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Scales Of Seafloor Sediment Resuspension In The Northern Gulf Of Mexico

Title: Scales Of Seafloor Sediment Resuspension In The Northern Gulf Of Mexico.
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Name(s): Diercks, Arne-R., author
Dike, Clayton, author
Asper, Vernon L., author
DiMarco, Steven F., author
Chanton, Jeffrey P., author
Passow, Uta, author
Type of Resource: text
Genre: Journal Article
Text
Journal Article
Date Issued: 2018-04-18
Physical Form: computer
online resource
Extent: 1 online resource
Language(s): English
Abstract/Description: Seafloor sediment resuspension events of different scales and magnitudes and the resulting deep (>1,000 m) benthic nepheloid layers were investigated in the northern Gulf of Mexico during Fall 2012 to Summer 2013. Time-series data of size-specific in-situ settling speeds of marine snow in the benthic nepheloid layer (moored flux cameras), particle size distributions (profiling camera), currents (various current meters) and stacked time-series flux data (sediment traps) were combined to recognize resuspension events ranging from small-scale local, to small-scale far-field to hurricane-scale. One small-scale local resuspension event caused by inertial currents was identified based on local high current speeds (>10 cm s(-1)) and trap data. Low POC content combined with high lithogenic silica flux at 30 m above bottom (mab) compared to the flux at 120 mab, suggested local resuspension reaching 30 mab, but not 120 mab. Another similar event was detected by the changes in particle size distribution and settling speeds of particles in the benthic nepheloid layer. Flux data indicated two other small-scale events, which occurred at some distance, rather than locally. Inertia-driven resuspension of material in shallower areas surrounding the traps presumably transported this material downslope leaving a resuspension signal at 120 mab, but not at 30 mab. The passage of hurricane Isaac left a larger scale resuspension event that lasted a few days and was recorded in both traps. Although hurricanes cause large-scale events readily observable in sediment trap samples, resuspension events small in temporal and spatial scale are not easily recognizable in trapped material as they tend to provide less material and become part of the background signal in the long-term averaged trap samples. We suggest that these small-scale resuspension events, mostly unnoticed in conventional time-series sampling, play an important role in the redistribution and ultimate fate of sediment distribution on the seafloor.
Identifier: FSU_libsubv1_wos_000430649900001 (IID), 10.1525/elementa.285 (DOI)
Keywords: sediment traps, continental-shelf, deep-water-horizon, Deepwater Horizon, santa-barbara basin, marine snow, baltic sea, bnl, faeroe-shetland channel, nepheloid layers, oil-well blowout, particulate-matter, Resuspension, settling speed, sinking velocity
Publication Note: The publisher’s version of record is available at https://doi.org/10.1525/elementa.285
Persistent Link to This Record: http://purl.flvc.org/fsu/fd/FSU_libsubv1_wos_000430649900001
Owner Institution: FSU
Is Part Of: Elementa-Science of the Anthropocene.
2325-1026
Issue: vol. 6

Choose the citation style.
Diercks, A. -R., Dike, C., Asper, V. L., DiMarco, S. F., Chanton, J. P., & Passow, U. (2018). Scales Of Seafloor Sediment Resuspension In The Northern Gulf Of Mexico. Elementa-Science Of The Anthropocene. Retrieved from http://purl.flvc.org/fsu/fd/FSU_libsubv1_wos_000430649900001