May 28 (Bloomberg) -- A 4.7-magnitude earthquake struck Japan's main island of Honshu today 240 miles (385 kilometers) north of Tokyo, the U.S. Geological Survey said.

The temblor, which was about 3.8 miles deep, was recorded at 1:41 a.m. local time 50 miles south-southeast of the city of Akita, the USGS said in a statement posted on its Web site. No alert was immediately issued by the U.S. National Oceanic and Atmospheric Administration's Pacific Tsunami Warning Center.

To contact the reporter on this story: Chris Dolmetsch in New York at cdolmetsch@bloomberg.net.

Last Updated: May 28, 2008 16:33 EDT