Coasts Flashcards
What is corrosion
this is chemical action of the sea water the acids in sea water slowly dissolve rocks causing them to erode
What is a contour line
Contours are brown lines that are drawn. At regular intervals to show heights above the sea level contours join points of equal height
What is attrition
Materials carried by waves collide with each oh her they are smoothed then broken into smaller particles
What is abrasion
This is when the coast is worn down by material carried by waves they throw materials at the rocks and it erodes the rocks in a sand papering action
What is hydraulic action
Waves enter cracks in the coastline and compress the air within the crack when The wave retreats, the air within the crack expands quickly causing a minor explosion this is repeated
What are the advantages of rock armour
They protect the area behind the wall, help and prevents flooding,stops undercutting
What are the disadvantages of rock armour
They are expensive to obtain. And difficult to transport
What are the advantages of groynes
They trap sand and pebbles and build them up to make a barrier
What are the disadvantages of groynes
They are unattractive and costly to build and maintain
What are the advantages of a sea wall
Reflects waves and prevents flooding
What are the disadvantages of a sea wall
Unattractive,expensive to build and maintain this can also erode
What is the formation of a spit
When the coasts changes direction, the process of longshore drift may continue out into the sea. Swash and back wash continue to transport material and this is eventually deposited to form a narrow bridge of sand known as a spit
What is swash
Swash-materials carried by waves as they wash up the beach.the waves move up the beach at an angle being influenced by the prevailing wind direction
What is back wash
Material carried back down the beach at right angles
What is longshore drift
The transport of sand and pebbles along the coast by waves
