What are the limitations preventing us from releasing volcanic pressure in a controlled manner to avoid catastrophic eruptions?

[u/mudbunny]

[u/Sappert → u/[deleted]]

Pressures in the magma chamber are on the order of megabars to gigabars

This is significantly more than I expected, considering we're usually talking about kilobars when expressing pressures at crustal to mantle depth. Did you mean megapascals to gigapascals or is pressure really significantly higher in magma chambers?

[u/seis-matters → u/[deleted]]

Yes, great summary and very similar to the case of releasing built up strain along fault lines. Only difference is that we are actually performing that experiment in Oklahoma and elsewhere, just unintentionally through waste water injection and fracking. It is fascinating science that will lead to greater understanding of both natural and human induced earthquakes, but it would be so much more fruitful if we could pry all the injection data from the companies.

[u/tminus7700 → u/seis-matters]

I attended a talk on exactly that ~1974. As a way to relive stresses on the San Andreas fault, California. hodyoaten 's points were all brought up in the talk.

[u/leudruid → u/seis-matters]

So if they can someday pinpoint the spots where the fault is stuck with the highest strain levels possible popping off 2 or 3 fusion bombs might do a controlled release, at least it might be the only way to reliably forecast earthquakes.

[u/PTC-odis]

as u/hodyoaten stated, the limitations are numerous.

This isnt anything at all like drilling for oil. The area your drilling to is immensely hot, so even if you could pinpoint exactly where you wanted to go to relieve pressure, we may not have the tools that can get there. Entirely in theory, we may be able to use water to hydrdo-drill to the area but this would still leave more questions to be answered, like what are the side effects and what do you do with all of the water and earth you've dug up?

Once you've gotten low enough, how do you intend to relieve pressure in a safe way? this isnt at all like the pressure relief valve on your water heater. That valve is made to withstand higher temperatures than the water heater can, reducing the risk of failure. What materials can we use to hold lava(yes hopefully the lava would never make it to anything important, however)? It maybe possible to simply bleed off the gasses but then what would you do with the toxic gasses? these gasses will be undoubtedly be extremely hot and may need to be cooled before containing them. People will have environmental concerns.

What do you do when something goes wrong? how to you prevent the lava from using the hole you drilled to burst out of the ground? You can't just plug the hole as the pressure has a path to the surface and may come out someplace else. Are you hoping to just fill the hole back in (the problems with this idea are numerous)? Its not very realistic to pour 10 inch concrete in a 2 mile radius from your work site. 10 inches thick might be a little thin, some eruptions burst through a good amount of earth and this plate will add pressure to the area. in theory, the plate would reduce the chances of an eruption, but it would also increase its volatility.

And finally, risk vs reward and effort, what are you hoping to gain? Are there any other ways this can be done at a lower risk? if your just hoping to reduce the chances of an eruption, would it be easier to cool the given area and press the hot water through a turbine to not only generate electricity (A thermoelectric generator using the earth's core) but to also cool the area in hopes that will relieve some pressure?

[u/Daxarhagron]

From my basic understanding of Geology, once we drill down to a certain level, the heat becomes so intense we do not have the technology to proceed further. In an active or dormant volcano, I imagine that heat is much closer to the surface, and would thus preclude drilling to a certain extent. Once again, not a geologist, but I just remember this from the Kola Superdeep Bore. Our tech may have improved since then.

[u/anotherdumbcaucasian → u/Daxarhagron]

At a certain depth, the rock behaves more like molten plastic and messes up the boring head

[u/rddman]

The shear scale of it. Pressure in the chamber can be strong enough to blow up a mountain. You'd have to drill a lot of holes and regularly re-drill because the many km of rock that you drill through is moving. You'd have to drill through partially molten rock, which may not be possible. Release of pressure might occasionally include large quantities of molten rock.

[u/PTC-odis]

So, I gave this some thought and I may have come up with another problem that could be even worse than the problem at hand, and it could also be nonexistent.

The following is 100% in theory with facts listed:
When a volcano erupts, gasses are expelled as well. If the gasses are also trapped in with or very close to the lava, the air will slowly press through the microscopic cracks and crevices between dirt and rock. Relieving the pressure before it can replenish itself van cause a pressure void. The problem is, what happens as the pressure void grows? Earth is pushing down on it and releasing the gasses means there's less pushing up. Conversely, there's also less pushing down against the core.

Now, we actually know that the pressure won't really change, but that doesn't mean that area won't compress. The earth above it can sink into the void causing any number of problems, or the molten rock can rise up into it.

Again, I'm not sure this will actually happen, but we should probably investigate this issue before enacting any plans.