A tsunami warning is extended across the Pacific to include the Philippines, Indonesia, Taiwan, Hawaii, the Pacific coast of Russia and North and South America.
A number of international cruise ships are sailing in the region but it is unclear how many have been affected.
Azamara Club Cruises' Azamara Quest is in Nagasaki and Royal Caribbean's Singapore office confirmed to Seatrade Insider the vessel is safe and 'well sheltered from the affected zone'. The company said it is monitoring the situation closely before deciding whether the ship will proceed to Osaka, her next port of call.
Cunard's Queen Mary 2 was in Osaka yesterday and is at sea headed for Nagasaki, her next scheduled port, located south west and away from the quake zone. A bridge webcam dated March 11 17:43 on the company's website relayed calm sea conditions at that time.
Costa ships are not affected, according to a company spokesman. Costa Classica is sailing from Singapore to Thailand, Vietnam and Malaysia, far from the impacted areas. AIDA Cruises' AIDAaura is also in south east Asian waters.
A Princess Cruises spokeswoman said she would have information shortly.
Norwegian Cruise line told Seatrade Insider its Hawaii- and California-based ships are safe.