MEDC - ICELAND Eyjafjallajokull april 2010
iceland lies on the Mid-Atlantic Ridge, a constructive plate margin separating the Eurasian plate from the North American plate. As the plates move apart magma rises to the surface to form several active volcanoes located in a belt running roughly SW-NE through the centre of Iceland. Eyjafjallajokull (1,666m high) is located beneath an ice cap in southern Iceland 125km south east of the capital Reykjavik
Local impacts: 800 people evacuated, Homes and roads were damaged and services (electricity & water) disrupted, Local flood defences had to be constructed, Crops were damaged by heavy falls of ash, Local water supplies were contaminated with fluoride from the ash, good warning system in place meant that text was sent to giving them 30 mins warning in advance, Jokulhaups were caused due to melting flood water and led to the icelandic government destroying part of the route 1 main road as a loss minimisation approach
National impacts: Drop in tourist numbers - affected Iceland's economy as well as local people's jobs and incomes, Road transport was disrupted as roads were washed away by floods, Agricultural production was affected as crops were smothered by a thick layer of ash, Reconstruction of roads and services was expensive
International impacts: Over 8 days - some 100,000 flights were cancelled,10 million air passengers affected, cost airlines more than 200million a day and estimated that 2bn was lost overall, Industrial production halted due to a lack of raw materials, Fresh food could not be imported, Sporting events such as the Japanese Motorcycle grand prix, Rugby leagues challenge cup and the Boston Marathon were affected, ash cloud 11,000M into the air into the south easterly directed jet stream spreading the fine ash over europe, as the ash was silica rich caused problems with planes as melt into glass in the turbines
MEDC - ST HELENS MAY 1980
Washington-> DESTRUCTIVE PLATE BOUNDARY -> Juan de fuca is being subducted beneath the north american plate... From march 1980 there were signs that an eruption could occur-> bulge on the side, small earthquakes, ash and steam released... On the 18th of may 1980 there was a large earthquake of a 5.1 magnitude followed by a massive eruption of volcanic material... The eruption covered a 600km2 fan shaped area north of the volcano... almost all vegetation and buildings were destroyed in the blast zone which reached around 30km from the volcano.
ECONOMIC - total cost of damage was $1.1bn, 200 homes destroyed more damaged, over 1000 commercial flights cancelled and airports closed for upto 2 weeks, 300km of roads destroyed
SOCIAL - 57 killed by inhaling volcanic ash, hundreds lost homes, thousands unemployed initially, emotional stress
ENVIRONMENTAL - 240km2 of forrest destroyed, 12 million young salmon killed, sediment dumped in spirit lake raised the bottom by over 90m and the water level by over 60m, water quality reduced.
RESPONSES - emergency responses were co-ordinated by FEMA ( federal emergency management agency) -> face masks distributed to 2M people, emergency shelters for homeless, 900,000 Tonnes of ash removed from roads buildings airport, 18.4M trees have been replanted, domestic water supplies monitored to ensure they arent contaminated
MANAGEMENT - When the earthquakes began in march the usgs started a 24/7 monitoring system which included gathering seismic data + measuring growth and swelling + ground temperature + sulfur dioxide gas, issued warnings and made recommendations about hazardous zones, in march acess to the volcano was restricted and 2000 people were evacuated.
LEDC - Montserrat 25th June 1997
Soufriere hills was a composite volcano in Montserrat... It lies on a destructive plate boundary where the north american plate is being forced beneath the carribean plate... on the 25th of june 1997 there was a series of small earthquakes which was followed by pyroclastic flows... 4-5Million m3 of material was released over a 20 min period... there were eruptions over the next few months and the airport was destroyed by pyroclastic flows
ECONOMIC - total loss in value from destroyed homes and investment was around £1Bn, 20 villages and 2/3rds of homes destroyed by pyroclastic flows, plymouth the capital was in the exclusion zone implemented so business was massively hit, got some eco-tourism to see the volcano
SOCIAL - 19 deaths due to people entering the exclusion zone, Hundereds lost homes, fires from pyroclastic flows destroyed government buildings such as gov offices + police and petrol stations, population decresed by 66% as 8000 of the islands 12,000 enhabitants have left since the operation began in 1995.
ENVIRONMENTAL - Large areas were covered with volcanic material - plymouth covered under 12M of mud and ash, vegetation and farmland destroyed, ash has improved soil fertility.
RESPONSES - people were evacuated to the north of the island and temporary accomodation was built, temporary infrastructure was built providing people with gas and electricity, the UK provided £17M in aid as its an overseas territory, The montserrat Volcano Observatory has been set up to try and predict future eruptions
MANAGEMENT - Little management before the event increased the severity of impacts as ledc so less funding available, scientists studied the report in the 1980 but their report wasnt given attention, there was no plan in place so responses were slow, key infrastructure was built in high risk areas.
LEDC - Mount Nyiragongo 17th Jan 2002
Democratic republic of congo - Located on the constructive east african rift valley where the Nubian plate moves west and the somalian plate moves east... The volcano was a stratovolcano with steep sides located 20km north from the capital goma... the main crater is 2km wide and usually contains a lava lake... After months of increased seismic and fumarolic activity a 13km fissure opened on the south flank of the volcano with the lava reaching the capital city of goma in a few hours... the lave flows were 200m to 1km wide and were 2M deep when going through goma
The primary effects - The speed of the lava reached 60kph which is especially fast. The lava flowed across the runway at Goma airport and through the town splitting it in half. The lava destroyed many homes as well as roads and water pipes, set off explosions in fuel stores and powerplants and killed 45 people, 400,00 people were evacuated into the neighbouring rwanda wheren there had been mass political unrest which led to rwandan gangs threatening and intimidating the congo refugees... at least 80% of gomas buildings were destroyed leaving 120,000 homeless... high release of toxic local carbon dioxide from the emission of fumaroles and is deadly due to no wind
The secondary effects - Half a million people fled from Goma into neighbouring Rwanda to escape the lava. They spent the nights sleeping on the streets of Gisenyi. Here, there was no shelter, electricity or clean water as the area could not cope with the influx. Diseases such as cholera were a real risk. People were frightened of going back. However, looting was a problem in Goma and many residents returned within a week in hope of receiving aid. Damaging to the tourist trade which completely collapsed after 2-3 years..There were more deaths in the following days as refugees, short of food and water, took water and fish from the nearby Lake Kivu. As the lava entered the lake it turned it acidic, poisoning the water and the fish. It also caused methane gas to be released from the lake – which suffocated many people who were camped on the banks of the lake.