Major 7.5-magnitude earthquake strikes off Japan, tsunami alert issued

Waves as high as two and a half feet have already been reported amid tsunami warnings and advisories in parts of Japan.

The highest wave so far was at Kuji Port in Iwate prefecture, measuring about 31.5 inches in height. There were also waves at Miyako Port in Iwate (15.7 inches), Hachinohe Port in Aomori prefecture (11.8 inches) and Urakawa Town in Hokkaido.

There were also waves at Mutsu Ogawara Port in Aomori, Ofunato Port in Iwate and Kamaishi Port in Iwate, the heights of which have not been reported.

Residents in affected areas are still being encouraged to evacuate, as the second and third waves can sometimes be higher, Japanese broadcaster NHK reported.