Factors that contributed to the vunerability:
Off Sendai there is a very old oceanic crust which is cooler and denser, it was assumed that the crust would easily slide into the mantle so only small earthquakes are predicted.
Warping of the pacific plate means that it gets stuck rather than sliding smoothly into the mantle causing pressure build up.
Rugged Ria coastline, many inlets caused tsunami waves to be concentrated, causing waves to encroach further.
70% of Japan is mountainous, making settlements cramped into narrow low lying coastal areas.
Much of japans land is reclaimed which is very susceptible to liquefaction or ground shaking potentially causing landslides
Government officials admitted that officials were too complacent & believed in technical infallibility.
Effects of the Earthquake:
Primary effects:
Magnitude quake of 9 that lasted for 3-6 minutes.
This caused lots of ground shaking that triggered lots of secondary effects
Secondary effects:
Physical:
An 10-meter tsunami was seen at the port in Sendai, near the epicenter.
Japan’s east coast was moved up 4meters out into the Pacific Ocean, some areas sunk by more than a meter.
Ground shaking caused buildings to collapse; some caught fire due to gas pipes bursting.
The tsunami swept inland, mainly along the north-east coast swallowing boats homes vehicles trees and anything else.
50sq kilometres of land were flooded.
When water receded trains, had vanished, ships and cars were tossed everywhere.
Tokyo’s earthquake proof skyscrapers were swaying lots however damage was limited.
An oil refinery exploded in the town of Ichihara, a commuter town of Tokyo.
In Sendai the areas nearest to the focus, areas near the sea were very badly damaged, but inland near the city was largely undamaged.
In Mionami-Sanriku only half the population of 17000 escaped alive and nearly all buildings were destroyed.
Over 25,000 dead or missing due to the tsunami however many more would have perished if the early warning system hadn’t been in place.
Aftershocks continued for two weeks terrifying people, there were 700+ recorded. A tsunami measured at anywhere from one meter to 7.3 meters hit at various places along the coast
Aftershocks were continuing, with one hitting magnitude 7.1, according to the USGS. Tall buildings swayed violently in central Tokyo as the aftershocks hit.
Other effects:
Half a million people were made homeless for weeks, 150,000 people lived in temporary shelters.
At least 1 million homes did not have running water, 6 million homes did not have electricity & cars queued for rationed petrol.
There were shortages for food, water & medical supplies.
Hydrogen explosion and the melt down of two nuclear reactors in Fukushima nuclear powerplant caused wide spread panic and evacuation due to the spread of nuclear material. They melted down due to the tsunami breaking over the 8meter high barrier and engulfing the backup generators which cooled the rods.
Panic selling occurred in global markets due to the panic of a nuclear disaster
Responses:
Immediate responses:
A Tsunami warning was issued 3 minutes after the earthquake.
Rescue workers searched the decimated coastline of submerged homes for survivors.
Helicopters plucked survivors from wreckage or rooftops.
100,000 soldiers were mobilised to establish order, distribute bottled water, food and petrol .
Offers of aid came in from lots of different countries including the USA and China.
The UK sent 63 fire service search and rescue specialists, two rescue dogs and a medical support team. People were rescued after being trapped for several days.
An exclusion zone was set up was set up around the Fukushima nuclear plant. Homes were evacuated and iodine tablets which prevent radiation sickness were distributed.
There were no cases of looting or violence.
Social networking such as Twitter were bringing updates on the situation far earlier than the media, showing how modern technology can be used in disaster situations.
Long term responses:
Japan has the world’s highest debt and the cost of the repair will force the government to borrow more still.
Private companies faced hardship due to businesses being destroyed, however Japan is a developed MEDC and will recover over time.
Japan’s previously thought infallible tsunami defences will be reviewed and rebuilt stronger so that if another tsunami occurred of the same scale the area would be better protected.
Now what are the developments in 2012?
Japan still has a quarantine zone around the Fukushima plant where radiation levels are high.
Caesium levels in fish stocks off the coast for Japan are still high, this may be a long lasting effect on the environment that could cause damage to the food chain or decreased biodiversity.
Fears of more nuclear disasters such as Japan may occur in Europe for example In Germany, Europe's largest economy and power market, seven nuclear power plants have been closed .