[q1w2]

I think the answer is good, but misses one important point - it is not like there is a thin barrier where there's a sharp pressure gradient, such that you can "pop" the volcano, or allow it to fizz like a shaken coke can with a tiny hole.

When you drill down into the volcano, the hole just collapses on itself and plugs itself back up. The closer you get to the caldera, the rock become viscous and hot. Not only does your drill bit melt, but it's like trying to a hole into warming ice-cream - you don't accomplish anything.

Geothermal energy plants function by drilling holes near magma chambers, and allowing some heat to radiate into the bore hole, and then up the shaft. ...and while this process extracts some heat, the energy withdrawn is orders of magnitude smaller than what is present.

[deepsun]

> the hole just collapses on itself and plugs itself back up

Same with modern day oil holes. They just reinforce the walls of the hole with concrete. Much harder problem is to prevent oil and gas from rushing up through the well, and breaking the rig (it always ignites afterwards). Imagine that with lava.

[hinkley]

When you core a tree to look at growth rings you have to be fast because the wood will begin to swell almost immediately. If you get distracted then you lose the corer. The tree is stronger than the handle.

I would think rocks under high pressure would do the same thing. You’d either have to dig a conical hole to get a cylindrical bore, or the boring machine would have to have cutters on both the face and the sides to keep grinding away rock that expands into the void you are creating.

[tombh]

Thanks, I think yours is actually a much more relevant answer than the one in the article. Personally, I took the original question as a _geophysical_ one, not a logistical one. I mean sure it's geophysically interesting that our current drills are just orders of magnitude too inconsequential, but your answer actually corrects the implied intuition that both I and the question asker wrongly had, namely that magma is like coke in a can.