Mount Merapi (EDC) 2010

Proportion of the population living within 100km of an active volcano (one that has erupted in the last 10,000 years).

75%

Number of Indonesian eruptions causing fatalities (a higher number than any other country in the world).

114

Type of plate boundary making up Indonesia's tectonic setting

Convergent (destructive). The Indo-Australian plate subducts the Eurasian plate.

Length of Indonesian subduction zone.

3000km

Nature of volcanism in Indonesia

Explosive

Merapi volcano type and altitude.

Strato-volcano reaching nearly 3,000m

Characteristic hazard at Mount Merapi

Dome collapse producing pyroclastic flows (VEI 3-4).

Volcanic bombs

Volcanic bombs and hot gases of up to 800°C spread in all directions over 11km away.

Pyroclastic flows

Extended 4km to the north, 11.5km to the west, 7km to the east and 15km to the south. Travelled down the mountain at speeds of up to 100km/h.

Ash falls

Ash fell up to 30km away and 5km into the sky. 15km away, villages were under 30cm of ash

Sulphur dioxide emissions

Blown across Indonesia and as far South as Australia, causing acid rain.

Lahar

The eruption occurred at the beginning of the rainy season, triggering lahars fed by ash from the eruption and from earlier eruptions. (Occurred in September, just before midday)

Date and magnitude of 2010 eruption

VEI 4 from 26 October to 12 November 2010

Number killed (differs according to source)

367

Number injured (differs according to source)

277

Number displaced, becoming refugees

410,000

Evacuation zone

There was a 10km evacuation zone which was extended to a 30km radius

Impact on education

Schools were closed up to 120km west of the volcano

Impact on agriculture

Large numbers of livestock were killed and ash fall and pyroclastic flows amounting to 130 million m3 of material destroyed crops and infrastructure.

Evacuation centre secondary hazards

Overcrowded leading to poor sanitation, no privacy and serious disease risk.

Environmental impact to rivers

Lahar deposits (volcanic mudflow) also proved an ongoing issue with the deposits causing blockages in the multiple river systems that descend from the volcano

Socio-economic impact

The eruption caused major disruptions in the area including in nearby Jogjakarta city with temporary airport closures and persistent ash fall affecting businesses and the wider community alike.