Case studies Flashcards
Asian Tsunami 2004
- caused by an earthquake on the 26th december
- caused by the subduction of the denser oceanic australian plate under the continental eurasian plate
- billions of tonnes of sea water displaced
- magnitude of 9.0 and lasted for over 4 minutes
- 30km deep focus (shallow)
- hit the coast of Indonesia half an hour after eq
- water was travelling at around 50mph but slowed down in shallower water, increasing height
- little prediction systems
- no ocean sensors or water level sensors
- tsunami warning system in the pacific alerted of the eq however only 2 of 11 impacted countries belonged to the system
impacts
primary
- 250,000 killed in 14 countries
- over 500,000 injured
- 1.7 million left homeless
- serious infrastructure damage
- water sources contaminated
- $10 billion in damage
secondary
- 1 million left unemployed
- aftershocks
- tourism economy badly damaged
- loss of fishing boats
- diseases like cholera and dysentery spread
responses
short term
- people fled to higher ground
- bodies buried in mass graves to prevent disease spread
- governments provided over $7 billion in aid and cleanup
- temporary shelter provided
long term
- tsunami early warning system installed
- whole towns rebuilt
- community homes and orphanages set up
Japanese Tsunami 2011
- japan is the meeting point of 3 tectonic plates
- japan experiences many earthquakes due to the pacific plate being subdued under the eurasian plate
- 7.2 magnitude earthquake followed by a 9.0 magnitude earthquake 2 days later
- after shocks of up to 6.0
- produced a 40m tsunami travelling 10km inland
- japan is relatively well prepared
- 40% of coastline has sea walls of 10m
- japan is trained every year on how to survive earthquakes
- many buildings are earthquake proof
- agency detected the eq and sent warnings out
- coast is most vulnerable area
- fukushima nuclear power station was directly in line with the epicentre
impact
- 15,749 killed
- 26,992 injured
- 130,000 buildings collapsed
- 500km2 of land damaged
- fukushima had released of radioactive material causing contamination
- $235 billion in damage
responses
short term
- military was sent to help civilians
- shortages of food and water
- rescue teams sent out from other HIC countries
- people evacuated
long term
- infrastructure like motorways repaired
- temporary housing built
- small coastal areas raised
- small businesses given grants to recover
Eyafjallajokull Volcano 2010
- volcano at the divergent plate boundary of the NA plate and the Eurasian plate
- 4 on the VEI
- lava launched 150m into air
- caused major flood as destroyed glacier covering volcano
- some warning signs despite long time since last eruption
- 3000 earthquakes in the area before eruption
- area was prepared
- Met office in Iceland monitored earthquakes
- no deaths or injuries
- people had to wear goggles and face masks due to ash
- led to a flood causing 700 people to evacuate
- contaminated soils and livestock
- 3,000 tonnes of CO2 but had little impact on climate
- major impact on air travel in the region and in europe (100,000 journeys cancelled)
- £130 million lost a day from airlines
- affected world trade
Mount Pinatubo, Philippines 1991
Volcano
- on convergent plate boundaries where the oceanic plate is being subdued under the eurasian plate
- part of the pacific ring of fire
- preceded by mini earthquakes and sulphur dioxide releasing from the volcano
- 8 days before the eruption a lava dome extruded
- 15th june eruption
- pyroclastic flows and a 22 mile ash cloud
- the US and philippines predicted the eruption saving 5000 lives and $250 mil in damages
- lahar detectors and hazard maps showing vulnerable areas
impacts
- 364 communities and 2.1 mil people affected
- 847 killed: 300 from collapsing roads, 100 from lahars and 447 from disease
- 100,000 made homeless
- 1 million farm animals starved to death
- $700 million in damages
- $40 million in agricultural losses
- 200,000 acres of farm land destroyed
responses
- US airforce helicopters helped with evacuation
- evacuation camps set up
- red cross, organ and HICs helped to provide aid
- millions of £ sent by EU countries for relief and rehabilitation
- aeta people resettled
- new houses placed on stilts
- dikes and dams constructed to help prevent lahar flows
Haiti Earthquake 2010
- country lies on the boundary of the caribbean and north american coast plates
- one of the poorest countries in the world
- 86% of people living in capital city live in slum conditions
- governance is weak and corrupt
- 7.1 magnitude
impacts
- 160,000 people died
- bodies bulldozed into mass graves to prevent disease
- 300,000+ injured
- 1.5 million became homeless
- cholera outbreak
- $11.5 billion in damages (120% of haitis GDP)
responses
- Dominican republic provided emergency water and medical supplies as well as machinery
- emergency rescue teams arrived from abroad
- after one year there were still 1300 refugee camps
- schools are being rebuilt
- cash for work schemes are paying haitians to help clear rubble
Christchurch, New Zealand 2010/11
Earthquake
- slippage along the conservative boundary between the indo-australian and pacific plate
- not predictable
- 6.3 magbitude
- low vulnerability
- vulnerable to liquefaction (eq causing saturated soils to lose strength)
impacts
- 200 people injured
- 181 killed
- 50% of city’s central buildings damaged
- water supplies disrupted by burst pipes
responses
- red cross provided grants to families with children under 5 who were living in damaged homes
- $989 million paid in building claims
- temp housing provided
- urban search and rescue helped
- art gallery turned into emergency response centre as eq proof
- cardboard churches built
Jurassic coast
- 185 million years old in parts
- old harry & wife represent a cave-arch-stack-stump sequence
- lulworth cove formed after the ice age
The holderness coast
fastest eroding coastline in the UK due to:
- geology of boulder clay and glacial sands that make up large amounts of the coast
- power of the waves (hydraulic action and abrasion occur due to the long fetch that the waves have when they meet the coast)
- material in the sea being carried away by longshore drift
Mike Needly - Ringborough farm
- bought 145 acres in 1939
- due to erosion rates of 1-2 metres per year he now has half that
- has diversified to selling bottled natural gas to survive
- building and maintaining defences is expensive and may harm coast further down
- no money is given for loss of land
- Withernsea, Hornsea and bridlington have seen sea defences built as cost benefit analysis shows it is worth it
- defenses have been built in mappleton due to the risk of the loss of road that connects this village (defences cost £1.9 million in 1991) however this caused terminal groyne syndrome in the town of cowden
- Kilnsea east riding have not had defences built due to lack of funds
- local people have instead implemented flood drainage ditches which last 20 years
- sandy beaches caravan park has lost land due to a lack of defences, one storm caused 10m to be lost
- sediment cell concept
Dalmatian coast, croatia
- long narrow island running parallel to the coastline
- produced by sea level rise flooding the coastline with the geological structure of folds aligned parallel to the coast
- croatia has 520km of this
Aswan Dam and Nile delta
- Located in Egypt
- built in 1971
- controls the regular flooding of the nile and reduces the supply of sediment
- water supplies more reliable and electricity generated
- caused some types of fish to disappear
- 95% of population live here
Deltawerken, Netherlands
- hard engineering project following the 1953 storm surge
- series of gates to control the flow of water during a storm surge
- reduces the length of the coastline exposed to the sea
- cost more than $5 billion
- costs $1 billion a year to maintain
- allows 4 million people to live below sea level
- some nature reserves lost during construction
1953 and 2013 storm surges
context: low air pressure allows water to bulge up in a dome, the dome gets higher the lower the pressure
1953
- low pressure raised water levels, high northerly winds
- funnelled between england and holland
- 2.5 metres above sea level
- over 300 people died
- 24500 houses damaged
2013
- storm surges reached heights of 6.3m
- wide spread flooding
- low pressure, high winds, high tidal pressures combined
- 2 deaths in the uk
- 1400 homes flooded
- £1 billion in damage
- thames barrier protected some areas
Cycle Sidr, Bangladesh 2007
- 6m high storm surges and 223km/h winds
- 3500 fatalities due to drowning
- drinking water contaminated
- country is very low lying (1-3m abv sea level, 70% is less than 1m)
- storm funnelled through bay of bengal
- deforestation of mangroves meant little dissipation of wave energy
Tuvalu, Maldives
- example of environmental refugees
- average height of 1.5m above sea level, even lower in tuvalu
- highest point is only 4.5m above sea level
- coral reefs have been destroyed by increased wave energy and and global warming
- ground water sources are contaminated by salt water
- high population density
- 400,000 residents with nowhere to go
Medmerry
- managed retreat
- flooded farmers fields
- cost £28 million
