2011 Tōhoku earthquake and tsunami in the context of "Fukushima nuclear accident"

The Japan Trench is an oceanic trench part of the Pacific Ring of Fire off northeast Japan. It extends from the Kuril Islands to the northern end of the Izu Islands, and is 8,046 metres (26,398 ft) at its deepest. It links the Kuril–Kamchatka Trench to the north and the Izu–Ogasawara Trench to its south with a length of 800 kilometres (497 mi). This trench is created as the oceanic Pacific plate subducts beneath the continental Okhotsk microplate (a microplate formerly a part of the North American plate). The subduction process causes bending of the down going plate, creating a deep trench. Continuing movement on the subduction zone associated with the Japan Trench is one of the main causes of tsunamis and earthquakes in northern Japan, including the megathrust Tōhoku earthquake and resulting tsunami that occurred on 11 March 2011. The rate of subduction associated with the Japan Trench has been recorded at about 7.9–9.2 centimetres (3.1–3.6 in)/yr.

Sendai (仙台市, Sendai-shi; [seꜜn.dai, sen.daꜜi.ɕi] ) is the capital city of Miyagi Prefecture and the largest city in the Tōhoku region. As of 1 August 2023, the city had a population of 1,098,335 in 539,698 households, making it the twelfth most populated city in Japan.

The modern city was founded in 1600 by the daimyō Date Masamune. It is nicknamed the City of Trees (杜の都, Mori no Miyako); there are Japanese zelkova trees lining many of the main thoroughfares such as Jōzenji Street (定禅寺通, Jōzenji dōri) and Aoba Street (青葉通, Aoba dōri).In the summer, the Sendai Tanabata Festival, the largest Tanabata festival in Japan, is held. In winter, the trees are decorated with thousands of lights for the Pageant of Starlight (光のページェント, Hikari no pējento), lasting through most of December. The city is also home to Tohoku University, one of the former Imperial Universities. On 11 March 2011, coastal areas of the city suffered catastrophic damage from a magnitude 9.0 offshore earthquake, which triggered a destructive tsunami.

The Kyushu Shinkansen (九州新幹線, Kyūshū Shinkansen) is a Japanese Shinkansen high-speed railway network. It is an extension of the San'yō Shinkansen from Honshu connecting the city of Fukuoka (Hakata Station) in the north of Japan's Kyushu Island to the city of Kagoshima (Kagoshima-Chuo Station) in the south. The line runs parallel to the existing Kagoshima Main Line and is operated by Kyushu Railway Company (JR Kyushu).

The southernmost 127 km (79 mi) section of the track was constructed first, opening on 13 March 2004. The dual-track offered a significant improvement in transit time over the equivalent single-track section of the Kagoshima Main Line, despite the need for passengers to change to a Relay Tsubame narrow gauge train at Shin-Yatsushiro, and the remainder of the journey to Hakata Station. The northernmost 130 km (81 mi) section opened on 12 March 2011, enabling through-services to Shin-Osaka (and with an interchange, to Tokyo). However, opening ceremonies were cancelled due to the 2011 Tōhoku earthquake and tsunami.

The Fukushima Daiichi Nuclear Power Plant (福島第一原子力発電所, Fukushima Daiichi Genshiryoku Hatsudensho; Fukushima number 1 nuclear power plant) is a disabled nuclear power plant located on a 350-hectare (860-acre) site in the towns of Ōkuma and Futaba in Fukushima Prefecture, Japan. The plant suffered major damage from the magnitude 9.1 earthquake and tsunami that hit Japan on March 11, 2011. The chain of events caused radiation leaks and permanently damaged several of its reactors, making them impossible to restart. The working reactors were not restarted after the events.

First commissioned in 1971, the plant consists of six boiling water reactors. These light water reactors drove electrical generators with a combined power of 4.7 GWe, making Fukushima Daiichi one of the 15 largest nuclear power stations in the world. Fukushima was the first nuclear plant to be designed, constructed, and run in conjunction with General Electric and Tokyo Electric Power Company (TEPCO). The sister nuclear plant Fukushima Daini ("number two"), 12 kilometres (7.5 mi) to the south, is also run by TEPCO. It also suffered serious damage during the tsunami, at the seawater intakes of all four units, but was successfully shut down and brought to a safe state. See the timeline of the Fukushima II nuclear accidents.

Matsushima (松島) is a group of islands in Miyagi Prefecture, Japan. There are some 260 tiny islands (shima) covered in pines (matsu) – hence the name – and it is considered to be one of the Three Views of Japan.

Nearby cultural properties include Zuigan-ji, Entsū-in, Kanrantei, and the Satohama shell mound.

On 11 March 2011, a major nuclear accident started at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The direct cause was the Tōhoku earthquake and tsunami, which resulted in electrical grid failure and damaged nearly all of the power plant's backup energy sources. The subsequent inability to sufficiently cool reactors after shutdown compromised containment and resulted in the release of radioactive contaminants into the surrounding environment. The accident was rated seven (the maximum severity) on the International Nuclear Event Scale by Nuclear and Industrial Safety Agency, following a report by the JNES (Japan Nuclear Energy Safety Organization). It is regarded as the worst nuclear incident since the Chernobyl disaster in 1986, which is the only other incident rated seven on the International Nuclear Event Scale.

According to the United Nations Scientific Committee on the Effects of Atomic Radiation, "no adverse health effects among Fukushima residents have been documented that are directly attributable to radiation exposure from the Fukushima Daiichi nuclear plant accident". Insurance compensation was paid for one death from lung cancer, but this does not prove a causal relationship between radiation and the cancer. Six other persons have been reported as having developed cancer or leukemia. Two workers were hospitalized because of radiation burns, and several other people sustained physical injuries as a consequence of the accident.