Bill, I agree. To me, the term "Ring of Fire" is not really scientific but rather an ironical one inspired by a movie or something like that. I don't know how long this term has been used, though, and I don't really appreciate the term.
Dave and Bill, indeed we share the same fear and sorrow in relate to the earthquake...
Hugh, I well remember the severe earthquake in Christchurch just a couple of weeks before the totally devastating one in the northeastern part of Japanese archipelago. Again, we share the same fear and sorrow.
According to the modern study of the earthquakes in the eastern Asia area, the earthquake attacked Japan in 2011 is said to belong to the series of ones that would occur once in every millennium. And the earthquake would occur as a set of the earthquakes that attacks the north-eastern, central and south-western part of the archipelago. We have only had the north-eastern one yet, we stay warned and horrified.