Geo

• Waves attack a line of weakness along a headland. Erosions ha,ab widens the line of weakness creating a cave. Continued erosion erodes the back of the cave creating an arch. Weathering freeze thaw weaskens the top of the arch making it unstable. Eventually collaspes forming a stack. The stack is erododed from the base by the sea and weakened at the top by weathering. This creates a stump.
• • a headland is a cliff that sticks out into the sea
  • a bay is a cresent indentation in the coastline between headlands.
  • heads and bays occur along a disconcordant coasline.
  • these are coastlines with bands alternating hard and soft rock
  • the 2 diff rock types erode at diff speed
  • hard rock erodes moree slowly = headlands
  • soft rock erodes quickly= bays
  • bays are shelted as a result deposition occurs and beaches are formed.
• a wave cut plaform is a plaform of rock at the base of a cliff formed due to eerosion and eathering

  waves attack the base of the cliff between high anf low tide marks

  processes of eroosion such as hy and ab erode the base of the cliff creating a wavecut notch and a overhanging cliff.

  furtjher erosion makes the wave cut notch larger and overhangung cliff unstable

  eventually cliff collapses leaving a wave cut platform

  cliff retreats
• Mass movement is a downhill mobement of material cauded by gravity.
• rotational slump and landslidde

  • during periods of rain water infiltrates permeable rock= makes rock heavier
  • eventually rock becomes saturarted and unstable
  • line of weakness foemed in the unstable rock
  • lime of weakness= slip plane
  • material moves down along the line of weakness
  • rotation slump= curve line of weakness
  • landslide= straight LOW
• rock fall

  • where rock falls down the cliff fue to gravity
  • freezethaw weakens trhe rock at the top of the cliff
  • the weakend rocks fall to the base of the cliff
  • material that collects at the bottom of cliff= scree slope
• 3 primary effects of haiti

  • 220,000 deaths
  • 300,000 injured
  • 300,000 homes destroyed
• 3 secondary effects of haiti

  • trauma and diseases spread from dead bodies
  • High crime rates
  • 2million wu food or water
• 2 immediate responses of haiti

  • usa gave 100M for emergency kits
  • usa sent ships and helicopters to search and rescue
• LT response for haiti

  • 3/4 buildings were repaired
• mitigation= remove greenhouse gases from the atmosphere to slow climate change
• 4 mitigation stategies=

  1. co2 is captured from the power stations transported in pipes and stored deep underground or in oceans
  2. afforestation
  3. renewable energy= generating energy from natural renewable sources
  4. international agreements= kyoto protocol 1997= over 170 countries agreed to reduce co2 emissons by 5.2%
• 3 ways to predict earthquakes

  1. previous earthquake data
  2. measure for small tremours - seisometer
  3. unusual animal behaviour
• Threats to the desert:

  • climate change- more droughts- die
  • desertification- desert Gets larger -soils dry
• 2 adaptations of joshua tree:

  • deep roots to reach water underground
  • small needles like leaves to reduce water loss
• 3 adaptations of cactus:

  • succulent- stores in water
  • thick waxy cuticle = reduces water loss from transpiration
  • deep roots to reach water underground
• 2 adaptations of lizard

  • burrows during day and emerges at night
  • camoflague
• economic opputunites in sahara

  • mining = hassi mesaoud- 50% algeria gdp comes from oil and gas- employs 40,000
  • solar panels= tunisia= energy sold to western- reneable = sand storms
  • agriculture- egypt- 13% egypts income, employs 32%= leaves salt crystals= salinity
  • tourism - egypt - income for development- pollution
• challenges for development in sahara:

  • extreme temp - over 40
  • inaccesibility - Huge
  • water supply
• over grazing= too many sheeps and cattes eat vegetation= soil no longer held together= soil erosion
• overcultivation= population growth= more demand for food= roots dont bind= soil dry and erosion
• 4 causes of deforestration:

  • climate change
  • over grazing
  • over cultivavtion
  • deforestattion
• sustainable strategies in sahel:

  • afforestation
  • crop rotation- allow field to rest to regain nutrients
  • grazing rotation= move animalsa place to place reduce amount of vegetation eaten
• climate in rainforest= humid
• threats to rainforest= deforestation
• adaptation of spider monkey= have strong arms to swing from trees to trees in upper canopy
• adaptation of jaguar= can swim due to high rainfull and may rivers
• 4 uses of the. rainforest:

  • logging= cuttinf fown trees to sell causes 3% deforestation
  • builidng roads= farms mines need roads to reach them anf transport products to the coast for export
  • hydro- electric energy= building dams and reseviours to creare and sell energy - belo monte- brazil
  • mining= digging extract iron ore to seel
• 4 sustainablity in rainforests=

  1. selective logging= cutting only old trees - canopy saved = most animals live
  2. afforestation
  3. debt relief= hics giving money to lics to spend on repairements on trees and resources
  4. carbon sinks
• what are national parks = areas protectewd from development and deforestatio
• • waves attack base of cliff between high n low tides
  • erosion erodes the base of the cliff = wave cut notch and overhanging cliff
  • further erosion makes wcn larger and ohc unstable
  • ohc collapses leaving wave cut platform
  • cliff retreats
• constructive waves?

  • long wavelength
  • strong swash gentle backwash
  • gentle= calm conditions
• destructive waves?

  • short wavelength
  • weak swash and strong backwash = removes material
  • very powerful
• abrasion= material in sea hits against the cliffs and removes rock and soil
• spit:

  • lsd transports material along coastline in zigzag pattern
  • sudden bend in coastline= waves lose energy= material is deposited
  • strong winds and waves curve at end of spit= recurved
  • area behind the spit is sheltered waves= low energy= deposition
• bar= formed when a spit joins 2 headlands
• tombolo= when a spit joins to a island
• advantages of managed retreat

  1. reduced chances of flooding
  2. 7km of new cycle routes
• disadvantages of managed retreat:

  • people relocated from homes
  • cost £28m
• example of managed retreat= medmerry south england