Material transport from the nearshore to the basinal environment in the southern Baltic Sea: 1. Processes and mass estimates
Christiansen, C.; Edelvang, K.; Emeis, K.; Graf, G.; Jähmlich, S.; Kozuche, J.; Laima, M.; Leipe, T.; Löffler, A.; Lund-Hansen, L.C.; Miltner, A.; Pazdro, K.; Pempkowiak, J.; Shimmield, G.B.; Shimmield, T.; Smith, J.; Voss, M.; Witt, G. (2002). Material transport from the nearshore to the basinal environment in the southern Baltic Sea: 1. Processes and mass estimates. J. Mar. Syst. 35(3-4): 133-150. http://dx.doi.org/10.1016/s0924-7963(02)00126-4
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more
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| Keywords |
Models
Physics > Mechanics > Dynamics > Sediment dynamics
Resources > Natural resources > Mineral resources > Mineral deposits > Seabed deposits > Aggregates
Sedimentation
Suspension > Resuspension
Transport
ANE, Poland, Pomerania [Marine Regions]
Marine/Coastal |
| Author keywords |
sediment dynamics; aggregates; sedimentation; resuspension; materialtransport; models; Baltic Sea; Pomeranian Bight |
| Authors | | Top |
- Christiansen, C.
- Edelvang, K.
- Emeis, K.
- Graf, G., more
- Jähmlich, S.
- Kozuche, J.
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- Laima, M.
- Leipe, T.
- Löffler, A.
- Lund-Hansen, L.C.
- Miltner, A.
- Pazdro, K.
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- Pempkowiak, J.
- Shimmield, G.B., more
- Shimmield, T.
- Smith, J.
- Voss, M.
- Witt, G.
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| Abstract |
Processes involved in erosion, transport and deposition of cohesive materials are studied in a transect from shallow (16 m) to deep (47 m) water of the SW Baltic Sea. The wave- and current-induced energy input to the seabed in shallow water is high with strong variability and suspended matter concentrations may double within a few hours. Primary settling fluxes (from sedimentation traps) are less than 10 g m-2 day-1, whereas resuspension fluxes (evaluated from sedimentation flux gradients) are 15-20 times higher and the residence time for suspended matter in the water column is 1-2 days. Settling velocities of aggregates are on average six times higher than for individual particles resulting in an enhanced downward transport of organic matter. Wave-induced resuspension (four to six times per month) takes place with higher shear stresses on the bottom than current-induced resuspension (three to five times per month). The short residence time in the water column and the frequent resuspension events provide a fast operating benthic-pelagic coupling. Due to the high-energy input, the shallow water areas are nondepositional on time scales longer than 1-2 weeks. The sediment is sand partly covered by a thin fluff layer during low-energy periods. The presence of the fluff layer keeps the resuspension threshold very low (<0.023 N m-2) throughout the year. Evaluated from 3-D sediment transport modeling, transport from shallow to deep water is episodic. The net main directions are towards the Arkona Basin (5.5×105 t per year) and the Bornholm Basin (3.7×105 t per year). Energy input to the bottom in deep water is low and takes place much less frequently. Wave-induced resuspension occurs on average once per month. Residence time of particles (based on radioactive isotopes) in the water column is half a year and the sediment accumulation rate is 2.2 mm year-1 in the Arkona Basin. |
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