A powerful 7.2-magnitude earthquake struck off Japan's northern coast on Thursday, although authorities quickly confirmed there was no risk of a tsunami.
The Japan Meteorological Agency initially reported a tremor of magnitude 6.9 before upgrading it to 7.2, locating its epicentre off the eastern coast of Iwate prefecture at a depth of about 50km. The US Geological Survey also recorded a 6.9 magnitude.
