1. Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Energy
When waves crash into rocks over long periods of time, the rocks are broken down into smaller and smaller pieces until they become sand.
Waves usually play a major role in building up and breaking down the shoreline. A shoreline is the boundary between land and a body of water.

2. Wave Energy, continued Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Energy, continued
As the wind moves across the ocean surface, it produces ripples called waves. The size of a wave depends on how hard the wind is blowing and how long the wind blows.
The wind that results from summer hurricanes and severe winter storms produces large waves that cause dramatic shoreline erosion.

3. Wave Energy, continued Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Energy, continued
Waves travel in groups called wave trains. When wave trains reach shallow water, the bottom of the wave drags against the sea floor, slowing the wave down.
The upper part of the wave moves more rapidly and grows taller, and begins to curl and break. These breaking waves are known as surf.
The time interval between breaking waves is called the wave period.

4. Wave Period of Ocean Waves
Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Period of Ocean Waves
Click below to watch the Visual Concept.
You may stop the video at any time by pressing the Esc key.
Visual Concept

5. Wave Energy, continued Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Energy, continued
The Pounding Surf Tremendous energy is released when waves break. Crashing waves can break solid rock and throw broken rocks back against the shore.
Breaking waves also wash away fine grains of sand, which are picked up by the waves and wear down and polish coastal rock.
The process continues until rock is broken down in smaller and smaller pieces that eventually become sand.

6. Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Erosion
Shaping a Shoreline Wave erosion produces a variety of features along a shoreline. Much of the erosion responsible for coastal landforms takes place during storms.
Sea cliffs are formed when waves erode and undercut rock to produce steep slopes.
The next two slides show some of the major features that result from wave erosion.

7. Chapter G3
Section 1 Shoreline Erosion and Deposition

8. Chapter G3
Section 1 Shoreline Erosion and Deposition

9. Wave Deposits Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Deposits
Beaches are areas of the shoreline made up of material deposited by waves. Some beach material is also deposited by rivers.
Waves carry a variety of materials, including sand, rock fragments, dead coral, and shells.
The colors and textures of beaches vary because the type of material found on a beach depends on its source.

10. Wave Deposits, continued
Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Deposits, continued
Wave Angle and Sand Movement Waves moving at an angle to the shoreline push water along the shore and create longshore currents.
Longshore currents move sand in a zigzag pattern along the beach.

11. Wave Deposits, continued
Chapter G3
Section 1 Shoreline Erosion and Deposition
Wave Deposits, continued
Offshore Deposits When waves erode material from the shoreline, longshore currents can transport and deposit the material offshore, which creates landforms in open water.
A sandbar is an underwater or exposed ridge of sand, gravel, or shell material.
A barrier spit is an exposed sandbar connected to the shoreline.