Coastal Landscapes And Change Flashcards
What is the littoral zone
The coastal zone in which sediment are moved around
Where is the littoral zone
From the highest sea level line to shallow off-shore water
What are the 4 sub zones
Backshore, foreshore, nearshore, offshore
Name the three other zones
Breaker zone, surf zone, swash zone
What is lithology
The physical properties of a rock
What is sub-aerial weathering
Breaking down of a rock in situ
What is dynamic equilibrium
The littoral zone with inputs outputs and processes
Where a natural system tries to achieve a balance by making constant changes in response to influences within the system
Name the three different coastlines
Rocky cliff
Coastal plains: sandy and estuarine
What will determine the landscape of the coast
The amount of energy will determine whether it is retreating or advancing
What is energy provided by
Waves, but also weather, rivers and large and small scale sea currents
How are concordant and discordant coastlines created
When you have areas of differing rock types of varying resistance to erosion
What are the factors
How consolidated the material is, the number of joints and folds
Where is wave energy concentrated
At headlands and reduced around bays as as the water depth decreases so does wave energy
Name some landforms and examples low energy coastlines
Spits, salt marshes, beaches and the east Anglian coast
Name some landforms and examples of a high energy coastline
Cliffs, arches, caves and Atlantic coasts of Norway and Scotland
Where are the different rock types found around the uk
Igneous - dotted around, mainly around the coast
Sedimentary - north, Scotland and Northern Ireland
Metamorphic - east of the Tees-Exe line
The steeper then bedding plane the what?
Gentler the slope
What has unconsolidated sediment not undergone
Lithification
What is pore water pressure
The pressure water experiences at a particular point below the water table
Explain the three different types of lithology
Non porous and non permeable
Porous and permeable
Porous and non permeable
Explain each rock types and it’s erosion rate
Sedimentary - moderate to fast due to being classic and having many bedding planes
Metamorphic - slow due to pressure they have in faults and crystalline
Igneous - very slow due to interlocking crystals
Name the three types of sub aerial weathering
Chemical, mechanical and differential
Name the 4 types of chemical weathering
Hydrolysis - chemical reaction of rock and water
Carbonation - reaction between water and CO2
Hydration - minerals in the rock absorb water and swell
Oxidation - when minerals react with oxygen
Name the 2 types of mechanical weathering
Frost shattering
Salt crystallisation - saline water evaporating, leaving behind sodium and magnesium in joints and cracks which grow and exert pressure on the rock
Explain differential erosion
Coastal recession rates can be determined by comparing historical maps with new ones, or using LiDAR
It is the selective erosion of areas of weakness
What is plant succession
A progressive change in the dominant plant community over time
What are pioneering plants
A specialised plant which is the first plant to grow in its environment
What’s a halosere
A salt marsh environment with salty and damp conditions
What’s a halophytic
A plant which is highly salt tolerant
What is brackish
Slightly salty water
What is flora
Plants
What is fauna
Animals
What is humus
Organic component of soil formed of decomposed materials
What does a salt marsh need
Little wave action
Shelter from exposure
Low energy
Name and explain the three processes in salt marsh making
Sedimentation is when fine particles fall out of suspension
Accretion is when these particles build up
Flocculation is when negatively charged sea particles are neutralised by sea water as they are no longer repelling each otherother
What is the first stage of salt marshes
Microscopic algal growth where algae eg gut weed and sea lettuce grow on stones in the mud and trap particles
Stage 2
Mud experiences longer periods of emersion due to being built up and it reaches low mean tide height. Emersed 2-3 days of the year
Stage 3
Plants need these 2-3 days to germinate and extend its radicle eg glasswort
Stage 4
As these initial plants trap sediment and die, adding humus to the mud, less salt tolerant plants start to colonise the upper parts eg salt grass
Stage 5
Eventually upper parts are raised above regular submersion and will grow further. Even more complex plants will colonise the area until the climax community trees eg ash is reached with a fully developed creek system. This is known as vegetation succession
How are sand dunes formed
Formed by sand that has been deposited by constructive waves and blown in by the wind
What does xerophytic mean
Survive with very little water eg marram grass
What’s an embryo dune
First developed
Stabilisation occurs via marram grass which acts as a trap for sand
Conditions are very dry and plants adapt with long roots
What’s a yellow dune
Heights can reach 5m
Plants include sand sedge
What are fixed grey dunes
Limited growth due to distance from beach
More stable with plants like heather
What are dune slacks
Depressions between dune ridges which are damp in summer and water filled in winter
Species include water mint
What are blow outs
Evidence of human use, large holes in dunes
What is a psammosere
Succession of growth in plants in sandy conditions
What is a halosere
Succession of growth in plants in saline conditions
What type of breakers do constructive waves have
Spilling breakers
What type of breakers do destructive waves have
Plunging breakers
What is the frequency of each type
C - 6-8 per min
D - 13-15 per min
Name the four types of erosion
Hydraulic action
Corrosion
Abrasion
Attrition
What is corrosion
Sea water and salt spray may react with rock minerals that dissolved the minerals
What is a sediment cell
A stretch of a coastline which is usually bordered but two prominent headlands
Not a closed system
How many sediment cells are there on the uk
11
What is eustatic change
The level of water in the ocean which creates sea level
What is isostatic change
The level of the land relative to the sea levellever
What is isostatic subsidence
The land stinks due to the weight of overlaying iceice
What is isostatic recovery
The land rises as the weight of the land is reduced and the land becomes more buoyant
Which is the fastest change
Eustatic
What is causing the uk to tilt
Isostatic recovery
What is thermal expansion
The tendency of matter to change shape, area and volume in response to a change in temp
Name four features of rising sea levels
Rias, fjords, fjards and a Dalmatian coastline
What are rias
Drowned river valleys
What are fjords
Flooded u shaped valleys
What are fjards
Glaciated lowland areas that have been flooded
What is a Dalmatian coastline
Where valleys lied parallel to each other and are now flooded which creates a series of offshore islands
Give three features of falling sea levels
Raised beaches, relic cliffs, slope over wall cliffs
What is slope over wall cliffs
Soft rock on top of hard rock and erosion until an angle of rest is achieved
What does the IPCC predict for the future
Sea level rise by 55cm by 2100 and delta flooding risk increased by 50%
What can be done about climate change
Adaption- making changes to lessen the impact
Mitigation- making efforts to reduce the emission of greenhouse gases
Define hard engineering
Controlling natural processes with artificially built structures
Define soft engineering
Uses ecological principles and practices to work with the natural processes to achieve stabilisation of the shoreline
What three things does sustainability need to meet
Environmentally economically and socially
What does SCM stand for
sustainable coastal management
What does ICZM stand for
integrated coastal zone management
What do ICZM’s aim to bring together
economic decision makers and different government levels eg council and MP
What do ICZM’s aim to conserve
coastal ecosystems to ensure the ability of future generations to use the coast
What do ICZM’s emphasise
cooperation between stakeholders (anyone who has an interest)
Why is it a dynamic process
due to changing demands
Where are they used
across the world
What does SMP stand for
shoreline management policies
What are they based on
sediment cells
Why was SMP 1 criticized
for not listening to local people
How long are they meant to last for
100 years
What are the policies judged on
What is appropriate for the country
Name another mechanical weathering process
wetting and drying
What are the four options for SMP’s
hold the line
advance the line
managed retreat
no active intervention
In order to decide where to protect on coasts such as the Holderness Coast, what is used
cost-benefit analysis and an environmental impact assessment
