The 7.3-magnitude quake was felt strongly in Tokyo, but a tsunami warning has not been issued.
There are reports of about 50 people injured, officials say, and almost one million homes are without power.
The quake struck near the epicentre of a 2011 earthquake which triggered a tsunami and killed over 18,000 people.
That tsunami caused a nuclear accident at the Fukushima Daiichi Nuclear Power Plant - the world's most severe nuclear accident since the Chernobyl disaster in 1986.