Agents of Erosion
and Deposition
Devils Tower, WY
http://www.nps.gov/deto/learn/nature/geolog
icformations.htm
Agents of Erosion and Deposition
 Shoreline
 Wind
 Ice
 Gravity
Shoreline Erosion and Deposition

Shoreline: the place where land and
body of water meet
Wave Energy

Waves: wind moving across
the ocean surface


Size of wave depends on how
hard the wind is blowing and
how long the wind blows
Wave Trains: waves that travel
in groups uninterrupted
through ocean water
Wave Energy Continued

Surf: when waves meet shallow water; the
bottom of the wave drags against the sea
floor, slowing the wave down; the upper part
of the wave moves rapidly and grows taller
causing the wave to curl and break under
the weight

Wave period: the time interval between
breaking waves
Wave Energy Continued
• Pounding surf: the energy released when waves break
crashing into and breaking solid rocks back to the
shoreline (how sand is made)
Breaking waves crash
against the rock shore,
releasing energy
Wave Erosion
Wave Deposits

Beach: any area of the shoreline made up of material
deposited by waves
Beach in
England
Beach in
Hawaii
Beach in
Tybee Island,
Ga
Wave Angle and Sand Movement

Longshore current: a water current that moves the sand
in a zigzag pattern along the beach
Offshore Deposits
Waves erode material from the
shoreline, longshore currents can
transport and deposit this material
offshore.

Sandbar: underwater or exposed
ridge of sand, gravel, or shell
material

Barrier spit: exposed sandbar that is
connected to the shoreline
http://www.gosur.com/map/?gclid=Cj0KEQjwvo6wBRCG3Zv92ZSLlIYBEiQA5PLVAjTdueFXjC1F8GRBEpFY
kCpP9opADZDTuTyAdu-5hmEaAhtq8P8HAQ&z=11&ll=31.250278,-81.326804&t=hybrid&lang=en
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.
https://youtu.be/ChEHQUMEkXw