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by xg15 7 days ago
> or it could’ve been the eruption of a monster volcano, the sort that presently smolders beneath the Atlantic.

I know about Yellowstone, Campi Flegrei, etc, but I haven't heard about a supervolcano below the Atlantic. What's that referring to?
1 comments
MrDrMcCoy 7 days ago
There's a seam of volcanic mountains that runs down the center of the Atlantic, but nothing that resembles a supervolcano. The supervolcano complex under the Pacific is one of the largest known in the solar system, however.
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xg15 7 days ago
> There's a seam of volcanic mountains that runs down the center of the Atlantic

Yeah, that's the pacific rim, which in some sense is the opposite of a volcano.

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masklinn 7 days ago
No the seam at the center of the Atlantic is a mid-oceanic ridge, and it’s very much like a volcano since magma comes out. Icelandic volcanology comes from it being on the ridge.

There are ridges off of the US coast (Explorer, Juan de Fuca, Gorda) but the ring of fire which surrounds the pacific is mostly subduction areas.

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xg15 6 days ago
Sorry, you're right of course (and yeah, the Pacific rim can obviously not be in the Atlantic, typed too fast there...)

With "opposite" I meant the role in plate tectonics, in that classical volcanoes seem to mostly appear near subduction zones or hotspot but not on the ridges from what I know. (Iceland being the exception, but even there it's because of a hotspot that happens to be located right on the ridge)

But I think the ridge system usually does not have volcanoes in the sense that there are magma chambers that fill up or cause eruptions. So the usual scenario of the "asleep supervolcano" does not apply.

> The supervolcano complex under the Pacific is one of the largest known in the solar system, however.

That sounds interesting. Do you have some links about that?

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MrDrMcCoy 6 days ago
My recollection seems to have been from a very early story on the subject and got some terminology wrong. Apparently, supervolcanoes have to have had an eruption in the past of a certain magnitude in order to earn that title, and that hasn't happened yet. Pretty sure it was this: https://en.wikipedia.org/wiki/Tamu_Massif
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