Coastal processes

Coastal processes

1. How waves are formed - waves are caused by the wind dragging on the surface of the water

   • Fetch (distance)
   • Strength of wind/power
   • Duration

2. Waves

   • Top of the wave = Crest
   • Bottom of the wave = Trough
   • Distance between two crests = Wave length
   • Distance between crest and trough = Wave height

3. Swash - water that rushes up the sand

4. Back wash - the water going back into the sea

5. Types of waves

   • Constructive
     • Low wave height
     • Long wave length
     • Powerful swash - deposits material onto the beach
     • Weak backwash
     • Low frequency (6-8 waves per minute)
     • Short fetch
   • Destructive
     • High wave height
     • Short wave length
     • Powerful backwash - erodes material from the beach
     • Weak swash
     • High frequency (10-14 waves per minute)
     • Long fetch