Everyone loves a Dyson Sphere or a Ring World, so much more room to enjoy than a traditional round planetoid, it's all about space efficiency for the advanced civilizations. There are however a number of problems with these large artificial space environments, the one I would like to focus on today is erosion and other geological instabilities of artificial environments.
They all start out so pristine; an underlayer of unobtanium for structural support, lay down a few (approx. 1-10) km of rock, sculpt some mountain ranges, pepper the landscape with some comets for water, lay down some beginning soil layers and some desired flora and fauna, and enjoy your species ideal biosphere. But as the millennia pass there are problems; the mountains are eroding! All the rivers are dumping sediment and clogging up the seas, turning our ocean front property into swamp front disasters. What's a Ring World engineer to do, seriously what should they do?
Those inefficient spherical planets move their continents around on a huge masses of molten rock, this makes new rock, raising the continents and recycling the materials over long timescales counteracting that pesky erosion. That inefficient cycle won't work on our thin space structure.
Some ideas our engineers have been exploring:
- We could run some massive de-silting operations, dredge the seas and ship the mineral materials uphill to form new mountains, we could even try some massive automated pipeline type systems to create artificial subduction and mountain uplift zones.
- Maybe we're over thinking the problem, erosion is going to be fairly slow, we could just thicken the "crust" in areas subject to erosion. Surely this will be able to ensure a functional structural lifespan to meet or exceed our species lifespan (several million years).
- Could we make the rocks "harder" to resist erosion? But this wouldn't stop our topsoil from eroding.
- Perhaps an unorthodox method might work, could we flex the substructure to change the terrain periodically.
- Undersea nuclear detonations to blast the dust into the air?
- Put some asteroids in orbits to periodically drop meteors at low relative velocity to make new mountains?
What's the best method to keep our space construct's geology fresh? Something our engineers have proposed, or are our ideas flawed, is there another better solution we haven't thought of? Preferably something with a minimal input from the inhabitants societies (they have a nasty habit of technological regression over geological timescales). We owe it to our descendants to do this right.