Absolutely TONS of info, though I'm not a geologist, nor have I studied much, so I sadly do not know of any solid references I could simply point at. I've just picked up a few details over the years watching random geology videos on YouTube.

GeologyHub makes frequent short videos on current activity, and he always comments on the mechanisms at play, and even makes and explains his educated guesses on what will happen. A plug forming comes up quite often when eruptions slow, even in eruptions that are destined to continue erupting.

Maybe not geothermal per se, but something would be possible, with unlimited budget and resources.

Though the problem is just how MUCH energy volcanos have. Heat content is A LOT of energy. The vast (on a human scale) magma chambers contain an insane amount of energy. Rock has a heat capacity less than water by weight, but rocks weigh a lot more than water and can get a lot hotter.

So, it'd have to take away a TON of heat, likely more than humans use in a year for a single small eruption, but I'm too lazy to do the math right now...

Also, many eruptions are fueled by pressure from dissolved gasses in the magma. That pressure will stay present until the magma cools enough to resist it itself, which could require dropping an entire underground lake of lava by hundreds of degrees.

Then there are undoubtedly some eruptions that are driven by tectonics, meteor impacts, and other physical pressures that might not be manageable via heat control at all.

I think there are much easier ways to get massive amounts of power than try to interface with such an incredibly chaotic and unpredictable system.

An even bigger problem though is that most of the time geologists really have to aggressively make the case to anybody that their work is valuable when it isn’t directly contributing to finding oil or evaluating groundwater reserves.

Studying volcanoes, even in places with lots of volcanoes, is considered kind of a dubious practice by most people and taxpayers. Yeah sure, Mount Saint Helens goes off and all of a sudden people will take volcanoes very seriously for a bit, but generally people don’t give a shit about geology even if they haven’t been infected with “the earth is only 10,000 years old!” brainworms.

I mean, geologists will give a warning like “well, we could all die with no warning anytime from now through the next 50,000 years so we are very very due for a catastrophic eruption and we need to prepare!”.

Like yo, we can’t even agree to fucking give universal healthcare to people in my country…. sigh.

Yes, exactly on the idea. "The weakest spot" is distinctly NOT the hunk of solid rock cooled at the top, more often than you clearly think.

It doesn't have to have a huge effect to never the less completely change the nature of an eruption. Just look at Mt St Helens. The top didn't even have to pop. The magma just lubricated the side of the mountain enough until the whole damn side slid away, allowing the eruption to occur.

They don't often redirect every eruption, becuse many have NO other weak paths, so the magma pushes, and it either pops the rock plug or melts it. Not that many eruptions start fast enough to catastrophically pop the plug, and not all eruptions are remotely equal.

My point was NOT that the plugs make a HUGE difference, but that they make A difference.