EQ1

Question 1

Littoral zone

Answer 1

• A series of sub-zones representing features of the wider coastline from sea to land
• Backshore, foreshore, nearshore, offshore
• Zone reaches dynamic eq where there’s a balance between inputs and outputs
• Sediment is the key input & output of the system
• Inputs: actions of waves, currents, wind
• Outputs: washed out into sea by erosion

Question 2

Sediment cells

Answer 2

Sediment / Littoral cells:

• Erosion, transportation & deposition is contained within sediment cells
• 11 large sediment cells in England & Wales
• A closed system where no sediment is transferred from one cell to another
• Peninsulas act as natural barriers to sediment transfer e.g Llyn Peninsula Wales
• In reality it’s unlikely sediment cells are fully closed due to wind direction + currents

Names of sediment cells:

• St Abb’s Head
• Flamborough Head
• The Wash
• River Thames
• Selsey Ball
• Portland Bill
• Land’s End
• River Severn
• St David’s Head
• Bardsey Sound
• Great Orme
• Solway Firth

Question 3

Two main types of coast

Answer 3

Rocky/cliffed coastline:

• Cliffs varying heights
• Varying rock types

Coastal plains/alluvial coastline:

• Land gradually slopes towards the sea
• Sand dunes are common

Question 4

Longshore Drift (LSD)

Answer 4

• Waves hit the beach at an angle determined by the prevailing wind
• Swash pushes sediments onto the beach
• Backwash pulls sediments off the beach at a right angle due to gravity
• Over time, swash and backwash move the sediment along the beach in LSD

Question 5

4 types of coastal erosion

Answer 5

Abrasion:

• When rocks and sand in the ocean waves scrape against a cliff and wear away rock

Attrition:

• When rocks and pebbles in the waves hit against the cliff and become smoother

Hydraulic action:

• When the shear force of waves hits a cliff and forces air bubble into faults widening it and carries away material with the sea

Solution:

• Weak acids in the sea water react with sedimentary rocks and they dissolve

Question 6

4 types of coastal transportation

Answer 6

Traction:

• Large heavy pebbles are rolled along the sea bed

Saltation:

• Large sand grains or shingle are bounced along the sea bed

Suspension:

• Small particles like slits and clays are suspended in the flow of water

Solution:

• Minerals in rock like chalk and limestone are dissolved in sea water and carried in solution. Load is not visible

Question 7

Fetch

Answer 7

• The distance a wave has travelled
• Longer fetch = stronger wave

Question 8

High energy coast vs low energy coast

Answer 8

High energy coast:

• More powerful destructive waves
• Long fetch
• Erosion & transport, mass movement
• Cliffs, cave, arch, stacks, stumps
• Rocky coasts, exposed areas
• E.g Atlantic Coasts of Norway & Scotland
• Pacific coasts of Canada & Alaska

Low energy coasts:

• Less powerful constructive waves
• Short fetch
• Deposition and transport, LSD
• Beaches, spits, bars, salt marshes
• Lowland coasts, sheltered areas, coastal plains
• E.g Mediterranean Sea coasts
• East Anglian coastline

Question 9

Concordant and Discordant Coasts

Answer 9

Concordant Coasts:

• Alternating layers of hard rock and soft rock parallel to the coast
• Hard rock protects softer rock
• Prevents erosion
• Once hard rock is eroded, a cove can form
• E.g Lulworth Cove Dorset, Southern England

Discordant coasts:

• Alternating layers of hard and soft rock perpendicular to the coast
• Soft rock is exposed & eroded faster
• Headlands and Bays are formed
• E.g Count Kerry, West coast Ireland

Question 10

Mineral scale of hardness (rock)

Answer 10

• 1 = Chalk
• 2 = Gypsym
• 3/4 = Limestone
• 5 = Apatite
• 6/7 = Granite
• 7 = Quartz
• 8 = Topaz
• 9 = Corundum
• 10 = Diamond

Question 11

3 types of rock

Answer 11

Igneous:

• Very slow erosion rate <1mm per annum
• Crystalline = Interlocking crystals = hard
• Granite, Basalt, Dolerite few joins

Sedimentary:

• Fast erosion cm - several metres per year
• Geologically younger rocks weaker
• Many fractures in these rocks
• Sandstone, Limestone, Shale

Metamorphic:

• Slow erosion 1mm-10cm per year
• Foliation where crystals are all orientated in one direction = slight weakness
• Heavily fractured
• Slate, Schist, Marble

Unconsolidated material = weakest coastal material e.g sand, clay, silt

Question 12

Coastal vegetation

Answer 12

Vegetation:

• Plants stabilise loose material & hold it together which protects coasts from erosion
• E.g Coastal sand dunes, salt marshes & mangrove swamps
• Roots bind sediment and when submerged, plants provide a protective layer to avoid being exposed to water
• Plants reduce wind speed
• Halophytes = Can tolerate salt water
• Xerophytes = Can tolerate dry conditions

Plant succession:

• This is how a group of plants changes over time
• First plants are known as pioneer species
• Climax vegetation is when there’s no new species

Sand dune system:

• Embryo and fore dunes
• Yellow dunes
• Dune slack
• Health/woodland