Welllllllllllllllllllll . . . THAT'S sure a pile of interesting stuff. Thanks.
What's your sense of it all re Antarctica?
It's cold down there.
More seriously, I think we have little idea how much of the planet humans have tread upon, nor what civilizations existed which have been lost even to legend.
A friend who is a water well driller pulled a piece of brass out of a water well he was drilling about thirty years ago, from a depth below the glacial till from the last ice advance, as near as he could tell. Unfortunately, he just tossed it on the truck and it was lost, having thought nothing of it. Only later did he realize he had no brass fittings on the truck that were not employed...
I have long thought that humans have traveled farther and more extensively than the prejudices of Darwinism will permit people to believe. A stone axe found by my grandfather, loaned to the Smithsonian, was 'lost', but from descriptions was an order of magnitude larger than any modern man would have been comfortable swinging around.
An Archaeology professor I had as an undergrad made the heretical statement that Clovis was likely not the first wave of settlement in North America, and that as far back as 32K years ago there could have been other waves of settlement. He pointed out the different genetics expressed in the appearance of the Inca, the Aztec, the American Indian tribes, which despite being restricted gene pools had crossover and mingling from trade and captives/slaves who became members of the tribes which captured them (if they worked out). It made sense to me. After all, humans were, even then, busy visiting every part of the planet they could get to (again), and had been throughout recorded history, so why not before?
Add in that climate is not a given. It does change, whether humans have diddley-squat to do with that or not, and humans have ever been the sort who will take advantage of the opportunity to move into a new niche, will leave somewhere they can't survive for somewhere they can, and even fight over the turf. The Anasazi bugged out, the American Indian residents moved north, Europeans moved west (after a lot of shuffling), folks in the middle East moved east--people just don't stay put. It makes good sense, that given the opportunity, humans would have lived anywhere they could, and from modern distributions, that includes some outrageously difficult and demanding environments.
Whether there are vast monolithic structures under the ice--I don't know. I can't rule out the possibility, even though natural ice-carved features might well resemble pyramidal structures, especially under ten to fifteen thousand feet of ice, on whatever sensor readout is used.
Having seen a multitude of seismic profiles, those can be distorted by the intervening layers and the resemblance may be coincidental. Any signs of habitation or even cultures at the surface is another matter entirely, and should be thoroughly investigated.
So my answer is a definite maybe.
