The was a magnitude 9.0 (M_w) undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST (05:46 UTC) on Friday 11 March 2011, with the epicentre approximately east of the Oshika Peninsula of Tohoku and the hypocenter at an underwater depth of approximately . The earthquake is also often referred to in Japan as the and also known as the 2011 Tohoku earthquake, and the 3.11 earthquake. It was the most powerful earthquake ever recorded to have hit Japan, and the fourth most powerful earthquake in the world since modern record-keeping began in 1900. The earthquake triggered powerful tsunami waves that reached heights of up to in Miyako in Tohoku's Iwate Prefecture, and which, in the Sendai area, travelled up to inland. The earthquake moved Honshu (the main island of Japan) east, shifted the Earth on its axis by estimates of between and , and generated sound waves detected by the low-orbiting GOCE satellite.