What is the correct definition of longshore drift?
longshore drift. noun. the process whereby beach material is gradually shifted laterally as a result of waves meeting the shore at an oblique angle.
What is longshore drift an example of?
Longshore Drift (littoral drift) This usually occurs in one direction as dictated by the prevailing wind. For example, the prevailing wind along the Holderness Coast is north-easterly. As the result waves break on to the beach obliquely at an angle of around 45 degrees.
What is longshore drift quizlet?
Longshore drift (LSD) is the movement of material along the beach (1). It is comprised of swash – where breaking waves move material up a beach (in the direction of prevailing wind/waves (1), and backwash – where (due to gravity) material is dragged back towards the sea (1).
What is longshore drift and how is it related to a longshore current?
Longshore drift is the movement of sediments along a coast by waves that approach at an angle to the shore but then the swash recedes directly away from it. The water in a longshore current flows up onto the beach, and then back into the ocean in a “sheet-like” formation.
What are the effects of longshore drift?
As this sheet of water moves on and off the beach, it can “capture” and transport beach sediment back out to sea. This process, known as “longshore drift,” can cause significant beach erosion.
What is backwash in geography?
When a wave breaks, water is washed up the beach. This is called the swash . Then the water runs back down the beach, which is called the backwash . This means that the beach increases in size. If the swash is weaker than the backwash (destructive wave), very little sediment is carried up the beach.
Is longshore drift enhanced by groin placement?
Groins are much shorter structures built on straight stretches of beach away from inlets. Groins are intended to trap sand moving in longshore currents. After one groin is built, the increased rate of erosion effect on adjacent beaches has to be addressed.
What is the difference between longshore drift and beach drift?
Longshore drift is simply the sediment moved by the longshore current. This current and sediment movement occur within the surf zone. This process is called “beach drift” but some workers regard it as simply part of “longshore drift” because of the overall movement of sand parallel to the coast.
How does longshore drift create a Tombolo?
The process of longshore drift occurs and this moves material along the coastline. This causes material to be deposited in a long thin strip that is not attached to the coast and is known as a spit. If this feature moves in the direction of island and connects it to the mainland then it becomes a tombolo.
What drifts in longshore drift?
Longshore drift from longshore current is a geological process that consists of the transportation of sediments (clay, silt, pebbles, sand, shingle) along a coast parallel to the shoreline, which is dependent on the angle incoming wave direction. The process is also known as littoral drift.
What causes waves BBC?
Waves are created by wind blowing over the surface of the sea.
What is longshore drift in geography?
Quick revise. The transport of sand and pebbles along the coast is called longshore drift. The prevailing wind (the direction the wind ususally blows from) causes waves to approach the coast at an angle. The swash carries the sand and pebbles up the beach at the same angle (usually 45º).
How is Spurn Point formed by longshore drift?
Longshore drift transports material along the length of the Holderness Coast. At the southern-most edge of the Holderness Coast material is then deposited forming Spurn Point, a coastal spit. Find out more about landforms of coastal deposition. Spurn Point – a coastal spit formed by longshore drift.
Do ports and harbors pose a threat to longshore drift?
Both ports and harbors pose a short-term threat to longshore drift. Similarly, they are also a threat to shoreline evolution. Change of sedimentation patterns is one of the key impacts caused by the creation of harbors and ports on a shoreline drift. Such changes may result in the erosion of a coastal system or beach.
What interferes with longshore drift at Hengistbury Head?
A riprap armoured groyne interferes with longshore drift at Hengistbury Head. Longshore drift comes from the right of the image, transporting beach sediment along the coast from right to left. You can see that on the right-hand side of the image the beach is quite narrow and the waves have enough energy to form white tops.