The most widespread landforms of erosional coasts are sea cliffs. These very steep to vertical bedrock cliffs range from only a few metres high to hundreds of metres above sea level. Their vertical nature is the result of wave-induced erosion near sea level and the subsequent collapse of rocks at higher elevation.

What are two results of wave erosion along the coast? Over time waves can make large cracks larger and eventually pieces of rock to break off forming sea caves. Eventually waves erode the base of a cliff so the rock above collaspes which creates a wave-cut cluff. Sea archs can also be created.

Wave erosion can produce many features along a shoreline. For example, sea cliffs form when waves erode rock to form steep slopes. As waves strike the bottom of the cliffs, the waves wear away soil and rock and make the cliffs steeper.

Waves erode sediments from cliffs and shorelines. The sediment in ocean water acts like sandpaper. Land that sticks out into the water is eroded by the strong wave energy. The wave energy concentrates its power on the wave-cut cliff.

Hard structures partially hinder the recreational use of the coastal zone and can cause adverse ecological effects within the coastal zone. For example, when seawalls are constructed on eroding beaches, the erosion continues so that the beach in front of the seawall can become very narrow or disappear completely.

The transport of sediments by longshore currents is called longshore drift. Longshore drift is created in this way: Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. So longshore drift moves sediment along the shore.

The size of settleable solids will vary by water system – in high flow areas, larger, gravel-sized sediment will settle out first. Finer particles, including silt and clay, can be carried all the way out to an estuary or delta 17. In marine environments, nearly all suspended sediment will settle.

If the swash is stronger than the backwash (constructive wave), some of the sediment carried in the wave will be left behind to build up the beach. 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.

A sediment cell (or littoral cell) is a linked system of sources, transfers and sinks of sediment along a section of coastline. A sediment cell operates as a closed system, with virtually no inputs or outputs of sediment from the cell. This system contains inputs, transfers and outputs.

Groynes which are either structurally permeable or submerged (permanently or during high water levels) allow more sediment to pass alongshore, in comparison to impermeable or high groynes. The height of groynes influences the amount of longshore sediment transport trapped by the groynes.

Destructive waves They occur when wave energy is high and the wave has travelled over a long fetch. They have a stronger backwash than swash. They have a short wave length and are high and steep.

For constructive interference, the difference in wavelengths will be an integer number of whole wavelengths. For destructive interference it will be an integer number of whole wavelengths plus a half wavelength. Think of the point exactly between the two slits.

Destructive waves are usually found in more exposed bays, where they build pebble beaches. Although a destructive wave’s swash is much stronger than that of a constructive wave, its swash is much weaker than its backwash.

The highest surface part of a wave is called the crest, and the lowest part is the trough. The vertical distance between the crest and the trough is the wave height. The horizontal distance between two adjacent crests or troughs is known as the wavelength.

​matter & Energy A wave is a repeating disturbance or vibration that transfers or moves energy from place to place. A medium is a material through which waves can travel. It can be a solid, liquid, or gas. When waves travel through a medium, the particles of the medium are not carried along with the wave.

A wave is a disturbance that transfers energy from one place to another without transferring matter. Waves transfer energy away from the source, or starting place, of the energy.

Particles have momentum and positions. Particles will move in straight lines until something changes their direction. Particles can bounce off of other particles, and they can change trajectories.