Volcanic case study Flashcards
Mount Ontake, Japan eruption: When?
27th September 2014
Mount Ontake, Japan eruption: Was there warning?
No Until 1979 it was believed to be dormant. After a few minor eruptions, it was monitored. Despite it being monitored, the minor earthquakes which usually signal an impending eruption were not detected.
Mount Ontake, Japan eruption: Vulcanicity
Eruption was phreatic
- water seeped into the volcano and became super heated by the magma
- In a phreatic eruption, magma doesn’t actually erupt from the volcano, instead hot ash, rocks and steam do.
- The eruption wasn’t particularly explosive- Volcano Explosivity Index (VEI) of 3
- proximity of the hot ash to the hikers = dangerous
Mount Ontake, Japan eruption: Japan’s volcanic activity
- Japan one of the most volcanically active places in the world with 10% of the world’s active volcanoes being on Japanese islands.
meeting point of 4 major plates - the Pacific, Philippine, Eurasian, and North American.
Mount Ontake, Japan eruption: Effects
- huge pyroclastic flow which trapped 250 people on its slopes
- Over 50 deaths (most hikers)
- At least 40 others injured
- some cuts, bruises, and broken bones, some lung damage
The huge ash cloud billowed down the mountain for more than 3km, engulfing hikers in its path.
Mount Ontake, Japan eruption: Response
- 1000 Japanese rescue workers search the peak after the eruption.
- Recovery efforts were hampered in the early stages due to the volcanic conditions.
- volcano continued to eject toxic gases, rocks, and ash.
- Residents were warned of falling stones
- . On 29th September, rescuers abandon mission due to the levels of poisonous hydrogen sulphide becoming too dangerous.
- Typhoon Phanfone hit region on 5th-6th October, efforts were interrupted
- . A month after the eruption, death = 57 with 6 others still missing. search for the missing was continued on 29th July 2015 - 10 months after the eruption due to continued volcanic activity.
Mount Ontake, Japan eruption: Why was there no warning?
- eruption of hot ash and super-heated steam meaning was hard to predict.
- no visible signs that an eruption was about to occur.
Eyjafjallajökull eruption: When
March - April 2010
Eyjafjallajökull eruption: The eruption itself - details 4
- Problems arise in April when eruptions spread to centre of the volcano, a 3km wide crater surrounded by ice
- The ash plume reached 11,000m in the air VEI of 4 Lack of wind meant that the ash cloud wasn’t dispersed quickly.
Eyjafjallajökull eruption: Prediction 3
- Eruption followed several months of increased seismic activity in Iceland.
- The IMO’s weather radar on the southwest tip of the country showed the height of the ash plume, which is important for calculating the distribution of the ash.
- 24/7 watch at the IMO, where a meteorologist is present, and a seismologist and hydrologist are on call
Eyjafjallajökull eruption: Preparation and planning 5
- police call landlines and send text messages to all residents, summer houses and recreation centres.
- Evacuees hang a sign on their front door indicating that they have left.
- Rescue workers sweep the area to be sure it’s all clear and there will be evacuation centres just outside the area
- The EU has other transport mechanisms such as extensive road and motorway networks, rail networks and boat networks
- Travellers stuck by the ash cloud entitled to legal compensation from airlines and airlines were legally responsible for the well-being of stranded passengers.
Eyjafjallajökull eruption: Responses 6
- responses were entirely DOMESTIC.
- The countries affected by this hazard responded by themselves or collectively and had the capacity to do so.
- evacuated by European Red Cross Societies mobilised volunteers, staff and other resources to help people affected directly or indirectly by the eruption
- The European Red Cross provided food for the farming population living in the vicinity of the glacie
- r Set off a major flood in Iceland, when erupted lava partly melted a glacier - 700 people to evacuate.
Eyjafjallajökull eruption: Economic impacts 4
- Airlines lost combined £130 million per day in lost revenues
- Europe’s biggest tourism businesses lost between £5 million and £6 million per day.
- Kenya’s economy lost £2.8 billion because of flights to Europe being cancelled
- couldn’t export As staff being stranded abroad, meetings being cancelled and delays to air mail, many businesses worldwide lost money.
Eyjafjallajökull eruption: Social impacts 4
- The people living in the rural areas ‘downwind’ of the volcano had to wear goggles and facemasks as ash was thick.
- 500 local cattle farmers and families evacuated from around the volcano. ash contaminated local water supplies
. People stranded all across the world
Eyjafjallajökull eruption: Environmental impacts
Grounding of European flights prevented the emission of 2.8 million tonnes of carbon dioxide into the atmosphere
