coasts

Question 1

what are the characteristics of rocky coasts

Answer 1

resistant geology
(withstands erosive forces of sea, rain and wind), often in a high-energy environment
erosion > deposition

Question 2

what are the characteristics of costal plain landscapes

Answer 2

deposition > erosion
found near areas of low relief and result from supply of sediment from different terrestrial and offshore sources, often in a low-energy environment.

deposition and transportation

Question 3

what is responsible for concordant and discordant coastlines

Answer 3

Geological structure is responsible for the formation of
concordant and discordant coasts.

Question 4

what is geological structure

Answer 4

Geological structure (jointing, dip, faulting, folding) is an important influence on coastal morphology and erosion rates, and also on the formation of cliff profiles

Geological structure influences coastal morphology: Dalmatian and Haff type concordant coasts and headlands and bays on discordant coasts.

Question 5

dipping comes under geological structure, what are the 4 types of dipping

Answer 5

-horizontal dipping= more easily eroded

-seaward dipping (low angle)= may produce overhanging rock that is vulnerable to rock falls

-seaward dipping (high angle)= vulnerable to rock slides

-landward dip= stable cliff, reduced rock falls

Question 6

what does rates of costal recession depend greatly on

Answer 6

-bedrock lithology (igneous, sedimentary, metamorphic) and unconsolidated material (boulder clay) geology are important in understanding rates of coastal recession

• alternating strata in cliffs (permeable/impermeable, resistant/less resistant) produces complex cliff profiles and influences recession rates. (differential erosion)

-Vegetation is important in stabilising sandy coastlines through dune successional development and salt marsh successional development in estuarine areas.

-geological structure

Question 7

what marine erosion processes contribute to distinctive costal landscapes

Answer 7

• wave type (constructive and destructive)
  -erosional processes (HA, Corrosion, abrasion, attrition)

Question 8

apart from marine erosion, what other processes affect distinctive costal landforms

Answer 8

-transportation and deposition
-subaerial processes
-bedrock lithology and geology
-plant succession can stabilise coastlines

Question 9

what distinctive costal landforms does marine erosion create

Answer 9

wave cut notches, wave cut platforms, cliffs, the cave-arch-stackstump sequence

Question 10

what is sediment transportation influences by

Answer 10

s influenced by the angle of wave attack, the process of longshore drift, tides and currents.

Question 11

what distinctive costal landforms does deposition and transportation create

Answer 11

(beaches, recurved and double spits,
offshore bars, barrier beaches and bars, tombolos and cuspate forelands), which can be stabilised by plant succession.

Question 12

what do sediment cells explain

Answer 12

equilibrium and positive and negative feedback

Question 13

what is contempory sea level change caused by

Answer 13

-global warming
-tectonics

Question 14

sea level change has produced emergent coastlines, what are they

Answer 14

-raised beaches (a old beach now above tide level)
-fossil cliff (a steep slope found behind a raised beach exhibiting past evidence of marine erosion)

Question 15

sea level change has produced submergent coastlines, what are they

Answer 15

-dalmation coastline
-ria
-fjard
-fjord

Question 16

define eustatic

Answer 16

(ice formation/melting,
thermal changes)

Question 17

define isostatic

Answer 17

(post glacial adjustment,
subsidence, accretion and tectonics

land rises and falls relative to the sea

Question 18

what is rapid costal recession caused by

Answer 18

caused by physical factors
(geological and marine)**WHAT but can be influenced by human actions (dredging or coastal management) ( the Nile Delta

Question 19

Rates of recession are not constant and are influenced by different factors both short- and longer term, what are these

Answer 19

(wind direction/fetch, tides, seasons, weather systems and occurrence of storms

Question 20

what local factors increase flood risk

Answer 20

-low lying land
-degree of subsidence (water abstraction can lead to isostatic sinking seen in bangladesh and weight of the built environment can compress sediment leading to subsidence)
-levels of vegetation

a global factor is sea level rise

Question 21

what was the total cost of damage due to cyclone sidr

Answer 21

total damage estimated as $1.7 billion

Question 22

what did the IPCC identify in terms of future climate change

Answer 22

-that depressions are likely to become more common leading to greater storm surges
-medium confidence of stronger winds

Question 23

what is sustainable costal management

Answer 23

• relocation
  -monitoring costal change
  -educating communities
  -adapting to sea level rise
  -managing flood risk

Question 24

how much does a sea wall cost per metre

Answer 24

£3000-£10,000 per metre

Question 25

how mcuh does beach nourishment cost per KM

Answer 25

£20 million per KM

Question 26

whats CBA

Answer 26

Cost benefit analysis

Question 27

whats EIA

Answer 27

environmental impact assessment

Question 28

what are the main 5 factors affecting costal recession:

Answer 28

wind direction, weather systems, seasons ,tides, storm activities

Question 29

costal recession: wind direction

Answer 29

• the dominant wind produces the largest wave, most erosion occurs here, less erosion when winds are from other directions
  -links to fetch and how much the wavy can build up
• a longer fetch means a more powerful wave

Question 30

costal recession: tides

Answer 30

• there are two high tides and two low tides a day.
• high tides=spring tides (when sun and moon are aligned so gravitational pull=strongest)
• low tides= neap tides(when sun and moon are at right angles to each other)
  -tides determine where the waves will reach the shore
  -erosion at max when high tide is with destructive wave

Question 31

costal recession: weather systems

Answer 31

high pressure- air sinking- leads to dry conditions- brings about calmer conditions and smaller waves

low pressure- rising air- leads to wet weather- strong winds rotating in anticlockwise direction- larger waves

wind wants to go from high to low pressure zones- global warming has added more heat thus intensifying low pressure systems

Question 32

costal recession: storm activity

Answer 32

linked to a low pressure weather system, notably tropical cyclones and depressions. when air pressure is low over the sea, water is able to rise upwards, forming a dome of sea water under the depression. the lower the air pressure the higher the dome will be . the dome of water can then surge when the low pressure system moves near a coast. as tropical cyclones/ depressions are associated with strong winds, they create large storm waves the will appear on top of the dome. this adds height to sea levels and increases the risk of costal flooding, can join with high tide {all storms are low pressure systems}

Question 33

costal recession: seasons

Answer 33

winter waves= more destructive than summer waves.
winter waves- depressions are greatest - greater variety in difference in high and low pressure areas- greater wind speeds- low air pressure and faster winds- winter= season for hurricanes and storms (low pressure)- more erosion

Question 34

what is mass movement impacted by

Answer 34

-the angle of the slope or the cliff
-the rock type and its structure
-the vegetation cover
-how wet the ground is

Question 35

mass movement flows:
whats soil creep

Answer 35

-slow downhill movement of individual soil particles

Question 36

mass movement flows:
whats solifluction

Answer 36

-occurs where the ground is frozen. The thawed surface layer flows over the frozen subsoil and rock

Question 37

mass movement flows:
whats earthflows / mudflows

Answer 37

an increase in the amount of water can reduce friction- causing earth and mud to flow over underlying bedrock

Question 38

whats the difference between a slide and a flow

Answer 38

in a slide, the material remains intact, in a flow the material becomes jumbled up

Question 39

mass movement slides:
what are rock falls

Answer 39

occur when jointed and steep rockfaces are exposed to mechanical weathering.
-fallen material forms tallus/scree

Question 40

mass movement slides:
what are block falls

Answer 40

a large block of rock falls away from the cliff as a single piece

Question 41

mass movement slides:
what are rock/ debris slides

Answer 41

an increase in the amount of water can reduce friction causing sliding. Slabs of rock/ blocks can slide over underlying rocks along a slide or slip plane

Question 42

what are slumps

Answer 42

occur on moderate steep slopes in saturated conditions
rotational movement occurs
-slumping causes rotational scars
-repeated slumping creates a terraced cliff profile