Aquifer collapse creating a new canyon

More or less it's something random that's been bugging me in my thoughts. Can't really say it's a prediction as I have no timeframe for it nor good reason for thinking of it. (Might not ever happen in my own lifetime.) But basically the idea that there will be some seizmic event associated with the top of a fairly large aquifer collapsing. (Likely after being heavily drained and depleted, no hydraulic pressure to help support the rock and it crumbles out.) The remaining water in the bottom of the aquifer will get pushed out in quite a dramatic fashion when all that earth caves in on it, so after it all settles down there's going to be a new canyon system carved into the landscape. Geologists might see it as some unique thing to learn from, but it really sucks and will be a disaster for whoever/whatever may be on top of it when it happens.

Would be interesting if anyone else had similar bugging them. Hopefully it's just boredom and nothing ever comes of it.

Well no prophetic dreams to speak of but this has been a concern of mine for some time. Draining aquifers to feed megalopolises is highly unsustainable and creates giant pockets of air deep below the surface. Why wouldn't these collapse at some point?

a reply to: pauljs75

Well, most aquifers aren't solely pockets of water. That's one of the things that makes them usable for tapping. Most large aquifers are mostly sand and gravel by volume. And the water is somewhat filtered my this medium as it flows through it. The hydraulic pressure does indeed play a factor is subsidence, but there's not generally a chance of the water draining to leave just a large empty void.

Got any particular location in mind?

a reply to: pfishy

from what i remember from my college geo class... aqua-fillers take many many years to replenish. many more years than those of a human lifespan. as the water is depleted at a pace that is greater than can be replenished the ground usually begins to sink. take an aquifer as large as the ogallala aquifer, by most accounts we have drained 10% of its total volume, in some place less and in some more. its one of the largest aquifer in the world, we are now draining this aquifer at an accelerated rate. sometimes aquifers are drained so quickly that the ground will sink but not necessarily compress. if a big quake were to hit all that land would probably experience liquid faction.

a reply to: jgarc028

Yes, that's true. But I was just pointing out that the majority of aquifers are not just gigantic caverns full of only water.