Seismic Case Studies

When: 17th Janauary 1995 at 5.46am

Where: Japanese city of Kobe, epicentre = 20km to  south-west of Kobe in Osaka Bay

Magnitude: 7.2 on the Richter Scale

Physical Geography:

• 30-50km long rupture of a strike-slip fault occurred below Kobe
• In 2 weeks after main earthquake there were 1320 aftershocks (150 strong enough to be felt)
• Shallow depth = 14km
• Philippines Plate is subducting beneath the Eurasian = strain on Eurasian Plate = Median Tectonic Line = creates a new fault zone

• 6300 deaths and 35,000 injured
• 70% of water system inoperable
• Over 103,500 buildings destroyed
• All transport routes severly affected = collapse of elevated roads e.g. Hanshin Expressway suffered a collapse of a 630m section
• Only 20% of buildings in the CBD useable after the earthquake
• Port facilities severly damaged by liquifaction and lateral flow of soil - Kobe handles 30% of Japan's commercial shipping
• Gas and electricity supplies damaged = ruptured pipes/ collapsed poles
• Over 60% of deaths were people aged over 60
• Ruptured gas pipes led to over 3000 fires in Kobe
• 300,000 left homeless = 20% of Kobe's population
• Caused US$99.3 billion in damage
• Reconstruction price tag = $120 billion
• 20,000 people lost their jobs

• State's crisis-management system was shown to be deeply flawed = needed to be looked at
• All school children in Japan are put through emergency earthquake drills 4 times a year
• Earthquake kits can be bought in department stores
• Many companies observe a Disaster Prevention Day on 1st September every year = local drills and earthquake kit promotions in department stores
• Official response slow = 5 hour delay before Seld Defence Force brought in (only 200 strong)
• Officials debated for days where to draw the boundary on the disaster zone
• 3 days after earthquake the city still had no electricity
• Delays in accepting international help
• Caught off guard as citizens thought Kobe was not at risk from earthquakes

Aftermath:

• Public services restored between April and June 1995
• Hanshin Expressway restored by October 1996
• Many businesses and industries moved away from the area
• Of the 269 high-rise commercial buildings in Kobe, 62 were demolished but there are only plans to rebuild 19 of them

When: 12th May 2008

Where: Province of Sichuan in Central China

Magnitude: 7.9 on the Richter Scale

Hazard:

• 15 million live close to the epicentre
• People of Sichuan were very vulnerable to the quake = poor construction of buildings, Zipingpu Dam = could have even caused the earthquake!

Physical Geography:

• Major fault located at the border of the Indo-Austrialiam and Eurasian Plates = directly below Sichuan
• Plate moved north-eastwards (approx. 5cm a year) pushed against the Eurasian Plate = increased pressure on fault line
• On May 12th the stresses in the crust triggered a sudden movement along a thrust fault releasing powerful tremors across the region

• Up to 90,000 dead
• 375,000 injured
• 5 million left homeless
• Estimated 5.4 million buildings collapsed
• Further 21 million buildings destroyed
• 7000 classrooms destroyed = killed 10,000 schoolchildren
• In Dujianqyan City fewer than 60 children survived when a school of 900 collapsed
• At least 700 killed by a landslide at Qingchuan
• Landslides created 34 temporary barrier lakes
• Rising water levels on the largest barrier lake threatened to breach the temporary earth dam so the authorities were forced to evacuared 250,000 people downstream to higher ground

• Swift and decisive
• Committed US$1.3 billion immediatly to strengthening 2600 schools that remained standing
• Priority given to building nearly 4 million new homes, creating 1 million new jobs and constructions to be high quality and earthquake proof
• Reconstruction plan = 169 new hospitals and 4500 primary schools
• 3 million homeless rural families = new houses
• 860,000 city apartments to be built
• Welfare programmes extended to help the 1.4 million people driven to poverty by the disaster

Aftermath:

• Total bill for reconstruction = US$150 billion
• Want Sichuan earthquake to be an earthquake-proof society
• Became evident that in China the rush for economic growth, safety had been ignored
• Man-made or natural hazard?

When: 12th January 2010

Where: Island of Haiti which is situated off the coast of North America

Magnitude: 7.0 on the Richter Scale

Hazard:

• Port-au-Prince = high pop. density with 86% in slum conditions with only 1/3 have access to tap water
• More than half of Haitians were living on less than a £1 a day
• Inadequate building regulations

Physical Geography:

• Movement along the bounday between Caribbean and North American plates = conservative fault = Enriquillo-Plantain Garden Fault
• Focus = only 10km beneath earth's surface
• Transform nature of fault = shallow and sedimentary rocks = more prone to shaking
• Over 40 aftershocks of 4.5 to 5.9 on the Richter Scale

• 3.5 million people affected
• Estimated that 222,570 people died and 300,572 injured
• 2.3 million people driven out of their homes
• Over 180,000 homes destroyed = 1.5 million people made homeless
• 19 million cubic metres of rubble and debris in Port-au-Prince
• 1.5 million people ended up living in camps = over 100,000 at critical risk from storms and flooding
• Over 1100 camps, 54 of which housed over 5000 people
• Over 600,000 left their homes in Port-au-Prince and moved within Haiti
• Nearly 4000 schools were damaged or destroyed
• 1/4 of all civil servant died
• Many people from government, emergency services and aid workers died
• Main prisons were damaged = many criminals escaped = increased crime

• Medical services and aid organisations were relatively prepared for cholera outbreak
• 3000 temporary schools set up
• Relied on international aid for support e.g. Oxfam
• Intially aid piled up at the airports due to a lack of transportation to get it about
• Aid was tough to get to Haiti = only had one runway and the port was badly damaged
• Severe shortage of doctors
• Rescue teams took 48 hours to get there due to airport issues
• Rubble still remains!

Aftermath:

• In Oct 2010 cholera was reported across Haiti - Jan 2011 the Health Ministry reported that - 194,00 people had been infected, 109,000 of those recieved hospital treatment, 3889 people died and between 12th and 16th Jan deaths averaged about 8 per day
• In first week of Nov 2010 Hurricane Tomas was headed for Haiti but it only hit the west of the island = only blamed for death of 8 people but it could be much higher death toll

When: 22nd Feb 2011, 12:51pm

Where: New Zealand's second largest city

Magnitude: 6.3 on Richter Scale

Physical Geography:

• Aftershock of the 4th September 2010 which caused a surface rupture of up to 5m on previously unrecognised Greendale Fault
• Region of continental convergence across the Pacific/ Australian plate boundary
• Close and shallow earthquake = the fault was directed straight at Christchurch's CBD

• 185 deaths
• Parts of the CBD were cordoned off because of damage structure
• Estimated that 800 buildings in the CBD had to be demolished
• Also estimated that 10,000 out of 140,000 domestic dwellings in the city will also be demolished
• Extensive liquifaction and lateral spreading
• 200,000 tonnes of ejected silt were removed quickly from the city
• Costs were immediatly estimated as NZ$15-20 billion but probably more likely to be NZ$40 billion
• Christchurch contributes 15% of New Zealand's GDP = significant effects on the nations economy
• Over half of deaths that occured were in the six storey Canterbury Television building

• Estimated that it may take New Zealand 50-100 years to fully recover from this disaster
• China gave US$500,000 to the earthquake appeal
• Numerous music concerts were held across the world to raise money for the earthquake clear-up
• Approximately 450 fully serviced mobile homes would be located on sites across the city
• Canterbury University partially reopened on 14 March, with many lectures held in tents and marquees
• 163 primary and secondary schools were affected by the earthquake, most of which were closed for three weeks; 90 had full structural clearance and were able to reopen, 24 had reports indicating further assessment and 11 were seriously damaged

When: 26th January 2004

Where: Countries that felt the impact the greatest were India, Indonesia and Malaysia but the wave reached as far as Kenya and South Africa

Magnitude: Underwater earthquakes reached 8.9 on the Richter Scale and waves reached over 25m

Physical Geography:

• Indo-Austrialian plate was subducting beneath the Eurasian plate = slippage around 25km below India Ocean
• Section of the seabed was caused to rise by several metres = displaced the ocean and caused a series of tall and fast waves = a tsunami

• There was no established tsunami warning system
• Over 300,000 people killed (Sumatra = over 130,000 killed and 30,000 missing)
• 8 people in South Africa = over 8000km from the epicentre
• Tens of thousands were injured by the force of the wave and the debris it carried
• Hundreds of the dead and injured were Europeans (Christmas hols)
• In Northern Sumara estimated that over 1500 villages were destroyed
• Millions left homeless (over 500,000 in Sumatra)
• Massive damage to tourist infrastruture
• Widespread damage to coastal communities
• In Sri Lanka a train was derailed = 1000 dead
• Thousands could not feed themselves = coastal agriculture and fishing affected
• Many hosptials and clinics swept away

• Bodies buried in mass graves to prevent the spreading of disease
• Over US$7 billion provided by governments and NGOs in aid
• Up to 5 million people moved to refugee camps = shelter, water and food
• Took months just to clear the debris
• People from refugee camps moved straight to new homes but the building of these homes took much longer than expected

Aftermath:

• Diseases broke out in refugee camps = 150,000 killed
• Land disputes broke out as documents were lost in the devastation - some land even destroyed  by erosion
• Tsunami early warning system installed at a cost of US$20 million

When: 11th March 2011, 2.46pm

Where: Northern Japan

Magnitude: Measured 9.0 on Richter Scale with highest wave of 15m

Hazard:

• Off Sendai = old oceanic crust = people thought only small earthquake would occur
• Warping of Pacific Plate = doesn't move smoothly
• Ria coastline = concentrates waves in bays - focuses energy on the land
• 70% of Jaoan = mountaneous = forces development onto low-level land = soft reclaimed land

Physical Geography:

• Pacific Plate being subducted beneath Okhotsk Plate
• Seismic waves travelled along 500km interlocking fault system = 3 earthquakes consecutively
• Horizontal displacement of sea = seabed rose by 16m
• Groundshaking lasted for 6 mins, within 20 mins = tsunami
• 5 weeks after = 420 aftershocks over 5.0

• Fukushima Nuclear Explosion - shut down by earthquake but sea wall only protected from 7.5m tsunamis and fuel rods had not cooled down enough when the tsunami arrived
• Some tsunami shelters in the region were flooded
• Giant breakwaters protecting major cities were destroyed
• Final death toll = 20,000 with 3000 never accounted for = most deadliest of last 100 years
• Worst hit city = Ishinomaki
• Otsuchi lost 10% of its population
• 65% of victims aged over 60
• Panasonic had a total $9 billion losses and 17,000 jobs were lost
• 13,000 - 18,000 buildings destroyed completely by the earthquake, further 100,000 - 105,000 by tsnumai and 35,000 made inhabitable by nuclear explosion
• 80,000 (12-mile radius) had to be evacuated by nuclear explosion
• Landslides triggered

• Drills and education saved lives - 3000 children got to high ground before official warnings
• 90 second warning in Tokyo
• Recovery system established in April 2011 - safety, sustainability and compassion
• Reconstruction Agency established in Feb 2012
• Over a year later 330,000 people stil in temporary accomodation - 500 in evaucation centres
• Local governments given $25 billion for reconstruction
• Elevated land-based islands = solution for tsunami prone communities (£160 million per island)
• Plans for first indoor marina
• Only 5% of wreckage diposed of and 72% still on temporary sites
• All 54 Nuclear plants closed for routine checks = 30% of Japan's energy = $30 million to import

Aftermath:

• Some companies were recovered to pre-quake levels in 6 months (resilance of economy)
• Concerns about radiation in food chain
• Massive and sudden changes to coastal eco-systems - fishing and farming
• Population trend of decline likely to continue