Talk:Timeline of glaciation

Additions 2005

I added a graph of Atmospheric CO2 data from ice core samples which closely correspond to global temperature averages.

I tried to sort out the glacial periods and names as best I could, but the older names are known not to represent singular glacial periods, so I tried to represent that on the graph.

I expanded the table to track four sets of names, referenced in the article links. I also corrected the table to match the article dates, but it's still a mess on the older dates.

I welcome anyone else's effort to help clarify this information, even if it is less than well defined. I HOPED the CO2 graph could help shed some light on the glacial periods.

Tom Ruen 15:11, 3 December 2005 (UTC)

Asian glaciers?

The table is great - but it made me think of another question. Why aren't there Asian names? Was there an ice sheet over Siberia too? I've been looking for a map but with no luck. HMAccount 22:27, 25 June 2006 (UTC)

A good project if you can find more information. Good luck! :) Tom Ruen 21:36, 26 June 2006 (UTC)

Thanks :) I've had a look on the web, but it is taking too much time. I have found the Siberian ice sheet equivalent of the Riss-Wurm interglacial, the Kazantseva interglacial, and the Wurm equivalent is the Zyryanka glacial period. But there was also the Karginski interglacial and the Sartan glacial period which seem to have been more recently, in the late Wurm, which will throw off your table, so am holding off on adding to it. (reference: [1]) So far come up dry on any earlier glacial periods. Frustrated: I bet it's in any standard Russian geology text :) HMAccount 19:52, 27 June 2006 (UTC)

Dates are a big issue to connect up since there's different estimates even if you find names. If you feel confident in names and sources for the most recent periods, its seems worth putting up, at least if you include some stub articles in the linked names as well. Of course just including "research notes" here in talk can be helpful if someone else can find more. Tom Ruen 21:03, 27 June 2006 (UTC)

It is a problem and I notice that some foreign periods are being merged into the the North American system without any discussion or evidence for analogy that I can see. Can anyone link me to policy on this as the scheme is all over the place at the moment? - 217.33.16.99 11:13, 23 February 2007 (UTC)

The present Pleistocene ice age

The 2nd para refers to "The present Pleistocene ice age". But acc to the Pleistocene article, that era ended 12,000 years ago. If "Pleistocene" is being used in a different sense here, perhaps that should be explained. Nurg 23:18, 3 November 2006 (UTC)

Some are of the opinion there will come an ice age in the future, and call holocene a part of the pleistocene. 80.186.113.172 (talk) 16:18, 9 March 2009 (UTC)

This is not the point. It should be Quaternary ice age. Dysmorodrepanis (talk) 21:44, 18 May 2009 (UTC)

Brunhes-Matuyama reversal

Someone had added the sentence: "The Brunhes-Matuyama reversal occurred 780,000 years ago, approximately coincident with MIS19, the "Cromerian Complex" interglacial I, and can be used to date sediment cores." While I agree that the Brunhes-Matuyama reversal may be used to date certain sediment cores, and occurred ~780,000 tears ago, I think that the reference to the Cromerian may be off as well as MSI-19. Additionally, I am not sure that it belongs in the article, certainly not as a stray sentence after the Pleistocene tables. If verified, something like it might constitute a note to the table. --Bejnar 16:41, 3 May 2007 (UTC)

I thought it was interesting to have the time connection. How about added as a "see also"? (Even if the reversal article itself needs expanding!) Tom Ruen 20:03, 3 May 2007 (UTC)

Conflict with Article on Ice Ages

The other article (http://en.wikipedia.org/wiki/Ice_Age [2]not sourced) gives different dates for the earliest hypothesized ice age periods.

The variance could be due to different measurement techniques. Or one set of figures may have been superseded by a more valid set. JP 01:27, 21 September 2007 (UTC)

Wisconsin vs. Wisconsinan

Back 25 years ago when I was in college, the four main North American glaciation periods were referred to either by state name+term like glacial period/epoch or simply in the possessive form of the state most affected. Usage should be consistant.Krumhorns (talk) 17:15, 23 January 2008 (UTC)

Structure of the article + Pleistocene glaciation

The article starts with There have been four major periods of glaciation in the Earth's past. and expands a bit on that topic. The next three sections are about the Pleistocene glacial cycles, and finally there is a short section about glaciations in earth's history, of which the Pleistocene glaciation is but one. This section should precede the PG sections, I changed that accordingly.

Addionally there's either too much Pleistocene glaciation or too few about the older glaciations in this article. The Pleistocene glaciation is a link to and treated in great detail in Quaternary glaciation, and some of the information here in Timeline of glaciation seems to be missing there. I propose to move the in-detail stuff to Quaternary glaciation, and give a short outline of all four major glaciation episodes here.--Jo (talk) 19:33, 30 January 2008 (UTC)

Yeah, the QG is pretty much a half-finished article that is missing chunks of information here and there. ~ UBeR (talk) 16:02, 25 February 2008 (UTC)

Land-based chronology of Pleistocene glacial cycles

All names in the table column Alpine pointed to the North-American terms (second column, not linked). I pointed them to the appropriate article (currently most of them redirects to one of the different terms in each row) and added links to every unlinked term. The definitions of each of these stage are different and ought to have their own articles.Jo (talk) 09:47, 25 February 2008 (UTC)

Yeah, there was a rather fueled discussion about that at last glacial period, I believe. ~ UBeR (talk) 16:03, 25 February 2008 (UTC)

Been there... ;) I'm currently collecting sources: where, when, and who defined what. You have a nice collection on your page, quite inspiring. Jo (talk) 17:14, 25 February 2008 (UTC)

Yeah, I was thinking of adding (inter)stadials, but that's probably more work than I'm interested in. ~ UBeR (talk) 06:35, 26 February 2008 (UTC)

Disputed

The table entitled "land-based chronology of Pleistocene glacial cycles" is inaccurate. Firstly, the information contained in the table does not correlate with the cited source. The cited source is Gibbard figure 22.1. However, in this source no mention is made of the Alpine sequence, nor of anything in the North American sequence older than the Illinoian, nor of any Marine Isotope Stages. Therefore, this table is based on other uncited sources. The dates and Marine Isotope Stage correlations presented for the Mindel-Riss interglacial and the Mindel glacial are inaccurate. As I mentioned, these are nowhere to be seen in Gibbard's figure, so no source is cited. However, even within this Wikipedia artlcle, we have an evident contradiction. Observe the chart entitled "Late Pleistocene Atmospheric CO₂ and the Glacial Cycles. You will see that according to this chart, which is based on Antarctica ice cores, the Mindel consists of four stadials, with the oldest stadial about 530 ka and the most recent about ending 250 ka. Each of these stadials is a distinct Marine Isotope Stage, in fact they are MIS 14, 12, 10, and 8. Despite the Mindel apparently lasting from 530 to 250 ka, the table in question lists the Mindel at 455 to 380/300. The Gunz-Mindel interglacial would appear to be Marine Isotope Stage 15, dating 630-580 ka. Again, the table is inaccurate. The correlation of the Gunz-Mindel with stages 13 to 15 would also appear to be inaccurate.

Mranthro (talk) 23:22, 25 July 2008 (UTC)

Thanks for your contribution. The correct thing to do here is to talk on the talk page. Only if you can't get agreement here is it appropriate to go tagging the page itself William M. Connolley (talk) 23:46, 25 July 2008 (UTC)

There is no such rule! But getting a consensus on the talk page is a good strategy anyways. ... said: Rursus (bork²) 08:07, 13 April 2009 (UTC)

Didn't know, apologies.

Mranthro (talk) 00:07, 26 July 2008 (UTC)

I changed the tag to the section only: Template:Disputed-section for now, agreeing it all looks fuzzy to me and deserves attention. The MIS numbers labeled on an diagram at [3] page 6. These correlated closely to the Glacial CO2 graph I made Image:Atmospheric_CO2_with_glaciers_cycles.gif where I tried to match the apparent ages of the named glacial periods by their approx. ages with the CO2 peaks and valleys. You are certainly knowledgeable, and this page certainly could use help to correctly represent the best sources. I just worry that "random corrections" will just lead to FUTURE random corrections, so if changes are to be made, hopefully we can get it done as completely and consistently. Tom Ruen (talk) 00:11, 26 July 2008 (UTC)

Fair enough. I will try to find the time to post some sourced information here in the talk page. I have not been able to find one, single, source that puts together correlations between land glaciations, oxygen isotope stages, and dates throughout the entire Pleistocene. The information seems to be scattered throughout numerous scientific journals, most of them not carried by my library's databases. I'll do my best to put together a reasonable proposal, but the sequence of stadials and interstadials correlating with the Mindel glaciation is very confusing, so any comments and suggestions will be very valuable. If nothing else, we should resolve the contradiction between your CO2 graph and the Pleistocene glaciation timeline, and try to agree on reasonable dates for the Gunz, Mindel, and Riss glaciations and the associated interglacials. Mranthro (talk) 01:22, 26 July 2008 (UTC)

The Lisiecki and Raymo article you link to is very good. Aside from the figure 4 (page 6) that you refer to, I should also point out table 3 on page 10, listing "recent glacial terminations." Preliminarily, can we agree on the following: Lisiecki and Raymo's termination I (14 ka) represents the end of the Würm glacial; termination II (130 ka) represents the end of the Riss glacial; termination III (243 ka) represents the end of the Mindel glacial; terminations IV (337 ka), V (424 ka), and VI (533 ka) are the ends of stadials within the Mindel glaciation; and termination VII (621 ka) is the end of the Günz glaciation. What do you think? Mranthro (talk) 01:37, 26 July 2008 (UTC)

Not much time tonight, but let's see, first by the individual articles we have:

1. Würm glaciation (began about 110,000 years ago and ended between 10,000 and 15,000 BP)
2. Riss glaciation ( between 200,000 and 125,000 years ago)
3. Mindel_glaciation (410,000 and 380,000 years BP)
4. Günz glaciation (occurred around 600,000 years ago)

Versus: Table 3. Recent Glacial Terminations

Termination Magnitude, % Age, ka

I 1.78 ± 0.10 14 (Consistent with 10-15 above for Wurm)

II 1.86 ± 0.13 130 (close to 125 above for Riss, MIS 6)

III 1.18 ± 0.16 243 ? }

IV 1.64 ± 0.13 337 ? } Mindel mess

V 1.97 ± 0.12 424 ? }

VI 1.15 ± 0.14 533 ? }

VII 1.57 ± 0.15 621 (Close to 600 above for Gunz)

Well, I also note that the Mindel_glaciation article is actually a redirect to Kansan glaciation, and so it may all be rather a mess to match time intervals for different named events for different regions.

The Gibbard PDF has a detailed color chart on the last page that seems to do a similar (and wider) timeline comparison. [4] Perhaps that also can be useful to judge if the table reduction is reasonable.

I'm content if the whole table is scrapped for something that better allows the ambiguities of dates to be represented, like a pure graphic form. Tom Ruen (talk) 02:16, 26 July 2008 (UTC)

The MIS are the primary key; the game is then to match the various glaciations backwards to the MIS stages. No-one in ice core research uses "Wurm", "Mindel", etc, the terms are all obsolete, they use MIS, so it might be hard finding a paper to put it all together for you. Clearly the current state is a mess (thanks for noticing and caring). The Mindel-Riss interglacial leads to Hoxnian interglacial which is hopeless: which occurred between 300,000 and 200,000 years ago is badly misleading, since it implies it was 100kyr long. Obviously it wasn't. I presume what that means is that it lasted the standard ~10kyr, but we don't actually know which interglacial in MIS terms it refers to William M. Connolley (talk) 08:05, 26 July 2008 (UTC)

Hmmm... You're right, correlations with the Alpine glaciations may have to be scrapped, I'm not seeing anyone who uses those terms in the literature. Unfortunate. However, I have found attempts to correlate the North European glacial/interglacial events with various forms of marine data. I just found an article entitled "Correlation of marine events and glaciations on the northeast Atlantic margin" by D.Q. Bowen and G.A. Sykes, Phil. Trans. R. Soc. Lond. B 318:619-635 (1988) [accessible through JSTOR]. This article derives a sequence of sea level changes from analysis of variations in amino acid geometries in shells both on and offshore, with stratigraphic evidence of glacial and interglacial periods on land, focusing on the North Sea area. It then correlates these stages with known MIS. Table 3, page 219, offers up the following dates for MIS stages, with proposed glaciation correlations:

MIS 14, 565-524 ka, 'Elster' ('Elster I'?);

MIS 13, 524-478;

MIS 12, 478-423, 'Elster' (Anglian, 'Irish Sea');

MIS 11, 423-362;

MIS 10, 362-339;

MIS 9, 339-303;

MIS 8, 303-245 'Drenthe'? Paviland;

MIS 7, 245-186;

MIS 6, 186-128 'Warthe';

MIS 5e, 128-122;

MIS 5, 122-71;

MIS 4, 71-59;

MIS 3, 59-24;

MIS 2, 24-? Late Devensian, late Weichselian.

Another article in the same special issue is entitled "Climatic variability during the past three million years, as indicated by vegetational evolution in northwest Europe and with emphasis on data from the Netherlands" by J. de Jong, Phil. Trans. R. Soc. Lond. B 318:603-617 (1988). On page 615, figure 11 entitled "tentative correlation of the climate curve of the Quaternary in The Netherlands with the isotope stages in the deep-sea core V28-239 (from Shackleton & Opdyke 1976)" offers the following correlations:

MIS 19 to 11= Cromerian;

MIS 10 = Elsterian;

MIS 9 = Holsteinian;

MIS 8 to 6 = Saalian;

MIS 5 (first part) = Eemian;

MIS 5 (later part) to 2 = Weichselian;

MIS 1 = Holocene.

Jong also provides MIS correlations up to 23 and tentative dates for Praetiglian, Tiglian, Eburonian, Menapian/Waalian, and Bavelian. In figure 2, "Climate curve and chronostratigraphy for the Quaternary of The Netherlands," Jong names the interglacials and glacials within the Cromerian:

Interglacial I, Waardenburg = MIS 19;

Glacial A = MIS 16 and 18; MIS 17 an interstadial;

Interglacial II, Westerhoven = MIS 15;

Glacial B = MIS 14;

Interglacial III, Rosmalen = MIS 13;

Glacial C = MIS 12;

Interglacial IV, Noordbergum = MIS 11.

Finally, an outstanding correlation is presented by Pamela R. Willoughby, in The Evolution of Modern Humans in Africa: A Comprehensive Guide, AltaMira Press (Lanham, MD) 2007. Unfortunately, her synthesis extends only as far back as MIS 8. Table 3.1, pages 73-74, offers the following dates:

MIS 8, 297-251 ka, glacial;

MIS 7, 251-195 ka, temperate or cool;

MIS 6, 195-130 ka, glacial;

MIS 5e, 130-116 ka, last interglacial = Riss/Wurm or Eemian Interglacial in Europe;

MIS 5d, 116-105 ka, cooler;

MIS 5c, 105-95 ka, warmer;

MIS 5b, 95-85 ka, cooler;

MIS 5a, 85-75 ka, warmer;

MIS 4, 75-64 ka, stadial; intense cold; sea level about 75 m below present level;

MIS 3, 64-32 ka, interstadial; unstable climate that fluctuated on short time span; sea level about 70 m lower than present;

MIS 2, 32-13 ka, last glacial maximum (LGM); extremely cold and dry;

MIS 1, 13 ka to present, Holocene; warm conditions similar to present.

Based on these data, we can at least specify dates for MIS up to 14, and correlations with the North European glacial sequence back to the Bavelian. The question of Alpine-North European correlations remains unsolved. Weichsel = Wurm seems pretty evident. Riss = Saalian is less solid, if we accept Jong's joining of MIS 6-7-8 and correlation with Saalian, is Riss 6-7-8 or is Riss only 6? Mindel seems unidentifiable. I suspect that both Mindel and Gunz correlate with Cromerian, but I can't be sure. We could abandon the Alpine stages altogether, but since they represent real stratigraphic evidence, some correlation should be possible eventually. Perhaps a focus on the North European sequence would be better, with the Alpine correlation mentioned but no firm conclusions made for the time being.

If we stick with a table, which I like because it allows for precise dates to be specified, then you are right, the MIS should provide the primary framework, and names of glacial and interglacial stages should be attached to that framework, rather than vice versa.

Mranthro (talk) 14:49, 26 July 2008 (UTC)

Just found a very useful website http://www.geo.arizona.edu/palynology/geos462/01histplist.html Contains historical information on the development of the land-based glaciation chronology, with correlations between Alpine, Northern Europe, and England glacial stages; unfortunately, does not correlate North American and European glacial stages. However.... behold http://www.geo.arizona.edu/palynology/geos462/07nonmarin.html#doe In the section entitled "loess deposits," we have a proposed correlation between alpine stages and isotope stages, sourced to a researcher named Kukla (1977)! The problem is, this seems different from other systems that I have seen: Wurm, stages 2-6; Riss, stages 7-12; Mindel, stages 13-18; Gunz, stages 19-22; This is getting quite complex and occupying a lot of time I should be spending on other topics, though it seems quite important to work this out. Basically, I am now leaning towards a tripartite division for presenting the Pleistocene glaciation timeline. (1) Present the traditional sequence of glaciations, with regionally specific names, based on the geological research of the 19th and early 20th centuries, and without dates as befits a chronology established pre-absolute dating; (2) Present the marine isotope stage sequence as far as seems reasonable--at least to 19/20. Provide dates, specify which MIS represent glaciations; (3) Present proposed correlations. Different authors are proposing different sets of land-marine correlations, try to present a likely one along with information on points of dispute. I'll try to keep working on this as best I can, I think it's starting to take shape. I have a satisfactory sequence of dates MIS up to 16, with tentative dates (derived by using graphs and a ruler) up to 19, with connections to the glaciations up through the Cromerian. Correlations with Alpine, England, and North America do not seem impossible. If I really find the time, a citations index search of de Jong and Kukla would be useful to see who has criticized their work over the past twenty years. Mranthro (talk) 15:20, 27 July 2008 (UTC)

A person can find charts that show the correlation between the different glacial stages and MIS stages in

Sibrava, V., Bowen, D.Q, and Richmond, G.M., 1986, Quaternary Glaciations in the Northern Hemisphere, Quaternary Science Reviews. vol. 5, pp. 1-514.

This volume has one main correlation chart that shows the inferred relationships between the different glaciations, stages, and MIS stages in great detail.

More recent correlation charts, which illustrates the relationships between the different glacial stages in different parts of the world along with MIS stages are:

Gibbard, P.L., S. Boreham, K.M. Cohen and A. Moscariello, 2005, Global chronostratigraphical correlation table for the last 2.7 million years v. 2005c., PDF version 220 KB. Subcommission on Quaternary Stratigraphy, Department of Geography, University of Cambridge, Cambridge, England

Gibbard, P.L., S. Boreham, K.M. Cohen and A. Moscariello, 2007, Global chronostratigraphical correlation table for the last 2.7 million years v. 2007b., jpg version 844 KB. Subcommission on Quaternary Stratigraphy, Department of Geography, University of Cambridge, Cambridge, England

One obvious flaw with the "Land-based chronology of Pleistocene glacial cycles" chart is that it uses Nebraskan, Kansan, Yarmouth, and Aftonian stages. The problem with these North American stages is that they were abandoned as being obsolete and meaningless around 1986 to early 1990s. The Nebraskan, Kansan, Yarmouth, and Aftonian stages have all been merged together into an undifferentiated Pre-Illinoian stage. If a person looks at Giddard et al. (2005, 2007) and Sibrava et al. (1986), above, they will find that "Pre-Illinoian" is used instead of Nebraskan, Kansan, Yarmouth, and Aftonian stages. George R. Hallberg, Pre-Wisconsin glacial stratigraphy of the central plains region in Iowa, Nebraska, Kansas, and Missouri, in Sibrava et al. (1986) states:

The complexity of the stratigraphy, as it is currently understood, and the miscorrelations of early work necessitate abandonment of the archaic terms Kansan, Aftonian, and Nebraskan in stratigraphic terminology. Continued use of those terms will only promote confusion of stratigraphic nomenclature and erroneous correlations of stratigraphic units.

The complexity of Pre-illinoian glacial sediments is discussed by:

Roy, M.,, P.U. Clark, R.W. Barendregt, J.R., Glasmann, and R.J. Enkin, 2004, Glacial stratigraphy and paleomagnetism of late Cenozoic deposits of the north-central United States., PDF version, 1.2 MB. Geological Society of America Bulletin. vol. 116, no. 1-2; pp. 30-41; DOI: 10.1130/B25325.1

Roy et al. (2004) concludes that the Pre-Illinoian tills, which he studied, represent at least 7 different glaciations, all of which predate the Illinoian Stage. This completely invalidates the premise, on which the stages predating the Illinioan were based, of there being only two sets of tills, Kansan and Nebraskan, representing only two glaciations separate by a single interglacial. This and other problems are discussed by:

Boellstorff, J., 1978, North American Pleistocene stages reconsidered in the light of probable Pliocene-Pleistocene continental glaciation. Science. vol. 202, no. 4365, pp. 305-307.Paul H. (talk) 06:36, 16 August 2008 (UTC)

Under accounts of other theories of glaciation: I observe the Creationist veiwpoints are not considered. A brief mention of them would perhaps help. Roughly put, they hold that there was only one period of glaciation, in accord with the 'young earth' belief, and that this period occurred either before or following the worldwide deluge. The fundamentalists hold that the Deluge was followed by an Ice Age due to increased moisture. Other sources hold that the glacial period preceded the worldwide deluge and that it depressed the continents in the mantle, causing rapid melting and sea inundation over vast areas of the world. They explain the evidence cited for multiple ice ages by saying the single glaciation advanced successively several times. Also omitted in the mention of causes of the ice age was the theory that large areas of the Northern Hemisphere were lifted above snow line somehow. See Fr. O'Connell's Science of Today and the Problems of Genesis.--James Farrell

The Young Earth creationist viewpoint is not considered because it is based upon a willful ignorance of facts, i.e. interglacial paleosols and sediments that occur between tills and other glacial sediments, that totally refute the so-called "theory" that there was only one period of glaciation. Evidence that completely refutes the the spurious claim of there having been only one "period of glaciation" was observed by conventional Earth scientists and described in published papers as far back as 1909 for the glacial deposits of Europe and as far back as 1898 for the glacial deposits Midwestern United States as discussed in Bowen (1978). As discussed and illustrated in chapters of Sibrava et al. (1986), Ehlers and Gibbard (2004a, 2004b), Mangerud et al. (2004), and many other published papers, the observed and published evidence clearly demonstrates that there has been, at least eleven distinct glacial periods, not just one "religiously-correct" glacial period, during Late Pliocene and Quaternary. The inherently religious and nonscientific nature of the Young Earth creationist one glacial period "theory" puts it in the category of Creation science, not Quaternary geology.Paul H. (talk) 04:57, 3 February 2009 (UTC)

References Cited:

Bowen, D.Q., 1978, Quaternary geology: a stratigraphic framework for multidisciplinary work. Pergamon Press, Oxford, United Kingdom. 221 pp. ISBN 978-0080204093

Ehlers, J., and P.L. Gibbard, 2004a, Quaternary Glaciations: Extent and Chronology 2: Part II North America, Elsevier, Amsterdam. ISBN 0-444-51462-7

Ehlers, J., and P L. Gibbard, 2004b, Quaternary Glaciations: Extent and Chronology 3: Part III: South America, Asia, Africa, Australia, Antarctica. ISBN 0-444-51593-3

Mangerud, J., J. Ehlers, and P. Gibbard, 2004, Quaternary Glaciations: Extent and Chronology 1: Part I Europe, Elsevier, Amsterdam. ISBN 0-444-51462-7

Sibrava, V., Bowen, D.Q, and Richmond, G.M., 1986, Quaternary Glaciations in the Northern Hemisphere, Quaternary Science Reviews, vol. 5, pp. 1-514.

The correct correlation table can be found here sk:Ľadová doba (časť štvrtohôr). Hambra (talk) 00:25, 24 September 2009 (UTC)

Can someone document these MIS #s in an article? This article says, "and-based evidence works acceptably well back as far as MIS 6", but gives no information or link on what MIS 6 was. There's a chronology in this talk page (above), and I assume the #s refer to K-years, but it would be nice to have an article about this (or to document the system in an existing article). Mcswell (talk) 02:07, 11 December 2010 (UTC)

This section has been disputed for nearly a decade. I'm not an expert and can't speak to the factuality of the section, but it seems like at this point someone in the know should either certify it as factual, correct it, or remove it. Etherjammer (talk) 18:00, 20 February 2017 (UTC)

I agree but it is a question of someone sufficiently knowledgeable - or willing to do the research - taking it on. However the only obvious error I could see was starting the last glacial period at 71 ka, and I have corrected it to 110. I have no idea where the 'Backwards Glacial Index' comes from and I could not see from googling it. Someone good at tables should delete the column. Dudley Miles (talk) 20:39, 20 February 2017 (UTC)

Dear Wikipedians! The article had a section with a correlation table that had been disputed for ten years. It was based on a simplified model of land-based glacial cycles, which have largely been abandoned by modern science due to difficulties in establishing unambigous correlations with modern MIS indexes. Thus, there was no way of correcting that table, without running into lots of problems. Instead I have done two things: 1) A set of lists of historical names for various regions. The names are intended to emphasise that these are historical, and not always describing a real chronology. Thus, these can't be disputed on scientific grounds, but they may be improved from a history of science perspective 2) A new table based on the MIS indexes, which shows in white-green shades the complexity of the glacial record. It now clearly shows that there is a lot of uncertainty in the correlations. There is a risk that individual Wikipedians will use correlations found in individual sources to fill in and make this table more certain, which could make also this table disputed. If that happens, then I guess this table should be deleted. 216Kleopatra (talk) 06:01, 7 May 2018 (UTC)

9704 BCE

The extensive scientific study shows that it was precisely 11,711 years ago - and not the indeterminate figure of ‘some’ 11,000 years ago – that the ice withdrew, allowing humans and animals free reign.

That would be 9704 BCE. Can they really do that? I'm not qualified to judge the accuracy of the news article. If it passes muster, it ought to be added to the Wikipedia article. 75.15.122.59 (talk) 00:37, 31 December 2008 (UTC)

The 11,711 BP date is not, as interpreted above, the date that "that the ice withdrew, allowing humans and animals free reign." The date is simply the value assigned to the age of the Pleistocene-Holocene boundary. The retreat of the continental ice sheets started thousands of years before that date. For example, if a person looks at the various papers in Ehlers and Gibbard (2004), they will find that the Laurentide ice sheet started withdrawing from North America about 17,500 BP (radiocarbon) and finally disappeared soon after 5,000 BP (radiocarbon). Thus, it took about 12,000 years, starting within the Pleistocene and ending in the Holocene, for this ice sheet to withdraw and finally disappear from North America. As can be seen in the rapid rise of global sea level that started between 18,000 and 17,000 BP. (radiocarbon), ice sheets all over the world started losing ice and retreating well before 11,711 BP (Fairbanks 1989).Paul H. (talk) 21:54, 2 February 2009 (UTC)

References Cited:

Ehlers, J., and P.L. Gibbard, 2004, Quaternary Glaciations: Extent and Chronology 2: Part II North America. Elsevier, Amsterdam. ISBN 0-444-51462-7

Fairbanks, R. G. A., 1989, A 17000 years glacio-eustatic sea-level record: influence of glacial melting rates on the Younger Dryas event and deep ocean circulation. Nature. vol. 342, no. 6250, pp. 637-642.

Poor Chart & Graph Labeling

The graph: "Glacial and interglacial cycles as represented by atmospheric CO2,..." is poorly labeled, and pretty much meaningless. Wiki policy says it should function as an explanation, not a reminder to those already in the know (jargon). For example, what do all the colors mean?...red, yellow, cyan, grey?

"Glacial and interglacial cycles as represented by atmospheric CO2," Huh? Is that so? If there is supposed to be a relationship between the three, this is not shown in the graph. All that is shown is atmospheric CO².

IOW, while this graph may be fine in one publication, it is NOT OK here.

The graph: "500 million year record shows current and previous two major glacial periods" shows 50 million year "glacial periods"...that in fact, seem to be Ice Ages. IOW, conflicting definitions in the article need to be cleaned up or clarified. And what does the red "HOT" mean?...and so forth?

What is the context of the "Greenhouse and Icehouse Earth?" chart. "Icehouse?" No explanation anywhere!? Looks like some individual's pet term.

Hypertexting should not be used to define concepts, (lazy hypertexting,) but as icing on the cake since lazy hypertexting disrupts the flow. Often just a few words in context is better than digging paragraphs from an out-of-context, generalized hypertexted article.
--69.110.91.50 (talk) 05:59, 14 December 2011 (UTC)Doug Bashford

Removed "Co2 glacial cycles 800k" Graph

I removed this graph, the "Co2 glacial cycles 800k" graph, from the Timeline of glaciation section because it uses Quaternary stratigraphic terminology that is hopelessly antiquated, obsolete, and meaningless. Th specific reasons are discussed in talk section for that figure. Before this graph can be used in Wikipedia, the discredited Quaternary stratigraphic terminology needs to be removed from it and replaced with the correct Quaternary stratigraphic terminology. Paul H. (talk) 16:21, 17 November 2013 (UTC)

By the way, this is the same graph commented on in the "Poor Chart & Graph Labeling" section that is above my comments. Paul H. (talk) 16:23, 17 November 2013 (UTC)

For the official 2011 correlation chart for Quaternary chronostratigraphy go see the PDF file of Global chronostratigraphical correlation table for the last 2.7 million years for latest correlation chart and current Quaternary stratigraphic terminology. The home page for this chart is Stratigraphical charts for the Quaternary, Subcommission on Quaternary Stratigraphy. Paul H. (talk) 17:27, 17 November 2013 (UTC)

Timeline does not agree with any corresponding Wikipedia article

The ages in the column "Period (ka)" do not at all correspond to the ages mentioned in the Wikipedia articles on the glacial and interglacial periods concerned. Can you correct this or get rid of this article alltogether.Jgamleus (talk) 02:32, 19 May 2014 (UTC)

Technical problems

On 25 September 2018 Cloud forest inserted an ambitious table in the section Known Ice Ages. It works reasonably on a small screen. Unfortunately, when displayed on a wide screen, the factors of ten to the left get completely disassociated from the corresponding sub-tables. This information ought to be rendered in graphical form that works on all screens. 216Kleopatra (talk) 06:38, 18 October 2018 (UTC)

FYI, for reference here is a DIFF for the Sept 25 edit and by the version on Jan 27 2019 this appears to be fixed. So unless there's something else I'll mark this  Done NewsAndEventsGuy (talk) 13:50, 18 February 2019 (UTC)

The graphic discussed above is currently [late Nov 2019] showing only as coloured bars with no legend, captions or apparent hyperlinking to anything. As it dominates the intro section, can I suggest as a casual visitor to the page that it get removed until it works properly.27.33.62.180 (talk) 04:22, 17 November 2019 (UTC)

Papers about possible Pliensbachian cryosphere

Recent papers about a possible Pliensbachian cryosphere from Google Scholar are:

Platon Tchoumatchenco, M.P. and Yaneva, M., 2008. Did glaciation occur during the Toarcian (Early Jurassic) in the East Stara Planina Mts.(East Bulgaria)?. Comptes rendus de l’Académie bulgare des Sciences, 61(10).

Ruebsam, W. and Schwark, L., 2021. Impact of a northern-hemispherical cryosphere on late Pliensbachian–early Toarcian climate and environment evolution. Geological Society, London, Special Publications, 514(1), pp.359-385.

Ruebsam, W., Thibault, N. and Al-Husseini, M., 2020. Early Toarcian glacio-eustatic unconformities and chemostratigraphic black holes. In Stratigraphy & Timescales(Vol. 5, pp. 629-676). Academic Press.

Ruebsam, W., Reolid, M., Sabatino, N., Masetti, D. and Schwark, L., 2020. Molecular paleothermometry of the early Toarcian climate perturbation. Global and Planetary Change, 195, no. 103351.

More papers at Wolfgang Ruebsam Researchgate page. Paul H. (talk) 02:54, 22 August 2022 (UTC)

Glaciation and Global Warming

This page is being used to suggest that it supports cyclical warming and cooling periods and therefore contradicts global warming. Can it be updated to disambiguate that? MZProf (talk) 01:30, 31 October 2023 (UTC)

There is no contradiction. Both are generally accepted by experts. Dudley Miles (talk) 09:47, 31 October 2023 (UTC)

Top graphic mislabeled?

According to the article, the label "Glacial Periods" should be replaced with "Ice ages". Glacial periods are short intervals on the scale of 100 kY within an ice age. Mameister (talk) 18:20, 24 August 2024 (UTC)

That is true according to the definitions used in the article, but the graph was created by an expert who was using different definitions. Dudley Miles (talk) 18:47, 24 August 2024 (UTC)