Coasts Flashcards
What sources of energy can create coastal land forms?
Waves
Tides
What process occurs in a low energy environment?
Deposition
What processes occur in a high energy environment?
Erosion
Transportation
Why does wave refraction occur?
Near headlands it is shallower
As a result there is more friction so the slowing effect is greater at headlands
What is bathymetry?
The topography of the sea floor
Is a beach formed in a high or low energy environment?
Low
What can lead to the formation of a beach?
Constructive waves
Longshore drift
Tidal currents
Wave refraction
Why are particles on the beach larger at the top?
The backwash does not exert the energy required to move large pieces of matter
What is a Dalmatian coast?
When valleys flood
Example of a negative feedback loop in relation to coasts
As constructive waves create a steeper beach, the swash exerts less power and the backwash exerts more power which reduces the gradient of the beach
How does a saltmarsh form?
When was sediment supply from a river or the tide causes flocculation as the freshwater and saltwater particles mix. This is then colonised by vegetation with a pioneer species such as algae solidifying mud and causing more deposits as the water is slowed down
Examples of sub-aerial weathering
Freeze thaw
Chemical weathering
Salt weathering
Wetting and drying
Outline the process of chemical weathering
CO2 dissolves in rainwater, forming a weak carbonic acid which reacts with calcium carbonate causing rocks such as limestone to dissolve
Outline the process of wetting and drying
Clay gets wet and expands, exerting pressure
Outline the process of freeze thaw weathering
As water enters cracks, it may freeze and expand, weakening the rock within a cliff face
Outline the process of salt weathering
Salt crystals forms was water evaporates from a cliff face. As the crystals expand, they exert pressure on the rock
How do waves erode the coastline?
Solution
Abrasion
Hydraulic Action
Cavitation
Wave quarrying
Attrition
Outline the process of abrasion
Bits of rock and sediment smash into the cliff face via the waves
Outline the process of hydraulic action
Air in the cracks and faults of cliffs is compressed when waves crash in. This creates pressure, weakening the cliff
Outline the process of cavitation
As waves receed, compressed air expands rapidly, exerting pressure on the cliff face
Outline the process of wave quarrying
The energy of waves as they hit the cliff is enough to force some of it to break off
Outline the process of attrition
Rocks in the water collide with each other and break into smaller bits
