My left side forehead spikes are for EQs only and the S+ is for a very large EQ at some point in time, but only during its window. Volcanoes, for me, will cause coin size pain light ups on my head and pressure at the back of my head at the least. Popo, located on the top right side of my head, will have pressure, but hasn't always had a spike. Think it depends on the type of activity in the volcano.

This site: http://www.fnoc.navy.mil/otis/otis_glbl_sstanomaly.gif is now showing increased water heating off Japan. Not near as bad as I have seen it, but definitely some activity going on there.
You are right. Signs sure have been confusing of late.

Diane