1. Ocean Waves
wave a periodic disturbance in a solid, liquid, or gas as energy is transmitted through a medium
two basic parts—a crest and a trough

2. wave period the time required for two consecutive wave crests to pass a given point
wave height: vertical distance between crest and trough
Wavelength: distance between two crest or troughs

3. Wave Energy
Longer wind blows the more energy is transferred into the water = larger waves.
Wave movement:
Energy in waves move from water molecule to water molecule in the direction of the wave
circular motion
in a single wave period, each water particle moves in one complete circle
Only the energy not the water moves across the surface of the ocean.

5. Wave Size Three factors determine the size of a wave. Whitecaps:
Speed of the wind, the length of time the wind blows, and fetch.
fetch the distance that wind blows across an area of the sea to generate waves
Whitecaps:
When winds blow the crest of a wave off
reflect solar radiation, they allow less radiation to reach the ocean

6. Waves and the Coastline
Breakers
Wave moves into shallow water.
The bottom of the wave is slowed by friction
The top of the wave continues to move at its original speed.
the top of the wave topples over and forms a breaker, a foamy mass of water that washes onto the coastline.

8. Start of Wave Sequence

18. End of Wave Sequence

19. Refraction:
The bending of the wave crest in response to changes in wave speed
Shallow ocean water = slower speeds
Deeper ocean water = faster speeds

20. Undertows and Rip Currents
Water carried onto a beach by breaking waves is pulled back into deeper water gravity
Rip currents:
form when water from larger breakers returns to the ocean through channels that cut through underwater sandbars that are parallel to the beach.

22. Rip Current

26. Longshore Currents
currents form when waves approach the beach at an angle
currents flow parallel to the shore.
Great quantities of sand are carried by longshore currents
These sand deposits form low ridges of sand called sandbars.

27. Longshore Currents
geocaching.com

28. Longshore Currents
sci.uidaho.edu

29. Tsunamis giant seismic ocean waves
Most are caused by earthquakes on the ocean floor, but some can be caused by volcanic eruptions and underwater landslides
Nick name is tidal wave, but they are not caused by tides
has a tremendous amount of energy
In open ocean water they travel at a rate of around 760Km per hour or 483mph, that similar to the speed of a jet aircraft.
Not dangers in open water, but when they come into shallower the energy is transferred into height = destruction
The arrival of a tsunami may be signaled by the sudden pulling back of the water along the shore

30. Tsunami
tsunamis.com