GCSE Coastal Zone Flashcards
What factors shape our coastline
Waves
Rock type
Land processes
Marine Processes
What are the land processes shaping the coastline
Weathering
Mass movement
What are the marine processes shaping the coastline
Transportation
Deposition
Erosion
What is the fetch
The distance the wind has blown
What depends on the fetch
Size and strength of wave
Larger wave means
Greater fetch, stronger wind
Waves strongest from
South West Britain
Why do waves break
Waves slow at beaches because of FRICTION between wave and beach– causes it to break
Define swash
Forward movement of a wave UP a beach
Define backwash
Movement of a wave back DOWN a beach after the wave broken
Swash/Backwash transfer of energy
Transfers energy UP/DOWN a beach
Types of waves
Constructive, destructive
Characteristics of constructive
- builds beaches
- low waves
- carries material up the beach
- most common in summer
- material deposited when backwash soaks into sand/slowly drains away
Characteristics of destructive
- destroys beaches
- high and frequent waves
- strong backwash pulls material out to sea
- most common in winter
What affects height and shape of coastal scenery
Resistance, permeability, structure of rock
What is resistance
Rocks can be hard (granite) and soft (clay)
What is permeability
Rocks can be porous (chalk), permeable (limestone) and impermeable (granite)
What is structure
Rocks can have interlocking crystals, joints, faults and bedding planes
Weathering and mass movement are…
SUB-AERIAL PROCESSES/land processes
Define mass movement
Downhill shifting of rocks and loose material under the influence of GRAVITY which is greater than the force supporting it
What is slumping
Common when cliffs are of clay. During heavy rainfall- becomes saturated+heavy and oozes towards sea as part of a MUD or DEBRIS flow
(mudflow, rotational slip)
What is sliding
When large chunks of rock slide downslope quickly without warning
(landslide, rockfall)
Rotational slip
Rotational movement on a concave slide plane. Weak rock (clay)/soil becomes saturated- in response to GRAVITY simply collapses
Mudflow
Weak rock (clay, volcanic ash)/soil becomes saturated and FLOWS downhill. Can be slow/rapid. If mixed with melted snow/ice/ash from volcanoes– become lahars (deadly)