1.2 Coastal Landscapes Flashcards
Define Hydraulic Action
Water is forced into cracks in the rock and air is forced out explosively, breaking off pieces of the cliff
Define Abrasion
This is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth.
Define Attrition
This is when rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded.
Define Corrosion
When acid rain causes chemical weathering
Define Chemical Weathering
Acids in seawater slowly dissolve rocks
Define Biological Weathering
Roots of growing plants and burrowing animals or nesting birds can cause rocks to weather
Define Mechanical Weathering
Caused by repeated freezing and thawing of water in a crack or hole in the rock.
How does Freezing and thawing weather a rock?
(Mechanical weathering) water freezes and expands, putting stress on the rock, ice melts and the water sinks deeper into the rock and the process repeats.
Describe Rock Falls
Bits of rock fall off the cliff face, usually due to freeze thaw weathering
Describe Slumping
Saturated soil slump down a curved face
Describe Sliding
Saturated soil (filled with water) flows down a slope
Describe Traction
Process by which large, heavy pebbles are rolled along the river bed, this is most common near the source
Describe Saltation
Pebbles are bounced along the sea bed, this is most common near the source
Describe Solution
Lighter sediment is dissolves within the water, most commonly near the mouth
What is deposition?
When sediment, usually carried by waves is laid down or deposited
When does deposition occur?
When their is not enough energy to carry sediment any further
What does LSD stand for?
Longshore Drift
What does Longshore Drift transport?
Sand and sediment
Describe the process of Longshore Drift
The swash brings in sediment at an angle, the backwash brings this back out to sea at 90 degrees
This transports material up the coastline
In which direction does swash come at the coast from?
Prevailing Wind
Describe Constructive Wave
Strong Swash
Weak Backwash
Long wave in proportion to height
What happens to sediment in constructive waves?
It tends to be deposited
Describe Destructive Waves
Weak Swash
Strong Backwash
High wave in proportion to length
Tall Breaker (breaks downwards with great force)