Science

Ancient Flood Myths Confirmed?; Eggheads Crack Up Over Evidence of Frighteningly Recent "Megatsunamis"—Must We Watch the Sky for Our Doom?

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Astronomers and marine geologists are abuzz, the New York Times reports, over the "Holocene Impact Working Group" and their theory that megacatastrophic meteor hits on our big blue marble are more common than commonly believed–and that one may have smacked the Indian Ocean as recently as 4,800 years ago.

The key to their story is "chevrons"–inland sediment deposits–that the Working Group apocalypticians think can be explained only by huge huge waves. No, even bigger than you are imagining. "No tsunami in the modern world could have made these features," says Ted Bryant, a geomorphologist at the University of Wollongong in New South Wales, Australia, who thinks they are caused by meteor hits. "End-of-the-world movies do not capture the size of these waves. Submarine landslides can cause major tsunamis, but they are localized. These are deposited along whole coastlines."

Burckle crater, recently discovered 900 miles southeast of Madagascar, site of some intriguing "chevrons," was found by looking for it based on the theory that inland chevrons=meteor impacts somewhere relatively nearby in the ocean. Dallas Abbott, an adjunct research scientist at Lamont-Doherty Earth Observatory in Palisades, N.Y. who searches for, and often finds, big holes in the ocean based on chevrons on land, believes the crater is only 4,500-5,000 years old, though it has not been authoritatively dated. Abbott has interpreted chevrons 4 miles inland in Australia as being connected to ocean craters whose sediment cores "contain melted rocks and magnetic spheres with fractures and textures characteristic of a cosmic impact." And that impact might be only 1,200 years old.

This conclusion about big object hits being this frequent and recent goes against dominant astronomical beliefs, so there are understandably many doubters. One of the doubts as expressed in the NY Times doesn't make instant sense to me. Dr. David Morrison of the NASA Ames Research Center says that: "We know what's out there, when they return, how close they come…there is no reason to think we have had major hits in the last 10,000 years."

But if what the Holocene Impact people are saying is true, then the specific objects that slammed Earth are no longer out there, no longer returning, and already came as close as they're ever gonna get. Perhaps establishment astronomers out there can further explain how our recent telescopic observations of what's floating around our solar system can unequivocally tell us that it isn't possible that a big rock hit us as recently as 4,500 years ago? Is it based on a belief that all these objects come in groups, and that the rest of the groups' orbits and approaches are well understood? Otherwise, not sure what to make of Dr. Morrison's comment.

NEXT: They Took Our Jaaarrrrbs!

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  1. Brain Doherty,

    On the “flood” issue I wouldn’t discount the Black Sea Deluge theory just yet.

  2. Anyway, he may merely be looking at the present and extrapolating that into the recent past.

  3. Is it possible he just means that we know what’s in our area of space now and can calculate a current probability/frequency of being hit by one of these asteroids, and that it seems unlikely the probabilities would have been significantly different in the (geologically) recent past?

  4. This is all so preliminary. Let’s give the learned men of science a few years to sort it out. It could be bullshit (see canals on mars) or could be revelutionary (see contintal drift). Time will tell.

  5. Zeno

    The Black Sea flooding could have been conflated with other flooding events.

    Brian24

    If I understand your question correctly, the population of Near Earth Objects should not change radically on time scales less than 1 million years. Even a near pass of a neighboring stellar-mass object would cause a “spike” lasting several million years.

    Assuming there were impacts 1,200 and 4,800 years ago, there are two possible explanations:

    1) The Indian Ocean got unlucky.

    2) The population count of potential impactors is missing a source. My guess would be that the Oort Cloud has not been properly assessed as a source of impactors. The Apollo object count may be off by as much as one order of magnitude, but the implied frequency of the article suggests it is off by two to three orders of magnitude.

    Neither of these impacts, if confirmed, seem to be “civilization enders” although they would have done severe damage.

  6. A major strike c 800 AD? Seems like the effects would be documented somewhere, even if the strike itself was remote.

  7. True. Chinese astronomers documented the 1054 AD supernova that gave rise to the Crab Nebula. You’d think that some fairly good record would have survived of two impacts in 800 AD.

    On the other hand, they hit in the Gulf of Carpinteria. Australians at the time didn’t have a written language; neither, I think, did Papuans. Would any literate culture have experienced the effects?

  8. Well, I for one welcome our large, rocky..asteroid thingy kind of outer space overlords!

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