The quake was measured at a magnitude 7.3, according to preliminary reports from the U.S. Geological Survey.
The Japanese meteorological agency has reportedly issued a tsunami advisory for five prefectures on the eastern shores of the country.
The Weather Channel and Reuters both reported that a small tsunami of about 1 foot had been observed in the Miyagi prefecture of Japan. There were no initial reports of any damage on land.
The earthquake happened shortly after 7 a.m. HST at a depth of 6.2 miles.
Here is a link to the Pacific Tsunami Warning Center.
We will have more information on this developing story as soon as it becomes available.