2011 11 March 14:46 JST (Japan Standard Time) A magnitude 9.0 earthquake in the north-western Pacific Ocean strikes the north-eastern coast of Japan’s main island, Honshu. The Great East Japan Earthquake moves Honshu 2.4 m eastward and shifts the earth on its axis by between 10 and 25 cm.
The quake’s epicentre is 130 km from Sendai in the Tōhoku region and 373 km north-east of Tokyo. The Pacific Tsunami Warning Center issues more than 50 tsunami warnings for the Pacific Ocean from Japan to the west coast of the US.
15:26 JST (approx.) A major tsunami hits the Pacific coastline of Japan’s northern islands, inundating approximately 561 square km in 42 municipalities across four prefectures. Waves up to 10 m high sped out from the epicentre at about 700 kph, travelling up to 10 km inland in the Sendai area. About 90 per cent of the coastal seawalls are destroyed.
An estimated 18 000 Honshu residents are swept away and thousands of people are later recorded missing in the Tōhoku region. Tsunami waves eventually reach Alaska, Hawaii, Chile, Norway and Antarctica. About five million tons of debris is swept offshore.
20:15 JST The Japanese government declares a nuclear emergency at the nuclear power plants in the Tōhoku region. More than 60 000 Sendai residents evacuate to shelters.
12 March Aftershocks continue. Three reactors at the Fukushima Daiichi nuclear power plant experience complete meltdowns and four reactors suffer hydrogen explosions.
13 March Residents within 10 km of the Fukushima Daini and 20 km of the Fukushima Daiichi nuclear power plants are evacuated. Total evacuation reaches about 185000 as fears of radioactive leakage mount.
Prime Minister Naoto Kan sets up an emergency command centre in Tokyo. The Defense Ministry announces the deployment of 50 000 Japan Self-Defense Forces personnel, 190 aircraft and 25 ships to assist the rescue effort.
14 –15 March Almost 10 000 of Minamisanriku’s population of 17 000 are missing or presumed dead. The death toll in Miyagi Prefecture is expected to exceed 10 000.
Tsunami waves destroy back-up systems at the Fukushima Daiichi and Daini nuclear power plants. Three of the 10 reactors at Fukushima experience partial meltdowns and four suffer hydrogen explosions.
The Japanese government receives offers of assistance from more than 90 countries. Australia, New Zealand, South Korea and the US are major contributors to the rescue effort.
22 March The official death toll exceeds 10 000. About 250 000 people remain in emergency shelters in the Tōhoku region. The twin disasters create an estimated 24 025 million tons of rubble and debris.
April A magnitude 7.1 earthquake occurs off the coast of Miyagi Prefecture and a magnitude 6.3 earthquake is recorded in Fukushima Prefecture.
The severity level of the nuclear emergency at the Fukushima Daiichi facility is elevated to 7 – the highest level on the International Nuclear Event Scale. About 45 700 buildings have been destroyed and 144 300 are damaged by the disasters.
The estimated cost of the earthquake and tsunami is between $122 billion and $305 billion. Japan’s National Police Agency records 15 560 deaths with 5 689 injured and 5 329 people still missing.
2012 More than 5 000 aftershocks have now been recorded in Japan. Death toll reaches more than 15 850 people with 3 287 people listed as missing.
2013 More than 300 000 displaced residents remain in prefabricated temporary housing units in Sendai and other tsunami-damaged locations.
2014 An estimated 100 metric tons of radioactive water leaks from a holding tank at the Fukushima Daiichi nuclear power plant. Reconstruction continues along the Tōhoku coast.
2015 Over 340 000 people remain displaced. Most of the disaster debris has been removed. The Japanese government approves plans to build about 440 super seawalls up to 17 m in height along the north-east coastline in Fukushima, Miyagi and Iwate prefectures at a cost of over $10 billion. The government’s goal is to fortify 14 000 km of Japan’s 35 000 km coastline. Nationwide concern grows over the environmental and economic impact of seawall construction and the false sense of security it creates in residents.
2016 Japan’s Fire and Disaster Management Agency confirms an earthquake and tsunami death and missing toll of 22 000, with 2 000 deaths from post-disaster health conditions. An estimated 50 000 people remain in temporary accommodation with a relatively small percentage of town reconstruction completed in affected areas. 160 000 people fled radiation in Fukushima and almost 100 000 are yet to return to their homes.
Nationwide controversy continues around the construction of seawalls as national memorial ceremonies mark the fifth anniversary of the Great East Japan Earthquake and tsunami.