Japanese TV showed cars, ships and buildings swept away by a vast wall of water after the 8.9-magnitude quake.
A state of emergency has been declared at a nuclear power plant but officials said there were no radiation leaks.
At least 60 people have been killed by the quake, which struck about 400km (250 miles) north-east of Tokyo.
The region has been rocked by a number of powerful aftershocks.
Read More: @ bbc.co.uk
You might also like: