Coasts

Coasts (Chapter 12)

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

Sea Stacks

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?

Birth of a Reef

What type of reef is shown below?

Which type of reef is shown in

these photos?

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.

Credits/More Info.

• ocean.tamu.edu/~wormuth/coastal%20processes.ppt

• http://oceanz.tamu.edu/~wormuth/coastal%20processes.ppt#256,1,CHAPTER 10 The Coast: Beaches and Shoreline Processes