Erosional Coasts – removal of coastal material Land attacks from: Stream erosion, wind, freezing/thawing of water in rock cracks, plant roots, glaciers, rain Sea attacks from: Storms, surf, digging of marine organisms Can evolve into Depositional Coasts over time Ex: Rocky Shores , i.e. Southern tips of South America & Africa -highly erosional
Depositional Coasts – addition of coastal material Our most familiar depositional coasts: Beaches! Most deposition happens as a result of Longshore Currents Other examples of depositional coasts: Barrier Islands, Coral Reefs, Wetlands
Barrier Islands Narrow, exposed sandbars that run parallel to land Ex: Fire Island (our last field trip)
Coral Reefs Result from biological activity Types: Fringing – fringe the margin of land Barrier (Ex: Great Barrier Reef) – separated from land by a lagoon Atoll (Ex. Midway Atoll) – a ring shaped island of coral with a lagoon in the center What type of Reef is shown in these photos?