It may blow sooner than thought, or later than thought, but from what we do know it's unlikely to blow any time soon.
However, that's for a super-eruption. We're likely to see a (still cataclysmic, but not planetary scale) "normal" eruption any time now. The Yellowstone area has seen many such eruptions in the 600,000 years since the last major event. So if you hear about a possible eruption, don't head for the hills until you find out what sort.
Also, if the big one does happen, there'll probably be a couple of weeks or so notice.
Now that we have GPS-based ground level sensors we've been forecasting eruptions a week or more before they happen. And you'd expect a supereruption to cause a large, wide-spread swell that'd take time to happen. It's not a sudden thing, at least not if the volcano in question is monitored.
Can't say it'd take longer for sure, since we've never experienced a supereruption in modern times, but I doubt it'd take less.
The magma chamber beneath a volcano is heated by a plume of material from the mantle. It's sort of like a slushie, and it's fairly stable, until it starts collapsing and liquefying and releasing gasses. The pressure increases across the entire chamber, causing it to expand and the ground level to rise. Even if the volume of magma is large, the volume of the chamber is also large. Rock isn't very flexible, but it flexes some, and with a larger roof there's room for more movement before something cracks. Normal volcanic eruptions have been forecast a week or two ahead of time and I'd expect at least that much notice for a supereruption.
But wouldn't it work like a hole in a water balloon, where the smaller the release valve the higher the pressure of what's spewed out, and bigger holes can release more at once?
We're talking about before it starts erupting. After is another matter.
Going off on a tangent about the number of holes... We don't know how it would erupt. There was a TV show about it several years ago where they presented a theory that it'd open a lot of small vents in a ring around the caldera, it would erupt for several days, then when the pressure dropped the roof of the upper magma chamber would collapse, and the volcano would give a last big gasp and then the eruption would end. But that's only a theory.
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o0shad0o ago
It may blow sooner than thought, or later than thought, but from what we do know it's unlikely to blow any time soon.
However, that's for a super-eruption. We're likely to see a (still cataclysmic, but not planetary scale) "normal" eruption any time now. The Yellowstone area has seen many such eruptions in the 600,000 years since the last major event. So if you hear about a possible eruption, don't head for the hills until you find out what sort.
Also, if the big one does happen, there'll probably be a couple of weeks or so notice.
PANTSONMIXTAPE ago
Why? It could go down in a matter of hours and thousands of miles would be under the ash cloud within that time frame.
Maybe if you're on the east coast...
o0shad0o ago
Now that we have GPS-based ground level sensors we've been forecasting eruptions a week or more before they happen. And you'd expect a supereruption to cause a large, wide-spread swell that'd take time to happen. It's not a sudden thing, at least not if the volcano in question is monitored.
PANTSONMIXTAPE ago
Why would a huge eruption take more time to go off? Wouldnt it take less?
o0shad0o ago
Can't say it'd take longer for sure, since we've never experienced a supereruption in modern times, but I doubt it'd take less.
The magma chamber beneath a volcano is heated by a plume of material from the mantle. It's sort of like a slushie, and it's fairly stable, until it starts collapsing and liquefying and releasing gasses. The pressure increases across the entire chamber, causing it to expand and the ground level to rise. Even if the volume of magma is large, the volume of the chamber is also large. Rock isn't very flexible, but it flexes some, and with a larger roof there's room for more movement before something cracks. Normal volcanic eruptions have been forecast a week or two ahead of time and I'd expect at least that much notice for a supereruption.
PANTSONMIXTAPE ago
But doesnt more pressure lead to theoretically faster eruptiontime?
o0shad0o ago
More magma over more volume means similar pressure, and it'd take more time for the instability to propagate across the entire chamber.
PANTSONMIXTAPE ago
But wouldn't it work like a hole in a water balloon, where the smaller the release valve the higher the pressure of what's spewed out, and bigger holes can release more at once?
o0shad0o ago
We're talking about before it starts erupting. After is another matter.
Going off on a tangent about the number of holes... We don't know how it would erupt. There was a TV show about it several years ago where they presented a theory that it'd open a lot of small vents in a ring around the caldera, it would erupt for several days, then when the pressure dropped the roof of the upper magma chamber would collapse, and the volcano would give a last big gasp and then the eruption would end. But that's only a theory.
PANTSONMIXTAPE ago
Gotcha. Very interesting, thank you