Geomorphology Flashcards
(24 cards)
What are the 2 sets of geomorphological processes that affect coasts
Marine-a coastline that is connected with the sea, eg, waves, tides, LSD
Sub-aerial-on the land and affect the shape of the coastline, eg, weathering, mass movement, run-off
What are the 7 factors affecting the rate of coastal erosion
Wave steepness and breaking points
Fetch
Sea death
Coastal configuration
Beach presence
Human activity
Geology
What is lithology, and what are the 2 types
The study of rocks and their properties
Physical- particle bonds in clay (weak) and dense crystal bonds in basalt (strong/resistant)
What is the tees-exe line
Separates the UK into upland and lowland areas
How have glaciers affected rock
During the ice age, glaciers expanded and retreated in the British Isles. They deposited sediment in the meltwater, which made up ‘superficial ‘layers of rock
What is differential erosion
Variation in the rates at which rocks wear away
What makes some rocks like limestone more vulnerable to erosion
Well-jointed, meaning the sea can penetrate along lines of weakness
How does a concordant coastline affect erosion
Resistant rock forms cliffs that protect the rocks behind it from erosion
How does a discordant coastline affect erosion
Sea erodes weaker rock producing bays and headlands
What are the types of marine erosion
Hydraulic action
Wave quarrying
Corrasion
Abrasion
Attrition
Solution/corrosion
What is wave quarrying
A breaking wave traps air as it hits a cliff face. The force of water compresses the air into any gap creating pressure. Weakens the cliff
What is corrasion
Waves advance and pick up sand and pebbles from the seabed. When waves break at the base of the cliff chipping away at the rock
What are the types of chemical weathering
Oxidation
Hydration
Hydrolysis
Carbonation
What is oxidation
Causes rock to disintegrate when oxygen dissolved in water reacts with some rock minerals
What is hydration
Addition of water and minerals causing the rock to expand. Makes rocks more susceptible to further chemical weathering
What is hydrolysis
Mildly acidic water reacts with minerals to create clays and dissolvable salts degrading the rock.
What is carbonation
Co2 dissolved in rainwater makes a weak carbonic acid that reacts with the calcium carbonate in rocks to create calcium bicarbonate, which then dissolves easily in water. More effective in locations with cooler temperatures.
What are the types of biological weathering
Roots of plants
Some marine animals (shellfish) have shells that can drill into rock
Seaweed attaches itself to rock
Animal burrows
What are the different types of physical weathering
Freeze-thaw
What are the different transportation processes
Traction
Saltation
Suspension
Solution
LSD
When may marine deposition occur
Low energy waves
Coastal erosion provides abundant sediment
Sand and shingle accumulate faster than they are removed
Water pauses at the top of the swash before backwash begins
Water percolates into the beach material as backwash takes it back down the beach
What is aeolian deposition
Entrainment, transport, and deposition of sediment by wind
mass movement factors
Level of cohesion
Height of the slope and slope angle
Grain size within the sediment
Temperature and level of saturation
What are the types of mass movement
Landslides
Rockfall
Mudflows
Slumping
Soil creep
Solifluction
Run off
