Tectonics case studies

2010 Haiti Earthquake

7 Magnitude 

Followed pressure released on a strike slip margin (transform margin) creating a rupture of around 70km and a displacement of 1.5m

The epicentre was close to large populations, 25km from the capital, and the focus shallow 14km 

Violent ground shaking for around 30 seconds and ground fissures

Food sanitation act prevented sale of produce from contaminated farmland and marine ecosystems. South Korea placed a ban on all shellfish imports forcing state subsidies for local businesses 

Toyota had to evacuate 2 factories and their plant in Derby had to close for 5 weeks as vital components could not be imported from Japan

2011 Sendai Earthquake

 9 magnitude 

Deep focus tsunami based event

Destructive margin 

Epicentre  - 25km from the coast 

Sea floor earthquake near Japan was a big mega thrust event at a subduction zone creating a rupture 300km long and dispacement of up to 80m.

By the time seismic waves reached the coast a lot of energy had been absorbed, the displacement however generated a major tsunami with waves reaching up to 10m as they reached the continental shelf

Inability of the local government to cope and increasing violence and social unrest meant the US military had to take temporary control of the rescue plan. Locals formed their own vigilante groups to protect supplies from looters

Urgent need for outside rescuers to communicate with the Haitians whose main language is Creole. A translation programme had to be quickly written

Damage to telecommunications and hospitals retricted the aid and rescue efforts. Seriously injured people died from wounds due to lack of medical intervention and clean water

Haiti is the poorest country in the western hemisphere and didnt have an earthquake preparedness strategy

Seismologists had warned in 2008 that stresses had been building up for 250 years, The results of their report were printed in the national press, however the Haitian government failed to respond

A hazard zoning map for Port au Prince and its surrounding areas would have identified local geology where liquefaction was at more risk

The weak corrupt government means already limited building regulations were rarely obeyed

Collapsing buildings (due to weak planning regulations and liquefaction)

Destroyed 80% of Haiti's capital Port au Prince which is home to 2 million, killing 250,000 and leaving 1.5million homeless 

Infrastructure was also hit; damage to the airport and main road slowed down vital supplies needed in the relief effort causing food and water shortages and a lack of shelter in IDP camps. 50% of buildings collapsed, including key government buildings such and as the police headquaters and parliament 

8 major hospitals and Red Cross facilities were destroyed, killing a lot of staff in the process. This restricted much needed medical attention, contributing to the high death toll, and left many people untreated; including severe burns victims from fires that spread due to broken gas pipes

Escaping criminals from damaged prisons contributed to social disorder as the remaining police lost control, and claims of looting, vigilante squads executing the looters and mugging of the most vulnerable were reported 

Damage to marine and shoreline ecosystems occured; including significant deforestation

Size of displacement caused eastern side to sink by 2m, releasing debris into the Pacific Ocean. Inundation wiped out habitats, drowing over 1000 albatrosses and damaging forests 

A year later 1500 people had died from cholera in the IDP camps and 1.5 million people were still homeless

Many people left the city to look for relief in the countryside. This put pressure on already poverty sticken rural villages.

Some crossed into the Dominican Republic to get medical help with the strained resources there

Lateral spreading resulted in the ground slumping or falling away

The landscape was permanently changed - corals were pushed upwards to the north of the fault line whilst farmland collapsed into the sea in the south

Possibly a trigger for a sequence of much larger earthquakes

Strong aftershocks including a 6.1 magnitude earthquake on the 20th January

Experienced the economic strain of reconstruction costs, leaving Haiti almost entirely dependent on foregin aid

Local food prices at markets became to expensive for the majority of people

The meltdown of Fukushima nuclear plant, caused by flooding from the tsunami has displaced 500,000 people, some of these still cant return to their homes due to contaminted land.

Furthermore long term health effects on those exposed to radiation is largely unknown, cases of stomach illness, depression and alcholism have been reported

4.4 million households left without electricity and 1.5 million left without water

Sendai and other Japanese cities were protected from ground shaking due to strict building regulations - 230/18,000 deaths

However despite massive investment in tsunami defences Japan was not prepared for an event of this magnitude and waves inudated as far as 10km inland, causing 95% of the 18,000 deaths

In Minami, a coastal village close to the epicentre, half of the population was killed and few buildings survived as blue line zone was inadequate 

In the wider region 1 million people were left without water, roads and port facilities were destroyed. 700 aftershocks in 2 weeks induced extreme anxiety for many

Shearing damaged roads and infrastructure, fire at Sendai airport and collapse of Fujinuma dam

However in Japan protection was already in place; seismically designed buildings meant there was limited damage to cities, and the tsunami defence systems like Blue Line and Walls saved lives in the majority of the country, but not in Minami were half the population was killed due to inadequate Blue Line zones

Computer controlled bullet trains automatically shut down therefore no lives were lost on trains

Although Fukushima went into meltdown, elsehwere in the region 11 nuclear reactors automatically shut down - a feature of earthquake resistant design

Retrofitting was out into place, a reactive response in Japan following Kobe 1995. This includes fixing book cases to walls, bolting houses on to foundations and replacing heavy chimneys with alluminium tubes.

Comprehensive community preparedness in Japan: 1st September every years is Disaster Prevention day - Practice emergency routines in case of an earthquake or another natural disaster

Whereas in Japan, immediate live TV coverage of the disaster area and infomation including names of areas affected and details of intensity in each were flashed on TV screens, making people aware of the situation

Text messages automatically sent out after primary waves are detected. A well-coordinated response including evacuation zones in cities and blue line zones in coastal areas limited the number of people injured or killed

The UN donated $2 million to supporting the damaged textiles industry.

One positive is that construction projects have created local employment, which now use building codes and inspectors to enforce them

This will be helpful as geologists think another earthquake will hit the region and they believe it will be a high magnitude like the last one

A single fund is now in place of $11.5 billion for a longer term reconstruction with controls to prevent corruption

$175 billion of government money was allocated to rebuilding towns and villages

New Sendai disaster plan includes making hills from the rubble and planting coastal forests to break the force of tsunami waves

The governement  has redefined and 'active fault' from activity in the last 50,000 years to the last 40,000, therefore extending areas on a hazard risk map

Also become dependent on foreign aid, including £14 million from the UK

In Fukushima city, the Red Cross is funding Smile Park; an indoor playground for children who have been unable to play outside due to fears over radiation