Coasts EQ1 Flashcards
What is the littoral zone?
The wider coastal zone including adjacent land areas and shallow parts of the sea just offshore.
What are the four factors affecting coasts?
Terrestrial, Marine, Human, Atmospheric
How do earthquakes affect coasts?
They move rock and trigger tsunamis, which can destroy entire coastlines.
What do tectonic uplifts cause and what’s type of factor is it?
Emerging coastlines & terrestrial
What does the construction of ports, docks & transport do to the coasts?
Alters the shapes of coasts and boats can destroy coral reef & therefore increase the erosion of the coastline.
Can temperature alter the shape of coats?
Yes
Where is the backshore?
Top end of the beach/ cliffs.
Characteristics of high energy coasts
Destructive waves breaking on shingle beaches, higher rates of erosion.
Characteristics of low energy coasts
Constructive waves break on sandy beaches, the rate of deposition exceeds erosion rate.
What are the 2 main cliff profile types
Marine erosion dominated & sub-aerial process dominated.
Features of marine erosion dominated cliffs
Cliffs = steep & unvegetated, steep face, active undercutting, limited cliff base debris.
Fractures of sub aerial process dominated cliffs.
Cliffs have a curved slope profile,lower angle face and accumulated debris.
What is weathering
The chemical, biological, mechanical breakdown of rock into smaller fragments & new material in situ.
What is mass movement?
Landslides, slumps & rock falls, all of which move material downslope under the influence of gravity
What is surface runoff
Water, usually during heavy rain, flowing down the cliff face & causing erosion of it.
What is geological structure responsible for?
The formation of condardant and discordant coasts.
What’s a concordant coastline
Alternating bands of hard and soft rock
What is a discordant coastline
They have alternating bands of hard & soft rock at 90 degrees to the coast. Erosional landforms are more common.
Dalmatian coast
Made of offshore islands and coastal inlet running parallel to the coastline
Why do headlands and bays form on discordant coastlines
As the faster eroding, less-resistant rock retreats, this eaves behind the more resistant rock as headlands.
What does wave refraction cause?
Waves to change the way they approach the coastline - formation of headland featured (caves, arches, stacks & stumps)
What is a dip?
The angle the rock layer forms with the horizontal bedding planes.
What do seawards dips cause?
A gentle cliff profile vulnerable to mass movement processes, like rockfalls.
What do landward dips cause?
A steeper cliff profile - vulnerable to erosional processes, like hydraulic action & abrasion.
What is the geological structure of rocks determined by?
The deformation and stress placed on them from tectonic processes.
What type of rocks are more susceptible to the processes to erosion and weathering?
Sedimentary rocks
What are examples of igneous rocks, how do they form?
Basalt & granite, form from the crystallisation of magma.
What do igneous rocks contain which increase the strength of the rock.
Crystals - reducing the lines of weaknesses that would be exploited by physical processes
How are sedimentary rocks formed?
From the build up, compacting and hardening of sediments into layers over time by lithification
Examples of sedimentary rocks.
Limestone & sandstone
How are metamorphic rocks formed?
From the change in structure of sedimentary and igneous rocks , caused by variations in hear and pressure
What is the process of change in rocks called.
Rocks being “metamorphosed”
