- A second, slightly smaller quake hits about 30 minutes later in the same area
- The first, stronger 9-kilometer deep earthquake did not set off tsunami warnings
- It was centered about 550 kilometers (342 miles) north-northeast of Tokyo
- A stronger March 2011 quake triggered a tsunami that led to thousands of deaths
A 6.2-magnitude earthquake struck off Japan's eastern coast early Tuesday, the U.S. Geological Survey reported.
With a depth of 9 kilometers (5.6 miles), the tremor was about 96 kilometers (almost 60 miles) east-northeast of Miyako and 550 kilometers (342 miles) north-northeast of Tokyo, according to the U.S. agency.
The quake occurred just over a year and a half since a 9.0-magnitude earthquake triggered a huge tsunami off Japan, resulting in thousands of deaths and the world's worst nuclear crisis in a quarter century.
The Japan Meteorological Agency, however, did not issue any tsunami warnings or advisories immediately after the Tuesday morning quake, according to its website. No such warnings were issued by the Pacific Tsunami Warning Center either.
A little more than 30 minutes after this first earthquake, another significant, if slightly weaker one, hit the same general area.
This 5.1-magnitude tremor was about the same distance from Tokyo as the first and about 107 kilometers (66 miles) east of Miyako -- which was among the areas devastated by the March 2011 earthquake and tsunami -- according to the U.S. Geological Survey.
Tuesday's second quake was much deeper than the first, rooted about 38 kilometers (23.6 miles) below sea level.