GEOS126 Lecture Notes - Lecture 8: Sediment Transport, Delta Wave, Wind Wave
12 Dec 2018
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Document Summary
Lecture 9 - sedimentation on the coast and shelf. Majority of the materials that arrives in the ocean is delivered by rivers. Varies geographically (some places do not receive enough sediment to be depositional coasts) Water depth (fundamental control on what processes dominate) Transport and deposition of sediment in shallow marine settings is controlled by: tidal currents, waves, density currents. Larger particles require more velocity to move. Requires 10 times more velocity to erode than to keep sediment moving. Implication: once in suspension, weak current can keep sediment moving. Sediment transport the role of grain size. Settling velocity is a function of grain size (stoke"s law) Results: brief, high-energy events result in substantial lateral transport, fine grains move further than coarser grains, grainsize deceases in a downstream direction or away from the coast. Current speed is a function of tidal range: large tidal range: coarse sediments, small tidal range: fine sediments, slack tide: suspended sediments settle out.
