Coastal processes Flashcards
Test
(EL)
Erosional Landforms
(EL) How is a wave cut platform formed?
Waves attack base of cliff through abrasion, corrosion, hydraulic action, attrition.
(EL) What happens over time in a wave-cut platform
The cliff will be undercut and a wave-cut notch is formed
(EL) What happens after the notch in a wave cut platform
The cliff becomes unstable and collapses
(EL) Example of a wave-cut platform
Kimmeridge Bay, Dorset
(EL) What happens to less resistant clay in Headlands and Bays.
Wave attack through Hydraulic action and attrition cause erosion to soft clay, making hard rock stick out as headlands.
(EL) What happens after this in the middle of two headlands?
During calm periods the sheltered bay allows deposition leading to beaches forming.
(EL) What is a concordant coast?
Has the same rocktype all along so less headlands and bays formed. (just soft and hard rock)
(EL) What is our example of a concordant coast?
Lulworth Cove
(EL) What is a discordant coastline?
different rocks and clay with different levels of erosion needed to erode.
(EL) What is our example of a discordant coastline?
Swanage Bay
(EL) What causes Caves, Arches, Stacks and Stumps
Processes of hydraulic action and attrition acting over time develop these landforms.
(EL) What is our example of a coast with Caves, Arches, Stacks and Stumps
Harry’s Rock, Dorset
(EL) Where do Geo and Blowholes occur?
Occur on the same coastline as caves, arches, stacks and stumps.
(EL) What is a Geo
An inlet that looks like a waterfall gorge that has been eroded over time.
(EL) What is our example of Geo’s and Blowhole’s?
Harry’s Rock, Dorset
(EL) What is a blowhole
A hole in the top of the rocks that has been created by up-welling waves and cutting through the top of the rock.
(DL)
Depositional Landforms
(DL) What tides create the largest beaches?
Spring tides create the largest beaches with lots of material carried within the swash.
(DL) What changes the type of material on coastline?
The strength of the tide
(DL) What is our example of a beach
West Wittering
(DL) How are spits formed?
Formed through the process of LONGSHORE DRIFT transporting the material. Form due to a change in shape of the coastline.
(DL) How does swash move in LSD?
At angles depending on wind strength and direction
(DL) How does backwash move in LSD?
Directly back out to see, due to the influence of GRAVITY.
(DL) What is our example of a spit?
Spurn point
(DL) What is an Offshore bar
Deposits of sand and shingle situated some distance from a coastline - Usually form below sea level. Big waves crash down and bring sediment back
(DL) Why do Offshore bars form?
in shallow seas when waves away from shore, where steap waves hit a beach and a big backwash occurs.
(DL) What is our example of an offshore bar
Loe bar, Cornwall
(DL) What is a barrier beach
A lagoon surrounded inland
(DL) How is a barrier beach formed
Created where a spit develops across a bay as there are no strong currents to stop the process.
(DL) What is our example of a barrier beach
Slapton, Devon
(DL) What is a Tombolo
A spit which has grown from mainland out to conjoin an OFFSHORE-BAR
(DL) One method of Tombolo formation
Drift alligned - so in the direction of longshore drift depositing sediment.
(DL) What is the other method of Tomolo formation
Through wave shadow if wind is coming from the offshore direction.
(DL) What is our example of a Tombolo
Chesil beach, Weymouth
(DL) Where do Sand dunes get taller
The further inland you go
(DL) What is an embryo dune
The smallest dune nearest to the coast
(DL) What makes Sand Dunes sturdy?
Marram grass and other vegetation
(DL) What colours are sand dunes?
Yellow closer to sea, grey further out due to bacteria.
(DL) What separates each sand dune
A slack, formed by sediment removed by wind.
(DL) What is our example of a Sand Dune?
Studland beach
(DL) How are salt marshes formed
They’re created when mud and silt are deposited along a sheltered part of the coastline.
(DL) What vegetation is in salt marshes
Halophytic vegetation
(EM)
Emergent features (appear when sea level falls)
(EM) what is a Marine platform
A staircase style cliff, with an overhang on lower layer due to hydraulic action and attrition on the rocks.
(EM) What is our example of Marine Platforms?
Quatemary Marine, NZ
(EM) What is a raised beach
Areas of former wave-cut platforms and their beaches which are lying above sea level
(EM) What is our example of a Raised Beach?
Kincraig point, Scotland
(SM)
Submergent landforms, appear when sea level rises
(SM) What is a Ria
A drowned river valley
As sea level rises they have flooded the river valley and left only high land visible
(SM) What is our example of a Ria
Kingsbury, Devon
(SM) What is a Fjord
A drowned glacial valley.
As sea levels rise, U-shaped valleys left by glaciers are submerged.
(SM) What are features of Fjords?
Steep tall sides, narrow body of water leading into away or into coast
