MERAPI, INDONESIA 2010

EDC

How many active volcanoes in Indonesia?

80 have erupted in historic times

How is Indonesia’s tectonic setting similar to Japan?

Its an archipelago straddling tectonic plate boundaries

What happens along the archipelago?

Widespread subduction along the entire 3000km length of the Indonesian archipelago

How is Indonesia’s tectonic setting complex?

• Much is an Island Arc formed by subduction of the Indo-Australian plate beneath the Eurasian plate.

• To the east of chain of islands, the continental shelf of northern Australia collides with Eurasian plate.

How are the population impacted by Indonesia’s tectonic setting?

Over 75% of Indonesia’s inhabitants live within 100km of a volcano thats erupted in the past 10,000 years.

How has infrastructure been impacted?

• Damage to infrastructure & 114 facilities.

• More than any other country in the world.

What is Indonesia’s landscape dominated by?

• Volcanic peaks

• Its history, culture & personal experiences of its people are closely tied to volcanoes.

What type of eruptions are manny of the volcanoes?

Highly explosive

Example of a highly explosive eruption?

• 1883: Krakatau

• Cataclysmic eruption

• Generated devastating tsunami

Example of super volcanic activity?

• Norther Sumatra: Lake Toba fills the caldera

• Caused by super-volcano eruption 70,000 years ago.

What level was the volcanic explosivity index (VEI) for the Merapi volcanic eruption?

VEI = 4

When was the eruption?

26 October - 12 November 2010

Pyroclastic flows?

• Extended 4km north

• 11.5km west

• 7km east

• 15km south

Lava bombs?

Thrown 4km from summit in all directions

Lahars?

• Happened at beginning of rainy season

• Triggered lahars fed by ash from eruption & earlier eruptions.

Ash fall?

Forced closure of Yogyakarta airport for over 2 weeks

Gas emissions?

Emissions of sulphur dioxide caused acid rain to fall over large part of the region.

Social: How many ppl killed?

367 died

Social: How many injured?

277 injured

Social: How many became refugees?

Approx. 410,000 became refugees

Economic: Impacts on farmland/infrastructure?

• Lot of livestock killed

• Ash fall + pyroclastic flows = 130 million m3 of material destroyed.

• Crops, infrastructure e.g. buildings, power lines & bridges.

Economic: What was the total economic impact of the eruption?

• £450 billion

• Negative impacts: farming, tourism & manufacturing.

Political: How did the eruption test the government?

• Tested the governments ability to respond effectively to natural disasters in crisis.

• Showed need for improved disaster preparedness.

Political: What did the government need to improve on?

• Response mechanisms

• Coordination among government agencies

• Preparation

Political: How did the public’s perception of the government change after their ineffective response?

• Criticisms of slow + inadequate gov. action.

• Public dissatisfaction

• Affected govs credibility & popularity.

Political: How do natural disasters potentially disrupt political stability?

Creates social unrest & discontent amount affected populations

Political: What is crucial for political stability during volcanic eruptions?

• Govs. ability to manage aftermath of eruption

• Provide assistance to affected communities

• Maintain order

MODIFYING VULNERABILITY

Vulnerability: What was established in 1920 to help observe volcanoes?

• Indonesia’s Centre for Volcanology & Geological Hazard Mitigation (CVGHM).

• Key division = Volcano Observation Section.

• Permanent observations on several active volcanoes.

Vulnerability: Monitoring Mount Merapi?

• 1st seismograph set up on Merapi in 1924.

• Capability of technology at the time was limited.

Vulnerability: Why was managing volcanoes a low priority for Indonesia in the past?

• Dutch colony until end of WW2.

• Emergence into independence was accompanied by: political tension & violence among competing groups.

Vulnerability: How has the CVGHM improved monitoring?

• Upgraded monitoring instruments & widened geographical coverage.

• Over 60 volcanoes now monitored.

Vulnerability: What does their sophisticated equipment measure?

• Gas emissions

• Inflation as magma rises

• EQ activity in some volcanoes

Vulnerability: What is the biggest threat from volcanoes to Indonesia?

• Threat from lahars = high

• Quantities of ash erupted by Indonesian volcanoes.

• + humid tropical climate & high rainfall (>1800mm per annum)

• Rainy season = November to March.

Vulnerability: What agency has the CVGHM established?

• National Agency for Disaster Management.

• Association with university-based researchers - both Indonesian & foreign.

• Lahar sensors & close-circuit TV installed to monitor locations at greatest risk.

Vulnerability: Who does the CVGHM work closely with?

• Local governments

• Advising them on mitigation e.g. community preparedness.

Vulnerability: Example of mitigation strategies?

• Permanent settlement on Mount Merapi is forbidden - on highest slopes around crater.

• Villages on southern slopes (greater risk) are encouraged to relocate to safer zones.

• Some receive financial assistance.

MODIFYING LOSS

Loss: How is relocating settlements a problem?

• People have strong bonds with village site & their family fields.

• Often return, rebuild & accept risks.

Loss: Issues with resources?

• Indonesia = EDC - resources to deploy once eruption is underway are limited.

• Many farming communities also have limited resources.

Loss: However, how is Indonesia prepared?

• Indonesia has some well-trained & well-equipped emergency services.

• E.g. military, experienced in search & rescue.

Loss: How have authorities reduced flooding risks?

Cleared river channels of volcanic material & other debris - reduce risk of flooding & contain lahars.

Loss: How does clearing river channels help people living along the river?

• Some material has commercial value e.g. roads.

• People use it for rebuilding houses & community facilities.

Loss: What is set up in case of evacuation?

• Temporary shelters in safe zones

• In case of evacuation

• Sometime upgraded into permanent residential areas.