I found the above El Hierro thread a little difficult to read.

However, from what i have gleened...of late there has been a lot of seismic activity under the island, parts of the island were evacuated this week due to potential of volcano erupting (last erupted 1790's?). I think as at today the evacuees have been allowed home.

Why people are worried about a potential disaster from this eruption, is due to nearby island La Palma having a fault line or split which, if there were an eruption could cause a massive landslide and tsunami. A tsunami big enough to make it to the US west coast.

I am wondering though, if it is El Hierro that is erupting...to what degree will it effect the fault line of La Palma?