A. Volcanoes Flashcards
Java’s population density is over ___ people per km2
Java’s population density is over 800 people per km2
How many people live on the slopes of Mount Merapi?
1.1 million
How many people live in Yogyakarta city, and how far is it from Mt Merapi?
3 million people live there, just 25km away from the volcano
Why is Merapi active?
- On a volcanic island arc
- Destructive plate boundary - Australian Plate subducting under Eurasian (Sunda) palte
When did Merapi erupt?
26th October 2010
What were the primary ground-based hazards of the Mt Merapi eruption?
- Earthquakes preceding eruption - averaging about 10 a day, up to magnitude 2.5 on Richter scale
- Pyroclastic flows from the summit on eruption day (travelled 8km), later followed by over 35 further pyroclastic flows (travelled up to 18km).
- Over the first five days of eruption, explosions were felt more than 20km from the volcano
What were the primary aerial hazards of Mt Merapi eruption?
- Ash plumes up to 18km high in altitude; ash fall in towns over 240km away, heavily in towns within 26km.
- Thunderstorms from ash clouds - St Elmo’s Fire
What were the primary social impacts of Mt Merapi eruption?
- December 2010 death toll - 353 people
- Additional 487 people hospitalised and 800 recorded as suffering psychological effects from the loss of family and livelihood.
- Kinahrejo village destroyed, killing 35 people including Merapi gatekeeper Mbah Maridjan.
What were the primary economic impacts of Mt Merapi eruption?
- 870 hectares of forest and farmland destroyed, costing an estimated $3.6 million
- Villages of Selo, Magelang and Muntilan were covered in 4cm of ash
- Merapi Response Radio reported that all schools within 120km of the volcano were to close due to concerns over ash fall.
- Flights from Yogyakarta and Solo airports were cancelled for two weeks - one plane had to make an emergency landing due to ash and tephra.
What were the secondary hazards of the Mt Merapi eruption?
- November-April rainy season caused heavy rainfall to mix with earlier pyroclastic flow material, forming lahars, which often flowed down river valleys, affecting villages up to 26km from the volcano.
What were the secondary impacts of the Mt Merapi eruption?
- Lahars damaged houses and farms in the Magelang district up to 26km from the volcano, affecting around 3,000 people.
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21 January lahar ran down the Amat river valley: villages of Rangkah and Kinahrejo obliterated, killing a further 33 people and all the local cattle, making farming impossible.
It also destroyed 44 houses and a number of businesses in Jumoyo, but there were no casualties. - New industry of mining and selling the material emerged - volcanic debris makes excellent building material when mixed with water.
- Some members of the community took to selling drinks and pictures to tourists who came to see the lahar and the stone spirits.
How did the Indonesian government respond to the Mt Merapi eruption?
- US$2.6 million of support allocated for disaster, managed through the National Disaster Mitigation Agency
- Military used to build makeshift hospitals and public kitchens in the safe zone and serve evacuated persons
- Merapi Response Radio reported that all schools within 120km of the volcano were to close due to concerns over ash fall.
How did NGOs react to the Mt Merapi eruption?
- Further assistance granted from NGOs including Action on Hunger, Indonesian Red Cross and the Red Crescent Authority
- World Health Organisation provided support alongside Indonesian Ministry of Health - distributed blankets, 6 tons of emergency energy biscuits across shelters and over 100,000 face masks prioritised for shelters closest to the volcano.
How did Indonesia recover from the Mt Merapi eruption?
- 15,000 earthquake resistant houses built
- Housing assistance grants to ‘build back better’ - 48% of households who received housing assistance reported an increase in quality of life post-disaster
What were the total damages and losses from the eruption which Indonesia needed to recover from?
Total damages and losses from the eruption were over $600 million; this was due to the decline of tourism, lost livestock and damage to manufacturing and agricultural centres.