Geography B Unit 1 Dynamic Planet

Shield Volcanoes:

• constructive boundaries
• gentle slopes
• basaltic lava
• erupt frequently but not violently

Composite Volcanoes:

• destructive boundaries
• alternating layers of ash and lava
• pyroclastic flows
• andesitic lava
• erupt infrequently but violently

• Crust: oceanic plate- basalt, continental plate- granite
• Mantle: melted rock, 375', solid but has consistency of treacle, biggest section
• Outer Core: molten rock, 3000', iron/nickel
• Inner Core: 5700', iron/nickel

Factors Causing Damage In An Earthquake:

• Focus and epicentre
• Magnitude
• Population density
• Building design
• Time of day

Preparing For A Hazard

• evacuation routes
• earthquake drills eg Japan
• strengthening structures eg. shock absorbers, deep foundations, reinforce framework, base isolators, flexible gas and electric pipes

Response To A Hazard

• sending aid/relief and food and water
• evacuate people
• set up shelters

Haiti Earthquake LEDC

• 7 magnitude
• Primary impacts: 316,000 deaths, 300,000 injured, £8.5bn economic loss, 1,300 schools damaged
• Secondary impacts: 1 million people made homeless, damage to road and ports stopped trades, spread of cholera due to poor sanitation
• Reasons for high death rate: densely populated area, poorly constructed houses, epicentre was close to capital

New Zealand Earthquake MEDC

• 7.1 magnitude
• Primary impacts: no deaths but 100 injuries, £1.8bn property damaged
• Secondary impacts: major aftershock
• Reasons for low death rate: more economically developed to have better-constructed buildings, more prepared with drills, flexible pipes and wires

Natural causes of climate change

• energy radiated from the sun changes every 11 years
• volcanic eruptions pump ash dust into the atmosphere causing a cooling effect
• large asteroid collisions can cause cooling as it blocks the sun

greenhouse gases: CO2- fossil fuels, methane- animals and rice, nitrous oxide

UK's predicted climate change

• avg. temp may rise
• less predictable rainfall patterns
• longer summers and colder winters
• Because: north Atlantic current will move which will reduce sea temp and bring less rainfall, more air masses from the north bringing more storms and snow

polar regions are high in latitude

Climate change in the UK- increase temp:

-Positives

• increase the growth of wine and other agriculture products
• warmer and sunnier summers increase coastal tourism

-Negative

• loss of ski resorts
• more cases of malaria
• more severe storms and longer droughts
• climate change refugees will increase
• fishing industries on how fish will migrate due to colder water
• rising sea levels will bring more erosion leading to loss of property ie caravan parks
  
• species migrate elsewhere

low-lying country already experiencing flooding. it has a large, poor population

-environmental impacts

• more severe flooding from heavier rains
• tropical storms would be more frequent
• dry seasons are longer=droughts

-economic impacts

• rise in sea level reduces agriculture output
• homes and businesses destroyed leading to the disruption of the economy as money is spent on repairs
• cost of repairing homes is more than what the government can afford
• coastal flooding damages farmland increasing the salinity which makes it hard to grow crops
• increased flooding increases spread of water- borne diseases

Biome- a large ecosystem                                                                                                       degradation- the social and economic and environmental decline of an area                                 biosphere is influenced by the atmosphere (air), hydrosphere (water cycle), lithosphere (rocks and soils)

factors affecting biomes:

• global factors: precipitation, temperature, latitude, distance inland
• local factors: altitude, geology, soils, human interference

changes for the UK if temperatures increase by 2-4'

• changed growing season
• new marine life
• moving tree line

biosphere conservation/management: CITIES- penalties for poaching  endangered animals, national parks- protects 13% of land

How humans affected the biosphere

• mining- roads built to transport materials
• timber- homes and mahogany furniture
• agricultural land- cut forest for firewood and grow crops
• soya craze- clear land for soya beans to sell or feed cattle
• people pressure- brazils increasing population
• deforestation- more CO2 in the atmosphere

Challenges to sustainability

• population increase
• rising resource consumption
• climate change: increases in evaporation and precipitation rates
• conflicts with different stakeholders of biomes eg. local people and the government

The Hydrological Cycle

• Overland flow (run-off)- rain falls onto the ground and flows on the surface to rivers and lakes.
• Through flow- rainwater soaks into the soil (infiltration) and flows slowly through it to rivers.
• Goundwater flow- rainwater soaks into rocks below the soil. flows through cracks and air spaces.

Hydrological Processes:

• evaporation
• condensation
• precipitation

Threats to the hydrological cycle:

• causes of river pollution: human waste, industry waste and fertilisers from farms
• managing river pollution: sewage is treated, heavy fines for industries, plastic and other waste is sent to recycling centres.

Intermediate Technology eg. Hand pump, wells, water harvesting:

• Installed by Water Aid and other charities
• reduces walking distance so you can work and go to school
• clean, safe water
• prevents diseases like cholera from dirty water

Impacts on unreliable water supply- Sahel: droughts, desertification, food and water insecurity

Humans disrupting water supply- Coca-Cola: wells dried up, since helped to deliver water tanks

LEDC/NIC Large scale water management scheme- Three Gorges Dam:

• Benefits: reduced flood risk, produces electricity equivalent to 15 nuclear reactors, non-renewable energy, jobs for locals, 
• Costs: flooded good farmland, increased risk of landslides, 1.4million people were forced to relocate, sediment building up, expensive, fish can't migrate

Irrigation- the supply of water to land or crops to help growth, typically by means of channels.

Impacts on water quality- Bangladesh: diseases eg cholera, industrial waste dumped reduces biodiversity, litter and rubbish

MEDC Large scale water management scheme- Colorado river, USA:

• Benefits: regular water supply all year to Las Vegas, reservoirs create recreational grounds, less flood risk, dams create electricity, water can be used for irrigation
• Costs: fish can't migrate, sediment gets stuck behind dams so riverbanks can't form, less water downstream in Mexico

erosion processes:

• attrition- pebbles carried by waves (rock on rock)
• hydraulic action- air pressure
• abrasion- rock on cliff
• weathering- biological, chemical, physical

longshore drift: swash pushes sand and gravel up the beach, backwash carries sand back 90', zig zag motion, over a period of time you get a sand spit

• concordant- same rock type along the coast
• discordant- rock type alternates along the coast

soft rock coasts- Hornsea: made of mud and clay, less steep, erodes more easily

hard rock coasts- land's end in Cornwall: high and steep, some rocks and boulders at the foot of the cliff, have erosion features such as caves, arches and stacks

fetch- distance wave has travelled

destructive waves: strong backwash, weak swash, destroys beaches, high frequency, short wavelength

constructive waves: weak backwash, strong swash, builds up beaches, low frequency, long wavelength

Hard engineering:

• sea wall: protects cliffs and buildings, expensive
• Groynes: prevents sea removing sand, exposes other areas of coastline
  
• Riprap: rocks absorb wave energy, expensive
  
• off-shore reef: waves break on reef and lose power, expensive and may interfere with fishing

Soft engineering:

• beach replenishment: sand reduces wave energy and maintains tourism, expensive
• managed retreat: people and activities avoid erosion by moving inland, expensive
• Cliff regarding: reduces slippage, foot of cliff still needs protection from the waves