1. Friday April 8, 2011 (Shoreline Features; Stabilizing the Shore; Coastal Classification)

2. The Launch Pad Friday, 4/8/11 Explain the process of “beach drift.” When waves wash up onto shore, they don’t always hit at 90 o to the beach. They will wash up at the angle of the wind. However, when the water recedes back from the beach, it is usually at 90 o. Therefore, the angle of swash doesn’t equal the angle of backwash, and a zigzag pattern is set up. This will steadily move the material on the beach down the coastline.

3. Announcements Test next week (day TBD)!

4. Assignments For This Six-WeeksDate IssuedDate Due Video Quiz - Lakes, Rivers, and Other Water Sources 2/27 WS - Running Water and Groundwater (Part 1) 2/253/4 PowerPoint Project – Rivers (P5 only)2/283/3 WS - Running Water and Groundwater (Part 2) 3/23/9 Video Quiz - Groundwater3/3 Cornell Notes - Ice3/83/9 WS - Ice3/93/25 Test 83/11 Video Quiz – Ocean’s – Earth’s Last Frontier 3/23 Cornell Notes – Intro to Oceanography3/254/4 Lab Exercise – Introduction to Oceanography 3/284/1 Cornell Notes – The Dynamic Ocean4/4?? Lab Exercise – Waves and Currents4/54/8

5. Complete Cornell Notes The Dynamic Ocean

6. Shoreline Features Shoreline features created by erosional effects include: Wave-cut cliffs Wave-cut platforms Marine terraces Sea arches Sea stacks

7. Figure 15.24 A

8. A Sea Stack and a Sea Arch Figure 15.21

9. Shoreline Features Depositional Features A spit is a ridge of sand extending from the land into the mouth of an adjacent bay with an end that often hooks landward.

10. Figure 15.24 C

11. Shoreline Features Depositional Features A baymouth bar is a sand bar that completely crosses a bay.

12. Aerial View of a Spit and Baymouth Bar Along the Massachusetts Coastline Figure 15.22 A

13. Shoreline Features Depositional Features A tombolo is a ridge of sand that connects an island to the mainland.

14. Figure 15.24 B

15. Shoreline Features Depositional Features Barrier islands occur mainly along the Atlantic and Gulf Coastal Plains. They run parallel the coast and can originate in several ways.

16. Stabilizing the Shore Shoreline erosion is influenced by several local factors – the proximity to sediment- laden rivers – the degree of tectonic activity – the topography and composition of the land – the prevailing wind and weather patterns – the configuration of the coastline

17. Stabilizing the Shore Responses to Erosion Problems “Hard stabilization” refers to building structures to lessen the effects of shoreline erosion. Types of structures Groins are barriers built at a right angles to the beach that are designed to trap sand. Breakwaters are barriers built offshore and parallel to the coast to protect boats from breaking waves. Seawalls armors the coast against the force of breaking waves. Often these structures are not effective.

18. Stabilizing the Shore Responses to Erosion Problems Alternatives to hard stabilization: In beach nourishment, sand is added to the beach system. Relocating buildings away from a beach

19. Miami Beach Before and After Beach Nourishment Figure 15.28 A

20. Stabilizing the Shore Responses to Erosion Problems Shoreline erosion problems are different along the different U.S. coasts. Along the Atlantic and Gulf Coasts, development occurs mainly on barrier islands that face the open ocean. These islands receive the full force of storms. Development has taken place more rapidly than our understanding of barrier island dynamics.

21. Stabilizing the Shore Responses to Erosion Problems Shoreline erosion problems are different along the different U.S. coasts. The Pacific Coast is characterized by relatively narrow beaches backed by steep cliffs and mountain ranges. The major problem here is the narrowing of the beaches. Sediment for beaches is interrupted by dams and reservoirs; therefore, rapid erosion occurs along the beaches.

22. Coastal Classification Shoreline classification is difficult, and is based mainly on changes with respect to sea level. An emergent coast is caused by an uplift of the land, or a drop in sea level.

23. Coastal Classification Features of an emergent coast include: wave-cut cliffs marine terraces

24. Coastal Classification Submergent coasts are caused when the land adjacent to the sea subsides, or sea level rises. Features of a submergent coast include: a highly irregular shoreline estuaries – drowned river mouths

25. Major Estuaries Along the East Coast of the United States

26. Complete Lab Exercise Waves and Currents