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Flashcards in Seismicity- Case Studies Deck (11)
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Background facts on Haiti

- situated to the north of Caribbean Plate on a transform conservative plate boundary with the North American Plate moving west
- 7.0 magnitude on 12th January 2010 at 16:53 local time
- focus 13km below surface (shallow)
- epicentre 16km west of Port-au-Prince
- tremors lasted for one minute


Primary effects in Haiti

- 3 million people affected
- around 230,000 identified as dead
- 300,000 injured
- 1 million homeless
- 250,000 residences and 30,000 commercial buildings collapsed or severely damaged e.g. the UN and World Bank HQs as well as schools, hospitals, government buildings
- roads, bridges, telephone lines, electricity systems damaged
- port was hit making it hard to ship in aid to the capital


Secondary effects in Haiti

- spread of fire and disease
- poor living conditions and lack of sanitation:; cholera
- shortages of food and water
- small local tsunami
- one fifth of jobs lost
- 52 aftershocks in following 12 days (one was 5.9 magnitude)


Why was Haiti so badly affected despite the magnitude not being that great

- shallow depth
- struck most densely populated area of country
- poorest country in the Western Hemisphere
- buildings in poor condition and not constructed to be earthquake resistant
- 3 million people live in Port-au-Prince with the majority in slum conditions after rapid urbanisation
- only one airport with one runway; the control tower was badly damaged and the port was also inaccessible
- aid piled up but lack of trucks and people to distribute it so took days to arrive
- rescue teams took up to 48 hours due to problems at the airport so local people had to dig people out with bare hands
- severe shortage of doctors meant people died of injuries such as broken limbs


What was the building like in Haiti

There were building codes but they were not conformed to and so a typical finding was that insufficient steel had been used to reinforce concrete. Half of all the buildings were destroyed.


Christchurch background facts

- New Zealand is a highly tectonically active country
- the South Island is on a conservative boundary between the Indo Australian and Pacific Plates though the 2011 earthquake was caused by smaller faults that ruptured, previously unknown to geologists
- a wealthy country; GDP $41 per capita
- very mountainous interior so majority live on coastal plains (where Christchurch is located); population distribution is uneven which has a disproportionate effect on the population when earthquakes hit
- built on alluvial sediment (allowing liquefaction)
- strict building codes reviewed every 10 years
- The Greendale Fault ruptured Sept 4th 2010; 7.1 at 10km deep
- The Christchurch Earthquake 22nd Feb 2011 12:30pm; 6.3
- struck at built up area; 10km SE of the city at 5km deep at lunchtime when many were on the streets


Primary effects in Christchurch

- water pipes, roads, bridges, power lines, phone lines damaged
- brought down many buildings previously damaged in sept 2010
- many heritage buildings severely damaged e.g. the cathedral and Christ church's tallest building the Hotel Grand Chancellor (which was demolished)
- extensive liquefaction; eastern parts of the city were built on a former swamp and properties were covered in thick layers of silt
- water and sewage on the streets
- house foundations cracked and buckled; many houses had to be demolished and some areas of suburbs were never recoccupied
- confusion and panic in the centre; phone lines immediately jammed
- 185 people died, thousands are injuried
- 115 died when 6 storey Canterbury Television Building collapsed
- 169 people died in the centre of the city


Responses in Christchurch

- National Crisis Management Centre activated and a national state of emergency declared
- Japan, UK and other countries sent specialist rescue teams
- land use zone map drawn up in June 2011 showing red areas where rebuilding was dangerous
- Central Business District remained cordoned off more than 2 years afterwards
- electricity restored to 75% of the city within 3 days but water and sewerage systems took years to restore
- 70,000 people left the city
- Timaru, a town 157km South saw a swell in population by 20% and thousands of pupils enrolled in schools in other cities and towns
- over 1000 buildings had to be demolished including the spire of the cathedral which remains un-reconstructed


What is the current situation in Christchurch

- remains a "ghost town"
- waiting for insurance payouts and planning decisions
- charities have been set up e.g. "Greening the Rubble" schemes building temporary parks on the sites of destroyed buildings
- widespread frustration with the rate of recovery


LEDC case study and MEDC case study?

LEDC- Haiti
MEDC- Christchurch


Human factors involved in Haiti

GDP is $1200
Life expectancy 62.51 years (20 years lower than the UK)
Total fertility rate 2.98 per woman
Literacy rate 52.9%