The earthquake magnitude was revised up to a 7.7
No major tsunami is expected, local media reported initial waves were recorded as high as 40cm. The Japan Meteorological Agency forecasted up to 3m (10ft) waves.
I don't believe this earthquake is a big deal. Large earthquakes (M7.0+) happen in Japan several times a year, and given this happened in the middle of the ocean, I don't expect any major damage.