Tectonic event in an HIC: Japan earthquake

• Causes / Background information

  • Friday 11 March 2011 (14.46 Japanese time)
  • Magnitude 9 on Richter scale
  • Caused by thrust along subduction zone between the Pacific and North American plates
  • Shallow Epicentre (30km) 129km east of Sendai
• Ground shaking during the 2011 Tōhoku earthquake shifted parts of Japan 2.4 metres further east.
• Ground subsidence during the 2011 Tōhoku earthquake caused a 400 km stretch of coastline to drop vertically by 0.6 metres, allowing the tsunami to overtop defences and travel further and faster inland.
• Soil liquefaction occurred in areas of reclaimed land around Tokyo, damaging more than a thousand buildings.
• Around 4.4 million households in north-eastern Japan were left without electricity and 1.5 million without water after the 2011 Tōhoku earthquake.
• The 2011 Tōhoku earthquake resulted in 15,845 deaths, 3,375 missing persons, 5,894 injuries, 128,479 totally destroyed properties, 3,918 roads damaged, and 78 bridges damaged.
• Tsunami: It reached a maximum height of 39 metres at Miyako city and travelled up to 10 km inland.
• Flooding: there was massive coastal flooding.
• Shipping was disrupted due to closure and destruction of ports.
• Commuting and travel was affected due to damage to transport links.
• The main Tohoku Expressway was closed until 24 March.
• Agriculture in the Tohoku region was devastated.
• It accounts for 3–4% of Japan’s rice production, and seawater contamination of the soil could affect rice crops for years.
• Nuclear power plants were damaged.
• In the Fukushima region over 200,000 residents were evacuated and are still unable to return to the area.
• The economic impact: The Japanese government estimated that the damage alone could cost US$300 billion, and Japan’s gross domestic product (GDP) shrank by 3.7% between January and March 2011.
• Within 30 minutes of the earthquake, 11 military aircraft had responded and identified communities such as Hakozaki as being completely cut off.
• The Japanese army moved in on the ground and within two days all debris had been cleared and emergency goods could be delivered twice a day.
• Due to the destruction of homes, an estimated 452,000 people were in evacuation shelters within days of the disaster.
• A 20 km evacuation zone around the Fukushima plant was declared to reduce the threat of radiation exposure to local residents.
• 91 countries offered aid, from blankets and food to search dogs and military transport.
• The priority for Japan’s long-term response is to rebuild the infrastructure.
• About half – 347 km out of 675 km – of the Tohoku Expressway which links the region to Tokyo was damaged.
• By 24 March this had been repaired and re-opened.
• As of November 2011, 96% of the electricity supply had been restored, 98% of the water supply and 99% of the landline network.
• The Japanese government set up an expert advisory body called the Reconstruction Design Council to plan a long-term strategy.
• In order to fund this grand strategy the Japanese government has approved a budget of 23 trillion yen (approximately £190 billion) to be spent over a period of 10 years.