Measurement and modelling of deep sea sediment plumes and implications for deep sea mining
Measurement and modelling of deep sea sediment plumes and implications for deep sea mining
Deep sea mining concerns the extraction of poly-metallic nodules, cobalt-rich crusts and sulphide deposits from the ocean floor. The exploitation of these resources will result in adverse ecological effects arising from the direct removal of the substrate and, potentially, from the formation of sediment plumes that could result in deposition of fine sediment on sensitive species or entrainment of sediment, chemicals and nutrients into over-lying waters. Hence, identifying the behaviour of deep-sea sediment plumes is important in designing mining operations that are ecologically acceptable. Here, we present the results of novel in situ deep sea plume experiments undertaken on the Tropic seamount, 300 nautical miles SSW of the Canary Islands. These plume experiments were accompanied by hydrographic and oceanographic field surveys and supported by detailed numerical modelling and high resolution video settling velocity measurements of the in situ sediment undertaken in the laboratory. The plume experiments involved the controlled formation of benthic sediment plumes and measurement of the plume sediment concentration at a specially designed lander placed at set distances from the plume origin. The experiments were used as the basis for validation of a numerical dispersion model, which was then used to predict the dispersion of plumes generated by full-scale mining. The results highlight that the extent of dispersion of benthic sediment plumes, resulting from mining operations, is significantly reduced by the effects of flocculation, background turbidity and internal tides. These considerations must be taken into account when evaluating the impact and extent of benthic sediment plumes.
Spearman, Jeremy
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Taylor, Jonathan
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Crossouard, Neil
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Cooper, Alan
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Turnbull, Michael
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Manning, Andrew
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Lee, Mark
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Murton, Bramley
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1 December 2020
Spearman, Jeremy
42cc3306-d7ce-4884-ad69-7291cc3eb812
Taylor, Jonathan
917fb402-c6be-47bb-b247-bc8c6a6cf31f
Crossouard, Neil
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Cooper, Alan
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Turnbull, Michael
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Manning, Andrew
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Lee, Mark
4b13298c-21fa-44f6-bd25-daef448ff044
Murton, Bramley
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Spearman, Jeremy, Taylor, Jonathan, Crossouard, Neil, Cooper, Alan, Turnbull, Michael, Manning, Andrew, Lee, Mark and Murton, Bramley
(2020)
Measurement and modelling of deep sea sediment plumes and implications for deep sea mining.
Scientific Reports, 10 (1), [5075].
(doi:10.1038/s41598-020-61837-y).
Abstract
Deep sea mining concerns the extraction of poly-metallic nodules, cobalt-rich crusts and sulphide deposits from the ocean floor. The exploitation of these resources will result in adverse ecological effects arising from the direct removal of the substrate and, potentially, from the formation of sediment plumes that could result in deposition of fine sediment on sensitive species or entrainment of sediment, chemicals and nutrients into over-lying waters. Hence, identifying the behaviour of deep-sea sediment plumes is important in designing mining operations that are ecologically acceptable. Here, we present the results of novel in situ deep sea plume experiments undertaken on the Tropic seamount, 300 nautical miles SSW of the Canary Islands. These plume experiments were accompanied by hydrographic and oceanographic field surveys and supported by detailed numerical modelling and high resolution video settling velocity measurements of the in situ sediment undertaken in the laboratory. The plume experiments involved the controlled formation of benthic sediment plumes and measurement of the plume sediment concentration at a specially designed lander placed at set distances from the plume origin. The experiments were used as the basis for validation of a numerical dispersion model, which was then used to predict the dispersion of plumes generated by full-scale mining. The results highlight that the extent of dispersion of benthic sediment plumes, resulting from mining operations, is significantly reduced by the effects of flocculation, background turbidity and internal tides. These considerations must be taken into account when evaluating the impact and extent of benthic sediment plumes.
Text
s41598-020-61837-y (1)
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More information
Accepted/In Press date: 19 February 2020
Published date: 1 December 2020
Additional Information:
Funding Information:
The MarineE-tech project is part of the SOS Minerals Research Programme and funded by the UK National Environmental Research Council [grant number NE/M011003/1]. The authors would like to thank all the National Oceanography Centre staff who assisted on the cruise to the Tropic Seamount and in particular the Isis ROV team.
Publisher Copyright:
© 2020, The Author(s).
Identifiers
Local EPrints ID: 439733
URI: http://eprints.soton.ac.uk/id/eprint/439733
ISSN: 2045-2322
PURE UUID: ee5af6aa-106b-48c2-b110-acc809b3cb34
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Date deposited: 30 Apr 2020 16:35
Last modified: 16 Mar 2024 07:44
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Author:
Jeremy Spearman
Author:
Jonathan Taylor
Author:
Neil Crossouard
Author:
Alan Cooper
Author:
Michael Turnbull
Author:
Andrew Manning
Author:
Mark Lee
Author:
Bramley Murton
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