The quake, with a preliminary magnitude of 7.1, hit at 6:39 a.m. ( 4:39 p.m. Monday EST) and was centered just below the ocean bottom off the east coast of Japan 's main island of Honshu , Japan 's Meteorological Agency said.

Small tsunami waves measuring 12 and 20 inches hit the coastal city of Ofunato and smaller waves hit at least four other towns. Tsunami waves — generated by earthquakes — are often barely noticeable in the ocean but can rise to great heights once they arrive at shore.

Ross Stein, a geophysicist with the USGS in Menlo Park , Calif. , said the swell amounted to "a surfable tsunami."

The quake hit at a depth of about 18 miles and was centered off the coast of Sanriku in northern Japan , 330 miles east of Tokyo , the U.S. Geological Survey said. It shook buildings across a wide area across northern and eastern Honshu , including Tokyo , and Hokkaido .

Japan is one of the world's most earthquake-prone countries because it sits atop four tectonic plates . A 7.2-magnitude earthquake shook northeastern Japan in August, injuring at least 59 people, triggering landslides, damaging buildings and causing widespread power outages.

There was no destructive Pacific Ocean-wide tsunami threat following Tuesday's earthquake, based on historical quake and tsunami data, according to the Pacific Tsunami Warning Center in Ewa Beach , Hawaii.

However, earthquakes as large as Tuesday's can generate a local tsunami capable of causing destruction along coastlines within 60 miles of the epicenter, according to the center.