Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport
An edited version of this paper was published by AGU. Copyright (2018) American Geophysical Union. Hong, W.-L., Torres, M.E., Portnov, A.D., Waage, M., Haley, B. & Lepland, A. (2018). Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport. Geophysical Research...
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Online Access: | https://hdl.handle.net/10037/13863 https://doi.org/10.1029/2018GL077309 |
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ftunivtroemsoe:oai:munin.uit.no:10037/13863 2023-05-15T14:23:45+02:00 Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport Hong, Wei-Li Torres, Marta E. Portnov, Aleksei D Waage, Malin Haley, B. Lepland, Aivo 2018-04-19 https://hdl.handle.net/10037/13863 https://doi.org/10.1029/2018GL077309 eng eng American Geophysical Union (AGU) Geophysical Research Letters info:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/ Hong, W.-L., Torres, M.E., Portnov, A.D., Waage, M., Haley, B. & Lepland, A. (2018). Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport. Geophysical Research Letters, 45(9), 4153-4162. https://doi.org/10.1029/2018GL077309 FRIDAID 1581062 doi:10.1029/2018GL077309 0094-8276 1944-8007 https://hdl.handle.net/10037/13863 openAccess VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 VDP::Mathematics and natural science: 400::Geosciences: 450 fluid migration free gas methane Arctic methane seep Journal article Tidsskriftartikkel Peer reviewed 2018 ftunivtroemsoe https://doi.org/10.1029/2018GL077309 2021-06-25T17:56:09Z An edited version of this paper was published by AGU. Copyright (2018) American Geophysical Union. Hong, W.-L., Torres, M.E., Portnov, A.D., Waage, M., Haley, B. & Lepland, A. (2018). Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport. Geophysical Research Letters , 45(9), 4153-4162. https://doi.org/10.1029/2018GL077309. To view the published open abstract, go to https://doi.org/10.1029/2018GL077309 . Methane fluxes into the oceans are largely dependent on the methane phase as it migrates upward through the sediments. Here we document decoupled methane transport by gaseous and aqueous phases in Storfjordrenna (offshore Svalbard) and propose a three‐stage evolution model for active seepage in the region where gas hydrates are present in the shallow subsurface. In a preactive seepage stage, solute diffusion is the primary transport mechanism for methane in the dissolved phase. Fluids containing dissolved methane have high 87 Sr/ 86 Sr ratios due to silicate weathering in the microbial methanogenesis zone. During the active seepage stage, migration of gaseous methane results in near‐seafloor gas hydrate formation and vigorous seafloor gas discharge with a thermogenic fingerprint. In the postactive seepage stage, the high concentration of dissolved lithium points to the contribution of a deeper‐sourced aqueous fluid, which we postulate advects upward following cessation of gas discharge. Plain Language Summary : How methane moves in the marine sediment, as a gas or a dissolved component, determines the environmental impact of this important greenhouse gas. In contrast to observations of biosphere activity beeing supported by dissolved methane, free gas methane cannot be used by microorganisms and can escape to the ocean more easily. Here we report the different ways methane moves in the sediments of an Arctic methane seep. We show that methane moves as free gas during the most active stage and as a dissolved component in the pore water before and after the most active period. Our results show that the supply of free gas methane in the sediments can explain why some of the seafloor features in our study area are more active than the others. Article in Journal/Newspaper Arctic arctic methane Arctic Storfjordrenna Svalbard University of Tromsø: Munin Open Research Archive Arctic Storfjordrenna ENVELOPE(17.000,17.000,76.000,76.000) Svalbard Geophysical Research Letters 45 9 4153 4162 |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 VDP::Mathematics and natural science: 400::Geosciences: 450 fluid migration free gas methane Arctic methane seep |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 VDP::Mathematics and natural science: 400::Geosciences: 450 fluid migration free gas methane Arctic methane seep Hong, Wei-Li Torres, Marta E. Portnov, Aleksei D Waage, Malin Haley, B. Lepland, Aivo Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 VDP::Mathematics and natural science: 400::Geosciences: 450 fluid migration free gas methane Arctic methane seep |
description |
An edited version of this paper was published by AGU. Copyright (2018) American Geophysical Union. Hong, W.-L., Torres, M.E., Portnov, A.D., Waage, M., Haley, B. & Lepland, A. (2018). Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport. Geophysical Research Letters , 45(9), 4153-4162. https://doi.org/10.1029/2018GL077309. To view the published open abstract, go to https://doi.org/10.1029/2018GL077309 . Methane fluxes into the oceans are largely dependent on the methane phase as it migrates upward through the sediments. Here we document decoupled methane transport by gaseous and aqueous phases in Storfjordrenna (offshore Svalbard) and propose a three‐stage evolution model for active seepage in the region where gas hydrates are present in the shallow subsurface. In a preactive seepage stage, solute diffusion is the primary transport mechanism for methane in the dissolved phase. Fluids containing dissolved methane have high 87 Sr/ 86 Sr ratios due to silicate weathering in the microbial methanogenesis zone. During the active seepage stage, migration of gaseous methane results in near‐seafloor gas hydrate formation and vigorous seafloor gas discharge with a thermogenic fingerprint. In the postactive seepage stage, the high concentration of dissolved lithium points to the contribution of a deeper‐sourced aqueous fluid, which we postulate advects upward following cessation of gas discharge. Plain Language Summary : How methane moves in the marine sediment, as a gas or a dissolved component, determines the environmental impact of this important greenhouse gas. In contrast to observations of biosphere activity beeing supported by dissolved methane, free gas methane cannot be used by microorganisms and can escape to the ocean more easily. Here we report the different ways methane moves in the sediments of an Arctic methane seep. We show that methane moves as free gas during the most active stage and as a dissolved component in the pore water before and after the most active period. Our results show that the supply of free gas methane in the sediments can explain why some of the seafloor features in our study area are more active than the others. |
format |
Article in Journal/Newspaper |
author |
Hong, Wei-Li Torres, Marta E. Portnov, Aleksei D Waage, Malin Haley, B. Lepland, Aivo |
author_facet |
Hong, Wei-Li Torres, Marta E. Portnov, Aleksei D Waage, Malin Haley, B. Lepland, Aivo |
author_sort |
Hong, Wei-Li |
title |
Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport |
title_short |
Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport |
title_full |
Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport |
title_fullStr |
Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport |
title_full_unstemmed |
Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport |
title_sort |
variations in gas and water pulses at an arctic seep: fluid sources and methane transport |
publisher |
American Geophysical Union (AGU) |
publishDate |
2018 |
url |
https://hdl.handle.net/10037/13863 https://doi.org/10.1029/2018GL077309 |
long_lat |
ENVELOPE(17.000,17.000,76.000,76.000) |
geographic |
Arctic Storfjordrenna Svalbard |
geographic_facet |
Arctic Storfjordrenna Svalbard |
genre |
Arctic arctic methane Arctic Storfjordrenna Svalbard |
genre_facet |
Arctic arctic methane Arctic Storfjordrenna Svalbard |
op_relation |
Geophysical Research Letters info:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/ Hong, W.-L., Torres, M.E., Portnov, A.D., Waage, M., Haley, B. & Lepland, A. (2018). Variations in gas and water pulses at an Arctic seep: fluid sources and methane transport. Geophysical Research Letters, 45(9), 4153-4162. https://doi.org/10.1029/2018GL077309 FRIDAID 1581062 doi:10.1029/2018GL077309 0094-8276 1944-8007 https://hdl.handle.net/10037/13863 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1029/2018GL077309 |
container_title |
Geophysical Research Letters |
container_volume |
45 |
container_issue |
9 |
container_start_page |
4153 |
op_container_end_page |
4162 |
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1766296240462495744 |