Restless Earth

Kilauea has been in constant gentle eruption since 1983

Lava is usually basaltic

Made almost entirely of solidified lava, gently sloping sides

Lava flows quickly, and is thin and runny

• Example: Mt Pinatubo
• Steep sides, small area, alternate layers of ash and lava
• Viscous lava often 'freezes' in central vent, granitic lava
• Infrequent, unpredictable eruptions

Causes:

• Hotspots - tectonic plate moves over column of rising magma
• Destructive boundaries - some lightweight materials melt and rise to the surface to form volcanoes

Impacts:

• Kill more with gas and ash than with lava
• Disrupt air travel
• Generate earthquakes and tsunamis

Preparations:

• Evacuation
• Well-trained and funded emergancy services
• Gas emissions, earth tremors and bulging flanks can be used to predict eruptions
• Hazard resistant buildings

Primary Impacts:

Social:

• 360,000 evacuated, some refused to go and others returned during the eruption
• 275 killed by pyroclastic flows
• 570 injured

Economic:

• 2000 farm animals killed
• Villages destroyed, widespread crop damage
• Many flights cancelled

Secondary Impacts:

Social:

• 10km around the volcano declared a danger zone, 2600 unable to return
• Thousands spent weeks living in cramped emergency centres

Economic:

• 1300 hectares of farmland abandoned
• $600 million loss due to severely reduced farming and tourism

Causes:

• Conservative boundaries - pressure builds up, then sudden release of pressure = earthquake

Impacts:

• People killed as a result of shaking and property destruction
• Lack of shelter and basic supplies
• Fires

Preparation:

• Can't be predicted
• Evacuation routes
• Hazard resistant buildings
• Land use planning
• Disaster kits
• Well-trained and funded emergency services

Collision boundary

Social Impacts:

• 70,000 died
• 375,000 injured
• 5 million homeless

Economic Impacts:

• Repair of buildings and infrastructure cost £76 billion
• 1 billion unemployed

Responses;

• Prime Minister flew in
• Countries sent aid such as money, medicine, tents and rescue teams

Destructive boundary

Port built on reclaimed land that liquified allowing buildings to collapse and sink

Social Impacts:

• 5000 died
• 26,000 injured

Economic Impacts:

• £100 billion damage

Responses:

• Immediate - fire extinguishing, rescue attempts
• Within 8 months - gas, water, electricity, railways and phone lines working again

Variations:

• Volcanoes are less damaging than earthquakes because people don't live as close
• Some are just more powerful
• Earthquakes vary based on:
  • distance from epicentre
  • time of day
  • preparedness
  • quality of emergency services
• LEDCs suffer more socially because:
  • higher population density
  • less money to spend on preparation and warning systems
  • less money to spend on repairs
• MEDCs suffer more economically because:
  • people insure property and businesses
  • structures cost more