2B.5A: Sediment Transportation

• Traction

  Large, heavy rocks roll and slide along the seabed.
• Saltation

  Lighter sediment bounces and skips along the seabed. Usually sand particles.
• Suspension

  Very light sediment is carried aloft in the water. E.g. silt or clay particles.
• Solution

  Sediment is dissolved and carried out to sea. E.g. nutrients from calcium carbonates
• Longshore drift

  This is the net lateral transport of material along the coastline when waves approach the coast at an angle. 

  1. Incoming swash transports sediment up the beach at an angle (movement contains an up-beach component and a lateral component)
  2. Gravitational backwash then transports sediment back down the beach at 90' to the coastline. 
  3. A sediment particle comes to rest some distance along the beach from the original starting point due to net lateral movement. 
  4. Particle moves in a zig-zag fashion along the beach with each incoming wave.