case studies

Question 1

Earthquake in Haiti - 12 January 2010, 16:53

Answer 1

• poverty, environmental degradation, corruption and violence
• 7.0 on the Richter Scale, 25 km SW of Port-au-Prince
• 300 000 people died, 250 000 injured and 1 million made homeless
• 60% of buildings were shoddily constructed and unsafe even under normal conditions
• 3 million people (a third of the population) required emergency aid and only 200 000 received it after 7 days
• Challenge to the international community who has failed over decades to lift the island state out of poverty, corruption of violence
• Since 2000 more than $4 Billion has been given to rebuild communities and infrastructure devastated by tropical storms, floods and landslides, but mismanagement and lack of coordination and attempt by global institutions to use Haiti as an economic test bed frustrated all efforts
• A foreign debt of $1.5 billion weighed down the economy
• Hispaniola sits on the Gonave microplate, a small strip of crust squeezed between the North American and Caribbean tectonic plates
• economic damage 7.8 billion dollars

Question 2

Tohoku, Japan earthquake and tsunami 2011

Answer 2

• East coast of Japan on 2011 was magnitude 9.0
• Most powerful earthquake to ever hit Japan
• Tsunami that generated waves of 12 metres that hit 10-30 min after main shock
• Waves higher than sea walls, were build on smaller experienced tsunamis: Japan has invested billions of dollars of anti tsunami sea walls along at least 40% of the 35 000 km coastline
• 16 000 deaths, more than 2500 missing, over 225 000 forced to relocate temporary or forever
• 90% of casualties died by drowning
• 125 000 buildings collapsed, further 1 million damaged
• 4.4 million households in NE Japan left with no electricity and 1.5 million with no water
• Tsunami caused accidents in nuclear power stations like the Fukushima Daiichi
• 10% of fishing ports damaged
• Widespread shortages of food, water, shelter, medicine and fuel
• Short term economic impact: suspension of industrial production in many factories, long term: cost of rebuilding estimated at $122 billion
• One minute before the earthquake was felt in Tokyo, the Earthquake Early Warning System sent out warnings to millions

Question 3

Nepal earthquake, 2015

Answer 3

• april 2015 Magnitude of 7.8
• Killed over 9000 people and injured more than 23 000
• Major aftershock 7.3 in may 2015, over 200 people killed, more than 2500 injured
• Caused by release of built up stress along a fault line where the Indian plate is colliding against the Eurasian plate
• Rebuilding the economy could exceed $5 billion or about 20% of Nepal’s GDP
• Rainfall and aftershocks complicated by additional secondary effects like landslides and further building collapsing
• Impassable roads and damaged communication infrastructure posed substantial challenges to rescue efforts

Question 4

Nevado del Ruiz, Colombia lahar and mudflows

Answer 4

• Rain brings soot and ash back to the ground and this becomes a heave saturated mudflow
• Heat from volcanoes melts snow and ice - the resulting flow pics up sediments and turns it into a destructive lahar
• Is a volcano in Colombia that rises to an altitude of 5400 metres and is covered with an icecap of 30 metres, covering an area of about 20 km2
  1984/1985
• small scale volcanic activity resumed, large scale returned in november 95, recorded earthquakes
  Soon after volcanic eruption threw hot pyroclastic material onto the icecap, causing it to melt
• Condensing volcanic steam, ice-melt and pyroclastic flows combined to form lahars
• Moved down mountain engulfing the village of Chinchina, killing over 1800 people and destroying the settlement
• Conditions worsened and further eruptions melted more ice creating more lahars capable of travelling further down into the floodplain of the Rio Magdalena
• Within an hour it reached the city of Armero, 45 km away
• 22 000 residents suffocated and crushed under 8 m thick flow
• Volcanic eruption was relatively small, ice made it hazardous

Question 5

Cyclone nargis, 2 may 2008

Answer 5

• Formed 27th april 2008, made landfall by 2nd of may, died by 3rd
• Winds up to 165 km/h and 215 km/h, at its peak, air pressure dropped 962 millibars,
• Around 146 000 ppl killed,$10M damage
• As well as Burma (Myanmar) , parts of Bangladesh, India and Sri Lanka were affected
• UN estimated 1.5 M ppl affected
• Relief efforts delayed for political reasons: estimate cause of 1 M deaths, Burma’s political leaders rejected international help
• Government provided no warning of cyclone, even though Indian meteorologists warned gov 48 hour before
• Two weeks later, relief only reached 25% of people in need

Question 6

The European avalanches of 1999

Answer 6

• Killed 75 people in the Alps in February 1999, in 3 weeks:
• Over six feet of snow falls over a few days (2m)
• Sheer weight of massive new snow causes avalanche
• Snow crashed down into village
• Snow storms at night prevent rescue helicopter teams
  rescue work was hampered by low temperatures (below minus 7) which caused compact snow, impossible to dig, moved uphill 40 m crashing into village of Le Tour
• Area thought to be fairly safe, villages of Montroc and Le Tour at the head of Chamonix Valley ( no defences)
• Precautionary measures: avalanche wall to village of Taconnaz
• The avalanche, 150 m wide, 6 m high, up to 90 km/h that swept through the Chamonix valley killed 11 people and destroyed 18 chalets, some chalets carried as far as 400 m
• Montroc in ‘white zone’ - villagers and tourists in fake sense of security (global warming weather patterns: heavier snow later in season : re-evaluation (rising T and melting permafrost) )
  Avalanches are more likely when:
• Slopes are steeper than 30 degrees
• A lot of new snow falls over a short period
• Winds lead to drifts
• Old snow melts and refreezes, encouraging new snow to slide off

Question 7

Human Causes: The Italian Mudslides, 1998

Answer 7

• May 1998, mudslides swept through towns and villages in Campania
• Killed 300 people, P18 million allocated for repairing damage,
• Since 1892, 1173 serious landslides, since 1945, landslides and floods have caused an average of 7 deaths/month
• Geographically unstable area, active volcanoes, (Etna and Vesuvius), fast flowing rivers
• Humans: part of River Sarno had been cemented over, clay soils in surrounding mountains been rendered loose by fires and deforestation, houses built up hillsides (1960: enter into industrial age: uncontrolled building of houses, roads and deforestation) : poor infrastructure, mass construction, poor planning
• Over 20% of houses built without permission, most shoddily built over 2m thick layer of lava formed by the Vesuvius eruption, (w/o proper drainage and foundations)
• heavy rain makes lava liquid: 900M tonnes of material washed down this way every year.

Question 8

China’s landslide 2010

Answer 8

• Deadliest landslide in decades(60yrs), 700 dead, more than 300 houses collapsed, landslides levelled an area abt 5 km long and 500 m wide,
• NW Gansu province, avalanche of mud and rock engulfed small town in the valley
• Heavy rain quickly ran off the steep, barren hills, triggering mudslides and swelling river (antecedent/prolonged rainfall/intense)
• Government warned mountain area vulnerable for years (2009)