Marine Processes

Aim
  • types of waves
  • component of waves
  • erosional processes: corrasion, corrosion, hydraulic action, attrition
  • onshore and offshore movement
  • longshore drift
  • wind actions and dunes

Waves

  • energy transmitted through matter
  • the medium (solid liquid gas) does not actually travel as the energy passes, but its particles vibrate as the energy passes through
  • Progressive waves
  • Size of wave depends on fetch= distance a wave travels
  • The greater the fetch, the larger the wave
  • The stronger the wind, the larger the wave
  • As the wave approaches the beach, it slows down due to friction between water and beach, and this causes the wave to break.
  • terms: break, swash, backwash
  • If swash is bigger than backwash, more deposition occurs so beach is created. If backwash is bigger than swash, beach is destroyed
  • Destructive waves destroy beaches. Back wash has less time to soak into sand. So it carries a lot of sand with it. As waves continue to hit the beach, more running water carry material to the sea.
  • Wind generated waves originate in windy places of the ocean
  • They keep on moving along large areas without the aid of wind
  • As wind blows over ocean surface, it creates pressure that deform the surface of the ocean
  • If power increases, it becomes gravity waves