[AnimalMuppet]

1. Cataclysmic meteor strikes ending the ice age? Aren't they more likely to prolong it?

2. Is there any evidence of either glaciation or flooding at the Richat structure?

3. If no on 2, then why should their civilization leave virtually zero evidence, even if it collapsed? Macchu Pichu is still there. Teotihuacan is still there. The Nasca Lines are still there. Chan Chan is still there. The Minoan ruins are still there. If this was just an abrupt collapse. why should it leave no trace?

[FloorEgg]

1. Yes. I don't know, but there is lots of geological evidence that 12-13,000 years ago there were several cataclysmic meteor strikes, and the earths temperature swung up and down wildly, eventually settling at a much higher temperature (ending the ice age). I am pretty sure this is accepted by the geological community.

2. There is evidence of tremendous flooding, yes. You can actually see it on google earth yourself if you go look...

3. The theory assumes there was massive flooding, which is why we have to look harder for evidence (careful subsurface excavation) compared to sites like Macchu Pichu. Also Macchu Pichu is 600 years old, and the theory of the Richat structure housing a city assumes it was destroyed 12,900+ years ago.

4. Keep in mind that it's widely accepted that 13k years ago the Sahara was lush grasslands and forests.

[jcranmer]

> I don't know, but there is lots of geological evidence that 12-13,000 years ago there were several cataclysmic meteor strikes, and the earths temperature swung up and down wildly, eventually settling at a much higher temperature (ending the ice age). I am pretty sure this is accepted by the geological community.

You're wrong about this. There's not a lot of evidence for the Younger Dryas Impact Hypothesis. In particular, the best evidence--an actual meteoric impact crater--is completely missing. This is why proponents have instead suggested either that it was a series of large airbursts or an impact in the Laurentide ice sheet itself, to be able to keep a large crater from forming.

The current consensus hypothesis is that it's a reconfiguration of the glacial lake outflows on the margin of the Laurentide ice sheet that induced a breakdown of the thermohaline circulation system, which also explains some peculiarities of the Younger Dryas (like its effects were a lot worse in North America than the rest of the world).

[FloorEgg]

Thank you for taking the time to point this out respectfully. Looks like you're absolutely right about the current consensus, and my summary didn't fairly reflect all the evidence.

Times like this I wish I could edit older comments. I would update it to incorporate what you are saying and diminish the confidence in the impact hypothesis.

[AnimalMuppet]

Dude. Somebody told you you're wrong, and you listened? Refreshing to see.

And I'll try to return the favor. If they were airbursts, and so were providing heat but not stuff thrown up into the atmosphere, then I could maybe see meteors ending an ice age.