Ocean Waves
| We go to the coast in droves in the summer attracted by the sun and the surf. How many of you have surfed the waves with a board, raft or even your body? Now, how many of you understand the process that gives many such great pleasure? What causes waves to form? What causes waves to break in the surf zone?
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| The motion of wind-driven surface waves extends downward to the wave base, a distance equal to one-half the wavelength (wavelength is the distance between successive waves). A wave eventually collapses and breaks in shallowing water as interference between the circular wave motion and the ocean bottom causes the wave to grow higher and steeper. Wave refraction or bending occurs when a wave approaches shore and the wave base reaches the bottom, realigning the wave so more energy is focused on land that protrudes into the ocean. Ultimately, this focused erosion can result in a straight shoreline.
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 Visit
this site on waves from Kettering
University for good diagrams of wave motion. |
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Visit
this optional site which is a lecture on ocean waves from Flinders
University; specifically wave types and formation. This lecture
is detailed and contains higher level content, but the format allows
you to read the text and view the figures in a separate frame at the
bottom of your viewing screen. |
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| Use
the following website from the Coastal and Marine Geology program
of the U.S. Geological Survey for information on current
ocean reports. Use the search fields to find research report,
educational resources, and other useful items. |
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Question: How do longshore currents transport sediments? |
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