1. Chapter 12
Section 1 Shoreline Erosion and Deposition
Bellringer
Where does sand come from? How do ocean waves create sand from rock?

2. Chapter 12
Section 1 Shoreline Erosion and Deposition
Objectives
Explain how energy from waves affects a shoreline.
Identify six shoreline features created by wave erosion.
Explain how wave deposits form beaches.
Describe how sand moves along a beach.

3. Vocabulary Chapter 12 sandbar shoreline barrier spit wave sea stacks
Section 1 Shoreline Erosion and Deposition
Vocabulary
shoreline
wave
wave train
surf
wave period
sea cliffs
beach
longshore current
sandbar
barrier spit
sea stacks
sea arches
sea caves
headlands
wave-cut terraces

4. Section Summary Chapter 12
Section 1 Shoreline Erosion and Deposition
Section Summary
As waves break against a shoreline, rock is broken down into sand.
Six shoreline features created by wave erosion include sea cliffs, sea stacks, sea caves, sea arches, headlands, and wave-cut terraces.
Beaches are made from material deposited by waves.
Longshore currents cause sand to move in a zigzag pattern along the shore.

5. Chapter 12
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.

6. Chapter 12
Section 1 Shoreline Erosion and Deposition
Wave Energy
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.

7. Chapter 12
Section 1 Shoreline Erosion and Deposition
Wave Energy
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.

8. Chapter 12
Section 1 Shoreline Erosion and Deposition
Wave Energy
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.

9. Chapter 12
Section 1 Shoreline Erosion and Deposition
Wave Erosion
The process continues until rock is broken down in smaller and smaller pieces that eventually become sand.
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 rate at which the sea cliffs erode depends on the hardness of the rock and the energy of the waves.

10. Chapter 12
Section 1 Shoreline Erosion and Deposition

11. Chapter 12
Section 1 Shoreline Erosion and Deposition

12. Chapter 12
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.

13. Chapter 12
Section 1 Shoreline Erosion and Deposition
Wave Deposits
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.

14. Chapter 12
Section 1 Shoreline Erosion and Deposition
Wave 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.