Talk:Younger Dryas/Archive 1

Archive 1

Was the Younger Dryas global?

This section is totally unsourced, and contains no information about timing William M. Connolley 17:47, 25 March 2006 (UTC)

New talk at the end

Of note is the massive release of fresh water into the Atlantic from several sources which resembles the melting of the Artic and Greenland ice today. 11,000 BP, the source was Lake Agasizz fresh water taking one of three routes into the sea. If you don't know what Lake Agasizz was, look it up.

While the earth was warming so rapidly that seven feet of the North American Glaciers was melting per year, suddenly the trend reveresed.

Will the massive release of fresh water today suprise climatologists? Will the earth suddenly today as it did 11000 years ago plunge into an unexpected cold spell.

Stay tuned.

No. No. William M. Connolley 08:53, 25 April 2006 (UTC)

Just Europe. It's the possible Shutdown of thermohaline circulation that is the concern, though not troubling to William M. Connolley .--Wetman 16:34, 16 January 2007 (UTC)

On the topic of the article, the Lake Agassiz wiki page says that the lake finished draining into the Hudson Bay at around 8.4kaBP, which means is would have triggered the 8.2kaBP cooling and aridification event rather than the Younger Dryas. Is this a case where the dating is so uncertain that it's impossible to know? Or is the article that this page cites out of date? - Unregistered 20:44, 20 October 2008

Citation style

I'm currently updating the citation style used in this article at User:SparrowsWing/Younger_Dryas. Will put the updated article here once it's all complete. SparrowsWing _(talk) 00:30, 31 January 2007 (UTC)

I've updated the page - can we remove the message at the top now? SparrowsWing _(talk) 00:57, 31 January 2007 (UTC)

I've removed the message as no one seems to have objected - let me know if further work on the reference style is required. SparrowsWing _(talk) 19:36, 31 January 2007 (UTC)

Bad: "Was the Younger Dryas global?"

That entire section needs to be rewritten. Encyclopedic articles never pose questions to the reader. The reader is here to find answers, not to have questions thrown at them. — SMcCandlish [talk] [cont] ‹(-¿-)› 07:20, 3 April 2009 (UTC)

"Recent reseach"

Re [1]. I don't think we should be including just-published papers, unless there is some truely urgent reason to do so. Also, the edit misinterprets it. The wind shift isn't said to be the *cause* of the YD - that remains chnages in tthe overturning, or whatever. Its just the transmission William M. Connolley (talk) 07:19, 7 August 2008 (UTC)

Where do you draw the line between "just published" and "well established"? One year? Ten years? ––Bender235 (talk) 09:56, 7 August 2008 (UTC)

I agree, though it should be noted it is new. The paper is published, let it say what it says. I also agree with William's comment on my poor phrasing :) Perhaps the theorised north american impact and ice sheet destabilisation lead to the dramatic wind shifts reported in the new paper. A meteorologist view is needed. --Insider201283 (talk) 14:22, 7 August 2008 (UTC)

There is, of course, no firm line. Something like giving people time to read and respond is right. This helps, because Nature has a short-turn round time, so a few months is good enough. Slower journals need 6 months to a year William M. Connolley (talk) 15:05, 7 August 2008 (UTC)

Can you please clarify what "that remains chnages in tthe overturning" is supposed to mean? I'm not picking on you. I have parsed what I figure the intended words were, and it still doesn't make any sense to me. On other matters: I agree that a couple of months is good enough in the case of Nature, but have to disagree that 0.5 – 1 year is required in any other cases. Four months max. This is not 1981 any longer. Things move much faster now in the academic world. — SMcCandlish [talk] [cont] ‹(-¿-)› 07:26, 3 April 2009 (UTC)

that remains chnages in tthe overturning - nope, cos I don't know where you got it from. Can you provide a diff? There are plenty of slow journals William M. Connolley (talk) 08:55, 3 April 2009 (UTC)

Looks like this is coming round again. I just took out [2] as over-excited. Discuss William M. Connolley (talk) 23:23, 30 November 2009 (UTC)

Here's a new study that links the Younger Dryas to glacial melting. Could be usefful: http://www.eurekalert.org/pub_releases/2010-03/uos-ism032910.php Nathan McKnight -- Aelffin (talk) 20:01, 5 April 2010 (UTC)

Dating problems

This article gives dates of 12,800 to 11,500 BP for the Younger Dryas, but the article on the Older Dryas dates it 11,700 to 12,000 BP, and later in the same article 14,000 to 13,700. There are similar contradictions in academic sources. So far as I can see the earlier dates of c. 12,000 BP for the Younger Dryas and c. 14,000 BP for the Older Dryas are correct, and the confusion arises because some authors use uncalibrated dates. If this is correct, I think it would be better if Wikipedia articles stuck to calibrated dates, that is real dates. Uncalibrated ones, before allowing for variations of C14 in the atmosphere at different times, are just a confusing technicality.

Can someone more expert than me say whether I have got this right, or is the confusion over dating due to some other cause, such as genuine differences over when the Dryas ice ages occurred (major differences, not the minor ones discussed in the sources), or authors sometimes using BC instead of BP? Dudley Miles (talk) 15:32, 14 August 2010 (UTC) —Preceding unsigned comment added by Dudley Miles (talk • contribs)

tya

I propose a reversion of the recent conversion to non-standard "tya" notation. The abbreviation "ka BP" is more acceptable. JIMp _talk·cont 01:43, 19 April 2011 (UTC)

Misc. Uncollected Comments

"The magnitude and abruptness of these changes would suggest that low latitude climate did not respond passively during the YD/DCR." What the hell does "did not respond passively" mean? It sounds like a note taken during a lecture that nobody reading this page was at. —Preceding unsigned comment added by 75.87.138.107 (talk) 05:40, 5 May 2011 (UTC)

What, pray tell, is a stadial? Ice-age or something? Kesuari 13:44, 16 Dec 2004 (UTC)

A stadial is a colder episode within an 'Ice-Age' or more correctly a glacial period. It's confusing, because the term 'Ice-Age' has been used inconsistently (sometimes to refer to a geological era, sometimes a particular glacial period, sometimes a particular stadial episode!). Technically, there are glacial and interglacial periods, and within glacial periods, stadials and interstadials (short episodes marked by warming). So, for example, the Younger Dryas is a stadial episode in the Weichselian glacial period. Hope that helps...NickW 22:43, 18 Dec 2004 (UTC)

Was it named after someone called Younger? Or was there an Elder Dryas? Adam 07:15, 6 September 2005 (UTC)

The latter! The Yonger Dryas was preceeded by the warmer Allerod interstadial, which followed the Older Dryas stadial. All part of the 'Lateglacial' period of climate change in NW Europe circa. 14-10k 14C yrs. BP. NickW 18:39, 6 September 2005 (UTC)

Thanks. Perhaps the article should explain this. I am reading Steven Mithen's After the Ice at the moment, and he doesn't explain the origin of the term either. Adam 00:48, 7 September 2005 (UTC)

I think we need an article dedicated to the Lateglacial. However, it's a tricky one! Lots of different definitions / perspectives on the same terms. I'll put it on my list of things to do! NickW 11:02, 7 September 2005 (UTC)

Another reasonable question a reader needs answered: Why is this stadial named for a wildflower? I'll come back eventually and answer it myself if no one cares to. There aren't many suggestions for improving this article to be gleaned from looking at "What links here" (!). Why isn't Younger Dryas mentioned in numerous articles? --Wetman 07:40, 17 December 2005 (UTC)--Wetman 07:40, 17 December 2005 (UTC)

..because pollen from this taxa was found in abundance in what were identified as YD sediments, and so the reconstructed flora would have included that taxa, which would of been a characteristic feature of the stadial landscape... I also think an explanation should be included, but maybe not in the opening para. NickW 12:59, 17 December 2005 (UTC)

Methane

I took out:

Another theory is that hunting of the newly arriving humans in the Americas lead to the Quaternary extinction event which significantly reduced methane gas emissions into the atmosphere. Methane is a powerful greenhouse gas and the removal from the atmosphere triggered sudden global cooling. [3]

the ref isn't good and the idea doesn't sound very plausible William M. Connolley (talk) 09:48, 25 July 2010 (UTC)

• This theory is based on a paper[4]. The interview points out that the predicted drop in methane from the extinction event matches the decrease of methane in the atmosphere measured in ice cores. —Preceding unsigned comment added by 99.233.132.120 (talk) 19:00, 25 July 2010 (UTC)

A paper is good. Sadly that one is behind a payway: all I get is About 13,400 years ago, the Americas were heavily populated with large-bodied herbivores such as mammoths, camelids and giant ground sloths; the megaherbivore assemblage was richer than in present-day Africa. However, by 11,500 years ago and within 1,000 years of the arrival of humans in the New World, 80% of these large-bodied mammals were extinct1. which isn't illuminating William M. Connolley (talk) 21:49, 25 July 2010 (UTC)

Just read the paper (actually, a letter to the editor). It is not a theory, but rather a speculation. IMO, it has some significant holes, such as, "why is there the time lag to the Younger Dryas that is >> the 100-year residence time of atmospheric methane". But my opinion isn't important here. What is important is that the authors present it not as an established theory but as an untested possibility: it could come to be known to be important, but it isn't seen that way right now, and they fully admit that. Once an actual paper with evidence comes out, then we might consider including it. Until then, it might just be something that you'll be interested in watching.

By the way, if either of you want the letter to the editor, please send me an email (there is a link on the sidebar when you go to my user page or user talk page). Awickert (talk) 05:40, 27 July 2010 (UTC)

Agree with Conolley and Awickert. If the theory has merit someone will write a peer reviewed study. Until then it deosn't merit inclusion as a theory.72.75.1.89 (talk) 12:05, 23 July 2011 (UTC)

timing of northern and southern hemispehere cooling and impact event review needed

the article as of this date states in global affects section: "The Huelmo/Mascardi Cold Reversal in the Southern Hemisphere began slightly before the Younger Dryas and ended at the same time." In the causes section it states: "This theory [lake agassiz] does not explain why South America cooled first."

I am under the impression from surveying current material that the current dating of the cooling southern hemisphere and south America is in quesiton and indeed that the majority of current material suggests it occurred well after the earliest estimated boundary of the onset of YD in the norther hemisphere. my understanding is that the earliest onset of Huelmo is estimated at 12.4k BP and of YD is 12.9k bp on the calibrated. Moreover more recent scholarship on the huelmo reduces the likelihood its at the early end of its estimates, (eg http://www.sciencedirect.com/science/article/pii/S0277379100000937 and there i s even scholarship suggesting that the two events are unrelated and the huelmo was a much smaller local pheonemana than previous thought (http://www.sciencedirect.com/science/article/pii/027737919390043L and http://www.sciencemag.org/content/321/5887/392.abstract)

In short the absolute statements: "The Huelmo/Mascardi Cold Reversal in the Southern Hemisphere began slightly before the Younger Dryas" and "This theory does not explain why South America cooled first" should be removed of changed, since the margins of estimate for YS and H/M already allow the possibility that YD occurred first, and H/M maybe a smaller, local and less pronounced event anyway.

Also of concern is the discussion and debunking of the impact theory. This theory is now rejected by most in the field based on the evidence not being duplicatable and fairly definitive proof that the evidence had been misinterpreted. yet it and it rejection dominates the majority of causes section. At this point, given we now know the nanodiamonds interpretation as incorrect, it should simply be one sentence to the effect of: "Researchers had thought they found nanodiamonds that might indicate an impact event associated with YD onset, but those finds were misinterpreted, the nanodiamonds are not present, and the consensus is now that no such impact event occurred."12:03, 23 July 2011 (UTC) — Preceding unsigned comment added by 72.75.1.89 (talk)

I should add to my own comment that the impact hypothesis is not just rejected, it is widely thought to be based on incorrect interpretation but likely fraudulent data. see: Pinter et al The Younger Dryas Impact Hypothesis: A requiem, ESR, 2011 and http://johnhawks.net/weblog/reviews/climate/clovis-comet-fraud-2011.html 72.75.1.89 (talk) 12:10, 23 July 2011 (UTC)

Too Hard to Read?

Does anyone else think this article is too technical for the lay person to read. I came here because a friend of mine is writing a book involving the Younger-Dryas Event but instead of being illuminated on the subject, I find myself awash in jargon and formulas that very few people outside of the geology world can comprehend. You can accuse me of wanting this dumbed down if you want, but this is supposed to be a few pages of encyclopedic knowledge so that someone who knows nothing about this event can begin to learn about it. In the state that this page is in now I think it is far too difficult for the common person to understand. --24.145.160.174 23:59, 29 July 2007 (UTC)

i do think the article is written as if cramped for space and could relax and open up in more discursive style. --Wetman 08:44, 30 July 2007 (UTC)

The leadin for this article is way too technical. After I read it, I had no interest at all in reading the rest of the article. I am sure it is technically correct and an expert in the field would have no trouble understanding it, but an expert would turn to a textbook, not an encyclopaedia. I'll start with the phrase "approximately 12.8 and 11.5 ka BP". I have an engineering degree, decades of experience, and an unexplainable interest in obscure measurements, but this one stumped me. Now I'm glad that "ka" and "BP" are linked, but it took me four clicks and some reading to realize that the phrase means "about 11,500 to 12,800 years ago". Not only is this just a precise as the text in the current article, it is also much easier to understand, and it allows the numbers to be placed in the order that makes more sense to a casual reader.

I turned to the graph. Pictures always simplify things, right? No, I just got more frustrated. Firstly, the graph is too small. I had to click it in order to read anything on it. Secondly, the numbers on the horizontal axis are unitless. I gathered they must years (or "a", to be precise :) ), but they are displayed in scientific notation rather than the SI units used elsewhere in the article. Since the exponent is not a multiple of 3, I had to calculate to figure out where on the graph to look. Thirdly, the graph runs backwards! Yes, I know you can define any units you want for the horizontal axis, but why would you choose to have time run from right to left when every algebra problem consistently runs time from left to right? Fourthly, now that I know the graph runs backwards, it appears that the temperature RISES at the critical time. Ok, further reading tells me that the vertical axis does not really measure temperature, it measures a "temperature proxy" known as "δ18O", which must vary inversely with temperature. This is not intuitive.

I am not an expert in this subject, but I am a technical, educated reader. If I misunderstood the facts in my complaints above (and I certainly might have), I believe they were not explained very well. If I got it all right, then the leadin is way too technical. Cwelgo (talk) 22:07, 18 August 2011 (UTC)

Article protected for a day

I've protected this article for 24 hours. Please sort out the dispute before it's unprotected, as further edit warring will almost certainly end up with blocks. Thanks. Dougweller (talk) 20:43, 14 April 2012 (UTC)

BP and ka

I strongly disagree with the change from "12,800 and 11,500 years BP (before present)" to "12.8–11.5 ka". The first is clear to the non-expert reader, the second incomprehensible. I think I have come across ka before, but I would need to check what it meant if I could not deduce it from the context. The article on year shows it as the SI prefixed equivalent of kyr, in other words not a usage which would be familiar to most Wikipedia users who want to know something about the Younger Dryas. Dudley Miles (talk) 14:12, 17 April 2012 (UTC)

Since ka (kiloannum according to the link on the Ka dab page) refers to calendar years, and BP does not, we must go by the source, and Muscheler et al seems to say BP. See [5] (which does give alternative dates). I'll revert to BP. Dougweller (talk) 14:22, 17 April 2012 (UTC)

I'm going to have to respectfully disagree with both of you. The difference between BP and ka (which assumes the "ago") is minor. It is about 62 years, and if you throw in ¹⁴
C error, that difference is probably smaller than that. My point in fixing it, which was done in complete good faith, was to make the reading consistent. Some of the citations use ka. Some use ka BP. And others use BP. ka was wiki-linked for definition. I realize that we need to write for the non-expert, but it is not our goal to write for the lowest common denominator of intelligence. And let's be honest, this article would be useful to a small number of people. It is an obscure field.

Almost every single geological wiki article, where pros (defined loosely as scholarly geologists) edit, makes the change to Ma, Ga, or ka; but obviously not all. For example, lists of volcanoes would be horrendously difficult to read if we changed from the vagaries of each underlying author. At an even broader level, we change titles of articles to "modern" names, even if there's no consistency in usage. The biggest sore spot, for me, is the Cretaceous–Paleogene extinction event, the so called modern name. However, numerous authors still use Cretaceous–Tertiary extinction event, or K-T event, but we "change" the terminology to be consistent.

Even in the dating scheme, peer-reviewed articles use four different styles: mya (million years ago, and is claimed to be deprecated), Ma (million years, with the "ago" assumed), Ma BP (which really is redundant), and BP. Are you saying a scholarly Wiki article should use all four? Well, I disagree with both of you completely, and I will continue to make articles consistent and easy-to-read. I won't revert on this entry (despite the fact that some useful edits were reverted, and in a couple of cases, the citations themselves were inconsistent), but I think the reversion make the article worse, not better in readability for the reasonably intelligent reader. How is it better to have ka, ka BP and BP as the dating units? How is it easier to read? It isn't And please understand that I am assuming good faith on both of your parts, and that this is a disagreement that probably has no legitimate answer, kind of like the old BC/BCE, AD/CE argument, always a favorite for edit-warring. But unless you can point me to The Official Laws of Wikipedia that state I'm wrong, why wouldn't my edits stand without some discussion? SkepticalRaptor (talk) 16:55, 17 April 2012 (UTC)

Assuming that this text will still be read in 1,000 years, ka will imply the wrong information. BP is years before 1950. ka is years before today. These do not mean anything close to the same thing. This is also why radio carbon dates are given in either BP or y2k, but never in ka. Q Science (talk) 05:41, 19 April 2012 (UTC)

We've moved on. SkepticalRaptor (talk) 05:45, 19 April 2012 (UTC)

Larcher See volcano

I do not agree with the deletion of the section on the Laacher See volcano, and particularly not with the accusation of bad faith. Wikipedia rules are that you should assume good faith in disagreements. However, I think the section does need amendment. The article on Laacher See states that it was not of a size which normally produces long term effects, although I do not have access to the sources cited to see whether this is referenced. The article at [6] states that Laacher See pre-dated the Younger Dryas by 200 years. I think these points should be incorporated into the section by an editor who has better access to the sources than I do. Dudley Miles (talk) 18:52, 20 April 2012 (UTC)

This editor as attempted to out me, attacked me on and off wiki, so AGF really hasn't been shown me. Please re-write what you think is appropriate. I know it's "original research" but it's clear that the it's impossible to nail the exact date of anything here to the year. Plus or minus 200 years sounds like it's within a reasonable error for the both the eruption and the start of the Younger Dryas. I've been doing a thorough review of all of the research in this area, and it's really clear that there's not a lot of clear indications of the what constitutes the actual boundary. Megafauna died out. But actually they didn't. The paleoindians die out. But actually they didn't. There were massive wildfires in North America. But actually there wasn't. The climate changed immediately. But we have no evidence of that. The Younger Dryas boundary is clearly critical to human and large mammalian evolution, but pinpointing it is hard. Also with respect to Laacher See, there is plenty of evidence that many boundaries that include an extinction event (and it's really hard to say there was an extinction event with the Younger Dryas), there are usually numerous causes in addition a singular event. For example the K-Pg extinction event was preceded by the Deccan Traps by 200,000 years, which may have begun the extinction of the archosaurs (except for birds), with the impact event sending the whole clade over the edge. Although the evidence for a impact event at the Younger Dryas is overwhelmed by the lack of evidence or misinterpreted evidence, even if it did exist, there are probably a large number of different geological and, without a doubt, biological causes of the wildly inconsistent extinction of organisms. SkepticalRaptor (talk) 19:32, 20 April 2012 (UTC)

The assertion that the volcano is considered a plausible cause needs a cite - based on a quick scan of the ref titles, the 2 later refs are only for the tephra layer, not for the cause William M. Connolley (talk) 22:53, 20 April 2012 (UTC)

The assertion that Laacher See is considered a plausible Younger Dryas contributor by anyone in the geological community is demonstrably false. CosmicLifeform (talk) 15:35, 21 April 2012 (UTC)

Recent News on Impact Theory

This may be useful as a reference (although, the original publication would be better).
Study Jointly Led by UCSB Researcher Finds New Evidence Supporting Theory of Extraterrestrial Impact 2012-06-11, UC Santa Barbara
— al-Shimoni (talk) 04:24, 8 July 2012 (UTC)

The new PNAS paper (Very high-temperature impact melt products as evidence for cosmic airbursts and impacts 12,900 years ago), Bunch et al. is now posted with free access: http://www.pnas.org/content/early/2012/06/14/1204453109.full.pdf+html Bkobres (talk) 17:48, 10 July 2012 (UTC)

Laacher See Volcano and the Younger Dryas =

The claim that the Laacher See Volcano is related in any way to the Younger Dryas Chronozone is a complete fabrication by SkepticalRaptor. Since he watches these pages like a hawk and reverts any credible edits by any credible editors, I will leave it up to someone else to attempt to revert this obvious fabrication. The Laacher See eruption is precisely dated by tephrachronology to 200 years before the onset of the Younger Dryas. Until this is sorted out I'm hitting this page with a POV tag as well. CosmicLifeform (talk) 19:24, 11 December 2012 (UTC)

Update 12/12/12 - If I thought editing this page would be productive I could easily proved cites for C14 dating and tephrachronology that soundly refute the Laacher See Younger Dryas connection. SkepticalRaptor feels that he has absolute control over these two Younger Dryas pages, yet he appears to be unable to perform even the simplist research that would refute his obviously fabricated claim that the Laacher See eruption was related to the Younger Dryas. Merely googling 'Laacher See Younger Dryas' produces the two relevant modern publications on this issue. CosmicLifeform (talk) 17:04, 12 December 2012 (UTC)

Further Update - SkepticalRaptor accuses me of calling him on the Laacher See Volcano section of the Younger Dryas wiki page, so I can only reiterate - the section is a complete fabrication not made in good faith, as demonstrated by this modern refernece : Radiocarbon age of the Laacher See Tephra; 11,230 + or - 40 BP. Irena Hajdas, Ochs D Ivy, Georges Bonani, Andre F Lotter, Bernd Zolitschka, Christian Schluechter

The Laacher See volcanic eruption event has NOTHING to do with the Younger Dryas.

Go ahead and ban me, I don't give a fuck anymore, this has become a farce.

No donations from me Mr. Wiki guy!

SkepticalRaptor has blocked CosmicLifeform unfairly for disputing the rational of including a particular piece of evidence as a possible cause of the Younger Dryas onset. The most recent authoritative article on this sides with CosmicLifeform in placing the Laache See eruption 200 years prior to the YD onset ( http://www.umr5059.univ-montp2.fr/doc_finsinger/Lane_etal_QSR_2011.pdf ). It is clear that SkepticalRaptor is a biased participant in the discussion and has been since the early part of this year, when s/he began editing Wikipedia. The following statement from SkepticalRaptor makes this contention very hard to deny:

http://en.wikipedia.org/w/index.php?title=User_talk:SkepticalRaptor&oldid=487399099

One more thing Mr. Weller. You're doing something about which I keep writing (off-wiki, of course); administrators threaten individuals when there's a so-called "content dispute." The the facts are these: the impact hypothesis is simply junk science, no different than homeopathy. There are only a few articles, when weighed against the vast number of articles that do not support the hypothesis, which would indicate an emotional attachment. My original intent was to clean-up the article, because it had some inaccuracies, including calling it a theory. A theory, in science, is something that is way up the list, kind of like Evolution, essentially a fact. Then when I investigated the "theory" I found more scientific articles ripping it to pieces, including a number of articles that couldn't repeat the experimental evidence. So, there really isn't a content dispute. There is on one side a POV editor who has resorted to on-wiki and off-wiki attacks. And there's me, who has no emotional attachment to this article, just enjoy editing. I like looking up citations to see if they actually state what the writer here says they state, and since you're an admin, you must know that there are frequent issues. Anyways, not that anyone cares, I'm just stating the facts. It's not a content dispute. It's POV vs. NPOV, and I stand by the fact that NPOV, especially in FRINGE beliefs, requires extraordinary evidence. And it's lacking. SkepticalRaptor (talk) 21:05, 14 April 2012 (UTC)

This 'editor' is doing a disservice to Wikipedia by including erroneous statements, such as pointed out above on this talk-page as well as the related YD-impact hypothesis talk-page, and refusing to correct these misstatements when pointed out. Perhaps one of the '10 mature, respectful WP administrators' SkepticalRaptor alludes to on his/her personal talk-page can rein in this adolescent personality. Bkobres (talk) 18:52, 14 December 2012 (UTC)

Causes

(This is an extract from my book: "World without war, made possible by empowered individuals" http://www.amazon.com/world-without-war-empowered-individuals/dp/1442181303/ref=sr_1_cc_2?ie=UTF8&qid=1296000774&sr=1-2-catcorr) The Maya of South America had one of the most accurate calendars; it started on 5 June 8,498 BCE. It was the day of a constellation of the Sun, Venus, Earth and its Moon. This is not a date for Creation, but it coincides with a possible date of the earth-shattering destruction of Atlantis and its advanced civilisation and a new beginning for the world of the Mayas. The destruction of Atlantis, according to Otto Muck, a German explosives engineer during World War II, was caused by an asteroid 11 kilometres in diameter, captured by the above constellation changing its trajectory towards earth, breaking up into two main parts and many smaller fractions and crashing into the Atlantic off Florida. The impact created volcanic eruptions all along the junction of the African/European and the American tectonic plates running along the north-south centreline of the Atlantic. It sank Atlantis (located on the fault line), and the asteroid’s slanted impact tilted the earth’s axis of rotation, plunging Siberia into a sudden arctic temperature drop, killing and deep-freezing the Mammoths. The enormous secondary effects altered the flow of the Gulf Stream that was no longer restricted by Atlantis and could then flow unhindered past the west coast of Britain, warming that part of the Atlantic and causing the end of the last Ice Age. This and the hovering dark smoke cover in the stratosphere that remained for thousands of years, changed the climate in the Northern Hemisphere. It was also the time of the last major flood of the Nile, and probably the cause of Noah’s flood, as huge amounts of water mixed with volcanic products were projected into the stratosphere and deposited as a thick alluvial band of fertile loess starting in France and extending to Turkistan and Northern China. “It is magma atomized into droplets and turned into volcanic ash, ejected together with calcareous marine ooze from the Atlantic seabed high into the stratosphere.”(Otto Muck – "The Secrets of Atlantis" – page 226 – translation copyright 1978 William Collins Sons & Co Ltd, published Book Club Associates) The pumice formed by lava falling into the ocean and floating over a very large area could well have been the ‘mud’ in Solon’s record of the event. — Preceding unsigned comment added by Nick veltjens (talk • contribs) 05:05, 17 January 2012 (UTC)

That sounds like a rather controversial theory, to put it very politely (there are much shorter expressions I could have used). You're not using Wikipedia as a platform for advertising your book are you? 81.101.197.228 (talk) 20:58, 5 January 2013 (UTC)

New Review Paper About Younger Dryas Impact Hypothesis

There is a new review paper, which documents serious flaws with claims of "high-temperature impact melt products" being found and other evidence used to argue for the Younger Dryas Impact Hypothesis. It is:

Boslough, M, K Nicoll, V Holliday, TL Daulton, D Meltzer, N Pinter, AC Scott, T Surovell, P Claeys, J. Gill, F. Paquay, J. Marlon, P. Bartlein, C. Whitlock, D. Grayson, and AJT Jull (2012) Arguments and Evidence Against a Younger Dryas Impact Event. In L Giosan and others, eds., pp. 13-26, Climates, Landscapes, and Civilizations. Geophysical Monograph Series. vol. 198, American Geophysical Union, Washington, D. C., doi:10.1029/2012GM001209.

The content of this paper is discussed in:

Singer, N (2013) Study rebuts hypothesis that comet attacks ended 9,000-year-old Clovis culture. Albuquerque, New Mexico.

Rannals, L (2013) Clovis Comet Hypothesis Called 'Bogus' By Credible Scientist. Red Orbit. 50.2.6.18 (talk) 04:18, 2 February 2013 (UTC)

Loch Lomond

Could we have some explanation of why Loch Lomond is so relevant that it lends its name? --Doric Loon (talk) 07:12, 29 June 2008 (UTC)

I don't know for sure, but people tended to name the events after the place they found evidence for them, so I presume that something interesting was found there. Who knows just what it was William M. Connolley (talk) 08:18, 29 June 2008 (UTC)

Evidence for the climatic deterioration associated with this time interval is widespread in the western highlands of Scotland and was indeed researched in the area of said loch. Geopersona (talk) 06:53, 12 February 2013 (UTC)

Horrid Caption

The current chart of three temperature records currently reads:

Three temperature records, the GRIP sequence (red) clearly showing the Younger Dryas event at around 11,000 years BP. The vertical axis shows delta-O-18, which is a temperature proxy showing the water molecule isotopic composition of 18O in an ice core.

Possibly the entire image needs to be scrapped, but certainly the word "clearly" does. Presumably (neither the caption nor the graph make it clear) 0 is present and the time scale extends into the past (although whether the chart is using RCYBP, cal BP, or calendar BP is also left unclear.) The vertical axis doesn't represent temperature (why not?) but a proxy, but it's left unclear whether the proxy is positively or inversely correspondent with temperature. Finally and most insanely, going from the right of the graph (past) towards the left (present), there isn't any sudden drop-off in temperature at all. In fact, there's a minimal, gradual fall, then a sharp rise. Perhaps it's meant that the proxy is inversely related, but that would never be the assumption of someone looking at the graph for temperature information and needs to be clarified (although a new, clearer, more straightforward graph would probably be an improvement at this stage.)

Also, while it isn't as... well, wrong as the above, the scientific notation for the years is completely unnecessary for something at such a small scale and is off-putting. If we do keep the image with an improved caption, it'd be great if someone could just photoshop in cardinal numbers. -LlywelynII (talk) 14:03, 14 February 2010 (UTC)

I agree. It's been over 3 years and no improvement, so I'm going to take that picture out. Let somebody else come up with something, hopefully something that can be read by people other than the person who made it. Nerfer (talk) 14:12, 20 December 2013 (UTC)

I disagree. Some of these comments are weird: The vertical axis doesn't represent temperature (why not?). Because its d-o-18. Like it says. By all means replace it with a *better* picture if you've got one William M. Connolley (talk) 16:31, 20 December 2013 (UTC)

Missing material - how we got from supernova to exploding comets

See David Meltzer's book here[7] starting p.55. In a 2004 edition of the Mammoth Trumpet there was a claim for a "Pleistocene doomsday. A supernova-caused neutron bombardment centered over the Great Lakes had fried the earth 12,500 years ago, Richard Firestone and William Topping announced.6' That nuclear catastrophe heated the atmosphere to over i,8oo8F, and radiated plants and animals at the equivalent dose of “a 5-megawatt reactor for more than 100 seconds.” Megafauna died en masse because they were—as the authors reported on the good authority of the Saturday Evening Post—especially susceptible to radiation. The explosion purportedly rearranged maize genes, readying the plant for human domestication; gouged out the Carolina Bays (oval depressions in the coastal southeastern states); and so spiked atmospheric radiocarbon concentrations that ages on Paleoindian sites were thrown off by up to 40,000 years." All nonsense of course, but should be in the article. Doug Weller (talk) 18:10, 7 July 2015 (UTC)

Online Summary Article About Younger Dryas

There is a reprint in PDF version of a encyclopedia chapter (summary / overview) about the Younger Dryas that is available online. It is:

Carlson A.E. (2013) The Younger Dryas Climate Event. In: Elias S.A. (ed.) The Encyclopedia of Quaternary Science, vol. 3, pp. 126-134. Amsterdam: Elsevier.

It should be of use to people working on this article. Paul H. (talk) 03:04, 27 July 2015 (UTC)

Math in opening section doesn't add up

This paragraph at the bottom of the opening section: "The Dryas stadials were cold periods which interrupted the warming trend since the Last Glacial Maximum 20,000 years ago. The Older Dryas occurred approximately 1,000 years before the Younger Dryas and lasted about 300 years.[5] The Oldest Dryas is dated between approximately 18,000 and 15,000 BP.[citation needed]"

As previously stated, the Younger Dryas lasted 1,300 years and lasted from 12,800 to 11,500 BP. If that is true, then the Older Dryas occurred some 2,500 years before the Younger Dryas, and not 1,000. Frunobulax (talk) 17:48, 2 August 2013 (UTC)

There is considerable confusion over the dates of the Dryases, which I raised in the section 'Dating problems' above. I think this is partly because different scientists have different views on the dates, and partly because the dates quoted are sometimes calibrated and sometimes uncalibrated. (Uncalibrated if I understand correctly means raw C14 dates which need adjustment because the amount of C14 in the atmosphere at different times varies, so C14 dates need calibrating to give real dates.) I once heard a scientist in the field complaining that even some papers he read did not make it clear whether they were quoting calibrated or uncalibrated dates. The whole thing needs clearing up by an expert. Dudley Miles (talk) 18:48, 2 August 2013 (UTC)

Yes, and the trouble also is that when a couple of different editors are tossing in different dates from different sources at different spots in the article, there is nobody around to take charge of the article as a whole. In the perfect Wiki world, these editors would gather together and discuss calmly and dispassionately on this talk page and agree on consistent dates, but in reality that rarely happens - here or elsewhere. Any one editor who threw in dates from the book or article he happened to have at hand is likely not going to be eager to admit that maybe there are better sources - more likely they'll just stick to their guns and say "we haven't reached a consensus here!". And you can't take every case of this kind to arbitration. So you end upo with a hodgepodge of different dates,m explanations etc, which could derive from scientists that are a hundred years apart. It's the same thing with articles touching ón the Bering Land Bridge and the immigration of paleo-indians, the dates offered for when the path across Bering Strait lay open seem to vary by thousands of years, because people have tossed in dates from old and new textbooks and surveys. 83.254.150.36 (talk) 20:52, 24 July 2014 (UTC)

Another possible reason for the differing dates for the start of the Younger Dryas is that onset of climatic shifts such as the one that happened at the start of the Younger Dryas are assumed to "...spread synchronously on continental to hemispheric scales." In a new study, Muschitiello and Wohlfarth (2015) "...found distinct and spatially consistent age differences between the inferred ages of the Allerød interstadial – Younger Dryas stadial pollen zone boundaries among the four sites. Our results suggest an earlier vegetation response at sites along latitude 56–54°N as compared to sites located along latitude 60–58°N." According them, the gradual cooling of the Younger Dryas started as early as c. 12,900 – 13,100 cal. BP further south and "significantly later" to the north around c. 12,600 – 12,750 cal. BP with the establishment of full stadial climate conditions. Thus, the confusion might be because people are falsely presuming the start of the Younger Dryas is synchronous on either continental or hemispheric scales when the in reality the vegetation changes that define it occurred at different times in different regions. If the start of the Younger Dryas is time-transgressive ( diachronous ), then people will get different dates for its start depending on the specific location that they study it. The reference is:

Muschitiello, F., and B. Wohlfarth, 2015, Time-transgressive environmental shifts across Northern Europe at the onset of the Younger Dryas. Quaternary Science Reviews. 109:49–56. Paul H. (talk) 13:06, 27 July 2015 (UTC)

Confusing dates - can someone change

Could someone change the headline dates in the opening statement?

It says 10,700 to 10,000 BP, but this is very confusing as a headline. As the later discussion point out the true start of the Younger Dryas period is more like 12,600 to 11,800 BP. And larger scale graphs like the following are much more explanatory that the one used here. The one presented is useless as pointing out the suddenness of the cooling and warming.

http://www.godandscience.org/images/youngerdryas.gif

Tatelyle (talk) 07:32, 16 October 2015 (UTC)

First, 10,700 to 10,000 radiocarbon years ago is more or less the same time period as 12,600 to 11,800 calendar years ago according to current radiocarbon calibration. Finally, the Encyclopedia of Quaternary Science, which is one of the citations, is a peer-reviewed scientific source unlike the non-scientific and self-published God and Science web page from your figure is a part. Paul H. (talk) 12:17, 16 October 2015 (UTC)

Scientists prefer radiocarbon dates because they can then apply their own view on the correct adjustment for a calendar date. This does not apply to Wikipedia, which is for general readers who mostly do not understand radiocarbon dates, let alone have their own views on how to adjust them. We should not be giving radiocarbon dates at all (except of course in specialist articles such as the one Paul links to), but calendar dates, if necessary citing a reliable source to adjust the raw date. As you have such a source, Paul, I suggest that you make the change. Dudley Miles (talk) 13:23, 16 October 2015 (UTC)

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Reference number 6 incorrect

The claim about Greenland's temperature being 15 degrees colder corresponds to the 7th link in the "references" section, not the 6th.

I would change it myself but I do not know how to update references in the article. --Dawei20 (talk) 09:40, 22 December 2008 (UTC)

Also, 15 C is not 27 F, it should be 59F — Preceding unsigned comment added by 164.68.25.145 (talk) 05:02, 2 May 2016 (UTC)

Map of Europe at the top

The map of ice and vegetation at the head of the page is a good idea, but it seems to need some more work. When it comes to the Nordic region it's completely off the mark; most of present-day Sweden, Norway and Finland were still beneath thick layers of ice at this time and the area north of the 60th parallel (roughly Stockholm - St. Petersburg) would not melt off until thousands of years later. This is something that's long been known through more than a century of studies of the postglacial evolution of the Baltic Sea and the Nordic region. I suspect the image of Russia on the map isn't all that adequate either.

See https://en.wikipedia.org/wiki/Baltic_Ice_Lake and http://www.havet.nu/?d=181 - the first two maps below the top on the Havet ("the sea") page depict the Nordic region around 11,6 and 11,2 kya. This is just after the end of the Younger Dryas period, so during the cold spell itself, the ice coverage stretched a few hundreds of miles further south. And this is stuff that's been known and established for a very long time. My grandma's school atlas, printed in the 1930s, had similar maps.

When the ice did melt off in central Sweden and most of Finland, which happened many hundred or thousands of years later, much of those regions were under deep water, having been pressed down by the ice. The province of Uppland, just north of Stockholm, which is marked as "polar desert" on the map, didn't emerge from out of the sea until around 6,000 years ago, same for the Åland archipelago between Sweden and Finland.

Also, the YD map shows a broad, solid land bridge between Asia Minor and Thracia/Greece, like a small Beringia. This is very doubtful and most geologists are not accepting the idea that the Marmara Sea and the Bosphorus were ever completely dried up towards the end of the ice age. I know the Black Sea deluge hypothesis has some adherents, but actually it's still very far from being taken seriously by most people in the relevant fields. Strausszek (talk) 01:14, 8 May 2016 (UTC)

Outdated sentence

The sentence "Geological evidence for such an event is thus far lacking.^[48]" may have been obsoleted by the paper "Identification of Younger Dryas outburst flood path from Lake Agassiz to the Arctic Ocean" by J.B. Murton, M.D. Bateman, S.R. Dallimore, J.T. Teller, and Z. Yang in Nature, vol 464, pp 740-743 (2010)... -- AnonMoos (talk) 19:31, 3 April 2016 (UTC)

Well, the outflow of meltwater itself has been established for some time, but the debated point seems to be about the effect: did it make a severe impact on thermohaline circulation (=weaken the Gulf stream convection of warm water towards Labrador and Europe)? That's much harder to determine. Even in case the sea cooled, there could be other reasons for this. Strausszek (talk) 00:50, 9 May 2016 (UTC)

Temperature graph

The temperature graph is utterly useless. Axes are not labeled with the quantities being measured nor annotated with their units. If the graph is "borrowed" and cannot be edited, at least provide this information in the caption, please. — Preceding unsigned comment added by Metricator (talk • contribs) 00:38, 3 June 2016 (UTC)

What does this mean?

What does this mean?

"The East Eifel volcanic field has been active since about 400-11 calendar years ago."

NCdave (talk) 12:48, 1 August 2016 (UTC)

It does not seem to mean anything. I have removed it and other excessive details. Dudley Miles (talk) 13:28, 1 August 2016 (UTC)

Y.Dryas and extinction

I've heard about this climate change, but i knew that it was happened about 9,000 yrs ago, too late for the mammuth and similar beasts. BUT, in this page we see that Y.D. happened about 11-12,000 yrs ago (it's a bit confusing all those dates about carbon years, calendar yrs, Before Present, Before Christ etc so it's easy misonderstood 9,000 11,000 or 13,000 yrs!). The article starts so: is a geological period from c. 12,900 to c. 11,700 calendar years ago (BP).

This pratically coincide with megafauna extinction (or, at the best, it preceded such extinction by few centuries). The article point out, among the effects:

Decline of the Clovis Culture and extinction of animal species in North America

Usually, the megafauna extinction is related to human presence in N.W. especially clovis, but today the scientific trend is to pose earlier humans in N.America and S.America, so the 'blitzkrieg model' so trendy for many years, definitively lost its strength. You can hold it if the overlapping is for few centuries, maybe a millennian, but if really some pre-clovis came from 20,000 yrs ago it's definitively unpratical to use it. The same applies for some australian species, such Sthenurus and Proctopdon, that seems to be survived about 20-30,000 yrs along with humans.

If so, the megafauna extinction event is MUCH MORE NEAR the Y.Dryas, rather the early human arrival.

Also very interesting is the recent work about nano-diamonds found in those old stratas, another thing i've never heard of. Good work anyway. S.M.71 (talk) 13:43, 19 January 2017 (UTC)

• Thanks. The impact hypothesis is still very much a minority viewpoint among scientists, but this may of course change in the future. Dudley Miles (talk) 14:31, 19 January 2017 (UTC)

S.M.71 -- However, many of those species had undergone comparable past climatic fluctuations without going extinct then. And there's nothing necessarily suspicious in positing that a human culture arose which had more deadly hunting practices than previous cultures. AnonMoos (talk) 01:24, 20 January 2017 (UTC)

Passage contains contradictions

Requesting help from an editor with subject expertise: "...the analysis of cores from Tahiti coral reefs found that sea level rose at a rate of about 7.5 ± 1.1 mm/yr during the Younger Dryas. Just after the end of the Younger Dryas, the rate of sea level rise accelerated to 17.4 ± 0.4 mm/yr and just before its start, it was 12.1 ± 0.6 mm/yr. This reduction in the rate of sea level rise..."

I thought mentioning the end of the YD before the beginning was confusing; I then edited to institute chronological order, and found that the rate of change in fact increased during the YD, according to the text of that passage. To me, the internal logic of the sentence seems broken. I have fixed the logic ("reduction" changed to "increased"), but don't have time to research its veracity. An alternative conclusion is that "beginning" and "end" were in fact reversed, rather than the conclusion being the opposite of the findings. Would appreciate your help. Thanks.--Quisqualis (talk) 19:04, 22 April 2017 (UTC)

I have concluded that this section needs analysis on a fairly minute level for logical contradictions and the use of words without surrounding context (sea level, step, etc.), as well as for what looks like "WP: Cruft" ("Possible evidence of short-term sea level changes has been reported for the beginning of the Younger Dryas. First, the plotting of data by Bard and others suggests a small step, less than 6 m, in sea level near the onset of the Younger Dryas. There is a possible corresponding change in the rate of change of sea level rise seen in the data from both Barbados and Tahiti. Given that this change is "…within the overall uncertainty of the approach…", it was concluded that a relatively smooth sea-level rise,..."). I pretty much give up. It needs a further edit by a person knowledgeable in climate change following the last ice age.--Quisqualis (talk) 20:39, 22 April 2017 (UTC)

Thanks for your efforts. Any edit would need access to the print sources, and it is likely that no editor will have access as the sources look quite obscure. If no one with such access can correct the text, I think the comments should be deleted. Dudley Miles (talk) 21:05, 22 April 2017 (UTC)

If the editor we seek does not show up fairly soon, does WP possess a list of Scandinavian editors who might have access to some of the papers? much of the confused writing has appeared (to me) to stem from a machine translation which did not go perfectly, and could have created inadvertent mistakes in facts as a result.--Quisqualis (talk) 23:15, 22 April 2017 (UTC)

Pacific Northwest YD

First, the section on North America is too small, although the Friele & Clague 2002 citation is great. There are many newer papers to add on the subject of the YD effects on various areas of North America, so I'll add what I can. Second, while it is true that the effects of the Younger Dryas were not as intense in the Pacific Northwest, there were noticeable effects, particularly around the pluvial lakes. Many were retreating and some began re-expanding temporarily during the YD. I will contribute to this page as soon as I figure out how to add more than just a comment here in the "Talk" section ^_^. Overall, I think the page has been pretty darn well maintained and I really like the organization. Chantel Saban (talk) 01:50, 25 April 2017 (UTC)

Thanks for your comments. It is best to click 'New section' at the top of this page when you want to start a new thread. This will put your contribution at the bottom of the page in its correct date position, but I will not move your comment now in case you cannot then find it. You can ask for advice on this page, or seek technical help here or on your own talk page by inserting {{helpme}}. Dudley Miles (talk) 07:10, 25 April 2017 (UTC)

Reads like an advertisement

The last paragraph of the subsection "Impact hypothesis" (section "Causes") reads like an advertisement. It's a quote from the UCSB Current, the news site of the University of California at Santa Barbara. They're interviewing one of their own professors (Kennett) about the results of the study described in the previous paragraph. Kennett is one of more than a dozen authors of the study. It just doesn't seem encyclopedic. Zyxwv99 (talk) 23:13, 1 July 2017 (UTC)

I am not sure whether it reads as an advertisement, but it is unattributed and unhelpful and I have deleted it. Dudley Miles (talk) 10:18, 2 July 2017 (UTC)

Thanks. Zyxwv99 (talk) 16:13, 2 July 2017 (UTC)

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New Data Published

The University of Chicago has recently published new data on this period that "concludes" it was caused by several small remnant impactors from a large meteor. I'm not a good writer so I'm putting this here in case someone would like to add this to the article. 83.33.175.88 (talk) 12:38, 5 February 2018 (UTC)

This has already been added. See the last section of 'Impact hypothesis'. Dudley Miles (talk) 13:12, 5 February 2018 (UTC)

Sudden Initiation of the three Dryas, Oldest, Older, and Younger

 I suspect, but have no basis for proving that three Dryasas were the result of the Oceans suddenly

having access to a large Volume Dry Basin such as the Mediterranian, which is now a Sea. Think about the Narrow access at Gibraltar having three flooding periods with the associated flooding into the basin,

a sudden lowering of Ocean Levels, and the sudden change in the Temperature at all elevations on all continents

that would lead to rapid mountain glaciation, followed by some high latitude Continental Glaciation. This would lower the ocean levels below the entrance at Gibraltar, and stop the inflow, and stop the erosion. Since the first two were only partial fillings of the Mediterranian Basin, there would have been more evaporation, than rainfall, in the basin, and more rainfall outside the Basin, over the Oceans. This would have occurred twice, one was 400 years long, and one was 200 years long, and then on the third try, Gibraltar eroded enough to fill the basin completely, so on the third attempt the process lasted 1200 years, and eventually when the Glaciers melted, and the Ocean levels rose 400 feet ( 120 meters) there is no longer any large basin to fill to repeat the process.

This does hint at an idea though, if we want to cool the planet a little, we might want to use Sunlight to fill the few remaining largish basins ( Dead Sea, Atacama, Salar de Uyuni, and several others with Ocean waters. This will lower Ocean Levels World wide, and effectively raise continents a little to cool them off. The art is to lower them a little, but not enough to create a run away Mountain, and continental Galaciation event. Mike Clark, Golden Colorado. 98.245.216.62 (talk) 18:40, 10 June 2018 (UTC)

'AD' year references

A could of AD dates have appeared in the Larcher See section. I think these should be converted into whatever the appropriate CE etc expression is — Preceding unsigned comment added by Lawrence18uk (talk • contribs) 18:39, 27 August 2018 (UTC)

Burying the lede?

Younger dryas is really only notable for the rapid shift in climatic temperatures, yet strangely this is completely missing from the lede.68.117.93.248 (talk) 16:38, 1 December 2018 (UTC)

Vegetation history in central Kentucky and Tennessee (USA) during the last glacial and deglacial periods

There are two citations to this article at [8]. I do not have access to the full text but according to the abstract it is wholly about periods before the Younger Dryas. Does anyone have access to check? Dudley Miles (talk) 12:40, 10 October 2018 (UTC)

I looked at the PDF version of:

Liu, Y., Andersen, J.J., Williams, J.W. and Jackson, S.T., 2012. Vegetation history in central Kentucky and Tennessee (USA) during the last glacial and deglacial periods. Quaternary Research, 79(2), pp.189-198.

this paper concludes, Our study confirms that the late-glacial records at both our sites are truncated by a hiatus that spans not only the later portion of the late-glacial, but most of the Holocene as well. Basically, Anderson Pond, Tennessee, is missing sediments and pollen for the period of time from 13,700 BP to sometime in the (Late?) Holocene. Jackson Pond, Kentucky, is missing sediments and pollen for the period of time from 15,400 BP to sometime in the (Late?) Holocene. The paleoclimatic record for the Younger Dryas is missing for both ponds. Paul H. (talk) 21:54, 23 December 2018 (UTC)

Evidence of volcanic emissions from cave layers

Elements in Texas cave sediments aren’t present in correct proportions for an asteroid or meteor to have hit the Earth. Rather the signature from osmium isotope analysis, and the relative proportion of elements matches data previously reported in volcanic gases. The geochemical signature associated with the cooling event is not unique and occurs four times between 9000 and 15,000 years ago. (Jeannie Kever (July 31, 2020). "A New Chemical Analysis Upends Conventional Explanation for Global Cooling". University of Houston. University of Houston. Retrieved 3 August 2020.)

From the research article itself: "...layers below, above, and in the YD have 187Os/188Os ratios consistent with incorporation of extraterrestrial or mantle-derived material. The HSE abundances indicate that these layers contain volcanic gas aerosols and not extraterrestrial materials. The most likely explanation is that episodic, distant volcanic emissions were deposited in Hall’s Cave sediments." A. D. Brandon; S. L. Forman; M. R. Waters; K. S. Befus (July 31, 2020). "Volcanic origin for Younger Dryas geochemical anomalies ca. 12,900 cal B.P.". Science Advances. 6 (31). American Association for the Advancement of Science. doi:10.1126/sciadv.aax8587. --Catrachos (talk) 12:24, 3 August 2020 (UTC)

Radiocarbon evidence also failed to support an impact analysis. (Ian A Jorgeson; Ryan P. Breslawski; Abigail E. Fisher (July 2020). "Radiocarbon simulation fails to support the temporal synchroneity requirement of the Younger Dryas impact hypothesis". Quaternary Research. 96. Cambridge University Press: 123–139. doi:10.1017/qua.2019.83.)) --Catrachos (talk) 13:35, 3 August 2020 (UTC)

Dates of the Younger Dryas onset and Laacher See eruption have just been pushed back by over 100 years

Recent research by Frederick Reinig et al. has pushed back the [Edit: Central European dating for the] Younger Dryas onset by around 130 years (to 12,807 ± 12 cal BP), and the Laacher See eruption by around 100 years (to 13,006 ± 9 cal BP).

There are a few areas of this article that will need updating but the main one is the Laacher See eruption hypothesis section; the precision of the measurements in the paper further rule out the Laacher See eruption as a possible cause for the Younger Dryas.

References

Aluxosm (talk) 13:35, 1 July 2021 (UTC)

That is interesting on Larcher See but I do not understand what they say about the onset of the Younger Dryas. If 12,807 is 130 years earlier than thought, that implies that the currently accepted date is c. 12,680 BP, but I have not seen any estimates that late. This 2020 paper says 12,870 BP. It is also of interest if secure tree ring sequences now go back over 13,000 years as the current northern hemisphere dendrochronological limit is 12,310 BP. Unfortunately, I do not have access to the full paper. Dudley Miles (talk) 16:14, 1 July 2021 (UTC)

@Dudley Miles: Sorry, I meant to add the press release that goes into the paper in more detail than the abstract. I also don't have access to the full paper but this does a good job at explaining it:

• Johannes Gutenberg-Universität. "Eruption of the Laacher See volcano redated". uni-mainz.de (Press release). Archived from the original on 2021-07-01. Retrieved 2021-07-01. That is 126 years earlier than the generally accepted dating based on sediments in the Meerfelder Maar from the Eifel region in Germany. ... This means that the [onset of the Younger Dryas] also occurred in Central Europe 130 years earlier, around 12,870 years ago respectively. This is in line with the onset of the cooling in the North Atlantic region identified in ice cores from Greenland. ... 'This strong cooling did not take place time transgressively, as previously thought, but rather synchronously over the entire North Atlantic and Central European region,' said Frederick Reinig. ... 'The trees were partially charred within the ash deposits and have been preserved to this day,' explained Reini

If I understand it correctly, due to the previous inaccuracies in dating the LSE, there was a discrepancy in the YDB dates from Central Europe. This paper states that they actually occurred "synchronously over the entire North Atlantic and Central European region." The lead author also explained that pyroclastic flows buried the local vegetation, which preserved it to this day.

This is actually really interesting. It seems like this is further evidence for the Younger Dryas impact hypothesis as well. I'm looking forward to the coverage from secondary sources on this! Aluxosm (talk) 18:18, 1 July 2021 (UTC)

Thanks. The press release clarifies the paper. I see that it does not change the date for the onset of the YD, but rather shows that a date for central Europe which differs from the international date is wrong, bringing both dates into line. I suggest deleting the reference in your note to correcting the YD date as misleading. I would also urge you to make the changes to the LSE text yourself rather than adding the query hatnote as you are obviously more informed on the subject than any other editor is likely to be.

As I read the press release, it also clarifies that the reference to dendrochronology is misleading as the dates are based purely on radiocarbon. Dudley Miles (talk) 18:58, 1 July 2021 (UTC)

@Dudley Miles: Thanks for putting it much more clearly than I did! That's actually one of the reasons I think it's better to discuss it here first. That, and time; there's a good amount of material that will need rewording and updating. I plan on doing a lot of it but I'm likely to miss something (it's good to have extra eyes), and it'll be a while before it's all done. I still haven't been able to read past the abstract as well, so I'm hoping that someone who has might help.

You can request copies of sources at Wikipedia:WikiProject Resource Exchange/Resource Request. Dudley Miles (talk) 21:43, 1 July 2021 (UTC)

@Dudley Miles: Thanks for that! I wasn't aware of The Wikipedia Library. I've just applied for access to Nature. Aluxosm (talk) 00:21, 2 July 2021 (UTC)

On the reference to dendrochronology, I would imagine that it's talking about radiocarbon dating calibration, but I'm not familiar with the northern hemisphere dendrochronological limit you mentioned (12,310 BP) so I'm probably missing something. Aluxosm (talk) 20:38, 1 July 2021 (UTC)

The dendro date is mentioned in an article updating radiocarbon dates at [9]. Dudley Miles (talk) 21:43, 1 July 2021 (UTC)

@Dudley Miles: Interesting, that paper is actually referenced by Reinig et al. (#18). Tempted to buy it now, I want to know the context! Aluxosm (talk) 23:44, 1 July 2021 (UTC)

@Dudley Miles: I've found another paper by the same lead author (Frederick Reinig et al. 2020 "Towards a dendrochronologically refined date of the Laacher See eruption around 13,000 years ago")—which might just be accessible on Sci-Hub—that clears up why the change in European dating of the onset of the Younger Dryas is significant: "Since ash fallout associated with the [Laacher See eruption] is widespread across Europe, the [Laacher See Tephra] represents an important time marker for precise synchronization of terrestrial and lacustrine paleoenvironmental records at the transition from the Late Glacial period to the early Holocene (van den Bogaard and Schmincke, 1985; Riede et al., 2011)." Thanks for the pointers! Aluxosm (talk) 01:05, 2 July 2021 (UTC)

I've just noticed that the Laacher See eruption hypothesis section was discussed here in April and December of 2012. A paper by Baales et al. 2002 that reported a 200 year difference (between the LSE and YDB) was mentioned by Dudley Miles but it looks like it wasn't enough evidence for some. However, the recent paper by Reinig et al. 2020 confirms this gap with much more precision, and the results were based on nearly 20 years of further research and advancements in dating techniques. Pinging SkepticalRaptor, CosmicLifeform, and Bkobres.

Using WikiWho, I was able to see that 5marconi5 made a significant edit on 12 July 2018; the section was changed from saying "the hypothesis has been generally dismissed" to "the hypothesis was dismissed". In light of the recent evidence, I plan on keeping as much of the section as possible, but to change it back to stating that the hypothesis is no longer valid. Aluxosm (talk) 14:02, 2 July 2021 (UTC)

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): ITroncin.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 05:21, 18 January 2022 (UTC)

Temperature graph mistaken

The temperature curve seems to have fallen victim to the "hide the decline" gang, as all Greenland ice cores show a significant drop in temperature after 6,100 BC.2A02:8108:9640:AC3:CCAC:8A8F:96:A433 (talk) 15:25, 28 January 2022 (UTC)

Are you referring to File:Younger Dryas and Air Temperature Changes.jpg? This is a copy of a US Geological Survey chart. Dudley Miles (talk) 12:19, 29 January 2022 (UTC)

The termination II

What is the termination II mentioned in this sentence: "However there is evidence that termination II had a post glacial cooling period similar to the younger Dryas but lasting longer and being more severe. "?

Termination II appears to be a past period of deglaciation ("the penultimate deglaciation, or Termination II" from http://www.sciencemag.org/cgi/content/abstract/295/5553/310). AtxApril (talk) 15:49, 27 February 2009 (UTC)

It is not-understood and not-sourced nonsense like the whole article, as can be seen in many, many justified criticism here. One of the worst articles in wikipedia.2A02:8108:9640:1A68:4DF8:A0AF:4F2D:BE71 (talk) 13:27, 4 September 2022 (UTC)

Impact hypothesis bias

It appears that the section on the impact hypothesis was written by a member of the YDIH booster club (aka the "Comet Research Group"). It completely ignores the vast body of published literature that rejects the hypothesis, mostly by acknowledged experts in impacts and archaeology. It is rife with incorrect and unsupported statements. This section needs to be rewritten from scratch by someone who is willing to take a neutral position. 76.173.207.210 (talk) 23:02, 10 October 2022 (UTC)

Recent edits

User Proxy data has twice reverted my deletion of an article in Pacific Standard as a source. Wikipedia:Identifying reliable sources (science) says "Ideal sources for these articles include comprehensive reviews in independent, reliable published sources, such as reputable scientific journals, statements and reports from reputable expert bodies, widely recognized standard textbooks and handbooks written by experts in a field, expert-curated databases and reference material, or high-quality non-specialist publications." Pacific Standard specialised in "issues of social and environmental justice" and does not comply with these criteria. Rex Dalton may be a professional science journalist but that does not make him an expert on the Younger Dryas, and even if he is that does not make his article a reliable source for Wikipedia. A reader should be able to judge that the journal is a reliable source in the field of the article, not need personal knowledge of the writer (unless he or she is a recognised expert on the subject, which does not apply here). Dudley Miles (talk) 21:36, 15 November 2022 (UTC)

Climate change

Have humans caused older drayas or younger dryas periods on earth? 73.220.11.19 (talk) 01:41, 5 December 2022 (UTC)

That seems highly unlikely. The various Dryas periods were periods in which global temperatures were temporarily lower than the general trend. Total human population during the Dryas periods was still very low, and I fail to see how any activity by a small number of humans using the technology available to them could have caused the Earth to cool down. - Donald Albury 13:16, 5 December 2022 (UTC)

Greenland Hiawatha crater

@FT2: I think this is too soon. The source doesn't suggest that, and we don't know the date.[10] I don't think we should be adding Wikipedia's weight to this and you know we get used as an unmentioned media source. Doug Weller talk 12:29, 15 November 2018 (UTC)

I agree. It is too speculative at this point. Dudley Miles (talk) 13:16, 15 November 2018 (UTC)

I also agree. There is a lack of hard evidence about how old this proposed crater is. In case of the proposed Charity Shoal crater and proposed Corossol structure, both were touted as being connected with the start of the Younger Dryas and have later turned out at best to be, respectfully, more likely Middle Ordovician and pre-Quaternary in age. Paul H. (talk) 00:24, 19 November 2018 (UTC)

I believe the evidence should be presented. This is a scholarly process and we are in a paragraph (Younger_Dryas#Impact_hypothesis) that implicitly states a hypothetical. I like this quote from Brian Clark Howard of National Geographic and Joseph MacGregor, a glaciologist with the NASA Goddard Space Flight Center in Maryland, 'If the discovery holds, the Hiawatha Crater could therefore be a tantalizing new piece of evidence for a very controversial idea[, called the Younger Dryas impact hypothesis]...One big problem with this hypothesis has long been the lack of a suitably large impact crater. If it's real and the dates match up, the Hiawatha Crater could be a plausible explanation, MacGregor says: “It’s a very speculative idea, but if this does turn out to be [the link], it would have had an outsize impact on human history.”'[11] If this section was about 'hard evidence', as Paul H. suggests, then we wouldn't be in a section about hypothesis. Present it as that, evidence to consider and spur on the investigation. It is just one among many listed here and it deserves the proper context. Whether this is ultimately correlated or not, this should be presented sooner than later. If it is uncorrelated and can be dismissed as a passing historical mention, it deserves mention now and then updated information to pass it out later. Either way, the Hiawatha Crater is now historically and permanently part of the discussion of the Younger Dryas either to its relation or its NON-relation to Younger Dryas.Pr0f3550r (talk) 18:45, 3 January 2019 (UTC)

Note that in 2022, a study came out dating the Hiawatha crater to 57.99 ± 0.54 million years ago, as referenced in the wikipedia page to Hiawatha Crater. Much older than the Younger Dryas. — Preceding unsigned comment added by Maarten.14C (talk • contribs) 20:36, 5 January 2023 (UTC)

Causes section needs complete rewrite

I do not know why this section is dominated by the two alternative hypothesis that are both rather obscure and not widely accepted, when the primary and widely accepted hypothesis involving thermohaline circulation disruption only gets one paragraph. The mainstream hypothesis should get far more explanation and description. It appears to me that the impact hypothesis and the Laacher Sea hypothesis subsections were written by advocates of those controversial ideas and do not represent the consensus mainstream view of paleoclimatologists. These subsections are far too long and rambling. I suggest that the mainstream hypothesis be expanded beyond one paragraph, and the alternative ideas be given a few sentences each, at most. The impact sentences should be consistent with the existng page that is dedicated to the Younger Dryas impact hypothesis. The impact subsection currently contains statements that contradict what is written on the YDIH page. Since this hypothesis is described in detail on its own page already it does not have to be repeated here. Proxy data (talk) 05:37, 25 January 2023 (UTC)

In future, new topics go at the bottom of the page. And there's no reason why you can't start the rewrite (properly sourced of course) yourself. Masterhatch (talk) 06:43, 25 January 2023 (UTC)

Sorry about my faux pas. I went ahead with the edits I suggested although I think more material should be added to the favored hypothesis that still only has a paragraph. Proxy data (talk) 16:23, 25 January 2023 (UTC)

Can the article use BCE rather than BP or YA?

BP is very annoying: how many people know that 0BP = 1950AD? It confuses readers and creates unnecessary complications as I had to pick up a calculator in order to understand that "11530±50 BP" really means "9580±50 BCE".

Then the article confuses that even more as it uses "between 14kya and 11.5 kya", without defining what "kya" means (is 0 kya 1950AD or 2000AD or..?).

Please use BCE. Thank you.--Fbastos 16:40, 15 October 2006 (UTC)

The use in the article reflects what the scientists involved tend to use. When your level of accuracy is 11.5 kyr, then +/- 50 isn't so important William M. Connolley 08:48, 15 October 2006 (UTC)

Thanks for the answer, William. I can understand 11.5 KYA better than 11530BP, but still why not use 11.3K BCE and 9580 BCE? I'm not a scientist, and most of the readers aren't either, so what's the benefit of tailoring the article to scientists (that would understand BCE just as well) and confuse casual readers with obscure terminology? I've been reading "BP" for 10 years, and I always thought that BP was the year I was in (1995, 2000, 2006, etc...), and it surprised me when I found that 0 BP = 1950 AD. Thanks, --Fbastos 16:40, 15 October 2006 (UTC)

Its the usuage used... I think it would get confusing transcribing dates from different formats. We could explain BP, that might be better... William M. Connolley 18:11, 15 October 2006 (UTC)

Historians (BCE) study human history, and rarely talk much to geologists(BP). (Or at least they didn't in 1950). That resulted in two systems. Until those two disciplines reconcile their dating terminology, we have to cope with two systems.--Quisqualis (talk) 19:39, 22 April 2017 (UTC)

The real reason they want to use bp is that they don't want to appear to be Eurocentric or don't want to appear to refer to history as being centered around Jesus Christ. Yet it's ironic that they settle on 1950 AD as the starting point. 1950 years after what? You guessed it.... 2601:486:280:A180:8943:9DF8:BB4:D752 (talk) 17:48, 6 March 2023 (UTC)

I am a little confused about the uncalibrated/calibrated usage. Perhaps the article should simply refer to calendar years and leave calibrated C¹⁴ years out of it?Stealth cat 17:07, 4 October 2007 (UTC)

Well, I too was confused by the awkward BP, and would prefer the much more common BCE. 76.10.128.192 (talk) 07:13, 6 June 2012 (UTC)

BP is better, for the reasons explained above. Science can be awkward sometimes. Since the meaning of BP is linked on first use, just treat this as a chance to learn something William M. Connolley (talk) 07:54, 6 June 2012 (UTC)

I want to lend a voice to support the use of less esoteric and more universally understood time scales. Wikipedia seems to be a general learning resource for all people, not specialists, and time measured in terms of "BCE" is much clearer to most people than the obscure "BP". Wikipedia should strive to make information on each page as understandable as possible without forcing the reader to go to another resource just to understand what terms such as "BP" mean. 98.230.199.85 (talk) 05:10, 13 August 2012 (UTC)

That would be solve-able with a WP template, but the resulting confusion would be huge. Think about it: the resulting articles would not be easy to read by scientist-readers if BCE is used universally; there would need to be 2 versions of every article containing BP or BCE, then, everyone might be happy.We must dream on.--Quisqualis (talk) 19:39, 22 April 2017 (UTC)

There are good reasons for using BP. See the discussion above. If you don't understand those reasons, then we should probably make an effort to explain them William M. Connolley (talk) 07:53, 13 August 2012 (UTC)

Frankly, I would like to know what reliable sources exist to support the claim that ""BCE" is much clearer to most people than the obscure "BP"." My impression is at best that the term "BCE", if anything, is as equally obscure, esoteric, and less universally understood as "BP" with most people used to the "AD" - "BC" terminology. Judging from usage in news articles about science, it would appear that it is "BP" is much more commonly used and that "BCE" that is the more obscure terminology. Before any changes are made, I definitely like to see some solid proof from a reliable source that ""BCE" is much clearer to most people than the obscure "BP"" has any truth to it. Finally, using "BCE" instead of "BP" when talking about Quaternary Geology misinforms people and misrepresents how Earth scientists discuss time and ultimately will only further confuses people in the long term. Paul H. (talk) 13:53, 13 August 2012 (UTC)

As confusing as it is, one editor believes we should use EXACTLY what is written in the supporting citations per WP:RS. We should probably do it. SkepticalRaptor (talk) 17:07, 13 August 2012 (UTC)

The beauty of Wikipedia is that it is so easy to link to other pages where everything can be explained. We should make efficient use of this functionality. 'BP' is widespead in the scientific literature and also in much that is not not quite so academic - let's explain it, let's link it but let's stick with it - there are good reasons for doing so. cheers Geopersona (talk) 06:50, 12 February 2013 (UTC)

I like BP, but get the bejeebers when I realize that the "Present" increases by 1 year with the passing of each year, and P is therefore a moving target. It's inaccurate for recent human history (imagine trying to figure out the start date of the First World War in BP, 77 years from now, or even today), although it is less inaccurate for prehistory.--Quisqualis (talk) 19:39, 22 April 2017 (UTC)

No, 'P' does not increase year on year -it is fixed at 1950 so the literature quoting BP dates remains true as one year rolls over to another - 2550BP remains 2550BP not say 2551BP - there is no moving target. Anyway I know of nobody wanting to use it for modern human history. Geopersona (talk) 06:23, 5 October 2018 (UTC)

Added "equally" to the intro (3rd paragraph) to make the statement clearer.

Since the worldwide average changed (see the 3rd picture in the article), it did affect the average worldwide, although not equally in every region of the planet. Bill the Cat 7 (talk) 16:48, 8 March 2023 (UTC)

I clarified a litte more. Bill the Cat 7 (talk) 22:29, 8 March 2023 (UTC)

Laacher See is not ruled out

The role of the Laacher See eruption (LSE), or volcanoes in general, as the cause of the Younger Dryas (YD) is not completely ruled out. The 200-year gap (between YD and LSE) was actually well-known and established back in the 1990s by varve counts (see [12]). 2021 Nature paper just determined absolute dates.

What has been long ruled out is the direct radiative effect from volcanic materials, e.g. aerosol clouds, as they have a relatively short lifetime of 2-3 years. The possibility of direct volcanic cooling was eliminated long time ago.

The indirect impact of the LSE (and the cluster of eruptions near the onset of YD) to long-term atmosphere-ocean-ice positive feedback, which operates on a timescale of decades to centuries, is not ruled out. This could have potentially played a role in triggering the YD, see more informed recent discussions [13] and [14].

High-latitude eruption weakening AMOC (main driver of YD) only decades after eruption is recently shown [15]

@Proxy data: I'm not claiming that LSE is the favored hypothesis (in fact it is not). It's just not ruled out (or fringe) as many commonly assume when they see the 200-year gap. Aleral Wei (talk) 16:31, 19 June 2023 (UTC)

Reversion of map.

I have reverted the addition of the map at [16], primarily because it is unsourced. All maps should be based on - and attributed to - a reliable source. There are two other points. 1. I am doubtful of its accuracy. Britain and Ireland are shown as connected. My understanding it that it is disputed whether they were connected at the LGM, and certainly not during the YD. 2. Several of the colours are impossible to tell apart for someone like myself who is colourblind. There are colourblind friendly palettes on the web, and it would be helpful to readers to use one of them. Dudley Miles (talk) 21:28, 30 July 2023 (UTC)

"Linked above"

Dudley Miles I knew it was linked above, I read 75% of the article, and then checked the See Also, and then used Ctrl+F to find the link to it, hence why I thought (as a directly related topic) Younger Dryas impact hypothesis would be useful in the "See Also" section where people will look for it. Other pages which are linked in the text appear in the See Also, such as Older Dryas, so your revert seems petty and makes the article worse. Lytel (talk) 17:39, 12 August 2023 (UTC)

Revert was in line with the manual of style, see MOS:NOTSEEAGAIN. Please assume good faith when interacting with other editors. Hypnôs (talk) 18:04, 12 August 2023 (UTC)

What's the point of making information harder to find in an encyclopedia? But as long as there's a policy, it will be followed bureaucratically without thought. "Whether a link belongs in the "See also" section is ultimately a matter of editorial judgment and common sense"... or is it? — Preceding unsigned comment added by Lytel (talk • contribs) 18:12, 12 August 2023 (UTC)

drastic or slight?

" but the average worldwide temperature changed drastically. For example, in the Southern Hemisphere and some areas of the Northern Hemisphere, such as southeastern North America, a slight warming occurred" An example should support, not go against, a general statement. "Drastic" and "slight" are pretty much opposites, so something needs changing. Kdammers (talk) 16:11, 28 August 2023 (UTC)

On the triggers of YD

@Volcano345 The section on causes, as well as in the short description, presents the consensual hypothesis of meltwater flux as apparently a dismissed theory, then proceeds to elevate volcanism to the position of the main cause. This is inaccurate. If the editor is willing to look hard enough, one can always find articles that reject the mainstream theory. If no one objects, I hereby propose to rewrite the section to reflect the mainstream theory, namely the freshwater flux hypothesis. However, I will still retain paragraphs on volcanism for the possible role it played in triggering the Younger Dryas (YD). The mainstream theory on the cause of YD is fairly consensual:

IPCC report (2007) on Palaeoclimate [17]: Freshwater influx is the likely cause for the cold events at the end of the last ice age, i.e. the Younger Dryas (p. 456)

Encyclopedia of Quaternary Science (2013) on Palaeoclimate [18]: The northward retreat of the southern margin of the Laurentide Ice Sheet from the Great Lakes caused a routing of freshwater from the western Canadian Plains from the Mississippi River to the St. Lawrence River, with the increased freshwater discharge to the North Atlantic slowing ocean circulation and ultimately causing the Younger Dryas (abstract)

NOAA on the cause of YD [19]: just prior to the Younger Dryas, meltwater fluxes were rerouted from the Mississippi River to the St. Lawrence River (p. 2)

Annual Review of Marine Science (2017) on AMOC [20]: most of the evidence is consistent with the long-standing hypothesis that the Younger Dryas cold event was caused by the routing of glacial meltwater into the North Atlantic (p. 98) Aleral Wei (talk) 07:22, 12 January 2024 (UTC)

I agree. The lead currently cites an article attributing the YD to the moderate Laacher See eruption 200 years earlier. This should not be in the lead. I am not clear about the status of the meltwater theory as it has recently been attacked. Dudley Miles (talk) 09:06, 12 January 2024 (UTC)

I think the case for meltwater is even stronger now than it was 20 years ago ([21], [22], [23], [24]), though so is volcanism. Some people mistakenly interpret Wallace Broecker's statement as an invalidation of the meltwater theory when, in reality, he disagreed with the specific hypothesis that the meltwater came from a catastrophic flood through the eastern outlet of Lake Agassiz. Overall, he still believed that pulses of meltwater resulting from deglaciation were the ultimate trigger for the weakening of the AMOC ([25]). Aleral Wei (talk) 01:04, 13 January 2024 (UTC)

If you are familiar with the current state of the debate then I suggest that you take on the revision. Dudley Miles (talk) 22:13, 13 January 2024 (UTC)