Some Geologists at Quelccaya

Just when I’d despaired of ever seeing anything as mundane as a site map of the Quelccaya glacier on a scale that did not also show all of South America, I stumbled (due to the wonders of google) on an interesting article by Mark et al (2002), a geologist from Ohio State – the same university as Lonnie Thompson – on glacial moraines in the Quelccaya area. Of course neither the NAS panel nor Thompson deign to cite an article as mundane as one by a geologist. It was nice to read an article that focussed on the presentation of facts without moralizing all the time.

I’ve mentioned that I’d like to see other stratigraphic and contextual information relative to the report of the 5000-year old Distachia reported in a recent pamphlet by Thompson – that it was published in PNAS does not elevate Thompson et al 2006 from being IMHO a "pamphlet". In any event, I’ve teased out some information including this from Mark eet al 2002:

Other peat exposed at the modern ice margin [from their Table 1, this appears to have been collected in 1977] dates to 2760 cal yr B.P., implying that the Quelccaya Ice Cap at that time was smaller than present and may have disappeared completely during the middle Holocene. Two ice cores drilled 154.8 and 163.6 m to bedrock through the ice cap contain records that are only 1350 and 1500 years old (Thompson et al., 1985).

Mark et al describe the Quelccaya ice cap as follows together with the Location Map shown below:

The summit of the highest of four domes on the ice cap reaches 5645 m, and short, steep outlet glaciers descend the escarpment of the plateau to elevations as low as 4950 m (Mercer and Palacios, 1977). To the west of Quelccaya is a broad till and outwash plain with an abundance of peat bogs, lakes, and moraines.Two valleys in particular provide the opportunity to date multiple series of moraines: the Upismayo Valley on the northwestern side of the Cordillera Vilcanota and the Huancane Valley on the western side of the Quelccaya Ice Cap. These valleys were visited by Mercer and colleagues, who provided the first radiometric dates for some of the moraines (Mercer and Palacios, 1977; Mercer, 1983).

FIG. 2. Map of the study area….. (b) the Huancane Valley, Quelccaya Ice Cap. Moraines and the numbered sample sites for radiometric dates (coinciding with Table 1) are shown. Also presented are the modeled paleoglaciers, overlaid on the topography of the digital elevation model (shown by contour lines).

Mark et al visited the site in 1997, describing their work program as follows:

During June and July 1997, extensive field reconnaissance was carried out in the Cordillera Vilcanota–Quelccaya Ice Cap region to map and date moraines (Fig. 2). Five lakes and three bogs were cored using a square-rod piston corer (Wright, 1991), samples for cosmogenic isotopic analysis were taken from erratics on moraine crests, and soils were described and sampled (Goodman et al., 2001). Organic material recovered in the field from lake cores, bogs, and buried peat was dated by accelerator mass spectrometry. Dates are presented as calibrated years before present (cal yr B.P.), based on CALIB version 4.0 (Stuvier and Reimer, 1993; Stuvier et al., 1998) (Table 1).

From moraine and other information, they estimated the size of the paleoglaciers at different periods as follows (H refer to the ones at Quelccaya that we’re interested in at present), with H1 being the LIA moraine:

Note. Preserved moraines define the extent of three different paleoglaciers in each valley, labeled in descending order from oldest to youngest as follows: Ice3, Ice2, and Ice1 for the Upismayo Valley; H3, H2, and H1 for the Huancane Valley. Volume (km3) of each reconstructed paleoglacier is calculated using gridded-model surfaces and the digital elevation model. Modern glacier volume was estimated from surface area by the formula V=28.5 S1.36 (after Chen and Ohmura, 1990). Deglacial interval (yr) represents the conceivable time range over which the paleoglacier deglaciated from successively less extensive end moraine positions. The interval is presented as a mean surrounded by the one-sigma range in calibrated radiocarbon ages. Where available radiocarbon dates include more than one constraining age for a moraine, the maximum and minimum possible intervals are provided as large and small intervals, respectively. Deglacial Volume (km3) represents the volume lost from the paleoglacier in two possible deglacial scenarios: a large volume from complete deglaciation and a small volume considering only the volume lost between successive moraine positions. Deglacial Rate (10àƒ⣃ ‹’€ ”‚¬’„¢5 km3 yràƒ⣃ ‹’€ ”‚¬’„¢1) is calculated by dividing the deglacial volume by the deglacial interval, such that the small rate equals small volume divided by large interval, and large rate equals large volume divided by small interval.

They discuss how they dated the various moraines, relying primarily on radiocarbon dating of peat deposits, often buried in moraines in disturbed contexts.

Peat buried in sandy outwash at 4745m altitude upvalley from the Huancane III terminus provides a minimum age of 14,290 cal yr B.P. for H3… Disturbed peat found under till associated with a Huancane II moraine provides a maximum limiting age for the H2 glacier advance of 12,830 cal yr B.P. The difference between this date and the minimum age of H3 cited above provides a minimum estimate for the deglacial interval of H3 as 1460 yr…. at no time since ~12,800 cal yr B.P. has the Quelccaya Ice Cap margin been more than 1 km beyond that of today (Rodbell and Seltzer, 2000)…. Huancane I moraines are unvegetated and, although present in all valleys surrounding the Quelccaya Ice Cap, are not dated directly in the main Huancane Valley. Peat entrained in a Huancane I moraine from a neighboring Valley provides a maximum limiting age of 300 (+202/àƒ⣃ ‹’€ ”‚¬’„¢300) cal yr B.P. for the H1 paleoglacier, noted by Mercer to be in the range of the Little Ice Age. Thus, the deglacial interval for H1 is 290 yr, the difference between the maximum H1 Peat buried beneath a Huancane I moraine dates to 11,190 cal yr B.P., a minimum age for the H2 paleoglacier, which indicates that deglaciation of H2 was rapid and extensive. By 11,190 cal yr B.P. the glacier was reduced greatly in size and within its Little Ice Age extent. This results in a 1640 yr deglacial interval for H2. ….Other peat exposed at the modern ice margin dates to 2760 cal yr B.P., implying that the Quelccaya Ice Cap at that time was smaller than present and may have disappeared completely during the middle Holocene. Two ice cores drilled 154.8 and 163.6 m to bedrock through the ice cap contain records that are only 1350 and 1500 years old (Thompson et al., 1985).

What information from this is relevant to the 5000-year old Distachia? Well, if the 5000-year old Distachia had been under a glacier uninterruptedly for 5000 years, then how did the peat form in 2760 BP at the "modern ice margin"? This is the same kind of problem that we observed in the Green Alps and in Alberta – there seem to be glacier advances and retreats. How do we know that the Quelccaya Distachia wasn’t exposed at surface at some point in its history? The only argument on this seems to be that, if it had been at surface, it would have decayed. How solid is this argument? I’ve seen references in passing to how long things can survive at surface in cold dry climates. How do we know that this didn’t survive? I’ll have more to say on this in another post.

Bryan G. Mark and Geoffrey O. Seltzer, Donald T. Rodbell and Adam Y. Goodman, 2002. Rates of Deglaciation during the Last Glaciation and Holocene in the Cordillera Vilcanota-Quelccaya Ice Cap Region, Southeastern Peru, Quaternary Research 57, 287–298 (2002)
Mercer, J. H. (1983). Cenozoic glaciation in the southern hemisphere. Annual Reviews in Earth and Planetary Science 11, 99–132.
Mercer, J. H. (1984). Late Cainozoic paleoclimates of the southern Hemisphere south of the equator. In “Late Cenozoic Paleoclimates of the Southern Hemisphere,” (J. C. Vogel, Ed.), pp. 45–58. Balkema, Rotterdam.
Mercer, J. H., and Palacios, O. M. (1977). Radiocarbon dating of the last glaciation in Per´u. Geology 5, 600–604.


  1. Steve Sadlov
    Posted Aug 14, 2006 at 4:40 PM | Permalink

    RE: “Of course neither the NAS panel nor Thompson deign to cite an article as mundane as one by a geologist. ”

    I view this as one of the systemic problems plaguing “Climate Science” and preventing competence and effectiveness in it. I get the strong impression that many in the field are either ignorant of “old school” sciences like geology (especially the hard rock and mapping areas, ala Dr’s Diblee and Sylvester) or, they find them to be an “inconvenient truth!”

  2. Jeff Weffer
    Posted Aug 14, 2006 at 6:20 PM | Permalink

    Geology is clearly a more refined and advanced field of science than Climatology. Perhaps it is because geologists have no agenda to advance and because they have a better toolbox of proven techniques and training courses which have developed over the years.

    It is interesting that geologists seem to be better glacialogists than any of the climatologists or even glacialogists. The climatologists need to take more geology training, if anything, just to learn about the actual proven techniques which are available.

  3. Stephen Berg
    Posted Aug 14, 2006 at 8:00 PM | Permalink

    Re: #2: “Perhaps it is because geologists have no agenda to advance”

    Puhleez! That has to be some of the biggest bunch of crap I’ve read in weeks! How about Petroleum Geologists? Huh? They want the status quo to continue for personal gain, i.e. getting hired to explore for more fossil fuel deposits without regulation.

    Jeff, I agree that a well-rounded knowledge of this planet is necessary, meaning that knowledge of geology is important to know what has occurred in the past. However, in learing about geology, one should realise how much we need to protect this planet, not resolve to mine every mineral deposit or drill every oil well possible.

    Also, regarding this:

    “It is interesting that geologists seem to be better glacialogists than any of the climatologists or even glacialogists.”

    No. To understand glaciation, one needs to understand the atmosphere more than the lithosphere. This means that a climatological knowledge is more important than one of the geological system. After all, the ice doesn’t come from rocks, it comes from fallen snow, which comes from where? The ATMOSPHERE!

  4. welikerocks
    Posted Aug 14, 2006 at 9:05 PM | Permalink

    Of course I agree with #1, they didn’t even cite any data at all?

    And I disagree with everything in #3, of course.

    For one thing Geology the scientific study of the origin, history, and structure of the earth. Glaciology is the study of glaciers and their effects on the landscapes. These sciences are called “Earth Sciences” Geophysics is: The physics of the earth and its environment, including the physics of fields such as meteorology, oceanography, and seismology. And Climatology is the study of climate.

    Another thing, my husband is an Environmental Geologist. He is out in the field everyday taking care of the earth. He works for oil companies sometimes, and it is because he wants to help the Earth stay clean and safe. And he wants a pay check, is that ok with you?

    Petroleum Companies, The US Military, and the US Government spend more money then any other entity in the whole wide world “to take care of the Earth” and spend more money then anyone to develope more ways to keep it that way. So? Does it matter who is doing this as long as someone is doing it? And these entities are all made up fellow human beings. Also consider, these entities were in place during WWII with the brains and knowlege, and resources “to save the planet” a that time, thank goodness. So explore their own pages and read the facts and the history. It so easy to judge people when you remember they are people. Exxon is paying for re-building almost all the schools in New Orleans, for instance. I looked up these things awhile ago.

    “explore for more fossil fuel deposits without regulation.” Where are these people operating without regulation?

    “No. To understand glaciation, one needs to understand the atmosphere more than the lithosphere”
    Hence no stratigraphy in any of these glacier papers?

  5. welikerocks
    Posted Aug 14, 2006 at 9:18 PM | Permalink

    correction: It NOT so easy to judge people when you remember they are people

  6. Pat Frank
    Posted Aug 14, 2006 at 9:28 PM | Permalink

    #3 “Puhleez! That has to be some of the biggest bunch of crap I’ve read in weeks! How about Petroleum Geologists? Huh? They want the status quo to continue for personal gain, i.e. getting hired to explore for more fossil fuel deposits without regulation.

    We see with Mr. Berg the result of 20 years of vilification of scientists in terms of employment-defined conflicts of interest. He damns an entire group of scientists as unethical by definition, merely in terms of their employment. It’s a methodology entirely analogous to racism.

    I suppose we can blame this state of affairs on the decades of deliberate lying by the tobacco companies. However, the attacks on science in terms of the employment of the scientist has now become a general pheonomenon, and as we see in #3 is now uncritically and unashamedly applied. Attacking the scientist in terms of venally-corrupted professional ethics has become the automatic method of choice employed to ‘discredit’ a scientific view.

    It’s not really your fault, Mr. Berg, as you have been systematically misled by a wide-spread social net of approval that regularly uses this method, and has provided it with a validating aura of righteousness. Mr. Bloom, exemplifying the high level of institutional support for this false methodological moralism, regularly engages a similar false polemic in the CA pages. However, you need to think more deeply on what you do.

    Scientific conclusions should be evaluated in terms of the science itself. If you have a problem with some petroleum-geological conclusion, then you should offer the countering theory or observations to disprove it, Mr. Berg. Vilifying a whole class of scientists is dishonest and unethical, and will not do. It’s time to stop this corrosive practice.

  7. Steve McIntyre
    Posted Aug 14, 2006 at 9:42 PM | Permalink

    I should have pointed this out in my post. Distichia muscoides seems to be something that can be found in peat deposits. Is Thompson’s discovery of peat at the modern Quelccaya ice margin something that Mark et al had not already found in 1997 and already published (and I suspect may have been mentioned in the 1977 article cited by MArk et al.?

    Other peat exposed at the modern ice margin [presumably as at 1997] dates to 2760 cal yr B.P., implying that the Quelccaya Ice Cap at that time was smaller than present and may have disappeared completely during the middle Holocene.

    Didn’t Thompson have an obligation to cite and discuss the earlier report? Didn’t the NAS panel – those diligent engineers – have an obligation to cite the earlier discovery?

    Prior to looking at this, I said that one needed to find the dates of other organics. To date, I’ve seen peat-type deposits dated to 2700 BP and 50,000+BP, as well as the 5000 BP deposit discussed in the NAS report.

    Both finds raise lots of questions – how did the 2700 year old peat form if the 5000 year old peat was covered continuously by a glacier? Then switch all the questions with the 50,000 BP peat?

    Didn’t Thompson have an obligation to mention and discuss all this in his PNAS article and in his chapter of the NAS panel report?

  8. stephan harrison
    Posted Aug 15, 2006 at 3:01 AM | Permalink

    Hello all. As a Quaternary and glacial geomorphologist, I agree that geological training is important to understand climate and associated landscape change over long timescales. I would also say that the multivariate and multidisciplinary nature of climate change makes a whole range of expertise valuable in understanding and assessing it. I tend to disagree with Stephen Berg; glaciologists are invariably physicists and to understand glaciers you need to understand how ice behaves under different temperature and pressure regimes.

  9. welikerocks
    Posted Aug 15, 2006 at 8:48 AM | Permalink

    #8 My husband says your field of study is the hardest and most complicated there is, good for you!

    #7 boy is that a bundle of stuff? Wouldn’t glaciers stir, mix and mess things up anyway because of the way they behave? I think that’s one of my husband’s concerns about collecting evidence from them. Also, I wonder would monsoons effect these sites in anyway? I have no clue; extreme wind, rain and weather in general can mix up the soil as well I would think? (my husband is not here to ask so I could be way off the mark in my thinking!)

  10. Steve McIntyre
    Posted Aug 15, 2006 at 9:06 AM | Permalink

    #8. I’ve dealt with geologists most of my life and have great respect for their acumen. If people are making policy recommendations based on finds of peat at glacier margins, it seems a matter of common sense that one would want a report on the stratigraphy by a geologist or glacial geomorphologist. One would have hoped for a less amateur performance from a blue-ribbon panel like the NAS panel.

  11. Tim Ball
    Posted Aug 15, 2006 at 10:10 AM | Permalink

    #8 underlines the problem, apparently without understanding, by suggesting that glacial studies are invariably done by physicists. Physics of ice movement “under different temperature and pressure regimes” is only one small component of the entire dynamic picture that results in formation movement and ablation of a glacier. This mistake is typical of a world in which specialization has been glorified and becomes more important than the final picture. The dictum that to specialize is the mark of genius to generalize the mark of a fool has led to a fragmentation and shattering of knowledge and information.
    The problem in climate is there are too many people coming from specialist areas who have no knowledge of important pieces of the puzzle in other specialist areas. ( I continue with this blog because Steve M recognizes this better than most). Despite this I give thanks for the serendipitous arrival of Steve and Ross into the tree ring debacle. The difference with their work and that of other specialists is it is around the technology and measures (in this case statistics) rather than climate pers se. I am still anticipating the arrival of modeling specialists into examination of their use and misuse in climate studies. This specialization problem partly explains how the small group that Wegman identifies was able to operate so independently and incestuously. Climatology is a generalist discpline because in order to understand and explain the white noise of climate and climate change you have to know most of the major pieces (red noise) and how they interact. Geophysical Research Letters was one of the first journals to recognize this problem in climate studies. Sadly some climate journals had already been taken over by those with a political agenda.
    I have used the analogy before and I will keep using it until people get the picture. Climate is like a puzzle made up of thousands of pieces and specialization is when you have one or maybe two of the pieces. Arguing for the importance of those pieces as key without having the boxtop is simply not likely to achieve any understanding and worse may distract from real issues. Of course, you can distract from this lack of knowledge by alleging that your pieces are critical and failure to consider them will bring about the end of the world as has been the case since climatology became politicized.
    When you reconstruct a puzzle you are most effective by working in some systematic way. Usually this means finding the four corners, then the edge pieces, then grouping like coloured pieces and finally determining how they interlock. In climate we haven’t even found the four corner pieces, which I would suggest are the sun, the oceans, the land and the atmosphere. We are even less sure of the edge pieces which I would suggest is how these pieces are linked together. The analogy is reasonable to this point because we are dealing with a static picture, however, it is vastly complicated by the changing dynamics of change in any one corner or edge piece and the subsequent interaction and implications for the entire picture. At this point each static puzzle is a still frame that becomes connected with countless others to create a movie. All this helps understand why computer models don’t work and are foreseeably limited by computer capacity. (see Amman’s comments to Steve on this blog)
    In the 1970s and 80s I was a member of the Canadian Committee on Climate Fluctuations that ran under the auspices of the National Museum of Canada with funding from Environment Canada. Specialists from all areas met once a year to discuss specific time periods or problems. It was amazing how often it was disclosed that problems in one specialist area had already been resolved in another. We were also trying to establish central committees to store and analyze, tree ring data, ice cores, and proxy data with access for all researchers. Maybe if these activities had continued we might have avoided some of the prolems we now face. The Museum was the natural location because they understand the problems of cross-specialization and cross-discpline research. They also understood other difficulties that confront climate science today. Including the relationship between humans and the environment and explaining science to the general public. Environment Canada pulled the funding because a political decision deemed it was needed for the very expensive study of global warming by computer models. They ran short of funding and pulled money from within the agency by closing weather stations and replacing many with unreliable Automatic Weather Observing Stations. Now Canada has less weather stations than in the 1960s and many records are questionable because of the unreliability problem. Ironically, this in turn reduces the potential for accuracy in the models as if that wasn’t already a serious problem.

  12. JMS
    Posted Aug 15, 2006 at 10:49 AM | Permalink

    The one thing that nobody has noted is that this was written up almost 10 years before the discovery of the distachia. You wouldn’t suppose that the ice front has receeded in those intervening years, hmmm?

  13. stephan harrison
    Posted Aug 15, 2006 at 10:59 AM | Permalink

    Re number 11. Thanks for your contribution Tim. You sais that I suggested that “glacial studies are invariably done by physicists. Physics of ice movement “under different temperature and pressure regimes” is only one small component of the entire dynamic picture that results in formation movement and ablation of a glacier”.

    I didn’t say this. I said that glaciology is usually carried out by physicists. There is much more to understanding glacial geomorphology, chronology etc. than just glaciology. However, the “formation, movement and ablation of a glacier” is very definitely within the realm of physics.

  14. Steve Sadlov
    Posted Aug 15, 2006 at 11:24 AM | Permalink

    RE: #12 – Well, go find the answer. Contribute something.

  15. Robert
    Posted Aug 15, 2006 at 11:57 AM | Permalink

    #11 – Tim Ball

    Well said, as Robert Heinlein once wrote: “Specialization is for insects” — Taking a wider view often brings new insights to bear on the problem at hand.


  16. Steve McIntyre
    Posted Aug 15, 2006 at 12:08 PM | Permalink

    Folks, I live in Ontario ,where our entire landscape was carved by glaciers. Geologists describe moraines and tills. In Ontario, there are dozens/hundreds of different till formations. The ravine of the Don River about half a mile from my home has many classic formations.

    Glaciologists may speculate on how you can get the particular sequence of tills and moraines from glacier first principles, but it’s a good idea to map the tills and moraines and sediments first, before you speculate too much.

    Unless, of course, you’re on the Hockey Team.

  17. fFreddy
    Posted Aug 15, 2006 at 1:54 PM | Permalink

    Re #15, Robert – Yaaaay ! Or rather, Rah Rah !

  18. muirgeo
    Posted Aug 15, 2006 at 2:25 PM | Permalink

    I still don’t see any 1000 year old organics being uncovered. Not even 2000 year old stuff. Um still looks like Mann was/is right. Warmer now then in over 2760 years.

    But hopefully for the Anti-Hockey Team those Medieval forest will be uncovered any time now by the rapidly melting glaciers….yeah that’ll prove your point….err..maybe…they must be up there some where.

  19. jae
    Posted Aug 15, 2006 at 2:27 PM | Permalink

    muirgeo: You just have to read the history books on that issue. Don’t need glacier voodoo.

  20. Steve McIntyre
    Posted Aug 15, 2006 at 4:11 PM | Permalink

    #18. In areas unaffected by glacier activity, there are lots of medieval forests above present treeline (Polar Urals, Sierra Nevadas, Finland,…). It is of course possible that treelines under present temperature conditions will reach medieval levels but so far they have not done so.

    The MWP was a lesser event than the HOlocene Optimum. In unglaciated areas, treelines were higher in the Holocene Optimum than in the MWP. So I would expect the same thing in glaciated areas.

  21. jae
    Posted Aug 15, 2006 at 5:23 PM | Permalink

    Why is it called the Holocene OPTIMUM? Was the planet a better place then? Will it be better if more warming occurs?

  22. muirgeo
    Posted Aug 15, 2006 at 7:11 PM | Permalink

    Re# 19

    The glaciers ARE the history books. You think they’ve been re-written…do you??

  23. Steve Sadlov
    Posted Aug 15, 2006 at 7:48 PM | Permalink

    RE: #22 – Oh yeah, them cathredral buildin’ days, that’s really ancient. Need stratigraphy and glaciers to discern what happened wayyyyy back then. Can’t trust them pre “Enlightenment” types to have written reliable accounts of the world they lived in. (/sarc).

  24. welikerocks
    Posted Aug 15, 2006 at 7:53 PM | Permalink

    #22 These glaciers never melted before?
    Nobody is arguing that they don’t hold clues to understanding history. What is in question is the interpretation. Alot of computer models are being used in the Thompson papers, and mention of AGW happens in these papers. That’s why we are looking at the geological work in this one paper conducted in the same area. And “It was nice to read an article that focussed on the presentation of facts without moralizing all the time. ”

    here’s a picture of the plant:

    I don’t get this paragraph:

    “Then in 2004, Thompson found additional plant beds revealed by the continued retreat of the melting ice and when tested, these proved to be carbon-free, suggesting that they might date back more than 50,000 years. If true, that would suggest that the climate in that region may not have been as warm as it is today in more than 500 centuries.

    From this article:

    How does that, suggest all that?

  25. Jeff Weffer
    Posted Aug 15, 2006 at 8:28 PM | Permalink

    The point should be that there are definite periods of glacial advance and retrenchment.

    I don’t think it matters if the MWP was warmer than today. The point is there was an ice age (30 of them or so in the last 3.5 million years), there was a Holocene Optimum, there was Roman Warm Period, there was a Dark Ages cold period, there was a WMP, there was a LIA and there is a (slight?) warming period from the middle of the 19th century to today.

    There are other more dominant factors affecting the climate. If the models of today cannot explain that, then they are absolutely no good.

    They cannot be trusted to model and forecast the climate in the decades ahead. The other more dominant factors must be incorporated. If the other factors cannot be forecast, then the climate can only be described as “choatic” and the field of science called global warming so just go away.

    5,000 year old plants under glaciers, 2,000 year old plants under glaciers, 1,000 year old plants under glaciers tell exactly the same story. It doesn’t matter. It just proves that other factors need to be incorporated into the models.

    The hockey stick, of course, was really just saying that the other factors are unimportant and our models are good. The main point was not “the last 1,000 years”, it was “CO2 is the only thing to worry about over any time period.” That is the real hypothesis that needs to be proven incorrect.

  26. JMS
    Posted Aug 15, 2006 at 9:43 PM | Permalink

    Rocks, note the qualifier — if true — since he didn’t report it the find may not have panned out. The other finds noted in this article confirm the initial find, though. Quelcayya has probably not retreated this far in ~5000 years.

    Jeff, as far as the hockey stick is concerned it and all of the similar studies are an attempt to figure out what natural climate variability is. Mann did and continues to come up with figures which are less than some of the other studies (in particular Moberg). I would have to say that at this point we do not have a really good idea of the exact amplitude of the natural variability, and may never get a more accurate number than we have now. However all of the studies show that natural variability over the last millenium does not exceed what we are observing at present. Some indicate that the MWP in the NH approached or equaled current values. None show that it exceeded current values.

  27. Steve McIntyre
    Posted Aug 15, 2006 at 9:43 PM | Permalink

    Note: The phrase “from their Table 1, this appears to have been collected in 1977” has been edited in replacing the phrase “presumably as at 1997” following JMS pointing out that they “eyeball bleeding” Table 1 indicated that this sample was collected in the 1977 survey.

  28. Lee
    Posted Aug 15, 2006 at 9:45 PM | Permalink


    “Well, if the 5000-year old Distachia had been under a glacier uninterruptedly for 5000 years, then how did the peat form in 2760 BP at the “modern ice margin”?”

    Well, if you were to glance at the map you posted accompanying the table, you will find that the 2670 (not 2760, but that’s just a nit) was collected on the margin of the ice cap, above 5,000 meters, and not a the glacial front – which is where the Distachia was said to be collected. Perhaps the dyamics of the margin of the ice cap, entirely above the equilibrium line, might be a bit different from the dynamics of a glacial front below the equilibrium line? In any case, you are comparing evidence from two different sites, only one of which is at the glacier.

  29. Steve McIntyre
    Posted Aug 15, 2006 at 9:56 PM | Permalink

    BTW in any proper geological report, all sample locations are marked clearly on a properly scaled map. It shouldn’t be detective work. I don’t follow you. Where was the 2670 sample collected? Can you give me a better location and reference.

    I don;t follow your argument about dynamics. If the the 2760 moss is up around the ice cap, isn’t that higher than glacier front?

    What about the 2200 moss discovered in 2003?

    All of whcih goes to show what a dog’s breakfast Thompson’s report is. Again I’m used to seeing professional reports by geologists, not these stupid pamphlets.

  30. Lee
    Posted Aug 15, 2006 at 9:59 PM | Permalink

    Steve, looka t the damn map and the nubmers on it, which correspond to the numbered lines on teh table. It isnt a detailed map, but it is detailed enlough to see that some samples are from the glacier, and some are not.

  31. JMS
    Posted Aug 15, 2006 at 10:07 PM | Permalink

    Lee, that’s how I figured it out. It was pretty easy — I just posted before I had actually figured it out. The table was in 2 pt. type or something and I didn’t want to take the time to figure it out. Once I did it was pretty clear.

  32. Steve McIntyre
    Posted Aug 15, 2006 at 10:12 PM | Permalink

    OK. I’m looking at the numbers. First of all, most of the sample are taken from older moraines. Of course, they are in diffrent locations – that’s obvious.

    My question was:

    Well, if the 5000-year old Distachia had been under a glacier uninterruptedly for 5000 years, then how did the peat form in 2760 BP at the "modern ice margin"?

    I appreciate that you’ve located this deposit on the map – but how does that answer my question? As I understand it, the ice cap is higher than the glacier front so that doesn’t solve anything. Plus the 2200 year old peat at the 2003 ice margin.

    BTW now try to locate Thompson’s deposits on a map – you can’t , isn’t that a shame.

  33. JMS
    Posted Aug 15, 2006 at 10:16 PM | Permalink

    Steve, why don’t you ask him for lat/long?

  34. Lee
    Posted Aug 15, 2006 at 10:23 PM | Permalink

    Steve, again, look at the damn map!

    One of those samples is around the margin of the ice cap well away from the glacier outfolw, above the glacier front in elevation, but NOT IN THE ICE FLOW OF THE GLACIER. The other is at the glacier.

    Thompson reported that his sample was found at the glacier front, during a particular year. That isnt compeltely precise, but it certainly means it is at the location of the glacier front that year, and could put a nice “X” in that map.

  35. Steve McIntyre
    Posted Aug 15, 2006 at 10:26 PM | Permalink

    Maybe I will at some point, but drawing maps for Thompson is not very high on my priorities. This is stuff that he should have done. Plus he should have reported and discussed the 2200- and 2670- peat in his PNAS article.

    Plus are either of you guys going to explain how the 2200- and 2570 peat formed while the 5000-year peat was continuously under a glacier?

  36. Steve McIntyre
    Posted Aug 15, 2006 at 10:30 PM | Permalink

    #34. I don’t get your point. The 2570 peat, which is said in Mark et al to be at the ice margin, would be higher than the peat in the glacier tongue. That works against your point.

    But let’s leave the 2670 peat aside and focus on the 2200 peat where we even have a picture. Explain that to me. How did this form while the 5000 year peat was continuously under a glacier?

  37. Lee
    Posted Aug 15, 2006 at 10:30 PM | Permalink

    dammit, steve.

    You are STILL, after this explanation, comparing uncovering at the glacial front of an active glacier, with an independent sample collected at a site that WAS NOT THAT GLACIER. And a sample that was apparently under the main stream of teh glacier flow, with samples taken from teh amrgin of the ice cap – entirely different situations.

  38. Steve McIntyre
    Posted Aug 15, 2006 at 10:34 PM | Permalink

    #37 are you talking here about the 2670 peat from 1977 or the 2200 peat from 2003 or both?

    I don’t see that the difference is relevant to your point – please explain other than saying that they are different? What’s your point?

  39. JMS
    Posted Aug 15, 2006 at 10:35 PM | Permalink

    Steve, it is fairly easy: the ice cap retreated in the interim 30 years.

    Lee, you got it wrong, the plant was collected at the margin of the ice cap, not a a glacial terminus. It was collected in 2002.

  40. Lee
    Posted Aug 15, 2006 at 10:44 PM | Permalink

    OK, thanks JMS. I’ll look again, my mepoory ws that it was at teh glacier – Steve’s insistence on not distinguishing glacier from ice cap isnt helping my memory, I must say.

    Steve, the ice cap isnt a glacier flowing downhill, it is basically a bowl – when it expands it fills UPWARD at the margin. When it shrinks, if retreats DOWNWARD at the margin. Adn older sampe unde rthe ice, coudl be ther while peat grows at the margin, and get scovered when the ice cap expands upward and covers it. When it retreats after a period of expansion, it will uncover the younger peat first, and then older peats as it shrinks more.

  41. Steve McIntyre
    Posted Aug 15, 2006 at 10:48 PM | Permalink

    1) Thompson’s 2200-year old sample was collected in 2002. Recession since 1977 has nothing to do with it. Can you explain this without talking about the other peat.

    2) The 1977 sample supposedly collected near the ice cap – I’ve seen reports of substantial retreat of the glacier, but the ice cap. How much has it receded? But the 2670-year old moss at the ice cap is well above the modern range. So what does that say.

  42. JMS
    Posted Aug 15, 2006 at 10:56 PM | Permalink

    Steve, read the book I recommened. You might learn something about what Thompson has been doing for, what, 25 – 30 years?

    Link to the 2200 BP sample? Where did he report collecting it? An outlet glacier or at the ice cap margin?

    BTW, the 2670 year old moss was PEAT, not moss. Peat is plant matter which is on it’s way to becoming coal. I would guess (since I don’t know for sure) that it would be considered pre fossil. It most definitely is not moss.

  43. bender
    Posted Aug 15, 2006 at 11:22 PM | Permalink

    I thought “peat” was semi-decayed Sphagnum spp. moss. As new moss grows over the old, the old stuff decays into peat. I think that is a matter of decades, not centuries. Then again I’ve never even heard of alpine peat until now.

  44. Dave Dardinger
    Posted Aug 15, 2006 at 11:33 PM | Permalink

    re: #42

    You have heard of “peat moss”, haven’t you? The fact is that most peat contains lots of, if not the majority of mossy material. Now it may be that the particular 2670 year old peat wasn’t moss, but you might want to state that more clearly, e.g., “Looking at [photo] you can see that this consists of reedy rather than mossy material.”

    If you’re trying to imply that merely because something is composed of fossilizing moss it’s not really moss at all, then I think you’re trying to be too clever by far. I’d say as long as it can be determined that a given sample was originally moss, it’s fair to call it moss.

  45. JMS
    Posted Aug 15, 2006 at 11:33 PM | Permalink

    Of course, sphagnum spp. is not found at those heights. I just finished reading a fairly extensive book on the coal industry and peat seems to be considered semi-decayed plant matter of no particular species. In some parts of the world it is mainly sphagnum.

  46. bender
    Posted Aug 15, 2006 at 11:44 PM | Permalink

    It’s not the taxonomy I was trying to point to, but the time-scale of the ecological process of peat formation in cold climates – living moss that grows overtop of dead moss of the same species as a substrate. The older stuff is ‘peat’ and (in the case of sphagnum anyways) it doesn’t take long for the succession to happen. Mere decades. As I say, I’m not a peatland ecologist. Just throwing in my 2c where it may help.

  47. JMS
    Posted Aug 16, 2006 at 12:20 AM | Permalink

    Bender, yes you are correct. However I would suspect that at higher, drier locations it might take a while for succession to happen. Most peat bogs are found in low, cool and moist areas. I have no idea of what the ecology might be near the ice cap, but they are probably different…

  48. Steve McIntyre
    Posted Aug 16, 2006 at 5:30 AM | Permalink

    Decay processes in high, cold situations are very, very slow. I saw an interesting comment that Roman and Celtic coins from recent archaeological excavations in a high Alpine pass were in pristine condition.

    I think that the possibility of very, very slow decay is the weak link in Thompson’s reasoning. I suspect that old plant material might be little changed at Quelccaya even if exposed for many thousand years. Thompson just arm-waves through this part of the argument without citing any authority on rates of decay.

    The reason why detailed stratigraphy is important is because, at other sites, you have multiple sediment beds with occasional bulldozing of sediments into moraines. You could have (say) Roman sediments accunulating on Holocene Optimum sediments after a period of stasis corresponding to the Peyto Advance, then bulldozing in the large LIA advance.

  49. Steve Sadlov
    Posted Aug 16, 2006 at 9:01 AM | Permalink

    It is apparent that neither Lee nor attacking pit bull JMS have ever been exposed to a proper geological report or a proper site assay. Either that, or, they pretend they have not. What a joke.

  50. Peter Hearnden
    Posted Aug 16, 2006 at 9:08 AM | Permalink

    Re #49, Steve, have you taken your tablets? (that’s a joke as well btw). You certainly seem very fired up.

    Strangly, when I mentioned John A had been call an ‘attack dog’ elsewhere (not by me!) it was deleted. It’s almost as if there is one rule for those supporting the party line here and another for dissidents. I bet you this post, but not yours, is deleted 😉

  51. Steve Sadlov
    Posted Aug 16, 2006 at 9:27 AM | Permalink

    Pete, chill out mahn. People may jokingly call you a troll but in reality you are more like the principled opposition, at least in my opinion.

  52. Peter Hearnden
    Posted Aug 16, 2006 at 9:46 AM | Permalink

    Re #51. Crikey, is that a compliment? Allways a good way to defuse things that :). The right medication is a wonderful thing eh? – he said winkingly. Oh, but to add, my views are little different to those of Lee and JMS.

    No, back to trying to keep up with all this stuff.

  53. Tim Ball
    Posted Aug 16, 2006 at 9:56 AM | Permalink

    Re #13
    Stephan you are correct. I had intended to remove the clause “apparently without understanding” which was part of a first draft response and failed to do so.

  54. Steve Sadlov
    Posted Aug 16, 2006 at 10:08 AM | Permalink

    Pete – no meds, I’m simply in “irritated manager” mode this week …. 😉

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