On the news they mentioned the M4.6 quake in Hawaii. I just checked, it occured about 3 hours after the Japan quake. It is on the SE rift zone of Kilauea volcano which has been erupting since 1983. It is located near the coast so not so close to the new rift eruption. It would be non-surprising if it was in part triggered by some surface wave of the Japan quake, but seismologists will determine this later by comparing arrival times.

This is kind of unimportant today but how quakes are triggered, and not triggered, is of course important.

Chris