Lesson 6 Flashcards
What are the 4 types of erosion?
attrition
hydraulic action
solution
abrasion
What is attrition?
Rocks hit each other
What is hydraulic action?
Waves herald against a cliff, wind brakes it further
What is solution?
Rocks dissolve in water?
What is abrasion?
Waves throw rocks at cliffs (sand blasting)
How do weather systems effect erosion?
In low pressure, wind causes an increase in wave strength causing more erosion where as high pressure is the opposite.
What are areas of depression? (2)
areas of low atmospheric pressure which produces fowel weather.
Low pressure systems that occur in the Atlantic
How does the depth of sea floor effect erosion?
A deeper sea floor = less friction (waves don’t break as much, more powerful). Shallow causing opposite effect resulting in more erosion
How does the wind and fetch effect erosion? (2)
Size of wave depends on its fetch
Greater the fetch/wind larger the wave
How does geology effect erosion? (4)
Depending on the mineral composition of the rocks and the presence/absence of lines of weakness.
Hard rock more resistant than soft rock.
Discordant coastlines erode more, cause headlands and bays, different rock types.
Concordant same rock (soft), slumping occurs.
How does beach size effect erosion? (4)
Narrow beaches have less protection for cliffs
Waves break later (more powerful)
Broad beaches have more protection, waves break earlier, less powerful.
How does wave type effect erosion?
Destructive occur in stormy conditions, wind blown for long time. Wave energy high, long fetch, they erode the coast.
Constructive occur in calm weather, less powerful, break on shore depositing material building up the beach.
Coastal features? (9)
cliff, headland, cave, stump, blowhole, wave cut platform, wave cut notch, arch, stack
