Coasts and rivers Flashcards
what is systems thinking
systems thinking is particuarlly usefull to help understand how natural landscapes work and humans interact with them. It is used to simplify and help make sense of complex things.
what is it called when matter or energy is added
input
what is it called when energy or matter leaves a sysstem
output
what is it called when matter or energy builds up
stores
what is it called when there is a movement of energy in a system
the flows
what is the limit of a system called
the boundarie
what are they key features of an open system
Open systems have input and output flows, representing exchanges of matter, energy or information with its surroundings.
what are the key features of a closed system
A closed system is a system in which only energy is transferred with its surroundings.
what is a dynamic equilibrium
when input and outputs are balanced
in reality there are samll variaition are so small that the inputs and outputs are balanced
for example in drainage basins the amount of water varries
what is poitive feedack
This amplifies the change ininput and output
this means the systems responds by increasing the effect of the change moving the system further from the origonal state
what is negative feedback
the counteracts the change in inputs or outputs
the system responds by deacreasing the effect of the change keeping the system closer to previous state
what are the 5 spheres
hydrosphere
cryosphere
atmosphere
biosphere
lithosphere
what is transfer flow
the movement of matter from one store to another
what is a store
when matter is temporarily held in a store
isolated system
No interactions whith anything outside the system boundary. RARE
closed system
energy is transfered into and out of the system. All matter is enclosed e.g the global water and carbon cycles
open system
Matter and energy can be transfered into and out of the system. ALL matter is enclosed e,g the drainage basin water or woodland
what is positive feedback
Where the effect of an action are amplified by changes to theinput/output/process
How are waves formed
Created by wind as the crest is pulled up
what causes friction
The wind blows on the surface of the water
what type of motion does water move in
circular orbit
The amount of energy gaines by the aes depends on what three things
wind speed length of lime the wind has been blowing and the distance of open water (fetch)
When waves reach the shallows what does friction do
Friction with the seabed slows the base of the wave
does the top of the wave slow down
No it becomes highre and steeper until the wave breaks
what is swash
swash carries material up the beach stronger in constructive waves
what is backwash
Backwash takes material away from the beach this is stornger in destructive waves
what is wave refraction
when waves approach a coastline that is not regular shape, they are refreacted and become increasingly parralel to the coastline
when does wave energy become concentrated
on the headland causing greater erosion
what is the wavelength
the distance between the two peaks of a wave
what is the techincal term forpeak of a wave
the crest
what is the wave height
the distance from the base of the wave to the crest
what is the technical word from base for a wave
the trough
how do waves form
created by wind as the crest is pulled up
what causes friction
the wind blows on the surface of the water
what moition do waves move in
they move in a circular orbit
the amonyut of energy the waves gained depends on what factors
wind speed
the lenghth of time the wind has been blowing
when the waves reach shallow watter what does friction do
Friction with the sea bed slows the base of the wave
does the top of the wave ever slow down
no it gets higher and steepoerunti it breaks
what are the key features of high energy coastlines
large headlands
potential sand banks
deep bay
more frequent and destructive
deep water
long fetch
high erosion rates
low deposition rates
what are the key features of a low energy coastline
small gentle waves
frequent constructive waves
shallow water
gentle winds
short fetch
low erosion rate
high deposition rate
what are sediment cells
in theory sediment cells are regarded as closed systems from which nothing is gained or lost
what happens to largere sediemnt cells
they are arranged into smaller sub cells to make it easier to study and manage
what happens within a sediment cells
sediment moves around the cell but never leves the cell
what factors affect erosion
wave steepness
geology
human activity
beach presence
coastal configuraition
sea depth
the fetch
what is geology
the study of rocks
what is lithology
this refers to the charcteristics of rocks
what are marine processes in relaition to erosion
operates upon the coastline and involve the erosion of the coastline by the action of the sea
What is a sediment cell
Sediment cells, also known as littoral cells, are reaches of shoreline that encompass the intertidal and nearshore movement of sediment
What is traction
Pebbles are rolled along the sea bed eroding them in high energy conditions
What is Saltation
Small stones are bounced along the sea bed and the beach
What is suspension
Very small particles of sand and silt are carried along by moving water
Solution
Solution means it slowly gets dissolved
What is weathering
Weathering weakens cliffs and makes them more vulnerable to erosion
What is chemical weathering
Caused by chemical changes rainwater that is slightly acidic slowly dissolved away the rock
Mechanical weathering is what
Physical dintigraition or break of exposed rock without any changes it it’s chemical composition
what is biological weathering
this is simply the distigraition of rock because of animals plants and or microbes
what is a rock fall
a rock fall is when fragments of rock fall away from the cliff face due to weathering
what is a landslide
rocks are blown off and slide down the hgill bring down more as it falls
what is a mud slide
this is when saturated soil flows down the slope
mass movements are impacted by what
they are all impacted by gravity
what are the different forms of deposition
marine deposition
areolian deposition
what type o coastline are headlands fromed at
discordent
what i an example of a headland and bay in the uk
swanage
where are cliffs and wave cut platfroms found
they are found at concordent coastlines
what is an example of a wav cut platform in the uk
kimmerage bag has a wave cut platform
what is an example of an arch whcih has developed into a stack
durdle door
how do tombolos form
A tombolo is formed when a spit connects the mainland coast to an island.
what are barrier islands
a barrier island is a long thin sandy stretch of sand arientated parallele to the mainland which thereofr protects the main isalnd from the full force of storms
what is a slat marsh
Saltmarshes are coastal wetlands that are flooded and drained by the tides. They’re boggy and marshy as their soils are composed of deep mud and peat. They’re found in most parts of the world where there’s low-lying land and a temperate climate.
what is the final plant succesor in the uk
it is an oak tree
what is the order of dune colours
embryo dune
fore dune
yellow dune
grey dune
dune slack
and finly the climax
what are the inputs of a sand dune
supply of sand strong onshore winds, large tidal range, obstacles to trap sand, vegitaition growth
how anre sand dunes formed
it is done by sand blown/sallated onshore by strong wids at low tide
how long does it take for embryo dunes to mature
400 years
how do tides and tidal ranges affect the coastline
Tides increase the rate of coastal erosion. Where tidal range is low, for example, in the Mediterranean, wave energy is less and many cliff faces are unaffected by marine processes. due to the rsie ad fall of water
why are narrower estuaries at a greater risk from tides than wider
this is due to it beig easier to be eroded 5677io;
what is it called when the earth sun and moon line up and their power combines to make exseptinally high tides
spring tides
what is a neap tide
A neap tide—seven days after a spring tide—refers to a period of moderate tides when the sun and moon are at right angles to each other.
what are rip currents
rip currents are strong surface currents which run perpendicular to the shore. they can be very dangerous to surfers and swimmers as they can move very fast taking them out into the ocean from the breaking waves they often form between sandbars or other physical features
What are fjords
These are flooded glacial valleys. It is where a glacier eroded steep u shaped valleys into the land. When it floods water fills these valleys creating fjords
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