Table of Contents
What currents move sediment along a beach?
Overview. Longshore drift is the transport of sediments by longshore currents. Longshore drift moves sediment along the shore. Landforms created by sediment deposition at the shore include beaches, spits, and barrier islands.
How do currents affect beaches?
The breaking waves and resulting currents pick up and move sand, making beaches dynamic, perpetually in motion. This subtle but steadily flowing river of sand moves laterally up and down the shoreline, as well as offshore during storms and back toward land between storms.
How do waves affect sediment?
As a wave crashes on the shore, the water pushes sediment up the beach and then pulls it back down the beach as the water slides back down. If the waves do not come in parallel to the beach longshore transport (littoral drift) of sand occurs.
What processes move sediment along a shoreline quizlet?
Waves and longshore currents move sediment along the coast, building up a long, low mound of sediment.
How does sand move from Beach to beach?
Sand grains travel southward down the coast, while finer particles of sediment are carried and deposited further out to sea. Along the way, sand is washed ashore, temporarily resting on beaches, until it is re-suspended in the ocean by wave action or wind.
How is the movement of sediment related to wave energy?
The movement is called longshore sediment transport and its rate is dependent on wave energy and the angle at which waves strike the coast (an angle around 30° being the most effective). The overall significance of sediment transport depends on whether it occurs along coasts of free or impeded transport.
What happens to the sediment when the beach ends?
If the beach ends the drift will continue to move in the same direction of the coastline building up sediment into what is called a Spit. As the Longshore Drift continues the Spit will gradually get wider and extend further in the same direction until the beach ends.
What happens to the sand when longshore drift occurs?
As this sheet of water moves on and off the beach, it can “capture” and transport beach sediment such as sand, gravel, and other small debris back out to sea. This process, known as “longshore drift,” can cause significant beach erosion.