Geog paper 1

• Natural Hazards

  An unexpected/uncontrollable natural event that threatens people

  [natural event that affects people]

  Risk affected by: population density, infrastructure, climate change etc
• Plate Boundaries


  Constructive [divergent]: two plates pull apart

  -shield volcanoes

  
  

  Destructive: two plates clash [oceanic subducted beneath continental].

  -Composite volcanoes, tsunamis, EQs, Fold Mountains

  
  

  Conservative: two plates moving in different directions/at different speeds

  -EQs

  
  

  *Hotspots: areas of thin crust, e.g. Hawaii
• Tectonic Plate movement [reasons]

  Alfred Wegener: theory of Pangea

  -Continental Drift: continents drifted apart due to tides

  -Convection Currents: Rise/Fall of magma in mantle pulling plates apart

  
  

  True reason:

  Ridge Push [constructive] - magma cools to form new crust, expanding + pushing plates apart

  Slab Pull [destructive] - denser plate sinks into mantle due to gravity; pulls the rest of the plate with it
• EQ's: Chile vs Nepal

  Chile, 2010: 8.8 Richter scale, destructive plate margin; HIC - quick + effective response

  
  

  Nepal, 2015: 7.9 Richter scale, destructive margin; LIC - little preparation
• Chile EQ effects

  -500 killed, 12000 injured; schools, ports, buildings destroyed; power + water cuts; US $30 billion

  
  

  -1500km roads damaged [landslides], tsunamis devastated coast, fire at santiago chemical plant
• Chile EQ responses

  Swift: international aid for field hospitals/bridges; repairs made to major highway; power+water restored ~10 days, $60million raised in emergency appeal -> 30,000 shelters

  
  

  Housing reconstruction plan (200,000); strong economy easily rebuilt
• Nepal EQ effects


  9000 deaths, 20,000 injured, 3 million made homeless; hospital overwhelmed, schools/shops destroyed; $5 billion in costs

  
  

  Landslides + avalanches killed + blocked roads; flooding; Airport became congested; blockade at Indian border limited supply
• Nepal EQ responses

  International Aid: Rescue teams, water, medical support; helicopters deployed for search+rescue; 300,000 migrated from Kathmandu

  
  

  Roads repaired, landslides cleared; thousands rehoused + reschooled; Everest routes repaired
• Weather vs Climate

  Weather: daily atmospheric conditions

  Climate: long term atmospheric conditions
• Lines of Latitude


  Imaginary lines that run east and west across the earth

  Arctic Circle - 66.5° N

  Tropic of Cancer - 23.5° N

  Equator 0°

  Tropic of Capricorn 23.5° S

  Antarctic circle 66.5° S
• Insolation [in relation to latitude]

  The amount of solar radiation reaching an area

  Equator has highest isolation, and is thus warmest (-> more evaporation + precipitation)

  The further from the equator (higher latitude) the lower the insolation - more atmosphere must be penetrated by rays==they are less concentrated
• GAC


  Global Atmospheric Circulation

  Equator + Arctic&Antarctic Circles: Low pressure, air flows in

  Tropics + Poles: High Pressure, air flows out

  Cells: Polar - cold air; Ferrel - temperate air; Hadley - hot air, closest to equator

  
  

  Winds caused by pressure + coriolis effect:

  North/Southeast Trade Winds

  N/S Westerlies

  Polar Easterlies

  
• Tropical Storm Formation


  27°C+ ocean temps

  5-13° latitudes (spin)

  To officially be a tropical storms, wind speeds must surpass 120kph

  
  

  - strong upward movement of air draws water vapour from warm ocean surface

  - evaporated air cools as it rises condensing to form large thunder clouds

  - The condensing air releases heat which powers the storm, pulling up more water vapour from the ocean

  -Smaller thunderstorms join together creating a massive spinning storm which develops a calm eye. (eye wall has harshest conditions)

  - storm is carried by prevailing winds and strengthened

  - Upon reaching land, friction and lack of water vapour causes storm to weaken
• Effects of Climate Change on Tropical Storms

  ^Frequency - warmer seas

  Different distribution - colder seas may become eligible for tropical storm formation (Brazil?)

  ^Intensity - warmer
• Reducing Natural Hazard Effects

  MP3

  Monitoring and Prediction (hazard maps; geophysical measurements)

  Protection (Emergency shelters, sea walls, storm drains; lava diversions; EQ-resistant architecture)

  Planning (high-value land uses protected; preparedness week in US; education)
• Typhoon Haiyan Context

  November 2013, Category 5 typhoon (~275kph winds) in the Philippines.

  LIC - minimal preparation, mass destruction.
• Typhoon Haiyan Effects

  Primary: ~6300 killed, most by 15m storm surge; 600,000+ displaced, 40,000 homes damaged - 90% Tacloban City destroyed; 30,000 fishing boats destroyed; Flooding (400mm rain); Ferry services disrupted, blocked roads, damaged airport

  
  

  Secondary: ~14 million affected; Flooding + Landslides caused blocked roads; Power cut off in some areas; Water, food & shelter shortages; looting and violence
• Typhoon Haiyan Responses

  Short-Term: International aid provided shelter, food, water, search&rescue, field hospitals; 1200+ evacuation centres erected; Philippines Red Cross delivered basic food aid.

  
  

  Long-Term: Financial aid, supplies & medical support offered internationally; 'Cash for Work' programmes offered citizens money for rebuilding work; 1000s homes built in safer areas; more cyclone shelters built
• UK weather roundabout

  
  

  UK weather hazards

  -Arctic air can bring heavy snow and bitterly cold conditions

  -Storms from the Atlantic bring heavy rain and strong winds

  -Hot and sunny weather from the south can lead to heatwaves and drought

  -Severe winter weather can come from the east

  
  

  Thunder, Rain, Wind, snow and ice, hail, drought, heatwaves
• Somerset Levels Flood Causes/Context

  Jan-Feb?, 2014

  Somerset: Southwest of UK, South of Bristol, East of Taunton

  Heavy rain caused widespread flooding

  Causes: Prolonged Rainfall -> Saturated Ground; High Tides and Storm Surges (preventing backwash); Low-Lying Land; Farmland (ground less able to retain water); Lack of Dredging Rivers
• Somerset Levels Flood Effects

  Roads + Railway cut off; contaminated floodwater; power cuts; 14000ha farmland submerged for 3+ weeks; £10 million in damages; 600 houses flooded; Villages cut off
• Somerset Levels Flood Responses

  Short-Term: 16 farms, Residents & 1000+ livestock evacuated; heavy rain warning; pumps drain 65million m cubed water, £15 million raised; Rescue boats used

  Long-Term: Debris cleared; Rivers Tone+Parratt dredged; flood defences erected; road levels raised; river bands raised
• Global Warming vs Climate Change

  Global warming: warming of earth's atmosphere in recent history, attributed to the advanced greenhouse effect

  Climate change: changes in any aspects of earth's climate
• Evidence for recent climate change

  ICE CORES - ice drilled and extracted, trapped gas concentrations from past measured

  Glaciers - GPS mapping, images, paintings record retreats in levels

  Temperature records (since ~1850)

  Coral
• Natural Causes of Climate Change

  Milankovitch cycles

  Volcanic Activity (Ash-Global Dimming; Sulphur Dioxide-Reflects light)

  Solar Activity; sun spots (~11 year cycle of min-max sun spot activity. ^sunspots = ^temps)
• Milankovitch Cycles

  Eccentricity, ~100,000 years; Δ orbit circular-elliptical

  
  

  Axial Tilt, ~41,000 years; Δ tilt of earth (21.5-24.5°)

  
  

  Precession, ~26,000 years; wobble in spin - changes lengths of days in certain areas
• Human causes of Climate Change

  Burning of fossil fuels inc. transport

  Deforestation

  Agriculture (Methane from cows + rice paddies)
• Greenhouse Effect [+gases]

  Warming that results when solar radiation is trapped by the atmosphere.

  Advanced by humans -- advanced greenhouse effect

  Due to greenhouse gases: CO2, Methane, Nitrous Oxides, H2O
• Impacts of Climate Change

  Shrinking glaciers + ice caps - loss of habitat, rise of sea levels - more habitats threatened

  Extinction due to unfamiliar environments

  Warmer oceans - more tropical storms in different locations (freak weather in general)
• Climate Change Mitigation

  Alternative energy (nuclear, solar, wind, tidal, hydroelectric etc.) - reduces reliance on fossil fuels = less CO2 emitted. (Unreliable, often require certain locations/conditions)

  
  

  Afforestation - carbon sinks (photosynthesis). (Take up space)

  
  

  Carbon Capture and Storage (CCS) - ^90% CO2 from fossil fuels can be captured and stored underground. (Expensive, requires space, CO2 still released)

  
  

  International Agreements - Raise awareness, combats on macro-scale; 2005 Kyoto Protocol, 2009 Copenhagen Accord, 2015 Paris Agreement. (Countries may refuse/not honour agreements)
• Climate Change Adaptation

  Management of Water - Redistribution from areas of surplus to areas of scarcity; Himalayas artificial glacier

  
  

  Agriculture - Different crops can be grown in different areas, climate-resistant strains, shade trees, new irrigation systems

  
  

  Sea defences - e.g.: Maldives - Sea walls, mangrove forests, artificial islands, houses on stilts, relocation
• Ecosystem

  Biotic/Abiotic

  A natural system made up of plants, animals and the environment.

  There are often complex webs of relationships between components.

  
  

  Biotic: Living features of an ecosystem (organisms)

  Abiotic: Non-living environmental factors (climate/soil/water)
• UK ecosystem example


  freshwater pond

  -producers = algae

  -consumers = stickleback fish

  -decomposers = rat-tailed maggots
• Nutrient Cycle


  Continuous flow of nutrients into and out of stores in the ecosystem

  
  

  Producers (organisms that convert environmental energy into sugars) take nutrients from environment.

  Leaf litter/death/consumption+excretion(consumers) return nutrients to ground.

  Decomposers break down biomass + return nutrients
• Biomes [by latitude]


  Tropical Rainforest: 5-15° -- high temps, heavy rainfall

  Tropical Grassland: 15-30° -- distinct wet/dry seasons

  Desert: ~30° -- high day temp, low night temp; high pressure=little rainfall

  Temperate Grassland: 30-40° -- Warm, dry summers; cold winters

  Mediterranean: 40-45° -- Hot, sunny summers; mild winters

  Deciduous + Coniferous forests: 50-60° -- shed leaves/evergreen respectively

  Tundra: 60°-artic circle -- cold, windy, dry; limited life

  Polar: Arctic/Antarctic -- low temps, dry conditions

  
  

  Affected by ocean currents, winds and land/see distribution
• Tropical Rainforest Biome + Layers


  Equatorial zone characterised by high, consistent rainfall and high temperatures

  Low pressure air; high insolation; lots of clouds; distinct wet seasons

  South America, Africa, Asia, Australasia

  Over 50% world's biodiversity

  Infertile latosol with thin humus layer

  
  

  Important for biodiversity [antifragility], drugs, choco, rubber etc

  
  

  Layers:

  Emergent Layer: 30+ metres, tops of trees

  Canopy: General tree cover

  Understory: beneath canopy

  Forest floor
• Plant Adaptations to Tropical Rainforests

  -Drip tips: funnel water off of leaf

  -Lianas: creepers/epiphytes that climb trees to reach sunlight. May be rooted, may not

  -Buttress Roots: Thick roots secure trunk; horizontally spread to access fertile humus layer

  -Strong smelling, bright flowers
• Animal Adaptations to Tropical Rainforests

  -Chameleons; flat-tailed geckos; crab spiders: camouflage

  -Armadillos; Pangolins: Curl up into balls for protection

  -Sloths/monkeys: Tails/claws for climbing

  -Bats/toucans/colugos: use wings to glide/fly
• Causes of Deforestation in the malaysia

  Logging (Malaysia is the world's largest exporter of tropical wood)

  mineral extraction (particularly tin)

  population pressure (about 15000 hectares deforested between 1956 and 1980s to make way for poor settlers from urban areas

  Commercial [palm oil] and subsistence farming [take space]
• Sustainable Development of Tthe malaysia

  SELECTIVE LOGGING: Malaysia has Selective Management System -- studies + marking of trees to be felled; surveying treating and replanting

  
  

  INTERNATIONAL AGREEMENTS: Hardwood forestry made sustainable by FSC | Debt Relief

  
  

  ECOTOURISM: promoted by Malaysia -- people benefit from keeping rainforests around so do

  
  

  Conservation Areas / Education