Geography Term 2 2016
Terms in this set (50)
Waves form when wind blows across the surface of the ocean but they are not a wall of water. Their energy is produced by the wind and they are the major force shaping the coasts.
The highest point of a wave
The lowest point between two waves
The horizontal distance between the crests of two consecutive waves
The vertical distance between the wave trough and the crest
Stronger winds produce higher waves
Onshore winds and Offshore winds produce different-shaped waves.
The amount of time that the wind has blown. The longer that the wind blows, the higher the waves are likely to be.
The area of water over which the wind has blown. The greater the fetch, higher the waves.
Steepness of the slope of the seabed. Along gently sloping coastlines, waves break further out, by the time they reach the shore they don't have much energy left
Occurs when waves are simply rising and falling, not breaking
The water that moves up the beach.
Water that runs back to the ocean.
The wearing away of the earth's surface by wind, water or ice. Waves wear away rocks, cliffs and headlands along the coastline.
The process by which eroded material moved from one location to another. Waves transport eroded material and deposit it to form new landforms.
The eroded material is deposited along the coast by waves to produce other landforms
Water is very heavy; as a result, quickly moving waves have a great deal of energy to lift and carry material.
As waves pound the coast, air is trapped and compressed in cracks and joints in cliffs or walls. As is repeatedly compressed, it can cause cracks to become larger and many pieces of rock may break away.
Abrasion or corrasion
Cliffs are worn away as the rocks and boulders that have been eroded are thrown against them by the waves
The process of sand, pebbles and boulders being carried along the coast, wearing away the coastline
Corrosion or solution
Salt spray, the alternate wetting and drying of rocks and chemical weathering from vegetation can literally dissolve and eat away coasts, depending on the type of rock that forms the coasts
Waves in which swash is stronger than backwash. They tend to be smaller, more gentle, lower energy waves.
Stronger and more powerful than constructive, backwash is larger than swash. Moves material down the beach face and back into the sea.
When waves hit the coastline at an angle, the movement of the water and material will run parallel to the coast. Moves sand in the direction of the dominant waves
Backwashes usually just flow back to the sea relatively evenly across the beach but sometimes it concentrates into strong current. Like rivers of fast flowing water flowing from shore line out to sea.
An offshore bank or ridge of sand lying parallel to the coast that can be exposed at low tide
Headlands or capes
A large headland of very resistant rock jutting out into sea
Bays or inlets
A wide indention in the shoreline usually between two headlands or peninsulas
The process by which the wave is bent or turned from its original direction, happens most around a headland
A small cut or indentation made at the base of a cliff by waves
A flat terrace cut across bedrock at the base of a cliff by waves or erosion
A hollow space along the coast produced by the action of the waves
A hole formed in the top of a cave through which air and water are forced by waves, eg Witches Cauldron at Noosa
A natural feature, usually formed by rock, that forms a bridge like arch as a result of erosion
A steep vertical column of rock in the sea near a coast; stacks are formed when a part of a headland is eroded by hydraulic action, when the top of the arch collapses.
This is covered by water only during the highest tides
This is covered and uncovered daily by the tides
This is below the level of low tide
This is narrow ledge or ridge of material deposited at the back of a beach by the highest tides
A curved build-up of eroded material that forms at the mouth of a river.
A hill or mound of sand formed by wind deposition on the land side of the beach.
A deposit of sand linking an island to the mainland or another island. Formed by longshore drift.
Designed to prevent erosion of cliffs and to protect buildings, roads & agricultural land behind the wall.
Loose rock wall
Slows down the force of a wave to protect the coast behind it.
Low walls perpendicular to the coast designed to stop longshore drift and keep beaches in place.
The rocks placed in a steel mesh cage that absorb the wave energy and reduce erosion.
Are walls built perpendicular to the shoreline to protect harbour mouths from closing.
Breakwaters are built parallel to the coast to protect it from wave erosion. They also provide a safe harbour for boats. Behind a breakwater, longshore drift can be weakened and material can build up. A tombolo may build up behind it.
Any piece of land reclaimed from water.
Artificially built sheltered harbour for boats and yachts. They can interfere with longshore drift.