Indonesia Mount Merapi 2010 - Volcano Impacts Case Study

• What plate boundaries does Indonesia lie on? Which plates?

  1. Convergent
  2. Oceanic (Indo-Australian)
  3. Continental (Eurasian)
• What features do you see at this plate boundary?

  1. Volcanoes
  2. Transform lines
  3. Ocean trenches
  4. Earthquakes (occur at all plate boundaries)
• Why is Indonesia a hugely tectonic region?

  Widespread subduction along 3000km archipelago
• Why is Mount Merapi particularly active?

  It is a young volcano - very active
• How many active volcanoes are in Indonesia?

  129
• Which island of Indonesia does Merapi sit on?

  Island of Java
• What % of Indonesia's inhabitants live within 100km of a volcano that has erupted in the past 100 years?

  More than 75%
• Why do people in Indonesia chose to live in areas vulnerable to eruptions?

  1. Traditional ties to an area - may be less inclined to leave
  2. Religious significance - people see volcanoes as spiritual
  3. Agriculture - fertile soil = high yield, crops grow quickly
  4. Tourism - income for locals (potentially no other jobs in area)
  5. LIDC - lack of choice = cheaper housing on slopes of volcanoes
  6. Physical barrier (ocean) - have to fly to leave - may not be possible
• What is Mount Merapi's eruption history?

  Erupting regularly since 1548

  1994, 1997, 2001, 2006
• What type of volcano is Merapi?

  Strato-volcano (reaches nearly 3000m)
• How far/what direction is Mount Merapi from Yogyakarta city?

  28km north
• When was the Mount Merapi eruption?

  26th October - 12th November 2010
• What was the VEI scale of the eruption?

  3-4
• What material was erupted?

  1. Lava bombs
  2. Ash
  3. Sulphur dioxide
• Where there any signs that an eruption was imminent in 2010? What were the stages before the eruption?

  1. Late October 2010, Centre for Volcanology and Geological Hazard Mitigation (CVGHM)- pattern of increasing seismicity from Merapi had emerged
  2. Lava from Merapi began flowing down Gendol river valley (23 - 24 October)
  3. 23 - 24 October- officials stated about 500 volcanic earthquakes recorded on the mountain/magma risen to about 1 km below surface due to seismic activity
  4. 25 October- Indonesian govt raised alert to highest level/warned villagers in threatened areas to move to safer grounds
• What were the social impacts of the 2010 eruption?

  1. 367 deaths/277 injured
  2. Health- 410,000 refugees in vicinity of volcano- refugee camp toilets = unhygienic- many at shelters experienced headaches, respiratory infection, high blood pressure//sulphur dioxide = irritation to skin, eyes, respiratory tracts
  3. Livelihood- lots of refugees- farmers lost their jobs (ash = loss to crops- fear for food shortages) = many forced to become miners- sell sand from eruption/take on jobs initiated. by govt (i.e. cleaning up volcanic ash)
  4. Psychological distress- survey 2 years after event = Cangkringan district experienced large distress in relation to environmental impact of event
• What were the economic impacts of the 2010 eruption?

  1. Total estimated cost = £450 million (mainly due to farming losses)
  2. Farming/plantation- damage to rice, fruit, vegetables- economic loss from agriculture = £13 million
  3. Tourism- 2010, domestic tourists decreased 30%/international tourists decreased 70%
  4. Flights- flights through ash cloud = engine failure = 2,500 flights cancelled for safety reasons/Yogyakarta airport closed for fortnight
• What were the environmental impacts of the 2010 eruption?

  1. Ash plumes- altitudes of 18 km, fell 30 km from peak of volcano- 2-4 cm thick layer of ash on ground = damaged 200 hectares of forest - albedo effect BUT: fertilisation of the soil = benefit farmers
  2. Lahars/pyroclastic flows- Cangkringan/Kemalang = most affected- rice fields, farms, infrastructure, river, soil = damaged- significant damage observed 2 years later
  3. Sulphur dioxide- reacts with environment = acid rain- 12,000-15,000 m sulphur dioxide cloud above Indian Ocean = albedo effect BUT: not enough to create observable difference in global temperature