You are right...the Mt. St. Helens and Pacific Rim volcanic "Ring of Fire" has magma of completely different chemistry than the Hawaiian arc volcanos. The calc-alkalic suite that makes up the Ring of Fire volcanos is highly explosive. Hawaii volcanoes flow, Cascade volcanoes blow up.
And thats all I have to say about that.
Hope you are in a safe location.
Hi horsie.
I sure I was I was back in Washington now for the eruption. The one in 1980 was soooooo COOL!