On the other hand ancient construction is generally much closer to being in its natural end state as a “big pile of stuff”. The most dramatic example being the Pyramids; much of the reason for their durability being that they have a limited ability to collapse from wear and tear, since they are already (by design) in a close to maximally collapsed state.
That’s the opposite of modern buildings, which are built with much less margin for stress and decay (because we know what those margins are and don’t need to overengineer as much), and built much father away from their natural rest state.
I believe there is a sweet spot somewhere where it is cold enough to freeze every night in winter and warm enough to thaw every day.
A temperate land climate at some altitude. (As in: above sea level) I’d say something like the top of Mnt. Ventoux would be the absolute worst place for thaw/frost
I am not sure a freeze/thaw circle will do as much harm as “advancing flora” does … so my money is on the tropics where “stuff” might get broken up by invasive plants etc…
Ask an archaeologist if they could identify a fallen tunnel (yes, they could). Any man-made hole in the ground would persist for thousands of years unless completely eradicated by erosion, millions in some cases, and in certain locations, be detectable after billions.
Earth palaeontology, in the far future, will have plenty of evidence from the Anthropocene.
Archaeology often starts (and sometimes can only proceed) with evidence of ground disturbance: foundations, post holes, roadways, tunnels, ditches, and the like.
It’s a case where humans aren’t building up, but digging down, and the changes persist simply because they’re less affected by the work of erosion and gravity.
no doubt on that … but depending geography and weather … you might get 1-10 days of those per year whereas in the tropics you might get up to 365 days of plant/root growth …
(I really need to get a shot of some concrete tennis courts that were abandoned some 5-10 years ago - I have a prime example a couple of blocks away from home… IIRC there are now some trees w/in the court) … point is: a motivated breed of plant can do surprising damage!
so, yeah … def. a “depends” thing … latitude, frost days, etc…
I posted a reply to a question on Quora where I pointed out that modern technology has left some spectacularly huge holes in the ground. That we’ve never found any such holes dating to prehistory argues against there having been a technological civilization before ours.
I don’t know; my archaeology-obsessed wife has taken me to some pretty interesting holes in the ground. The Ħal Saflieni Hypogeum for instance. But these holes were obviously excavated by cultures with a lower technology than we have today.
I’ve also been to every station on the London Underground (except Battersea Power Station Station) and through the Channel Tunnel, and those are holes that will be around for millions of years to come.
I am. And yes indeed we can. And yes, detectable ground disturbances do persist to the limits of human existence (and before that we get organism-made holes and burrows going back aeons in palaeosols).
The point of the comment was to note that a tunnel in a glacial front would likely only exist as a buried (probably collapsed and infilled) structure, where some people were implying they may have remained with some structural integrity.
It does raise the OP’s point (useful reminder after 50 posts), of
Unless there is physical removal of remains through a major ground-shifting mechanism like a glacier, massive metres-thick erosion or river shift, what’s there will in all likelihood be readily apparent to our squirrel archaeologist replacements for long geological periods. Human use enough building materials that are effectively stone (concrete, glass, brick, tile) that will endure as long as stone does. It may no longer integrate into readily recogniseable forms, but I bet a collapsed structure provides enough of its own fill to readily encapsulate standing wall elements, and become geologically stable for a long period.
A modern open pit mine will take a very long time to self-refill up to level with the surrounding terrain and will be evident on ground penetrating radar for long after that.
Not disagreeing with you, just tossing out another sort of really big hole. We also have a tendency to dig more of these in arid terrain. That local aridity may not last forever, but while it does it’ll certainly slow the progress of weathering the hole vs the rate in a wetter climate.
The future archeo-squirrels may not know who we were, but they’ll be certain somebody was here and left a big mess.
That’s going to happen in the temperate zones too: probably not quite as fast, but definitely fast enough, anywhere’ that’s not sterilized for miles around, to have significant effects in a lot less than a human lifetime.
Though I expect slower in arid areas. And, of course, what’s left will be identifiable to the skilled eye looking for it for a lot longer than it’ll be identifiable to the casual untrained eye looking at the surface.
That’s for sure. If nothing else, there’s going to be a planet-wide layer of tiny bits of plastic.
Not sure I understand this statement, but Rome and Detroit still exist. Even a lot of Roman Empire stuff is still around, including the city of Pompeii and that was blasted by a volcano.
Although ironically I think our modern buildings are a lot less durable than ancient Roman or Egyptian structures. They built what are basically giant piles of stone brick. Our structures are thin glass boxes
Even when the steel has all turned to rust, and the rust in turn washed away and just left reddish smudges on the concrete rubble, aluminium window-frames may be in good enough shape for the squirrels to pull out and sell on EBay.
One reason for moving to steam and fossil fuels was you could put your new factory anywhere. Relying on water power meant, practically, having to build where communities already existed. That meant having to hire local people who had ties and histories that made them more likely to organize and push back against terrible factory conditions.