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| Main Author: | |
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| Format: | Recurso digital |
| Language: | English |
| Published: |
Zenodo
2025
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| Subjects: | |
| Online Access: | https://doi.org/10.5281/zenodo.15784827 |
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Table of Contents:
- <p>Flocculation dynamics of inorganic mineral grains are quantified for ten mid-to-high latitude, deep coastal basins along the Atlantic, Pacific and Southern Oceans. Suspended particle populations are imaged in situ, capturing an undisturbed water column. The basins receive and accumulate low carbon sediment, but during sediment transport the particles carry a larger reactive organic carbon component. </p> <p>Particle reservoirs are distributed within type water column layers: 1) <em>Constituent and microfloc layers </em>feature low salinity turbid water carrying < 50 µm grains. 2) <em>Flocculation fronts,</em> 35± m thick, are located where brackish waters mix with seawater and along the demarcation zone separating basin waters from open-circulating shelf waters. Flocs increase their diameter by 660 ± 470 µm at 110± µm/hour, during a 19 ± 14-hour transit through an average front. 3) <em>Dilution layers</em> represent the estuarine resupply of low floc concentration shelf waters that increase floc separation, reduce floc concentration and slow floc growth. 4) <em>Steady-state layers </em>represent zones developing a balance between the horizontal and vertical flux of flocs, found at the base of some dilution layers or within deep basin waters. 5) <em>Semi-isolated basin waters are </em>located<em> </em>below sill depth and characterized by greatly reduced horizontal transport and little floc growth ~1 µm/hour. 6) <em>Bottom boundary layers (BBL),</em> 40± m thick, carry increased levels of turbulence that reduce floc size on average -13± µm/hour. 7) Floc-rich <em>nepheloid layers </em>extend <em>BBL</em> transport across deepwater basins. Fjords hold between 3% and 99% of the total SPM as flocs, depending on location. Temporal changes in floc properties range from a few % per hour to > 100% per hour reflecting variability in source delivery and dispersal currents. The particle transit time to reach the seafloor in fjords average 1 to 14 days, a time that varies with water depth and descent variations based on floc size and settling velocity. Evidence suggests multiple aggregation processes act simultaneously within fjord waters.</p> <p>Data are as Xcel sheets of floc size, concentration and sedimentation rates</p>