EVSC 2800 Lecture Notes - Lecture 2: Longshore Drift, Abyssal Plain, Alluvial Plain
18 Feb 2016
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Document Summary
Emphasis is on wave action and the energy for redistribution of clastic sediments; must know sedimentary rock types to write sensibly about this environment. We did not cover tides, hurricanes, storm surges, or topography of deep seafloor. Key terms active margin, beach, longshore current, passive margin. A passive margin is tectonically quiet, and is often called the trailing edge of the continent. Sediments eroded from the continent are delivered to the continental shelf, slope, and rise. Coarse sediments are deposited close to the shoreline and fine sediments are deposited farther out (silt and clay). Wind driven waves redistribute sediment at the coastline. Breaker zone waves become unstable, peak, and break in the zone. Swash zone water at the beach moves up and back. Wave refraction process by which the direction of propagation of a wave or group of waves is changed due to changes in the wave speed. Differences in wave speed are caused by variation in water depth.
