2011 Tōhoku earthquake and tsunami

The 2011 Tōhoku earthquake and tsunami Tōhoku Chihō Taiheiyō-oki Jishin literally "Tōhoku region Pacific Ocean offshore earthquake"was a 9.0-magnitude undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST (05:46 UTC) on Friday 11 March 2011.The epicenter was approximately 72 kilometers (45 mi) east of the Oshika Peninsula of Tōhoku, with the hypocenter at an underwater depth of approximately 32 km (19.9 mi).

The earthquake triggered extremely destructive tsunami waves of up to 10 meters (33 ft) that struck Japan minutes after the quake, in some cases traveling up to 10 km (6 mi) inland,with smaller waves reaching many other countries after several hours. Tsunami warnings were issued and evacuations ordered along Japan's Pacific coast and at least 20 other countries, including the entire Pacific coast of North America and South America.

The Japanese National Police Agency has officially confirmed 9,523 deaths,2,755 injured,and 16,094 people missing across eighteen prefectures, as well as over 125,000 buildings damaged or destroyed.The earthquake and tsunami caused extensive and severe structural damage in Japan, including heavy damage to roads and railways as well as fires in many areas, and a dam collapse.Around 4.4 million households in northeastern Japan were left without electricity and 1.5 million without water.Many electrical generators were taken down, and at least three nuclear reactors suffered explosions due to hydrogen gas that had built up within their outer containment buildings. On 18 March, the International Atomic Energy Agency described the crisis as "extremely serious."Residents within a 20 km (12 mi) radius of the Fukushima I Nuclear Power Plant and a 10 km (6 mi) radius of the Fukushima II Nuclear Power Plant were evacuated.

Estimates of the Tōhoku earthquake's magnitude make it the most powerful known earthquake to have hit Japan, and one of the five most powerful earthquakes in the world overall since modern record-keeping began in 1900.Japanese Prime Minister Naoto Kan said, "In the 65 years after the end of World War II, this is the toughest and the most difficult crisis for Japan."The earthquake moved Honshu 2.4 m (7.9 ft) east and shifted the Earth on its axis by almost 10 cm (3.9 in).Early estimates placed insured losses from the earthquake alone at US$14.5 to $34.6 billion.The Bank of Japan offered ¥15 trillion (US$183 billion) to the banking system on 14 March in an effort to normalize market conditions.On 21 March, the World Bank estimated damage between US$122 billion and $235 billion.Japan's government said the cost of the earthquake and tsunami that devastated the northeast could reach $309 billion, making it the world's most expensive natural disaster on record.