1055-2019⟩ [SDE]Environmental Sciences info:eu-repo/semantics/article Journal articles 2019 ftunigrenoble https://doi.org/10.5194/os-15-1055-2019 2024-04-18T03:28:47Z International audience Methane (CH 4) in marine sediments has the potential to contribute to changes in the ocean and climate system. Physical and biochemical processes that are difficult to quantify with current standard methods such as acoustic surveys and discrete sampling govern the distribution of dissolved CH 4 in oceans and lakes. Detailed observations of aquatic CH 4 concentrations are required for a better understanding of CH 4 dynamics in the water column, how it can affect lake and ocean acidification, the chemosynthetic ecosystem, and mixing ratios of atmospheric climate gases. Here we present pioneering high-resolution in situ measurements of dissolved CH 4 throughout the water column over a 400 m deep CH 4 seepage area at the continental slope west of Svalbard. A new fast-response underwater membrane-inlet laser spectrometer sensor demonstrates technological advances and breakthroughs for ocean measurements. We reveal decametre-scale variations in dissolved CH 4 concentrations over the CH 4 seepage zone. Previous studies could not resolve such heterogeneity in the area, assumed a smoother distribution, and therefore lacked both details on and insights into ongoing processes. We show good repeatability of the instrument measurements, which are also in agreement with discrete sampling. New numerical models, based on acousti-cally evidenced free gas emissions from the seafloor, support the observed heterogeneity and CH 4 inventory. We identified sources of CH 4 , undetectable with echo sounder, and rapid diffusion of dissolved CH 4 away from the sources. Results from the continuous ocean laser-spectrometer measurements, supported by modelling, improve our understanding of CH 4 fluxes and related physical processes over Arctic CH 4 de-gassing regions. Article in Journal/Newspaper Arctic Ocean acidification Svalbard Université Grenoble Alpes: HAL Arctic Svalbard Ocean Science 15 4 1055 1069 |
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Université Grenoble Alpes: HAL |
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ftunigrenoble |
language |
English |
topic |
[SDE]Environmental Sciences |
spellingShingle |
[SDE]Environmental Sciences Jansson, Pär Triest, Jack Grilli, Roberto Ferré, Benedicte Silyakova, Anna Mienert, Jurgen Chappellaz, Jérôme High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site |
topic_facet |
[SDE]Environmental Sciences |
description |
International audience Methane (CH 4) in marine sediments has the potential to contribute to changes in the ocean and climate system. Physical and biochemical processes that are difficult to quantify with current standard methods such as acoustic surveys and discrete sampling govern the distribution of dissolved CH 4 in oceans and lakes. Detailed observations of aquatic CH 4 concentrations are required for a better understanding of CH 4 dynamics in the water column, how it can affect lake and ocean acidification, the chemosynthetic ecosystem, and mixing ratios of atmospheric climate gases. Here we present pioneering high-resolution in situ measurements of dissolved CH 4 throughout the water column over a 400 m deep CH 4 seepage area at the continental slope west of Svalbard. A new fast-response underwater membrane-inlet laser spectrometer sensor demonstrates technological advances and breakthroughs for ocean measurements. We reveal decametre-scale variations in dissolved CH 4 concentrations over the CH 4 seepage zone. Previous studies could not resolve such heterogeneity in the area, assumed a smoother distribution, and therefore lacked both details on and insights into ongoing processes. We show good repeatability of the instrument measurements, which are also in agreement with discrete sampling. New numerical models, based on acousti-cally evidenced free gas emissions from the seafloor, support the observed heterogeneity and CH 4 inventory. We identified sources of CH 4 , undetectable with echo sounder, and rapid diffusion of dissolved CH 4 away from the sources. Results from the continuous ocean laser-spectrometer measurements, supported by modelling, improve our understanding of CH 4 fluxes and related physical processes over Arctic CH 4 de-gassing regions. |
author2 |
Centre for Arctic Gas Hydrate, Environment and Climate (CAGE) The Arctic University of Norway Tromsø, Norway (UiT) 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 |
Jansson, Pär Triest, Jack Grilli, Roberto Ferré, Benedicte Silyakova, Anna Mienert, Jurgen Chappellaz, Jérôme |
author_facet |
Jansson, Pär Triest, Jack Grilli, Roberto Ferré, Benedicte Silyakova, Anna Mienert, Jurgen Chappellaz, Jérôme |
author_sort |
Jansson, Pär |
title |
High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site |
title_short |
High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site |
title_full |
High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site |
title_fullStr |
High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site |
title_full_unstemmed |
High-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an Arctic seepage site |
title_sort |
high-resolution underwater laser spectrometer sensing provides new insights into methane distribution at an arctic seepage site |
publisher |
HAL CCSD |
publishDate |
2019 |
url |
https://hal.science/hal-02366680 https://hal.science/hal-02366680/document https://hal.science/hal-02366680/file/os-15-1055-2019.pdf https://doi.org/10.5194/os-15-1055-2019 |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
Arctic Ocean acidification Svalbard |
genre_facet |
Arctic Ocean acidification Svalbard |
op_source |
ISSN: 1812-0784 EISSN: 1812-0792 Ocean Science https://hal.science/hal-02366680 Ocean Science, 2019, 15 (4), pp.1055-1069. ⟨10.5194/os-15-1055-2019⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/os-15-1055-2019 hal-02366680 https://hal.science/hal-02366680 https://hal.science/hal-02366680/document https://hal.science/hal-02366680/file/os-15-1055-2019.pdf doi:10.5194/os-15-1055-2019 |
op_rights |
http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.5194/os-15-1055-2019 |
container_title |
Ocean Science |
container_volume |
15 |
container_issue |
4 |
container_start_page |
1055 |
op_container_end_page |
1069 |
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1798841424505995264 |