So this part of Indiana I live in is pretty flat. Dull, right? So I figure, why not have a volcano? Now… I get my magic drill machine that can drill as deep as I want it to drill.
If I drill a deep enough hole, say through the crust of the Earth, will it turn into a volcano?
Eheran@lemmy.world 1 year ago
That could actually work, since the hot material has a lower density and will thus be pushed out.
geogle@lemmy.world 1 year ago
Probably still won’t work unless there is serious overpressure in the area from some dynamic loading in the mantle. First off, no part of the mantle is naturally fluid at depth. The closest is the asthenosphere, at around 200 to 400 kn depth. This is still solid, but more like a soft wax. That too, the material is made of peroxides and has a density of between 5 to 15 percent higher than the granitic crust at depth and limestone that makes up the shallower crust of Indiana. Thus, it would be analogous to a whole in a wooden plank floating on a sea of dense soft wax…the wax won’t likely push through.
However, if you add water to the system while maintaining the heat, you can start to fluidize the gooey rock, and eventually it will reduce density enough to start creeping upwards. If you mix it deep enough and we’ll enough, you can start creating small steam bubbles within that will continue to grow as the rock ascends, further increasing the pressure (like a bubbly bottle of champagne). This will drive further upward pressures allowing for a surface eruption and formation of a volcano.
Source: am geophysicist and play(work) on volcanoes…just not in Indiana
perviouslyiner@lemm.ee 1 year ago
FlyingSquid@lemmy.world 1 year ago
You wouldn’t have much work here. Thanks for the expert information, I appreciate it!
Eheran@lemmy.world 1 year ago
If the lower layers are denser despite their much higher temperature and also super viscous, how can volcanos ever form? What if we drill right through this area with an even later size hole? In this caw tho, note that all of the back-pressure is missing at the hole, so gases would violently went to escape (10’000s of bar vs. 1 bar), which should be plenty of driving force to get stuff above the ground. Due to the outgassing the density should also massively decrease. Kind of like lowering a pipe into a volcanic lake that has CO2 dissolved in the deeper layers and letting that vent in a fountain.
Note that the pressure would go down, not up, as it ascends. But the volume would go up because of the lower pressure.
goddard_guryon@sopuli.xyz 1 year ago
It’ll get more complex than that. I’m no expert, but I’m guessing you have to consider the depth of the crust at your location, type of soil and the distance from (and time since) the last closest volcanic eruption, possibly distance from the nearest tectonic boundary, maybe even tidal forces (assuming they have a considerable impact on magma being pushed out, but this may be a bit too far)
FlyingSquid@lemmy.world 1 year ago
The closest eruption was the snag point I was thinking. We’re relatively near a fault line, but I don’t know of any volcanoes for a very, very long distance.
FlyingSquid@lemmy.world 1 year ago
Interesting. That’s not that big a diameter all things considered.