What is longshore drift?

AQA GCSE Geography > Physical Landscapes in the UK > Coastal Landscapes in the UK > What is longshore drift?

What is longshore drift?

Longshore (littoral) drift is the movement of material along the shore by wave action. It happens when waves approach the beach at an angle. The swash (waves moving up the beach) carries material up and along the beach. The backwash (waves moving back down the beach) carries material back down the beach at right angles. This is the result of gravity. This process slowly moves material along the beach and provides a link between erosion and deposition.

The material is transported through suspension, traction, solution and saltation. Longshore drift provides a link between erosion, transportation and deposition.

Longshore Drift

Longshore drift contributes towards the formation of a range of depositional landforms such as spits and onshore bars. For example, spurn Point is a coastal spit formed by the transportation of coastal sediment by longshore drift along the Holderness Coast. This material is then deposited at the mouth of the Humber Estuary.

Spurn Point

Summary

What Is Longshore Drift?
Longshore drift is the process that moves sediment along a coastline due to angled wave approach.
Swash and Backwash
Waves carry material up the beach at an angle (swash) and back down at 90° (backwash), creating a zigzag motion.
Material Movement
Sediment such as sand, pebbles, and shingle is transported along the coast through repeated swash and backwash.
Wave Direction
Waves driven by prevailing winds usually approach the shore at an angle, initiating longshore drift.
Coastal Landforms
Longshore drift contributes to the formation of landforms such as spits, bars, and beaches.
UK Example
Spurn Point on the Holderness Coast is a well-known landform created by longshore drift.