coasts

Question 1

wave formation

Answer 1

energy transferred from air to water, shelving increases friction, wave breaks

Question 2

coastal defences effect on physical geo.

Answer 2

disrupt physical geography processes, e.g. walls, groynes

waves change direction, energy taken elsewhere

Question 3

littoral zone and subdivisions

Answer 3

offshore (furtherest) - sea away from land
nearshore
foreshore
backshore (closest) - waves only reach during high tide
coast/land

Question 4

primary coast

Answer 4

dominated by land-based processes
e.g. deposition from rivers, volcanic lava
zavodovski island

Question 5

secondary coast

Answer 5

dominated by marine erosion / deposition

e.g. slapton

Question 6

coastline morphodynamics

Answer 6

things that change a beach are constantly changing, the way different factors make a coastline unique and how these factors are constantly changing.

short term processes: rivers, waves, tides
longer term processes: geology, sea level change

Question 7

wave size

Answer 7

wind strength
wind duration
water depth
wave direction

Question 8

percolation

Answer 8

downward movement of water through soil, sand, pebbles

Question 9

constructive

Answer 9

low height, low wavelength 
6-8 per min
uninterrupted swash, nearshore
strong swash
steeper beach 
gradient change over long distance

Question 10

destructive

Answer 10

high height, short wavelength 
13-15 per min
slower waves approach steep beach 
still circular motion
stronger backwash 
gradient change over short distance

Question 11

littoral zone

Answer 11

near shore area where sunlight penetrates sediments, allowing for aquatic life to flourish, but faces continuous change

Question 12

sea-level change

Answer 12

geology of cork coastline:
orientated 90 degrees perp., alternating hard/soft rock = elongated narrow bays
hard resistant areas = detached islands

storms = long fetch, help rivers erode = form valleys

sea level rise = valleys drowned
headland + bay = exaggerated

Question 13

role of wave refraction

Answer 13

deep water wave crests - parallel to the coastline
headlands: wave crests curve, refract, concentrated on headlands, spread outwards to the bays
headlands - accelerate erosion
material - deposited in bay
coastline: straight overall. headlands erode, material deposited in bays

Question 14

tectonic activity on beach shape

Answer 14

push sedimentary rock up from seabed - e.g. limestone
can fold them - plate collisions = creates weak points for waves to exploit
magma may have risen to the surface and cooled = igneous rock
sea removes layers above it
igneous rock exposed and resisting wave erosion

= gradually get a straight coastline

Question 15

rias

Answer 15

drowned river valley due to SLR

Question 16

dalmatia coastline

Answer 16

concordant coastline
drowned by SLR
limestone geology
horizontal strata - oldest at bottom, youngest at top
tectonics - compressed and folded layers - anticlines and synclines
sub-aerial erosion - eroded starta in weak places
rivers erode synclines
long narrow islands are left

Question 17

haff coastline

Answer 17

long sediment ridges
sand dunes
parallel to coastline
series of lagoons between ridges and shores

Question 18

marine erosion

Answer 18

synclines, beneath

Question 19

river erosion

Answer 19

anticlines and shapes landscape

Question 20

new zealand

Answer 20

convergent plate boundary
7.8 magnitude wave - 4 different faults broke at once
sea bed is now 2m higher
marine animals died
3km/second
6m uplift on one side, 2m uplift on other
new foreshore

Question 21

isostatic change

Answer 21

heavy ice pushes land downwards, melting ice means that land rebounds back
new cliffs formed through erosion, old fossil cliffs remain

Question 22

isostatic readjustment

Answer 22

soft vicious mantle, parts of crust respond to change

Question 23

norwegian fjords

Answer 23

submergent coastline as a result of eustatic SLR
200km inland
fracture system in bedrock
entrance at seaward end is shalower
gravel and sand deposits = made certain areas of fjords shallower

Question 24

wave-cut platform

Answer 24

sloping rocky shelf found at the foot of a retreating cliff and exposed at low tide

Question 25

periglacial

Answer 25

permanently frozen ground

Question 26

fjords

Answer 26

submerged u-shaped valley that has been over-deepened inland rock lip threshold - seaward entrance

Question 27

eustatic rise/fall

Answer 27

change in global sea level

Question 28

Louisiana

Answer 28

Mississippi river flows into Gulf of Mexico depositional coast - marshes, swamps, barrier islands huge levees and engineering projects to protect NO vulnerable to storm surges, global sea level rise, isostatic tectonic uplift

Question 29

eustatic fall

Answer 29

ice sheets formed during glacial period | evaporated water locked up as ice

Question 30

fall in SLR

Answer 30

``` offshore bars raised beaches fossil cliffs but... storm surges? tides? tectonics? ```

Question 31

sea level changes daily

Answer 31

high and low tides alter local sea level atmospheric air pressure = low pressure, slight rise winds = wave height varies

Question 32

marine regression

Answer 32

eustatic fall and isostatic fall - former seabed exposed = emergent coast

Question 33

marine transgression

Answer 33

eustatic ride and isostatic rise - areas of land flood = submergent coast

Question 34

North Antrim Coast rock types

Answer 34

igneous: (impermeable) basalt, dolerite and gabbro, granite, basalt strong, hard erosion-resistant rock few joints, limited weaknesses, erosion can't exploit ``` sedimentary: layers of rock formed over time sandstone (permeable) animals and plants moderate/fast erosion rate young rocks = weaker shale - most vulnerable ``` metamorphic: (impermeable) intense heat/pressure slate, schist, marble resistant to erosion foliation - crystals in one direction = weakness folded + heavily fractures folding = cracks, water gets in, permeable ``` ancient limestone(permeable): more resistant recently erupted volcanic lava = weaker, easily eroded ``` permeability = groundwater flow weakens rocks, exploiting joints and structure, binding materials high pore water pressures within cliff = reduce stability low seaward dip but places with landward dip

Question 35

entablature

Answer 35

unconsolidated laterite, more permeable, stores water water sits water builds up in entablature as it travels slowly in the colonnades, so gets heavier and rock materials fall = mass movement

Question 36

colonnades

Answer 36

columns, water goes down cracks and faults | water can get through but very slowly

Question 37

West Africa (Guinea)

Answer 37

700m of erosion 10cm of SLR since 1950 1m SLR by 2100 urbanisation high along coast: fishing, tourism stormy months loss of mangrove forests: harvested as fuel wood rainfall intensive sand mining in mangroves and rivers gold and diamond mining along rivers, gravel extracted from rivers each day but not returned use gravel to build local houses sand = removed from coastlines for construction sea walls = too expensive don't do beach nourishment major storms local construction: seawalls and revetments stop sediments being moved along coast tourist resorts = swept away saltwater intrusion - destroying marine habitats beach dunes reduced natural vegetation removed or dislodged steep cliffs - from weathering/undercutting

Question 38

Holderness

Answer 38

holderness coast 50 properties access road soft boulder clay cliffs 1-2m/ year rate of erosion coastal management scheme: £2million 2 types of hard engineering: Norwegian granite rock armour along base of cliff two rock groynes stopped beach material being moved south along the coast left area south of coast: Withensea unprotected increased erosion in south mappleton and cliffs no longer at great risk

Question 39

Trinidad and Tobago

Answer 39

small island, developing state low lying, susceptible to 0.06m/year rise in SL 70% population live/work on coast winter storms from Atlantic= higher swell waves southerly LSD, high erosion rates: Coco Bay coastal flooding along 20km Manzanilla beach, cut off roots weak sandstone + metamorphoc rock there are vital sites of oil industry= main source of GDP and exports economic losses: 3rd largest economy in America after US and Canada dependent on petrochemicals - 40% GDP, 80% exports natural gas pipelines infrastructure loss 300m major road access destroyed due to strom 2014 luxury beach homes - £700k 400,000+ tourists $5.8 million spent on rehabilitation work engineering firms + academic expertise social losses: loss of coconut plantations, watermelon+ vegetable cash crop transport access affected - can't access oil industry/tourist value of coastal homes = likely to decrease overtime damage to existing hotel and tourist industry some owners can afford a rubble war, some can't - rich/poor divide environmental loss: damage to turtles that may encourage ecotourism ecosystems can adapt - so small scale loss lack of understanding with regards to beach dyanmics