Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain
Cold seep habitats with authigenic carbonates and associated chemosynthetic communities in glacially influenced terrains constitute an important part of the benthic ecosystems, but they are difficult to detect in large-scale seabed surveys. The areas they occupy are normally small, and survey platfo...
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Language: | English |
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Online Access: | https://hdl.handle.net/10037/17503 https://doi.org/10.3389/fmars.2019.00708 |
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ftunivtroemsoe:oai:munin.uit.no:10037/17503 2023-05-15T17:43:42+02:00 Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain Thorsnes, Terje Chand, Shyam Brunstad, Harald Lepland, Aivo Lågstad, Petter Arthur 2019-11-26 https://hdl.handle.net/10037/17503 https://doi.org/10.3389/fmars.2019.00708 eng eng Frontiers Media Frontiers in Marine Science Norges forskningsråd: 223259 info:eu-repo/grantAgreement/RCN/?/223259?/Norway/?/?/ Thorsnes T, Chand S, Brunstad H, Lepland A, Lågstad PA. Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain. Frontiers in Marine Science. 2019;6(708) FRIDAID 1766680 doi:10.3389/fmars.2019.00708 2296-7745 https://hdl.handle.net/10037/17503 openAccess Copyright 2019 The Author(s) VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Journal article Tidsskriftartikkel Peer reviewed publishedVersion 2019 ftunivtroemsoe https://doi.org/10.3389/fmars.2019.00708 2021-06-25T17:57:06Z Cold seep habitats with authigenic carbonates and associated chemosynthetic communities in glacially influenced terrains constitute an important part of the benthic ecosystems, but they are difficult to detect in large-scale seabed surveys. The areas they occupy are normally small, and survey platforms and sensors allowing high-resolution spatial characterization are necessary. We have developed a cold seep habitat mapping strategy that involves both ship and autonomous underwater vehicle (AUV) as platforms for multibeam echosounder, synthetic aperture sonar (SAS) and a digital photo system. Water column data from the shipborne multibeam echosounder data are initially used to detect gas flares resulting from fluid flow from the seabed. The next phase involves mapping of flare areas by SAS, mounted on an AUV. This yields an acoustic image with a resolution up to 2 cm over a swath of c. 350 m, allowing detection of seep-related features on the seabed. The last phase involves digital photographing of the seabed, with the AUV moving close to the seabed, allowing recognition of bubble streams, seep-related features and giving a first order documentation of the fauna. The strategy was applied to a 3775 km2 large area on the continental shelf, northern Norway. This is a passive continental margin, with thick deposits of oil- and gas-bearing sedimentary rocks. Extensive faulting and tilting of layers provide potential conduits for fluid flow. The seabed is glacially influenced with a highly variable backscatter reflectivity. More than 200 gas flares have been identified, and a similar number of cold seep habitats have been characterized in high spatial detail. Two case studies are shown. In the first area, there is a close spatial relation between active gas seepage and carbonate crust fields. The second case study shows that carbonate crust fields are not necessarily spatially associated with currently active seeps, but represent dormant or formerly active gas expulsion. An important finding is that the bathymetric resolution of shipborne multibeam echosounders will often be too low to detect cold seep habitats. This means that a nested multi-resolution approach involving a multitude of platforms and sensors is required to provide the full picture Article in Journal/Newspaper Northern Norway University of Tromsø: Munin Open Research Archive Norway Tilting ENVELOPE(-54.065,-54.065,49.700,49.700) Frontiers in Marine Science 6 |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 |
spellingShingle |
VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Thorsnes, Terje Chand, Shyam Brunstad, Harald Lepland, Aivo Lågstad, Petter Arthur Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain |
topic_facet |
VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 |
description |
Cold seep habitats with authigenic carbonates and associated chemosynthetic communities in glacially influenced terrains constitute an important part of the benthic ecosystems, but they are difficult to detect in large-scale seabed surveys. The areas they occupy are normally small, and survey platforms and sensors allowing high-resolution spatial characterization are necessary. We have developed a cold seep habitat mapping strategy that involves both ship and autonomous underwater vehicle (AUV) as platforms for multibeam echosounder, synthetic aperture sonar (SAS) and a digital photo system. Water column data from the shipborne multibeam echosounder data are initially used to detect gas flares resulting from fluid flow from the seabed. The next phase involves mapping of flare areas by SAS, mounted on an AUV. This yields an acoustic image with a resolution up to 2 cm over a swath of c. 350 m, allowing detection of seep-related features on the seabed. The last phase involves digital photographing of the seabed, with the AUV moving close to the seabed, allowing recognition of bubble streams, seep-related features and giving a first order documentation of the fauna. The strategy was applied to a 3775 km2 large area on the continental shelf, northern Norway. This is a passive continental margin, with thick deposits of oil- and gas-bearing sedimentary rocks. Extensive faulting and tilting of layers provide potential conduits for fluid flow. The seabed is glacially influenced with a highly variable backscatter reflectivity. More than 200 gas flares have been identified, and a similar number of cold seep habitats have been characterized in high spatial detail. Two case studies are shown. In the first area, there is a close spatial relation between active gas seepage and carbonate crust fields. The second case study shows that carbonate crust fields are not necessarily spatially associated with currently active seeps, but represent dormant or formerly active gas expulsion. An important finding is that the bathymetric resolution of shipborne multibeam echosounders will often be too low to detect cold seep habitats. This means that a nested multi-resolution approach involving a multitude of platforms and sensors is required to provide the full picture |
format |
Article in Journal/Newspaper |
author |
Thorsnes, Terje Chand, Shyam Brunstad, Harald Lepland, Aivo Lågstad, Petter Arthur |
author_facet |
Thorsnes, Terje Chand, Shyam Brunstad, Harald Lepland, Aivo Lågstad, Petter Arthur |
author_sort |
Thorsnes, Terje |
title |
Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain |
title_short |
Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain |
title_full |
Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain |
title_fullStr |
Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain |
title_full_unstemmed |
Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain |
title_sort |
strategy for detection and high-resolution characterization of authigenic carbonate cold seep habitats using ships and autonomous underwater vehicles on glacially influenced terrain |
publisher |
Frontiers Media |
publishDate |
2019 |
url |
https://hdl.handle.net/10037/17503 https://doi.org/10.3389/fmars.2019.00708 |
long_lat |
ENVELOPE(-54.065,-54.065,49.700,49.700) |
geographic |
Norway Tilting |
geographic_facet |
Norway Tilting |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_relation |
Frontiers in Marine Science Norges forskningsråd: 223259 info:eu-repo/grantAgreement/RCN/?/223259?/Norway/?/?/ Thorsnes T, Chand S, Brunstad H, Lepland A, Lågstad PA. Strategy for Detection and High-Resolution Characterization of Authigenic Carbonate Cold Seep Habitats Using Ships and Autonomous Underwater Vehicles on Glacially Influenced Terrain. Frontiers in Marine Science. 2019;6(708) FRIDAID 1766680 doi:10.3389/fmars.2019.00708 2296-7745 https://hdl.handle.net/10037/17503 |
op_rights |
openAccess Copyright 2019 The Author(s) |
op_doi |
https://doi.org/10.3389/fmars.2019.00708 |
container_title |
Frontiers in Marine Science |
container_volume |
6 |
_version_ |
1766145834939842560 |