Volcano case studies
Mount Ontake, Japan- Saturday 27th September 2014
Background knowledge
Japan has 110 active volcanoes
Japan is one of the most tectonically active places in the world
Situated 200km west of Tokyo
Rises 300m above sea level
Popular area for climbers and trekkers, spiritual pilgrimage and is a popular tourist location
Social impacts
63 people killed, mainly due to falling tephra, and 40 people injured
250 people trapped on the slopes
Building collapsed under the weight of ash fall
Economic impacts
Tourist destination- most structures destroyed, less tourists coming to the area since the
eruption
Environmental impacts
Toxic gases e.g. high levels of hydrogen sulphide- had to call rescue mission off
The thin layer of ash that fell made soil fertile and rich with elements
Political impacts
Questions over why the eruption was not predicted
Mitigation against vulnerability
Seismometers monitoring the volcano- eruption caused by magma boiling ground water
until it exploded and was released as steam (phreatic eruption), therefore was undetectable
so there was no warning
Mitigation against losses
Rescue teams sent to help get people off the slopes
1km exclusion zone around the summit for 4 years after the eruption
Mount Merapi, Indonesia- 26th October to 12th November 2010
, Background knowledge
Over three-quarters of Indonesia’s inhabitants live within 100km of a volcano that has
erupted in the last 10,000 years
Reaches nearly 3000m above sea level
Highly active
Why people live there
Over 11,000 people live on the mountain’s slopes
Mainly poor farmers- depend on the riches of the soil for their living
Social impacts
353 killed and 577 injured
Approximately 410,000 people became refugees
People lost their livelihoods, particularly farmers
Maridjan (gatekeeper of the volcano) refused to leave- people listened to him- he was killed
Villages, such as Bronggang, 15 km from the volcano, were buried under 30 cm of ash
Roads were blocked with cars and motorcycles as residents tried to flee the hazard zone
Economic impacts
130 million m³ of material destroyed infrastructure and crops
Yogyakarta Airport closed for over a fortnight
Increase in vegetable prices due to lots being destroyed
Environmental impacts
Acid rain due to sulphur dioxide
Start of rainy season- lahars triggered
Volcanic bombs and heat clouds, with temperatures up to 800°C, spread over a distance of
10 km.
Mitigation against event
Dams build to hold back lahars
Mitigation against vulnerability
Volcano monitored
Evacuation of people- 20km exclusion zone
Mitigation against losses
Indonesian Disaster Management Agency mobilised volunteers, military and police to
circulate information, rescue survivors, control traffic, set up makeshift hospitals and
kitchens in evacuation centres
210 evacuation centres set up
Government made money available to farmers to help replace their livestock
Mount Ontake, Japan- Saturday 27th September 2014
Background knowledge
Japan has 110 active volcanoes
Japan is one of the most tectonically active places in the world
Situated 200km west of Tokyo
Rises 300m above sea level
Popular area for climbers and trekkers, spiritual pilgrimage and is a popular tourist location
Social impacts
63 people killed, mainly due to falling tephra, and 40 people injured
250 people trapped on the slopes
Building collapsed under the weight of ash fall
Economic impacts
Tourist destination- most structures destroyed, less tourists coming to the area since the
eruption
Environmental impacts
Toxic gases e.g. high levels of hydrogen sulphide- had to call rescue mission off
The thin layer of ash that fell made soil fertile and rich with elements
Political impacts
Questions over why the eruption was not predicted
Mitigation against vulnerability
Seismometers monitoring the volcano- eruption caused by magma boiling ground water
until it exploded and was released as steam (phreatic eruption), therefore was undetectable
so there was no warning
Mitigation against losses
Rescue teams sent to help get people off the slopes
1km exclusion zone around the summit for 4 years after the eruption
Mount Merapi, Indonesia- 26th October to 12th November 2010
, Background knowledge
Over three-quarters of Indonesia’s inhabitants live within 100km of a volcano that has
erupted in the last 10,000 years
Reaches nearly 3000m above sea level
Highly active
Why people live there
Over 11,000 people live on the mountain’s slopes
Mainly poor farmers- depend on the riches of the soil for their living
Social impacts
353 killed and 577 injured
Approximately 410,000 people became refugees
People lost their livelihoods, particularly farmers
Maridjan (gatekeeper of the volcano) refused to leave- people listened to him- he was killed
Villages, such as Bronggang, 15 km from the volcano, were buried under 30 cm of ash
Roads were blocked with cars and motorcycles as residents tried to flee the hazard zone
Economic impacts
130 million m³ of material destroyed infrastructure and crops
Yogyakarta Airport closed for over a fortnight
Increase in vegetable prices due to lots being destroyed
Environmental impacts
Acid rain due to sulphur dioxide
Start of rainy season- lahars triggered
Volcanic bombs and heat clouds, with temperatures up to 800°C, spread over a distance of
10 km.
Mitigation against event
Dams build to hold back lahars
Mitigation against vulnerability
Volcano monitored
Evacuation of people- 20km exclusion zone
Mitigation against losses
Indonesian Disaster Management Agency mobilised volunteers, military and police to
circulate information, rescue survivors, control traffic, set up makeshift hospitals and
kitchens in evacuation centres
210 evacuation centres set up
Government made money available to farmers to help replace their livestock
