Diagram demonstrating longshore drift 1=beach 2=sea 3=longshore current direction 4=incoming waves 5=swash 6=backwash
Longshore drift from longshore current is a geological process that consists of the transportation of sediments (clay, silt, pebbles, sand, shingle, shells) along a coast parallel to the shoreline, which is dependent on the angle of incoming wave direction. Oblique incoming wind squeezes water along the coast, and so generates a water current which moves parallel to the coast. Longshore drift is simply the sediment moved by the longshore current. This current and sediment movement occur within the surf zone. The process is also known as littoral drift.[1]
Beach sand is also moved on such oblique wind days, due to the swash and backwash of water on the beach. Breaking surf sends water up the beach (swash) at an oblique angle and gravity then drains the water straight downslope (backwash) perpendicular to the shoreline. Thus beach sand can move downbeach in a sawtooth fashion many tens of meters (yards) per day. 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.
Longshore drift affects numerous sediment sizes as it works in slightly different ways depending on the sediment (e.g. the difference in long-shore drift of sediments from a sandy beach to that of sediments from a shingle beach). Sand is largely affected by the oscillatory force of breaking waves, the motion of sediment due to the impact of breaking waves and bed shear from long-shore current.[2] Because shingle beaches are much steeper than sandy ones, plunging breakers are more likely to form, causing the majority of long shore transport to occur in the swash zone, due to a lack of an extended surf zone.[2]
^Gomez-Pina G (2002) "Sand dune management problems and techniques, Spain", Journal of Coastal Research, Iss 36: 325–332.
Longshoredrift from longshore current is a geological process that consists of the transportation of sediments (clay, silt, pebbles, sand, shingle, shells)...
perpendicular to the coastline. This asymmetrical motion of swash can cause longshoredrift as well as cross-shore sediment transport. The swash zone is the upper...
between coasts. Probably the most important effect is longshoredrift (LSD)(Also known as Littoral Drift), the process by which sediment is continuously moved...
river transport, sea cliff erosion and longshoredrift into an area. Sediment sinks can include longshoredrift of sediment away from an area and sediment...
features found on coastlines and lakeshores that are created primarily by longshoredrift. Formed by accretion and progradation of sand and shingle, they extend...
texture and shape. It is also colloquially referred to as drift glass from the longshoredrift process that forms the smooth edges. In practice, the two...
interacts with a coastal environment that is significantly affected by longshoredrift. The lagoons which form on the MSG coastlines are common on the east...
the ocean, groynes create beaches, prevent beach erosion caused by longshoredrift where this is the dominant process and facilitate beach nourishment...
sand, gravel/pebbles, and crushed shells as a result of longitudinal (longshoredrift) or transverse transport of sediment. Sometimes a peresyp may be formed...
starvation or erosion from longshoredrift. It stops the movement of the original beach material through longshoredrift and retains a natural look to...
littoral drift or longshoredrift. Rocks are occasionally eroded directly by wave action shed detritus, which is caught up in longshoredrift and washed...
lake was carried out of its new outlet and down to Monterey Bay by longshoredrift. Richard Hilton (29 August 2003). Dinosaurs and Other Mesozoic Reptiles...
moving tectonic plate above it, so a chain of islands results as the plate drifts. Over long periods of time, this type of island is eventually "drowned"...
transported along the coast in the direction of the prevailing current (longshoredrift). When the upcurrent supply of sediment is less than the amount being...
Littoral warfare – Military operations in coastal waters Longshoredrift – Sediment moved by the longshore current Marine debris – Human-created solid waste...
Longshore Sailing School Longshore drift Longshoreman This disambiguation page lists articles associated with the title Longshore. If an internal link led you...
The gradual evolution of beaches often comes from the interaction of longshoredrift, a wave-driven process by which sediments move along a beach shore...
beach or dune profile, and adjust well to moderate erosion, especially longshoredrift. However, they can cease to be an effective access surface if they...
sediments came from longshore sources. He proposed that sediment moving in the breaker zone through agitation by waves in longshoredrift would construct...
is divided from the mainland by the River Alde, and was formed by longshoredrift along the coast. The material of the spit comes from places further...
erosion and flooding.[citation needed] It also plays a large part in longshoredrift.[citation needed][clarification needed] Fetch length, along with the...
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