Geography Unit 1

Geography Unit 1

1. Restless Earth

   • Layers of the earth in order of surface to core: Lithosphere--> asthenosphere--> crust--> mantle--> outer core--> inner core
   • Oceanic and continental crusts
     • Oceanic
       • Thinner
       • More dense
       • Made up of basaltic rocks
     • Continental
       • Made up of granitic rocks
       • Thicker
       • Less dense
   • Plate boundaries
     • Destructive
       • Oceanic plate is subducted underneath continetal plate, creates oceanic trenches, volcanoes/mountains and large earthquakes.
     • Constructive
       • Two oceanic plates move apart, magma fills the gap, cools as it mixes with the water, can form islands like iceland.
     • Conservative
       • Two plates slide past each other, friction builds up and is eventually released in the form of an earthquake.
     • Collision
       • Two continental plates collide they buckle and push upwards creating mountain ranges and earthquakes
   • Hotspot theory
     • This theory was created to explain the hawaiian islands. It suggests that there are fixed spots in the mantle where magma rises to the surface. As the crust moves over these spots volacanoes are formed.
   • Shield and composite volcanoes
     • Shield
       • Mauna Loa Hawaii
       • Fluid, runny magma/ lava
       • Lava eruptions are rarely violent or explosive
       • The volcano is sloped as a result of the lava running off the sides, cooling and hardening.
     • Composite
       • Mt Pinatubo, Philippines
       • Sticky, viscous magma/lava
       • Prone to large explosions due to magma blocking up the top
       • Steep sided made up of all of the ash and debris of past explosions
   • Loma preita earthquake
     • California 1989
     • Very few deaths, mostly damage to property
     • Happened during rush hour
       • However there was a baseball match happening so many people were indoors
   • Kashmir earthquake
     • Pakistan 2005
     • Happened early in the morning
       • Many people were asleep/ unprepared
     • Happened on a school day= lots of dead children
     • LEDC
     • Lots of deaths and damage to property, many people who survived were homeless

2. Climate and change

   • Natural causes of climate change
     • Volcanoes
     • Orbital shift/tilt (i.e earth tilts slightly further away or towards the sun or its orbit becomes more eliptical, less circular)
     • Sun spots. These are black spots that show up when the sun is not producing heat evenly. More spots= higher temperatures
     • Asteroid collisions. Produces a large amount of dust and gas, blocks out the sun, reduces temperatures
   • How the UK may change
     • Weather may become less predictable
     • Increased temperatures and stronger, more frequent rainfall

3. Battle for the biosphere

   • Biome: very large, broad ecosystems that cover the earth
   • Local factors that effect biomes.
     • Human factors
     • Altitude differences (i.e higher altitude= colder climate etc)
   • Goods from the biosphere
     • Food
     • Medicine
     • Materials
     • Need for resources like soya, fuels deforestation in areas like Brazil
   • Rainforest converts large amounts of co2 into oxygen via photosynthesis. Often described as the "Lungs of the Earth"
   • Global biosphere conservation attempts
     • CITES: creates penalties for those who poach endangered species like rhinos and tigers
     • Rainforest conservation: Encourages countries to preserve their natural rainforests with monetary rewards
     • National parks: Areas of protected land across the world.
     • Wetland managment (Ramsar): Protects wetland areas from over explotation

4. Water world

   • Hydrological cycle processes and key words
     • Evaporation
     • Condensation
     • Precipitation
     • Run-off
     • Through flow
     • Infiltration
     • Ground water flow
   • The impacts of climate change on water supply.
     • Most states in the south-west of America are heavily dependent on water from the Colorado river. However as population increases the amount of water available dramatically decreases causing drought issues.
   • Australia
     • Naturally very arid (very little rainfall)
     • Overuse of water for agriculture and industry
     • Severe impacts on farmers as they cannot irregate their crops or keep their livestock healthy
   • Water pollution
     • Sewage disposal
     • Industrial disposal
     • Waste products (i.e plastic bags)
     • Intensive agriculture (eutrophication)
   • Coca Cola set up a factory in Plachimada, India. They over extracted (overabstraction) nearly all of the towns ground water supplys. Unsurprisingly this caused a drought which meant Coca Cola had to resupply the town with water.
   • Large scale water management
     • The colorado river
       • The water levels change on a seasonal basis and so they are managed so as to allow there to be a consistent amount of water all year round.
         • Several dams, including the Hoover dam, have been put into place in order to store large amounts of water.
           • This disrupted the marine ecosystems and caused several species of fish to die out
     • Three gorges dam
       • Uses the water that flows through it to hydroelectirically produce power
       • In China
       • Regulates water, helps china met growing water needs
       • Decreases risk of flooding
       • Forced some people to relocate in order to create the dam.
   • Small scale water managment projects
     • Afridev hand pump, uses intermediate technology

5. Coastal change and conflict

   • Hard rock coast lines and soft rock coastlines
     • Hard rock
       • High, steep, rugged
       • Little to no vegetation
       • Rocks and boluders at the base of the cliff
     • Soft rock
       • High, not steep and not rugged
       • Piles of mud and clay cover the cliff face
       • Sea is often brown from the mud and clay of the cliff
   • Waves eroding the coastline.
     • Hydraulic action
     • Abrasion
     • Attrition
   • Concordant and discordant coastlines
     • Concordant
       • This is where bands of hard and soft rock run paralell to one another
       • This causes very little erosion on the hard rock and then it widens out at the soft rock creating coves.
     • Discordant
       • Made up of alternating bands of hard and soft rock
       • The soft rock erodes and the hard rock stays the same forming bays
   • Constructive and destructive waves
     • Constructive
       • Long wavelength
       • Shallow gradient waves
       • Strong swash
       • Weak backwash
       • Builds material up on beach
     • Destructive
       • Steep gradient waves
       • Tall waves with short wave lengths
       • Weak swash
       • Strong backwash
       • Removes material from beach
   • Soft engineering: maintaing an area of coast without putting any physical tructures into place (i.e Beach replinshment, managed retreat etc)
   • Hard engineering: putting physical objects in place to stop erosion (i.e sea wall, groynes, rip rap etc)

6. Oceans on the edge

   • Climate changes impacts on the ocean
     • Warmer waters
     • Sea level rise
     • More acidic water and bleaching
   • Global actions to maintain oceans health
     • IWC: Bans and oversees the hunting and abuse of whales
     • UNCLOS: stats that the 156 nations that signed must follow the IWC's gudielines