6.9-magnitude earthquake strikes off Japan

(Photo: NHK)

(Photo: NHK)

JAPAN – A massive earthquake struck Tuesday morning off the coast of Japan, about 70 miles away from Fukushima, the U.S. Geological Survey reported Monday.

The magnitude was initially reported at 7.3, but the USGS later downgraded the strength to 6.9.

NHK World initially reported the tsunami was expected to reach nearly ten feet in height. All residents along the coast and in low-lying areas were urged to evacuate to higher ground.

Officials lifted the tsunami warning four hours after the earthquake. The biggest recorded wave was 4.6 feet.

NHK World has a live view off the coast here.

The USGS posted a map showing the impacted area.

(Map: USGS)

(Map: USGS)

You can read more the seismotectonics of Japan here.