A strong earthquake rocked the ocean floor east of Japan early Saturday, triggering a small tsunami.
The U.S. Geological Survey
reported the earthquake's magnitude at 7.1 and said it struck 10 kilometers below the surface about 3 a.m. local time Saturday .
Japanese media reported a 30-centimeter tsunami had reached Japan's east coast.
The quake hit about 400 kilometers from Japan's Fukushima Province, site of the ruined Fukushima Daiichi nuclear power station, which was hit by a devastating earthquake and tsunami in March of 2011.
There were no immediate reports of damage to the nuclear plant or anywhere else on land.
A geophysicist with the U.S. Geological Survey, Paul Caruso, said the earthquake was felt as far away as Tokyo.
"We have reports that the earthquake has been felt in Tokyo, but we don't have any reports of damage at this time," he said.
Caruso also said no tsunami was expected for the United States.
"The Pacific Tsunami Warning Center
has issued a statement that there's no tsunami warning, no tsunami expected for Hawaii or the Pacific coast of the United States," he said.
The Japan Meteorological Agency
in Tokyo measured the quake at magnitude 6.8 - somewhat weaker than the U.S. Geological Survey measurement but still strong.