The 2011 earthquake off the Pacific coast of Tohoku, also known as the 2011 Tōhoku earthquake, or the Great East Japan Earthquake, (Japanese: "Eastern Japan Great Earthquake Disaster" (Higashi Nihon Daishinsai)) was a magnitude 9.0 (Mw) undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST (05:46 UTC) on Friday, 11 March 2011, with the epicenter approximately 70 kilometres (43 mi) east of the Oshika Peninsula of Tōhoku and the hypocenter at an underwater depth of approximately 32 km (20 mi). It was 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. It was so powerful the island of Honshu was moved 8 feet eastward. The earthquake triggered extremely destructive tsunami waves of up to 40.5 metres (133 ft) in Miyako, Iwate, Tōhoku. In some cases traveling up to 10 km (6 mi) inland. In addition to loss of life and destruction of infrastructure, the tsunami caused a number of nuclear accidents, primarily the ongoing level 7 meltdowns at three reactors in the Fukushima I Nuclear Power Plant complex, and the associated evacuation zones affecting hundreds of thousands of residents.