Tohoku Earthquake

• In Fukushima, central Japan

  1. 2:46 pm on the 11th March 2011
• 2 days before, major tremors were felt, at 7.2 on the richter scale
• Epicentre


  • 24 km deep, 72 km off the coast of Sendai where the Pacific plate is being subducted under the Okhotsk plate
• Seismic waves travelled along the 500 km fault line where 3 earthquakes occurred consecutively
• 5 weeks after, there were 420 aftershocks greater than a magnitude of 5
• Only smaller earthquakes were expected due to old oceanic crust being cooler and denser
• Strain quickly builds up due to the warping of the Pacific plate
• Japan


  • 70% is mountainous so urban areas are forced into narrow, low-lying coastal areas
• Soft reclaimed land is susceptible to ground shaking
• Seabed is a highly seismologically active area
• The first warning was issued only 3 minutes after the earthquake
• Within 45 minutes, the 800 km East coastline was prepared for a 10 m high tsunami
• The highest wave height was 15 m and reached the coastline within 30-40 minutes
• Tsunami


  • Caused erosion of beaches and dunes, destroyed all man-made structures, and destroyed 95% of all vegetation
• Transported sediment up to 5 km inland and the load was deposited in fields and forests
• Fukushima nuclear power station

  Supplied 6% of the company's energy
• 3/6 reactors shut down in response to the earthquake
• The cooling system failed, causing pressure to rise until there was an explosion and hydrogen was released
• Radioactive substances escaped and fires developed
• 80,000 people had to be evacuated within a 12 mile radius
• Radiation had contaminated cows, soils, crops and seafood
• Rice exports had been banned
• Final death toll around 20,000 making it the 20th deadliest earthquake and tsunami
• 65% of victims were aged over 60 years old
• 300,000 buildings were destroyed, 4000 roads, 78 bridges, 29 railways costing $300 billion, making it the word costliest disaster
• Within 10 days, 452,000 people were living in evacuation facilities suffering from hypothermia
• 11 elderly died in temperatures of -4 degrees
• Cases of diarrhoea and vomiting spread due to the lack of medication
• Most people had lost their credit cards and queues for food were 2-3 hours long
• People scavenged for food despite the health risks
• Resettlement of thousands of people

  1. Relocate onto higher ground

  2. Integrated land use regulations for building on low-lying land

  3. Coastal levees

  4. Restore community life and livelihood

  5. Provide community care facilities

  6. Ensure education

  7. Emergency employment

  8. Recovery of agriculture, forestry and fisheries

  9. Improved energy efficiency
• The government was given $25 billion for reconstruction
• Elevated land-based islands have been designed to form town in the tsunami-affected region
• Each would have a particular function with most being residential
• There would be fuel stations, waste disposal and car parks at lower levels
• Other islands would have food processing and agriculture and the central islands would house schools, health centres, offices and leisure
• No technology can protect against a tsunami or earthquake, and even the wealthiest governments cannot cope
• The Japanese refused most external aid due to the pride of their country