Colonizing Jovian moons...practical issues of building large structures under the ice

[Mgellis]

Non-engineer doing research for a story...

Recently, there has been discussion of colonizing Jupiter's large moons in the long term. 

One solution offered to the problem that the Jovian environment has lethal levels of radiation is to simply build colonies under the icy surfaces of these moons.  This would also be done to provide access to the subsurface oceans of these moons.

But this got me thinking about another potential problem...how stable is the ice?  Especially if you are producing a town's worth of heat.  Wouldn't you eventually cause so much melting that whatever foundation was holding your town in place would fall apart or collapse?  Or have the ice shift in a way that would cause trillions of tons of it to squish your nice colony buildings?

Or...are there ways (with current physics/no magic) to keep this from being a problem?  Assuming you have the technological base to get people to the Jovian moons, would there be practical ways to brace/insulate/support the colony and/or divert heat away from the ice (radiator systems piping the heat to the surface, possibly capturing some of it for energy, etc.) so the colony would not constantly be at risk?  I mean, eventually, they might have to replace some components, etc. but that's just normal wear-and-tear on any mechanical system.  

Sorry in advance if I am missing something obvious...as I said, I'm not an engineer, so I just don't know.

Any thoughts on this?  Thanks in advance.

[swansont]

19 hours ago, Mgellis said:

But this got me thinking about another potential problem...how stable is the ice?  Especially if you are producing a town's worth of heat.  Wouldn't you eventually cause so much melting that whatever foundation was holding your town in place would fall apart or collapse? 

Igloos remain stable even with a heat source inside. If the ice/snow is really cold because the ambient temperature is low, and is some distance from the heat source, it won’t melt.

A town on a platform would be analogous to this. The pillars would be cold and not melt the ice. The hot air from the town would tend to rise.

[Mgellis]

Thanks for the reply.

What about settlements built into the ice?  I'm thinking that people might want to build deep into the ice, maybe hundreds of meters down, taking advantage of all that space.

Or would it simply be so much easier to build on the surface, put a foundation on the ice and then build the settlement on the foundation, and then cover the settlement with a layer of ice for radiation shielding, maybe even dome the whole thing over, that it just would not be worth bothering with deep ice tunnels and warrens?

One factor here is that people would want to build elevators down to the subsurface oceans, especially if they find life there.  But I imagine it is a lot easier to insulate a couple of elevator shafts than an entire town. 

It sounds like the critical factor is insulation...as long as you keep the heat away from the ice, it is much less likely to melt, shift, etc.?  And this can be done with a platform or some other kind of insulating layer(s).  Am I getting this right?

Thanks!

 

[swansont]

8 hours ago, Mgellis said:

What about settlements built into the ice?  I'm thinking that people might want to build deep into the ice, maybe hundreds of meters down, taking advantage of all that space.

Sure. You could build the pillars I mentioned much deeper, and have a space between the ice walls and any source of heat. You could vent any exhaust through a hole above the settlement. It would be even more like an igloo than a surface settlement.  (they could even call the settlements igloos, and come up with some backronym for that)

The heat could even help carve out the cave, and you could reach the equilibrium of where the ice stopped melting naturally. You'd have to excavate some of the ice, but some could melt and the runoff fill in any fissures that might exist, making the foundation even more stable. (though ice at that depth is probably pretty solid)

[Mgellis]

This is very helpful.  Thank you.