The quake struck at 12:43 pm (0343 GMT) in the Pacific Ocean off Japan's northern Aomori prefecture at a depth of 37 kilometres, the US agency said.
Aomori prefecture is some 600 kilometres northeast of Tokyo.
Japan's islands are situated at the conjuncture of several tectonic plates and experience a number of relatively violent quakes every year.
But, thanks to strict building codes, even powerful quakes that might wreak havoc in other countries frequently pass without causing much damage.