Effects of Waves: Beach Erosion Landforms, Erosion, and Storm Surges

The Situation… Slide: 1 What is happening on these shorelines? What are the dangers of this?

Slide: 2 The process shown on the previous slide is called erosion. Erosion occurs when land is worn away by wind and water. Why would it be important to control erosion at the beach? How might global warming be contributing to beach erosion?

The Situation… Slide: 3 Deposition is the area of accumulated sand, stone, or gravel deposited along a shore by the action of the ocean.

Slide: 4 Deposition is a natural occurrence and helps to create beaches. Why then do humans see this as a negative thing? These pictures were taken after Hurricane Sandy along the Jersey Shore.

Slide: 5 What you saw in the previous slides is known as Overwash. When waves exceed the elevation of the dune, sand is transported across the land in a process known as overwash. When overwash occurs, it often results in significant damage to coastal property.

Slide: 6 The results of overwash

Slide: 7 8

Slide: 8 Beach Erosion: Beach erosion occurs when waves and currents remove sand from the beach system. The narrowing of the beach threatens coastal properties and tourism revenue in coastal counties throughout the United States.

Slide: 9 Dunes are sand hills created by the action of wind and waves. The dunes closest to the ocean are called the primary dunes while the dunes closer to land are called secondary dunes. Primary dune Secondary dune

Slide: 10 Make a claim about the location and amount of vegetation on the primary dune. Support why this may be so. Secondary dune Primary dune Make a claim about the location and amount of vegetation on the secondary dune. Support why this may be so.

Slide: 11 Dune Erosion  Dune erosion occurs when waves attack the front face of the sand dune, reducing the volume and elevation of the dune, leaving coastal properties more vulnerable to future storms.

Slide: 12 Examine the diagram above, it shows what happens to a dune when high waters from storms reach the shoreline. Explain the effects of the high water on both the dune and the vegetation.

Slide: 13 Storm A Storm B Dune shape ---- Pre storm ---- Post storm Ocean waters Storm B

Slide: 14 Analyze the data: Both of the storms on the previous slide occurred over a three hour period. Make a claim about which storm was more violent. Support with 2 pieces of evidence.

Slide: 15 Focus your attention on the width of the beach. Click the mouse to see the same beach after Hurricane Sandy.

Slide: 16 If we did not use a beach restoration technique, what might occur to the beach during future storms?

Slide: 17 View the before and after pictures. Compare the area of the beach that had a sea wall to the area that did not. Write 2 pieces of evidence in favor of sea walls.

Slide: 18 Inundation and Island Breaching  Inundation occurs when the beach system, or the sandy profile located between the primary dune and the shoreline, is completely submerged under the rising storm surge. Strong currents may carve a channel in the island in a process known as island breaching.

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Slide: 20 Name two dangers of living near the ocean.

Slide: 21 Marsh Erosion  Marsh erosion occurs on wetland coastlines exposed to the open ocean or wide bays. Waves and currents erode the wetland soil, causing significant losses of land area.

Slide: 22 Look at this picture of a marsh. Name two reasons why salt water marshes are important.