There are two main types of coasts: erosional and depositional. Erosional coasts experience removal of material from land attacks like erosion and sea attacks like storms. Depositional coasts experience addition of material, forming features like beaches, barrier islands, coral reefs, and wetlands. Coral reefs can be fringing, barrier, or atoll reefs depending on their location relative to land.

1. Coasts (Chapter 12)

2. 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

3. Sea Stacks

4. 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

5. Barrier Islands Narrow, exposed sandbars that run parallel to land Ex: Fire Island (our last field trip)

7. 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?

8. Birth of a Reef

9. What type of reef is shown below?

10. Which type of reef is shown in these photos?

11. Wetlands – where are they in this photo? Hurricane Isabel breach, Hatteras Island, NC. Photo taken Sept. 21, 2003. Courtesy Duke University Program for the Study of Developed Shorelines.

12. Credits/More Info. ocean.tamu.edu/~wormuth/ coast al%20processes.ppt http://oceanz.tamu.edu/~wormuth/coastal%20processes.ppt#256,1,CHAPTER 10 The Coast: Beaches and Shoreline Processes