Beaches are areas of sand, pebbles and shingle that are formed by deposition produced by wave processes. Beaches are by no means uniform and contain a huge variety of sediment types and sizes, and have many different shapes. Gently sloping beaches are formed by strong destructive waves that backwash more material away from the beach that they swash up the beach. Steeply sloping beaches occur by constructive waves that swash more material up the beach than they backwash away, building up a steep beach gradient.
Spits are created by the process of Long shore drift. Some eroded material ends up caught up within the waves and is carried by the sea along the coastline in cells known as littoral cells. Material is carried along the shore in a zigzag fashion by waves as they swash material up the beach at an angle and backwash material down the beach at a right angle.
The angle of swash is determined by the prevailing wind the dominant or main direction in which the wind blows. Very little moisture exists in this area. The next stage is the formation of grey dunes and dune ridges. By this stage, the dunes are more fixed. The soil becomes increasingly acidic as more humus forms which in turn increases water retention. Combined this allows new species of plants to thrive e. As sand dunes become colonised with vegetation roots stabilise the sand and hold it together.
The video below shows an area of sand dune at Spurn Point where erosion has caused the dune to begin to collapse. The erosion has exposed a cross-section of the dune revealing the depth of the roots. Very little sand from the beach accumulates beyond the grey dunes and dune ridges which leads to the formation of wasting dunes. Here the soil is more acidic, water retentive and rich in humus. The typical vegetation here includes heather and gorse. Dune height here is usually between m high.
Salt marshes often occur in sheltered river estuaries or behind spits. Vegetation develops in the intertidal mudflats found in these areas.
An example of this is behind Spurn Point in the Humber Estuary. The image below shows the salt marsh in this area. The video below shows a close up of the salt marsh at Spurn Point at low tide. Landforms of deposition Coastal landforms of deposition occur where the accumulation of sand and shingle is greater than it is removed.
Beaches and associated features: berms, runnels and cusps Beaches are dynamic environments which for the buffer between land and sea.
Wave zones and beach morphology. Ridges and Runnels. Beach profile containing ridges and runnels. Ridge and runnels on Harlech beach. A berm at Hornsea beach. Spurn Point. Spurn Point, Holderness Coast. The formation of a bar. Sand dunes on Spurn Point. Search for:. Coastal Landforms of Deposition. Drainage Basin Hydrological System. Landforms of Erosion. Sub-Aerial Processes.
Spits are quasilinear, subaerial landforms that are caused by longshore deposition of sediment by the prevailing waves and currents along coasts. They may be found anywhere in the world where there exists a net longshore movement of material away from a break in shoreline orientation.
A spit represents longshore deposition, and is morphologically defined as extending from land into the offshore zone. Therefore it has exposed seaward and sheltered bayside shores of higher and lower energies, respectively. Skip to main content Skip to table of contents. This service is more advanced with JavaScript available.
Beaches and Coastal Geology Edition. Contents Search. Authors Authors and affiliations James R. Reference work entry First Online: 08 July
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