Super-tsunami 4,800 years ago?

Ancient Crash, Epic Wave is a story in The New York Times about an enormous impact 4,800 years which might have had world-wide repercussions:

At the southern end of Madagascar lie four enormous wedge-shaped sediment deposits, called chevrons, that are composed of material from the ocean floor. Each covers twice the area of Manhattan with sediment as deep as the Chrysler Building is high.
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The explanation is obvious to some scientists. A large asteroid or comet, the kind that could kill a quarter of the world's population, smashed into the Indian Ocean 4,800 years ago, producing a tsunami at least 600 feet high, about 13 times as big as the one that inundated Indonesia nearly two years ago. The wave carried the huge deposits of sediment to land.

If it killed 1/4 of the world's population, and probably a disproportionate number around the rim of the Indian Ocean, we would probably be able to see a concurrent population bottleneck, and subsequent demographic expansion, in the genetic record. The Toba Catastrophe Theory after all is predicated on population genetic signatures correlated with a volcanic explosion 75,000 years ago.

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Lets see 4800 years ago would be 2800BC. History is a bit fuzzy back then, but it was roughly the time of Egypt's second dynasty. Several other Fertile Crescent civilizations were alive and kicking around that time too. If something killed off 1/4 of their populations you would find some archeological evidence, which I don't believe we have. Color me very skeptical.

If something killed off 1/4 of their populations you would find some archeological evidence, which I don't believe we have. Color me very skeptical.

yeah, i'll have to look it up. the only thing i would caution is that i do know that mesopatamian culture had an early flowering and expansion into syria and anatolia around 3000 and pulled back after that.

Lets see 4800 years ago would be 2800BC. History is a bit fuzzy back then, but it was roughly the time of Egypt's second dynasty. Several other Fertile Crescent civilizations were alive and kicking around that time too.

None of which were in the Indian Ocean basin. But enough water would make it through the Persian Gulf to cause massive flooding in Mesopotamia.

"we would probably be able to see a concurrent population bottleneck, and subsequent demographic expansion, in the genetic record."

I have a newbie question: can you recommend a source on the use of this sort of genetic evidence for non-geneticists, e.g. a historian or demographer who is looking for ways to study population changes in the past?

hm. well, you can always look at the literature in places like PUBMED, but try history and geography of human genes by cavalli-sforza. a bit dated, but the biggest single review out there. the real eve by steve oppenheimer comes close too.

None of which were in the Indian Ocean basin. But enough water would make it through the Persian Gulf to cause massive flooding in Mesopotamia.

The water from a tsunami is not going to kill 1/4 or the world's population. You need a global event to do that. I think what they are talking about is climate disruption.

That kind of climate disruption would make dense urban life difficult if not impossible. If this happened I'd expect most if not all urban centers to be depopulated at exactly this time. That kind of thing should be fairly easy to find in the archeological record.