Coastal systems and landscapes

Question 1

coastal systems

Answer 1

coasts are open systems because they receive inputs from outside the system but they are considered closed systems as sediment cells

Question 2

sediment cells

Answer 2

often bordered by headlands they are sections which sediment movement is almost contained and they are in dynamic equilibrium

Question 3

sediment sources

Answer 3

rivers, cliff erosion, wind, glaciers, offshore bars and sinks, longshore drift

Question 4

sediment budgets

Answer 4

Coastal management tool used to analyse the inputs and outputs of a coastal system

Question 5

littoral zone

Answer 5

land between cliffs or dunes and offshore area past the influence of waves

Question 6

wave formation

Answer 6

wind moves across the water creating ripples and waves, shallower seabed means waves become more horizontal, as the height increases velocity and wavelength decrease

Question 7

factors affecting wave energy

Answer 7

strength of the wind, duration of the wind, size of fetch

Question 8

constructive waves

Answer 8

formed in open ocean, long wavelength, 6-9 per minute, strong swash weak backwash, occur on gently sloped beaches

Question 9

destructive waves

Answer 9

localised by stronger winds closer to the coast, short wavelength, 11-16 per minute, weak swash strong backwash

Question 10

tides

Answer 10

difference in high and low tide is called the tidal range, tend to be larger in channels and estuaries

Question 11

currents

Answer 11

underwater tides are caused by a buildup of water at the top of a beach and pose threats to the beaches and lives

Question 12

high energy coastlines

Answer 12

more powerful waves, large fetch, typically have rocky headlands and landforms and more destructive waves

Question 13

low energy coastlines

Answer 13

sheltered areas where fetch is lower so waves cant build in size, typically sandy beaches and more constructive waves

Question 14

wave refraction

Answer 14

when waves hit a headland they turn and lose energy so the areas around are hit with weaker waves

Question 15

erosion

Answer 15

removal of sediment from a coastline

Question 16

abrasion

Answer 16

sediment is moved along the coastline forcing it to be worn down over time

Question 17

attrition

Answer 17

Erosional process where rocks and pebbles hit against each other causing them to become more rounded

Question 18

hydraulic action

Answer 18

air is forced into cracks in rocks as waves hit them, high pressure makes them widen eventually forcing them to break the rock

Question 19

solution

Answer 19

acidic seawater can cause alkaline rocks to be eroded such as limestone

Question 20

wave quarrying

Answer 20

breaking waves hit cliff faces exerting lots of pressure on them forcing them to break which also weakens them leaving them more vulnerable

Question 21

factors affecting erosion

Answer 21

waves- destructive or constructive, beaches-they can absorb wave energy for cliffs behind, subaerial process- weathering and mass movement, rock type,

Question 22

rock types

Answer 22

sedimentary rocks are cemented sedimented particles so are weaker, igneous are interlocking crystals so more stubborn, metamorphic crystals organised in the same direction so resistant

Question 23

traction

Answer 23

transportation process where large heavy sediment rolls along the seabed forced by currents

Question 24

saltation

Answer 24

transportation where smaller sediment bounces along the seabed pushed by currents but too heavy to be carried by water

Question 25

suspension

Answer 25

transportation where where smaller sediment is carried by the water

Question 26

solution

Answer 26

transportation where sediment is dissolved in the water and then carried

Question 27

longshore drift

Answer 27

waves hit the beach at angles of the prevailing wind pushing sediment on the beach in that direction

Question 28

deposition

Answer 28

sediment becomes too heavy waves too carry so is dropped, explaining why beaches are either sandy or rocky

Question 29

mechanical weathering

Answer 29

freeze thaw- water enters cracks in rocks then expands breaking rock, salt crystallisation- water evaporates leaving salt which exerts pressure on rocks forcing cracks to widen, wetting and drying- some rocks expand when wet like clay and this repeated process weakens the rock

Question 30

chemical weathering

Answer 30

carbonation- rainwater absorbs CO2 creating a weak carbonic acid which can then lead to dissolving the rocks, oxidation- minerals become exposed to oxygen they expand causing rock to crumble, solution- rock minerals are dissolved

Question 31

biological weathering

Answer 31

plant roots- roots of plants grow in cracks exerting pressure, birds- some birds build burrows, rock boring- clams secrete chemicals that dissolve rocks, seaweed acids- sulphuric acid can dissolve rocks minerals, decaying vegetation- water flowing through it becomes acidic

Question 32

mass movement methods

Answer 32

soil creep, mudflows, rockfall, landslide, slump, runoff

Question 33

caves, arches, stacks and stumps

Answer 33

hydraulic action and abrasion cause small caves, overlying rock then collapses, caves widen because of erosion and subaerial processes opening up causing an arch, arch then falls under its own weight leaving a stack

Question 34

cliff profile

Answer 34

steep cliffs- rock is strong and resistant, gentle cliffs- areas with weaker rocks, rate of retreat- likely to be higher if its unconsolidated material

Question 35

wave cut notch and platform

Answer 35

when waves erode rock its concentrated at high tide mark usually though hydraulic action and corrasion create a wave cut notch, it becomes deeper then after a while fall in on its own weight leaving just the bottom part of the rock called a wave cut platform

Question 36

beaches

Answer 36

depositional landform, swash aligned waves arrive perpendicular so little longshore drift, drift aligned waves arrive at an angle so more longshore drift

Question 37

spits

Answer 37

longshore drift causes beaches to extent out to sea due to a change in the shape of the coastline, can’t extend all the way across an estuary become of the currents from the river

Question 38

bars

Answer 38

when a spit join’s 2 headlands trapping water behind it

Question 39

tombolo

Answer 39

when a bar connects a mainland to an offshore island and is caused by wave refraction off the coastal island reducing velocity

Question 40

offshore bars

Answer 40

offshore region where sand is deposited because waves don’t have enough energy to carry the sediment to shore so drop it

Question 41

dune plant succession

Answer 41

pioneer plans grow first for example marram grass, when they die they release nutrients which then means more vegetation can grow, embryo dunes and pioneer plants change conditions from harsh and salty to one where other plants can survive

Question 42

salt marsh succession

Answer 42

1. algal grows on mud which their roots bind together, 2.pioneer stage stabilise mud, 3.establishment stage grass grows creating a carpet of vegetation, 4. stabilisation plants grow and salt rarely gets beneath the surface, 5.climax vegetation rush, sedge and red fescue grass grows because the salt marsh is only submerged for a year

Question 43

sand dunes

Answer 43

occur when prevailing winds blow sand to the back of beaches, embryo dunes, yellow dunes where vegetation may develop, grey dunes sand becomes soil, dune slack, water is trapped helping plants, heath and woodland, sandy soils develop so much more plantlike can prosper

Question 44

mudflats and salt marshes

Answer 44

deposition occurs in river estuaries because flow of water from the river and sea meets and almost stops dropping sediment, can also occur behind a spit as they are sheltered

Question 45

sea level change

Answer 45

isostatic- when land rises or falls relative to the sea and is localised, eustatic- affects the whole planet and could be down to thermal expansion or changes in glacial processes

Question 46

emergent landforms meaning

Answer 46

land has been raised in relation to coastline such as arches, stacks and stumps

Question 47

submergent landforms meaning

Answer 47

landforms occur when sea level rise or coastline sinks

Question 48

submergent landforms examples

Answer 48

rias- rising sea levels flood inlets and valleys, fjords- rising sea levels flood deep glacial valleys, Dalmatian coasts- valleys running parallel to coast become flooded leaving a series of long islands

Question 49

storm surges

Answer 49

a result of low pressure caused by large weather events such as tropical storms, raising sea levels and causing a flood threat

Question 50

hard engineering examples

Answer 50

offshore breakwater-forces waves to break before shore, groynes- wood that traps sediment from LSD, sea walls-concrete that absorb and reflect wave energy, rock armour- large rocks which allow water through but reduce wave energy, revetments-wooden or concrete ramps which absorb wave energy

Question 51

soft engineering examples

Answer 51

beach nourishment- sediment is taken from external sources to build up a beach, cliff regrading- reduces angle of beach so is less likely to collapse, dune stabilisation- marram grass planted so roots bind sand together, marsh creation-managed flooding allowing low-lying areas to flood

Question 52

Cost benefit analysis

Answer 52

carried out before coastal management where costs and benefits are assessed and benefits have to outweigh costs

Question 53

Integrated coastal zone management

Answer 53

large sections of coastline are managed with one management technique, it also talks about the human aspect of these projects

Question 54

shoreline management plans

Answer 54

an SMP recognises all the activities that happen within a sediment cell human and natural

Question 55

holderness technical information

Answer 55

over 50km from spurn head to flamborough, winter storms across the North Sea produce higher and stronger waves and the rain they bring intensifies sub-aerial processes

Question 56

holderness stats

Answer 56

29 villages have been lost to sea since roman times, 2m erosion per year fastest in Europe, sometimes being 7-10 in one year because of storms