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therandombeast50 karma

But could a very large quake be the "thing" that starts the whole process of "waking up"?

therandombeast11 karma

Speaking of composition, have Hawaiian volcanoes ever erupted more evolved magmas than basalt, apart from Hualalai, which I know has erupted trachytes in the past? Also, is there any noticeable visual difference between a basalt lava flow and a basaltic andesite flow?

therandombeast0 karma

I have quite a few questions if you don't mind haha!

Does CVO count the 1989-1991 phreatic activity at Mt St Helens as an eruptive period? What about Rainier 1894?

Was its 1800 Plinian eruption from the summit or the north flank?

I've read that the largest eruption in Mt St Helens' history produced a 15km3 bulk deposit, making it a VEI6 eruption, is that accurate?

Is Mount Jefferson itself still capable of erupting?

Are the "minor" eruptive centres such as Blue Lake Crater, Belknap, Cinnamon Butte considered as active, or if eruptions happened in the area in the future, would it be a case of a brand-new system being formed, like at Ukinrek Maars?

Is the northernmost volcano in the Cascade Volcanic Arc Mount Meager or Silverthrone?

Seeing as the RED/WATCH alert level has never been used so far, can you give an example of what would make you assign that one instead of RED/WARNING? I was thinking maybe the March 8, 2005 explosion at St Helens would qualify if the current alert system had been used then, as there was hardly any ashfall but the plume did go above 30,000ft.

There is basaltic andesite and rhyodacite, but why nothing inbetween andesite and dacite?