There have been no reports of deaths, injuries or serious damage, and all tsunami warnings were cancelled at 19:20 local time (10:20 GMT), broadcaster NHK said Hong Kong weather
Warnings of the tsunami height had varied between 50cm and 2m.
The BBC’s Rupert Wingfield-Hayes in Tokyo says any such height would represent a far lower risk of devastation than the tsunami of up to 11 metres that struck in 2011 but that, since then, the country has clearly become jittery about any shaking of the earth.
The tsunami warnings had extended from the top of the main island of Honshu down towards Tokyo and evacuations were ordered from some of the affected areas 27
With Japan’s early warning system, NHK was able to break off its regular programming and issue an alert about the earthquake shortly before it struck.
A presenter on state broadcaster NHK then told viewers: “Remember last year’s quake and tsunami. Call on your neighbours and flee to higher ground now!”