Talk:Younger Dryas

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Horrid Caption[edit]

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)

Misc. Uncollected Comments[edit]

"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 (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)

Reference number 6 incorrect[edit]

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 (talk) 05:02, 2 May 2016 (UTC)

Was the Younger Dryas global?[edit]

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[edit]

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

Can the article use BCE rather than BP or YA?[edit]

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)

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. (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. (talk) 05:10, 13 August 2012 (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)

Citation style[edit]

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)

The termination II[edit]

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 AtxApril (talk) 15:49, 27 February 2009 (UTC)

Too Hard to Read?[edit]

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. -- 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)

Loch Lomond[edit]

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)

"Recent reseach"[edit]

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: Nathan McKnight -- Aelffin (talk) 20:01, 5 April 2010 (UTC)

Bad: "Was the Younger Dryas global?"[edit]

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)


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 (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. (talk) 12:05, 23 July 2011 (UTC)

Dating problems[edit]

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 (talkcontribs)


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)

timing of northern and southern hemispehere cooling and impact event review needed[edit]

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 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 ( and

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 (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 (talk) 12:10, 23 July 2011 (UTC)


(This is an extract from my book: "World without war, made possible by empowered individuals" 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 (talkcontribs) 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? (talk) 20:58, 5 January 2013 (UTC)

Article protected for a day[edit]

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[edit]

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
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[edit]

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)

Laacher See Volcano and the Younger Dryas =[edit]

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 ( ). 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:
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)

Recent News on Impact Theory[edit]

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: Bkobres (talk) 17:48, 10 July 2012 (UTC)

New Review Paper About Younger Dryas Impact Hypothesis[edit]

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. (talk) 04:18, 2 February 2013 (UTC)

Math in opening section doesn't add up[edit]

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. (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)

Missing material - how we got from supernova to exploding comets[edit]

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[edit]

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)

Confusing dates - can someone change[edit]

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.

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)

External links modified[edit]

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Outdated sentence[edit]

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)

Map of Europe at the top[edit]

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 and - 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)

Temperature graph[edit]

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 (talkcontribs) 00:38, 3 June 2016 (UTC)

What does this mean?[edit]

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[edit]

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)