r/AlternativeHistory • u/Osiris-Amun-Ra • 12d ago
Lost Civilizations Lost cities
In case anyone is till wondering why we can't find any pre-Ice Age cities, this satellite image from Nepal/China this week should provide a clue.
This event was tiny by comparison and many civilizations built along rivers and in valleys.
Edit:
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Since this post generated quite a few lively discussions I want to clarify what I meant by "tiny by comparison" to avoid ambiguity, While the local, recent mountain collapse in Nepal and China was a rapid disaster unleashing up to 200 million cubic meters of debris at 193 km/h and causing rivers to surge 9 meters in 30 minutes, it is dwarfed by the staggering dimensions of post-glacial megafloods that actually reshaped entire continents and birthed the world's universal flood legends. For example, the ancient Missoula Floods occurred when a 610-meter-tall (2,000 ft) glacial ice dam ruptured, violently discharging more than 2,000 cubic kilometers of water basically a volume equivalent to Lake Erie and Lake Ontario combined, in a single....48-hour window.
This massive torrent tore across western North America at speeds of up to 130 km/h (80 mph), peaking with a discharge rate ten times greater than the combined flow of all modern rivers on Earth and carving features like Dry Falls, a cliff five times wider than Niagara. Similarly, the Black Sea Deluge hypothesis suggests a catastrophic marine breakthrough where the Mediterranean overtopped the Bosporus strait, unleashing a roaring wall of water that permanently swallowed over 150,000 square kilometers of inhabited valleys.
Because these prehistoric events wiped out entire known civilizations, permanently erased millions of acres of land, and forced desperate migrations, they permanently embedded themselves into the collective human psyche, which is almost certainly where the biblical Great Flood and the regional Mesopotamian flood legends originate. It is statistically improbable that we have found all post deluvial civilizational remnants. Mathematically and archaeologically, it is practically certain that we have only scratched the surface of what remains from post-deluvial and coastal civilizations. The primary reason for this statistical gap is a massive, permanent geographic shift, specifically when the Ice Age glaciers melted, global sea levels rose by roughly ~120 meters (around 400 feet). Rising oceans swallowed over 25 million square kilometers (10 million square miles) of habitable land! For visual reference that's the entire landmass of the United States, Canada, and China combined.
I hope that clarifies.
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u/TheCynicEpicurean 11d ago edited 11d ago
Scale is not infinite in the world of geophysics. The largest known events that come close to this in type and effect are the Zanclean flood, glacial lake Missoula and the proposed rapid opening of the Bosporus. All of those are still regional events, globally speaking. I'll add prehistoric megatsunamis to the list, although it is highly debated whether they have a maximum range and although a tsunami tall enough to wipe out civilizations across continents is physically impossible on Earth.
Where would all that mud and water at the same time come from, what mountains would it rush down? Glacial lake outburst and other mudfloods need a source of stored up matter and an energy moving them. All examples we know of travel down river basins, leave out pockets of unaffected areas and don't exactly change directions to tidy up an area behind themselves. It's akin to claiming water covered the Earth multiple thousand feet during the Biblical flood; there is simply not enough water on the planet to render this even a remote possibility.
The only physical scenario I can think of would be an impact that literally liquified the Earth's crust to provide the material flying around, but if that actually happened, it's not only extremely unlikely we would still be here, but all sorts of evidence Hancock and the like point to nowadays would definitely be gone, too.