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divergent plate boundary coinciding with a hotspot
Eyjafjallajökull is in southern iceland
stratovolcano
swelling of 15cm was visible 11 weeks before
1500 tonnes of co2 released each day
ask plumes 11km high
VEI 4
volcanic - Iceland Eyjafjallajökull emergency services diverted the water from the main river so it
wouldn't damage the bridge
impacts:
- fluoride contaminated water supplies
- 800ppl evacuated due to flooding
- 1000 flights from Heathrow were cancelled
- Europe lost $2.6 bil in GDP. 11.7% drop in air passengers
- 2.8 mil tonnes less of CO2 emitted due to reduction in flights
4 active volcanoes, 2 dormant and over 123 extinct
effusive eruptions
mauna loa is an active volcano standing 42000m above sea level
volcanic - Hawaii intraplate hotspot
lava tubes/tunnels -> when lava flows through rock
lava stalactites -> at ceiling of tunnel due to gravity
black and green beaches -> when lava enters the sea
Fluid lava moved at 40km/h. Lava is unusually fluid. 3m thickness
245 deaths
20% city destroyed
volcanic - Nyiragongo DR Congo 2002 500,000 evacuated
Political instability
Economic disruption.
fertile land near volcano
stratovolcano
philipine and pacific plates subducting beneath eurasian
phreatic = water seeps into volcano and causes eruption due to
steam
volcanic - ontake japan 2014 63 killed
pyroclastic tepha and ash fallout
resuce efforts had to be abadoned due to high levels of toxic gases
such as hydrogen sulfide- typhoon Phanfone at start of oct meant
attention was put elsewhere
Philippines stratovolcano
subduction of Philippine plate under sunda plate
phreatic
volcanic - Mt Mayon 2018
300-500m lava fountains
topography means susceptible to lahars and pyroclastic flows
64,000 stayed in evacuation centres
gov. provided food for ppl for 100 days
Lava dome collapse triggered flows, killing 43 scientists at the
observatory.
volcanic - Mt Unzen Japan 1991
12,000 evacuated
warning systems and evacuation plans deployed
eruption melted glaciers, causing lahars to flow 60 km/h, reaching
town 2.5 hrs after eruption.
ice cap 30m thick
volcanic - Nev ado Ruez Colombia 1985
22000 deaths
costed $7bil
some died due to lack of antibiotics
volcanic management - st helens, may 1980
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