However, there has been no detectable effect at the Fukushima Daiichi nuclear plant damaged in last month's quake and tsunami, nor at two other nuclear plants in the area, officials say.
The Japanese authorities have ordered an evacuation from the warning zone.
Fukushima workers were also evacuated.
The tsunami was predicted to have a wave 2m (6ft) high.
Thursday's quake was 118km (78 miles) north of Fukushima, 40km offshore. It was initially reported to have a magnitude of 7.4 but has now been revised downwards to 7.1, according to the US Geological Survey.
The quake was strong enough to shake buildings in Tokyo, 265km to the south.
Japan's meteorological agency issued tsunami warnings and advisories for a stretch of coast 420km long, from Aomori prefecture in the north to Ibaraki prefecture in central Japan, just north of Tokyo.
Hundreds of aftershocks have shaken north-eastern Japan in the wake of the earthquake on 11 March, but few have measured higher than 7.0.
About 28,000 people are dead or missing, and hundreds of thousands were left homeless after the tsunami which ripped through Miyagi prefecture.
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