Fire From the Sky · source record · paper

A possible volcanic origin for the Greenland ice core Pt anomaly near the Bølling-Allerød/Younger Dryas boundary

Green, C. E.; Baldini, J. U. L.; Brown, R. J.; et al. · 2025

AI-verified citationSRC-GREEN-2025

identifier / locator: PLOS ONE 20(9): e0331811, published 2025-09-18. DOI: 10.1371/journal.pone.0331811
url: https://pmc.ncbi.nlm.nih.gov/articles/PMC12445550
verification note: Full text read from PubMed Central through the site's reading tool (2026-10-20, session 2026-10-20-session-site-124745). The paper's funding statement reads "The author(s) received no specific funding for this work," and its competing-interests statement declares none. A March 2026 summary by its corresponding author in The Conversation (republished by ScienceDaily) describes the same study and adds no data.
reliability notes: Durham and Royal Holloway authors outside both the proponent network and the 2023 critical review's authorship; the authors state their timing analysis was done independently of, and in parallel with, the three earlier analyses it confirms.
Its timing result re-analyses the same GISP2 platinum data (Petaev et al. 2013) on the same GICC05 chronology as the earlier analyses: independent work, not independent data.
The volcanic-source proposal rests on elemental-ratio comparisons and plausibility arguments; the authors state they cannot rule out an unknown type of meteorite.

Evidence drawn from this source

Supports· strongYDIH-E039

Green et al. 2025: an independent re-dating confirms the decades-long lag

what the source states: Comparing the GISP2 platinum series with annually resolved NGRIP oxygen isotopes, Greenland and Antarctic volcanic sulphate and a Spanish stalagmite record on the GICC05 timescale, the authors place the platinum peak at 12,822 yr BP and the cooling's onset about 45 years earlier. They write that their timing work "was conducted independently and in parallel with these works, without any knowledge of their results," and conclude: "Our results confirm the conclusions of these other works, that the Pt spike occurs several decades after the onset of the YDE, so whatever caused the Pt spike occurred too late to be a causal mechanism of the YDE."
what we infer: Four analyses (Svensson 2020, Abbott 2021, Holliday 2023, and this one) now agree on the lag, the last carried out without sight of the others. The case's best-attested single observation therefore cannot be the trigger's signature: if an impact cooled the North Atlantic, the Greenland platinum is not its fallout, or the fallout came decades after the cooling started. A multi-year debris-stream encounter of the kind the Taurid scenario describes would not by itself remove the problem, because the platinum still arrives after the cooling had begun.
limitations: Same platinum data and same GICC05 chronology as the earlier analyses: the agreement shows the transfer is reproducible, not that a second core shows the same lag. The authors' own first recommendation is to replicate the platinum signal in another deep Greenland core.
The authors are advocates of a rival (volcanic) trigger; the timing result does not depend on that view, but the paper's framing does.

Green, C. E. (2025)AI-verified citationYDIH-C507

Undermines· weakYDIH-E040

Green et al. 2025: the platinum's chemistry and duration read as volcanic, not as one impact

what the source states: The authors find that elevated platinum spans 12,833–12,819 yr BP and write that this "suggests a persistent yet variable flux of Pt lasting about 14 years, rather than a short-lived event like a single explosive eruption or a bolide impact." Comparing elemental ratios with meteorites, magmas, impact sediments and volcanic products, they report that "The most closely matching geochemical signature is that of volcanic gas condensates," and conclude: "Although we cannot rule out the impact of an unknown type of meteorite, the simplest explanation is that the Pt spike instead probably reflects a relatively small Icelandic fissure eruption." Their new measurements of Laacher See tephra find it platinum-poor, and they conclude the results "very strongly suggest that the LSE was not responsible for the GISP2 Pt anomaly."
what we infer: A terrestrial source for the Greenland platinum is now a published, specified proposal rather than a bare possibility, and the one named volcanic candidate that had been suggested (Laacher See) is ruled out by direct measurement. Carried as weak: the volcanic reading rests on which reference materials the spike's ratios sit nearest, and the spike resembles nothing well; it narrows the impact reading of the platinum without discriminating the source the way osmium isotopes would.
limitations: The authors also write that "we cannot rule out post-depositional diffusion of Pt within the ice to produce the Pt spike profile" — which weakens the duration argument they rest on the 14-year spread.
The ice-core spike's Pt/Al values are far from every reference group, volcanic condensates included; nearest is not matching.
No isotopic source tracer was measured; the decisive measurement (osmium isotopes on the same ice) remains undone.
Their 14-year span counts the elevated interval differently from the ~21-year span in the 2026 correction's characterization; both describe the same measurements.

Green, C. E. (2025)AI-verified citationYDIH-C011