Coastal Landscapes Glossary Flashcards
Relief
Relief describes the physical features of a landscape, including its height, steepness and how its features are shaped.
Waves
Ripples in the sea caused by the transfer of energy from the wind blowing over the surface of the sea. The largest waves are formed when winds are very strong, blow for lengthy periods and cross large expanses of water.
Fetch
The distance that wind blows over the sea before reaching land.
Beach
Deposited sand/rock/pebbles that have built up.
Crest
Top of a wave.
Swash
When a wave moves up the beach.
Backwash
When a wave moves back down the beach.
Constructive Wave
Powerful wave.
Strong swash.
Builds up the beach.
Destructive Wave
Formed by storm conditions.
Strong backwash.
Takes material from the beach.
Mass movement
The downhill movement of weathered material under the force of gravity. The speed can vary considerably.
Slumping
Rapid mass movement where a whole segment of a cliff moves downslope.
Sliding
Occurs after periods of heavy rain when loose surface material becomes saturated and the extra weight causes the material to become unstable and move rapidly downhill, sometimes in an almost fluid state, e.g. landslide.
Rockfall
Collapse of a cliff face.
Individual rocks fall from a cliff.
Landslide
Blocks of rock slide downwards.
Rotational Slip
Saturated (wet) soil and weak rock which slumps along a curved surface.
Chemical Weathering
The decomposition (or rotting) of rock caused by a chemical change within that rock; sea water can cause chemical weathering of cliffs.
Mechanical Weathering
Weathering processes that cause physical disintegration or break up of exposed rock without any change in the chemical composition of the rock, e.g. freeze-thaw weathering.
Hydraulic Power
Water is forced in to cracks in the cliff. Gradually making the cracks bigger and bigger.
Abrasion OR Corrasion
Rocks are flung at the cliff by powerful waves. They start to erode the cliffs.
Corrosion OR Solution
Rocks like limestone dissolve.
Attrition
Pebbles bang together making them smaller and smoother over time.
Transportation
The movement of eroded material.
Traction
Heavy rocks (boulders) are rolled along the sea bed.
Solution
Dissolved chemicals are transported in the water.
Saltation
Pebbles bounce along the sea bed in a leap-frogging motion.
Suspension
Lighter particles e.g. sand are suspended in the water.
Longshore Drift
Transportation of sediment along the coastline.
Waves approach the beach at a 45o angle and transport beach material (sediment) up and down the beach.
Sand Dune
Coastal sand hill above the high tide mark, shaped by wind action, covered with grasses and shrubs.
Embryo Dune
At the front of the dunes is the youngest dune called an embryo dune, this is very salty as it’s close to the sea.
Fore Dune
These are older, slightly higher and further from the sea than the embryo dune.
Yellow Dune
These are taller than the fore dune.
Grey Dune
These are the furthest dunes from the beach and the conditions are less salty so more plants can grow.
Dune Slack
Wind cam form depressions in the sand where ponds may form.
Headland
More resistant (hard) rock which juts (sticks) out in to the sea.
Bay
Bays are mainly circular and created out of less resistant (soft) rock. They form between the areas of more resistant rock and often have beaches.
Cliff
A steep, high rock face formed by weathering and erosion.
Wave-cut Platform
Wide sloping surface at the base of a cliff. Eroded by hydraulic erosion and abrasion.
Wave-cut Notch
Small notch (dent) cut in to the cliff at the level of high tide. Eroded by hydraulic action and abrasion.
Cave
Hydraulic action makes cracks bigger to create a cave.
Arch
The cave becomes bigger due to hydraulic action and abrasion. Eventually the cave breaks through the headland to create an arch.
Stack
The arch collapses as there is nothing to support it. Leaving an isolated rock stack.
Stump
The stack gets eroded further by erosion and weathering (wind and rain) to form a stump.
Spit
A finger of new land made of sand. It juts out in to the sea from the coast.
Bar
A spit which has grown across a bay.
It forms a bar of sand with a freshwater lake/lagoon trapped behind it.
Salt Marsh
Low lying (below sea level) coastal wetland.
