Case Study: Volcanoes (SL IB Geography)

Mount Merapi earthquake facts

• Name – Mount Merapi
• Location – Java, Indonesia
• Date – 25th October–30th November 2010
• Magnitude – VEI 4
• Plate boundary – Destructive plate boundary where the Indo-Australian plate is subducting below the Eurasian plate
• Type of volcano – Stratovolcano or composite

Location of Mount Merapi

Location of Mount Merapi

Impacts of the 2010 Eruption of Mount Merapi, Indonesia

	Primary impacts	Secondary impacts
Social	353 deaths Injuries and illness e.g. sulphur dioxide gas caused skin irritation and breathing problems Damage to over 19,000 homes and properties Displacement of 350,000 people	Nearly half of the people affected by the eruption suffered mental health issues e.g. stress, anxiety, depression Disruption to services such as healthcare and education Disruption to religious and traditional practices
Economic	Economic losses of £450 million due mainly to impact on farming, tourism and manufacturing Destruction of property and infrastructure e.g. 30 bridges were damaged Disruption of trade and economic activity e.g. about 2500 flights cancelled	Food prices increased due to destruction of crops and livestock Slower economic growth and development due to closure or relocation of businesses, decline in tourism, damage to crops etc. Tourism fell by 30% (domestic tourists) and 70% (international tourists)
Environmental	Destruction of biodiversity, habitats and ecosystems e.g. over 200 hectares of forest were damaged Poor air and water quality	Acid rain damaged ecosystems Long-term pollution of land and rivers
Political	Pressure on government to co-ordinate emergency response Social unrest, looting and political instability	Conflicts over government response and food shortages e.g. some residents claimed that the compensation scheme was inadequate and unfair

Factors affecting vulnerability

• The number of deaths, injuries and displacement of population was high during and after the eruption
• People were vulnerable to the impacts of the hazard
• People refused to leave their homes, which made them more vulnerable to the impacts of the eruption
• The reasons people stayed included:
  • Caring responsibilities for elderly parents
  • Responsibilities for livestock
  • Long-term residency and a subsequent unwillingness to leave
  • Cultural beliefs
• Population density in the area has increased 
• Local people don't always believe that scientific monitoring is accurate, relying instead on traditional warning signs
• Communication regarding the dangers of the eruption was slow and ineffective

La Palma, Spain

• Part of the Canary Islands, La Palma is located in the Atlantic Ocean off the coast of North Africa
• The Canary Islands are an [popover id="RAr2r~3MbVY7biGB" label=''autonomous region"] of Spain
• There are 33 volcanoes across the Canary Islands, 10 of which are in La Palma

Cumbre Viejo earthquake facts

• Name – Cumbre Viejo
• Location – La Palma, Spain
• Date – 19th September–December 2021
• Magnitude – VEI 2 or 3
• Plate boundary – Magma plume (hotspot)
• Type of volcano – Cinder cone (basaltic lava)

Location of Cumbre Vieja Volcano

Location of Cumbre Vieja Volcano

Primary impacts

• Almost 1500 houses were destroyed by the lava flow
• Over 1500 other buildings such as churches, shops and schools were destroyed
• The lava flow cut across the coastal highway and covered 1000 hectares
• The water supply was cut off for almost 3000 people
• 400 hectares of banana farms were destroyed
• Almost 1300 hectares of land were affected
• There was one death

Secondary impacts

• Air traffic was suspended on a number of occasions due to ash in the atmosphere
• Over 1000 people were evacuated after the eruption began on the 19th September
• A further 5600 people were evacuated over the next few weeks
• About 20,000 people were exposed to the eruption and its effects

Factors affecting vulnerability

• Although many buildings were impacted by the eruption, deaths and injuries were minimised as a result of:
  • Evacuation plans
  • Suspension of air traffic
• La Palma also has a Local Hazard Mitigation Plan, which aims to reduce the impacts of any hazard event
• People are encouraged to have an emergency kit ready in case of eruptions
• Insurance cover means that recovery from a hazard event is more rapid
• La Palma has well-trained and equipped emergency services