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Beaches: Sand on the move!

Description of longshore currents and transport
Waves bend (refract) as they approach the shore
Waves bend (refract) as they approach the shore

Waves bend (refract) as they approach the shore
Waves bend (refract) as they approach the shore

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Radiolarian

Longshore drift

  • Wind blows toward the shore, creating waves
  • Waves move sediment towards the shore at an angle (oblique)
  • Backwash (retreating waves) carry sediment away from beach at 90°, perpendicular to the shore
  • The effect of these processes is longshore transport (beach drift) of sediment parallel to shore in the general direction of the prevailing winds
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This page was last updated on 9/10/99