4 ms·

What's the citation for the ice core stuff? I found two papers that investigated this and neither found evidence to support the impact theory, so it seems ambig

What's the citation for the ice core stuff? I found two papers that investigated this and neither found evidence to support the impact theory, so it seems ambiguous to me, but this isn't my field so obviously I might just be failing to find a more recent result. If you wanna read em: Paquay, François S., et al. “Absence of Geochemical Evidence for an Impact Event at the Bølling-Allerød/Younger Dryas Transition.” Proceedings of the National Academy of Sciences of the United States of America, vol. 106, no. 51, 2009, pp. 21505–10 Surovell, Todd A., et al. “An Independent Evaluation of the Younger Dryas Extraterrestrial Impact Hypothesis.” Proceedings of the National Academy of Sciences of the United States of America, vol. 106, no. 43, 2009, pp. 18155–58. Update: Found (some?) ice core evidence, it is indeed more recent, but I'm hopelessly out of my wheelhouse at this point so I'll just cite it for anyone also interested and suggest that these more recent publications do seem pretty confident in their conclusion that the impact did happen. So it seems user moloch-hai is correct: Petaev, Michail I., et al. “Large Pt Anomaly in the Greenland Ice Core Points to a Cataclysm at the Onset of Younger Dryas.” Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 32, 2013, pp. 12917–20. Pretty cool stuff, thanks for sharing and prompting me to learn more about it.

moloch-hai 4y ago
Those are both from 2009, ten years before the smoking gun cited. They are studiously silent now. [Edit: Thank you for Petaev. I had not seen it.]
- jcranmer 4y ago
  > Those are both from 2009, ten years before the smoking gun cited. Just so you're aware, you haven't actually cited the study yet in this thread. (Kjær, Kurt H., et al. "A large impact crater beneath Hiawatha Glacier in northwest Greenland." Science advances 4.11 (2018) is the citation, for future reference) (FWIW, Kenny, Gavin G., et al. "A Late Paleocene age for Greenland’s Hiawatha impact structure." Science advances 8.10 (2022) disputes the age given for that impact crater.)
  - moloch-hai 4y ago
    As already noted, any connection to Hiawatha crater was only ever conjecture. Evidence that Hiawatha was not coincident with the YDB obviously tells us nothing at all about YDB events. A recent survey article is Sweatman, The Younger Dryas impact hypothesis: Review of the impact evidence https://www.sciencedirect.com/science/article/abs/pii/S0012825221001781?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S00128... The remaining controversy is how much the strike contributed to the Younger Dryas development and other coincident events, particularly extinctions. To me, it is ludicrous to blame those on Clovis people, or on a climate hiccup smaller than they had weathered easily many times before. Now that we know people had already been there for 10+ millennia, the sudden wipeout idea gets much sillier. The idea that the strike triggered the YD is appealing, but the record shows several other such cooling periods with very similar profile and duration in the past 100ky. It seems unlikely they were all triggered by comet strikes. But they could have been: we now know our records of comet strikes are woefully incomplete, having detected a very recent one only by enormous effort. See also Wendy S. Wolbach et al. Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ∼12,800 Years Ago. https://www.journals.uchicago.edu/doi/10.1086/695703 https://www.journals.uchicago.edu/doi/10.1086/695703
    - moloch-hai 4y ago
      Adding: it is disgraceful how sloppy and unscrupulous most opponents of the cosmic impact model have been. They should be ashamed. There is nothing wrong with demanding a high standard of evidence. Failing to maintain even the most basic standards for your own work is, especially in context, inexcusable.
      - puffoflogic 4y ago
        They are righteous defenders of what amounts to the current creation myth of scientism. Nothing to see here when The Science is understood to be a religion.

moloch-hai 4y ago

Those are both from 2009, ten years before the smoking gun cited. They are studiously silent now. [Edit: Thank you for Petaev. I had not seen it.]

jcranmer 4y ago
> Those are both from 2009, ten years before the smoking gun cited. Just so you're aware, you haven't actually cited the study yet in this thread. (Kjær, Kurt H., et al. "A large impact crater beneath Hiawatha Glacier in northwest Greenland." Science advances 4.11 (2018) is the citation, for future reference) (FWIW, Kenny, Gavin G., et al. "A Late Paleocene age for Greenland’s Hiawatha impact structure." Science advances 8.10 (2022) disputes the age given for that impact crater.)
- moloch-hai 4y ago
  As already noted, any connection to Hiawatha crater was only ever conjecture. Evidence that Hiawatha was not coincident with the YDB obviously tells us nothing at all about YDB events. A recent survey article is Sweatman, The Younger Dryas impact hypothesis: Review of the impact evidence https://www.sciencedirect.com/science/article/abs/pii/S0012825221001781?via%3Dihub https://www.sciencedirect.com/science/article/abs/pii/S00128... The remaining controversy is how much the strike contributed to the Younger Dryas development and other coincident events, particularly extinctions. To me, it is ludicrous to blame those on Clovis people, or on a climate hiccup smaller than they had weathered easily many times before. Now that we know people had already been there for 10+ millennia, the sudden wipeout idea gets much sillier. The idea that the strike triggered the YD is appealing, but the record shows several other such cooling periods with very similar profile and duration in the past 100ky. It seems unlikely they were all triggered by comet strikes. But they could have been: we now know our records of comet strikes are woefully incomplete, having detected a very recent one only by enormous effort. See also Wendy S. Wolbach et al. Extraordinary Biomass-Burning Episode and Impact Winter Triggered by the Younger Dryas Cosmic Impact ∼12,800 Years Ago. https://www.journals.uchicago.edu/doi/10.1086/695703 https://www.journals.uchicago.edu/doi/10.1086/695703
  - moloch-hai 4y ago
    Adding: it is disgraceful how sloppy and unscrupulous most opponents of the cosmic impact model have been. They should be ashamed. There is nothing wrong with demanding a high standard of evidence. Failing to maintain even the most basic standards for your own work is, especially in context, inexcusable.
    - puffoflogic 4y ago
      They are righteous defenders of what amounts to the current creation myth of scientism. Nothing to see here when The Science is understood to be a religion.