James Lane here noticed a couple of other useful references on Quelccaya and related the anecdotal information to this information. He observed:
It took me ages to put this post together, juggling between different sites. I don’t think one can conclude anything from the information, as presented, except that the moss has grown at higher altitudes in the past than now.
His location is a substantial improvement over what I’d posted up before, about which Lee complained. I’ll take another crack at collating the information in light of James’ additional thoughts on the matter.
First, James points out that the "glacier" and "ice cap" do not seem to have a fixed usage in many reports, but that a useful distinction does appear to exist. Here’s a differentiation according to Goodman et al 2001 (cited by James):
Whereas glaciers in the CV have receded into alpine cirques (Fig. 2), the QIC is surrounded by short, steep outlet glaciers up to »2 km long. The QIC covers 70 km2, reaches 5645 m in elevation, and is the largest tropical ice cap in the world (Mercer and Palacios, 1977) (Fig. 3).
I’ll try to follow this usage and limit "glacier" to the "short, steep outlet glaciers". Here once again is the location map from Mark et al (there’s also a useful map in Goodman et al 2001, which can be collated to this map. When we read about the receding Quelccaya glacier, I think that this is generally the outlet glacier in the Huancane valley marked in on this map. There is also evidence of outlet glaciers in other valleys in the past, which are no longer there, but which have left moraines, that are discussed in Mark et al and Goodman et al.
Figure 1. Mark et al 2002 FIG. 2. Map of the study area in two parts: … (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).
Here is a USGS map showing topography a little more clearly/
Samples Discussed in Mart et al and Goodman et al
Starting at the north, Mark et al report a result from Mercer and Palacios 1977 (MP77) marked as location 14 (altitude 5100 m) in the above map that is the "upper peat beneath an H1 terminal moraine". Thus there was an outlet glacier in this valley which has now receded back to the ice cap. It was dated BP 270 C14; 300 calibrated and was a basis for assigning an LIA date to H1 moraines. While the H1 moraine is shown in the map in the Huancane valley, it is presumably dated by cross-dated stratigraphy as no C14 date for this particular moraine in the Huancane valley is shown.
Location 10 (4820 m) in the Huancane valley is the H2 terminal moraine. The upper peat beneath the H2 terminal moraine is dated 10910 C14; 12830 calibrated. Pit Q4 is at this location. One of the samples is said to be "Peat and rootlets incorporated into till of Huancare 2 moraine". Another sample at this location (reported in Goodman et al ) is 10170 C14; 11890 calibrated.
Goodman et al report four samples associated with site 13 (altitude 5180 m), all of which are upvalley from Laguna Paco Cocha "modern ice margin above Laguna Paco Cocha" (not all of which are reported in Mark et al 2002). There appears to be an outlet glacier in this valley as well. The samples are said to come from a "time when QIC was smaller than present" – although it remains unclear whether "present" in this context means 1977 or 1997 (when the more recent geological visit took place.) The oldest sample, said to be "basal peat beneath modern glacier" was dated 2670 – C14; 2760 calibrated. A second sample, "upper peat beneath modern glacier" was dated 1950 C14; 1880 calibrated. A third sample, "upper peat beneath modern glacier" was dated 1625 C14; 1520 calibrated. A fourth sample, "upper peat beneath modern glacier" was dated 1395 C14; 1290 calibrated. In all cases, the table states that the the peat was created at a "time when QIC was smaller than presen".
Location 12 appears to be in the next valley to the south of the Laguna Paco Cocha valley. Goodman et al: "the youngest moraines, on which soil pits Q5 and Q6 were dug, are found 100–200 m from the ice margin." "These small ridges are composed of mostly fresh, ignimbrite cobbles and reveal little pedogenic development. Their stratigraphic position upvalley from the Huancane I moraines, which were dated at <270 § 80 14C yr B.P. (300 cal yr B.P.) by Mercer and Palacios (1977), indicates that these moraines also formed within the last several centuries, coincident with the Little Ice Age". Pits Q5 and Q6 (said to be at 5070 m in Mark et al; 5100 m in G01) reported two samples. The oldest sample, of "basal peat incorporated in Huancane I moraine (maximum age for Huancane I moraines and soils Q5 and Q6)" dated 905 C14; 790 calibrated. The younger sample, of "uppermost peat incorporated in Huancane I moraine" was dated 279 C14; 300 calibrated maximum age.
Thompson Samples
It’s hard work assigning Thompson’s samples to this map, but I think that James’ detective work has more or less located them. Here are two quotes that need to be coordinated:
"This year [2003], the researchers found a second plant near the southern tip of the ice field, some 6 kilometers (3.7 miles) south of their original plant find. Thompson believes that this second plant may provide important historical information about this site. Subsequent carbon dating of the second plant showed that it had been buried for the last 2,200 years, a time when other records showed another abrupt climate change."
A second quote is:
This time [2004], Thompson decided to look up a different valley, some 1.8 miles (3 kilometers) from the initial plant find. “But about a quarter-mile from there, I found yet another area of uncovered plants.”
James Lane:
"2) This places the 2200 BP sample well away from any of the sites on the Mark map (although the southern extremity is depicted in the map). This sample would appear to be from between 5000-5200 metres."
3) The above would appear to give us an indication of the location of the 5200 BP sample – i.e. 6 km north. This would place it near site 14 (the 270 BP sample), although whether it is above or below the terminal moraine is unclear. In the context of Thompson’s conclusions, one would have to think it was above the moraine.
4) The location of the 50,000+ BP sample is a mystery. The press report suggests that Thompson intended to look in a different valley 3km away (maybe somewhere near site 8 on the Mark map – BTW this is labled in Table 1 as “beneath H2 terminal moraine” WTF?). But it’s then reported that he found it closer: “But about a quarter-mile from there, I found yet another area of uncovered plants.” This site is reported as being at 5000m, which would make it lower than the 2670 BP site, at 5180 metres.
My take on this is that the 2003 plant deposit (2200 years old) was found in an outlet valley one valley to the south of the Location 12 valley where pits Q5 and Q6 were dug. I think that the above information suggests that the 2004 plant deposits (50,000 years old and 5000-6000 years old) might have been found in the Laguna Paco Cocha valley or in the location 14 valley if to the north, while the original 2002 discovery might be in the Huancane valley itself. All the samples appear to be associated with past and present outlet glaciers as opposed to the "ice cap" in the narrow sense.
Obviously this is speculative. Why the hell wouldn’t Thompson have included something as routine as a map showing the locations of the samples.
Update:
Here’s a picture of the 2003 plant deposit:
Caption: As the margin of the Quelccaya Ice Cap receded over the past year, it revealed a second large plant deposit that had originally been buried by the advancing glacier. At left, the plants with a field notebook (yellow) for scale. Carbon dating places the plant’s age at 2,200 years before present.
Here is a picture of the 2004 area of 50000 year old peat:
Original Caption: A team member gathers samples of plant material recently uncovered as the glacier’s margin retreated. Carbon-dating provided an age for the plants of at least 50,000 years.
Here’s a picture of the 2006 area of 4-6000 year old peat:
Caption: Above, OSU glaciologist Lonnie Thompson and University of Texas botanist Blanca Leon examine deposit of ancient alpaca moss recently exposed by the retreat of the Quelccaya ice cap in the Peruvian Andes. The deposit was covered some 5,200 years ago as the ice cap expanded. Recent warm periods in the region uncovered large mats of the moss.
References:
Adam Y. Goodman, Donald T. Rodbell and Geoffrey O. Seltzer and Bryan G. Mark, Subdivision of Glacial Deposits in Southeastern Peru Basedon Pedogenic Development and Radiometric Ages
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. (1977). Radiocarbon dating of the last glaciation in Peru. Geology 5, 600–604.
Here is a map from Goodman et al, together with a slight zoom of the same map.
Climate Audit 
100 Comments
Steve, FYI, your “posted up” link is to the second article, not the first one which contains the map and data table.
The moraine from which sample 14 was retrieved is roughly parallel to, and at most about 1 km away from the current ice cap. It is perpendicular to the currently active outlet glacier, and extends roughly from the margin of the active glacier to about 3 km to the north. The next morraine marked in that direction along the ice cap margin also is parallel to and close to the current ice cap, but it is not dated. I’m having a hard time viewing the contour lines on that map – theydotn shpow at all well on my monitor – but the sample 14 moraine appears to extend over a small ridge. Someone correct me if I’m misinterpreting based on not seing it well. At least, it appears to be on a relatively flat area, not a glacial valley.
It appears to me that the sample 14 moraine is not a glacial terminal morraine, but an ICE CAP terminal moraine, probably marking the greatest extent of the ice cap during the LIA, at an area adjacent to the active glacier, but not part of it. The peat date from the moraine woudl be consistent with this.
That argument also seems to apply to the moraine from which sample 12 was taken.
Lee, it doesn’t look to me that 14 is strictly part of the ice cap. There appears to be a valley with a ridge between it and the glacier to be sure but notice the lake feeding a stream at a lower altitude than the #14 moraine. Now we may be all basically saying the same thing but it looks to me like there’s a relatively flat area followed by a bit of a cliff and then another reasonably flat area leading up to the lake and the stream coming out of it. Of course there’s another stream working up toward that same area. Anyway, it would seem that the recent peat, assuming it’s properly dated wasn’t covered with ice and probably was just in a nice cove watered by melting ice sometime in the past 500 years or so. Since the ice didn’t quite reach there whenever it was, you can’t really prove much of anything from it.
#1. There’s a little lake to the west of 14. this looks to me like it’s in an outlet valley.
I get the impression that ALL of the plant deposits are related to past outlet glaciers in the sense that all of them seem to be in gullies or ravines or valleys of some type.
I agree with the first sentence, but I’m not sure about the rest. I think the original 2002 sample was found at the ice cap margin above the moraine dated by site 14. (I also think this moraine was formed by the ice cap itself, probably during the LIA). This is likely not in the Huancane valley, although at that altitude the watershed might not be obvious.
If that’s the case, the 50,000 BP sample couldn’t have been found in the Lago Paco Cocha valley (too far away, and not adjacent) – I suspect it was to the north of the original find, and again probably on the ice cap margin.
Taken on their own, Thompson’s discoveries might support his conclusion that “that the ice cap most likely has not deteriorated to its current size for any length of time in more than 50,000 years.” However the 2760 BP sample found at the ice margin (albeit in 1977) would tend to argue against this.
Mark et al concluded that “the Quelccaya Ice Cap at that time [2760 BP] was smaller than present and may have disappeared completely during the middle Holocene”.
BTW, the NAS report refers to “Thompson et al 2003 (in press)” [page 72]. Is it normal for a 2003 paper to be “in press” or is this some kind of typo?
Others have posted while I was preparing mine. I tend to agree with Lee that the Site 14 moraine is due to the ice cap, and probably the Site 12 moraine as well. But it’s a semantic argument – at some point the ice cap becomes an outflow glacier, and I don’t think anyone can indicate exactly where that happens. The US Geological Survey describes the entire Quelccaya Ice Cap as a “glacier”.
5.
James, it is partialy semantic and partially substantive- a terminal moraine for a glacier in a valley is going to be subject to stream and erosion effects to a different extent, or even of different kind, than ice cap moraines. For many arguments this wont matter, but for some it will.
re 2.
Dave, what you CAN conclude from the recent peat is that it grew at that elevation (or higher). Again, if it did so recently, that invalidates the argument that it must have been warmer for the older peat samples to have grown at those elevations, and this is true whether or not the recent peat was ever under the ice.
Since it is under the moraine, it also places a limit on the date of the moraine – I’m sure you’re aware of that, but sometimes it doesnt hurt to restate the obvious.
Lee, in fact the youngest sample was found at about the upper limit of vegetation Thompson cited in his recent PNAS article.
Gawd, Lee, was there a MWP or not?
For those who want the satellite view, load this location file into Google Earth: http://www.armands.net/Other/Climate/QuelccayaIceCap.kmz
re 10:
jae, you have asked and I have answered that question, at least once before.
What relevance does it have here – unless you are defining the MWP as “warmer worldwide that it is now” and considering anything less than that as denial of an MWP? The argument, whether or not there was an MWP exending to tropical high altitudes, is over whether it was warmer then than it is now.
re 8:
JMS, Steve and a coupe others have cited Thompson as saying the modern range is some 400m below the current ice cap, and are using that as evidence that it must have been warmer than it is now for peat to grow where the ~2000 and 5000 yo samples were found.
The 270 yo sample is some 80m below the ice cap. Even if the claim that the current observed limit is 400m below the cap were correct (it may not be, but I havent checked that) the 270 yo sample refutes the argument anyway – and that is my point.
Re: sample 14 (the “300 BP” sample). Since its one-sigma calibrated age range is 0-502 BP, I can’t see how its dating can be used to distinguish between the MWP, LIA, modern GW, or anything else that happened in the last millenium.
Re: #11
Lee, I’m a bit confused here. Exactly *what argument* is refuted by the 0-502BP sample under the #14 H1 moraine? There may have been a lot of local temp variation in the past 500 (750? 1000? not sure what the two sigma data extent is) years.
Lee is referring to the argument that because the moss does not presently grow at the altitudes where peat has been found, it must have been warmer in the past.
Despite what I wrote earlier, I agree with Lee that the 0-502BP sample weakens this argument. It shows that moss grew at altitude sometime in the last 500 years, possibly quite recently. At 5100m it is one of the highest peat sites in the area.
As with tree-rings, we should not assume that the moss is a good temperature proxy. For example the position of the site below the H1 moraine might provide an adventageous microclimate for the plant.
Note that this is a secondary argument. The primary argument is about the extent of the ice cap
and outlet glaciers on a millenial scale.
Re: #14
Again, I think it is unwise to assume that 502BP is the oldest that sample could be — a one-sigma interval is roughly a 2/3 chance, right? So, couldn’t sample 14 be from a warmer era 500-700 years BP, after which the ice extended further down the slope during a cooler period, and now is receding back up the slope?
I agree with your point about peat as a temperature proxy. Another problem that’s not been mentioned much is the whole issue of how a measurement of a feature that reacts *very* slowly (the position of a glacier front) and is dependent on both precipitation and temperature can be translated into a measure of temperature.
BTW, I want to make another plug for viewing the area with Google Earth, or a similar program that allows one to easily examine the site topography from various directions and perspectives.
Re: #14
PS – Just to clarify, sample 14 is from beneath the moraine (i.e. buried by it), not below it (i.e. downslope), right?
Thompson specifically states in his PNAS article that the current vegetation limit is ~5100m, about the altitude that the 270yo sample was found.
Re: #16
That’s a good question. I’d assumed it was downslope, but looking at Mark et al again they say “Peat entrained in a Huancane I moraine from a neighboring Valley provides a maximum limiting age of 300 (+202/’ˆ’300) cal yr B.P. for the H1 paleoglacier”
I guess that means the peat was in the moraine. Confusingly, Mark’s Table 1 uses the following words to desribe the relation of different samples to moraines: “beneath”, “under” & “inside” to which we can now add “entrained”.
In passing, Mark refers to the Site 14 moraine as for the “paleoglacier” (not ice cap). It also makes clear that the site is in a valley adjacent to the Huancane valley. A lot of topical stuff packed into one sentence!
Interesting as it is, I think we might have exhausted this topic. But to go right back to the start, I think it was fair of Steve M to criticise the NAS panel’s citation of Thompson’s (still unpublished) Quelccaya plant studies, especially while they ignore the evidence of Mark et al 2002.
re: 16,17
Here’s the scenario which comes to mind. Various peats were growing about about the #14 area a few hundred years ago, but it was getting colder. The ice cap started expanding, sending out new glaciers where a steep section was encountered. But then once more things changed and it started warming. The glacial tongues continued to advance for a little while though and pushed up a moraine near to this hardy patch of peat moss as a last effort and then started melting, which helped the peat grow but also sent streams of mud down which eventually covered and killed our sample. Then, a few years ago, some researchers came and found that the mud had washed away in a few areas and found our peat sample.
A fairly simple story and what it proves is 1. Peat can grow at 5100′ and 2. the recent warming started a few hundred years ago +- a few hundred years. Hardly a surprising result on any count and it has little or nothing to say about older plant finds, despite Lee’s thoughts on the matter.
OK, James and if your further additions in #18 may be entrained in my narrative, our poor peat may have been pushed along by the last gasps of the soon to be retreating glacial tongue and killed by mud or ice or whatever.
You can entrain my comments anytime, Dave. I think your scenario is exactly right (although it would have been moss before it became peat).
BTW, it’s 5100m, not 5100′. It sounds like a wonderful place, I’d love to go there, but I doubt my weary bones could hack the altitude.
I’d go. It’d be a great way to lose weight
Here’s a link to Regalado’s article on the plant.
I think that we need to have more information about the plants at the various locations.
The 50,000 year old plants from 2004 are Scorpidium moss about which is said:
The 5000-year old plant found in 2002 was Distichia muscoides, which is described as an aquatic plant, in the rush family. Here’s a link to an interview with the botanist who identified it. This URL says:
A 400-5oo m altitude difference is referred to in the Texas A&M presentation. However the PNAS article says:
All in all, it’s typical Thompson chaos, due to the lack of systematic reporting.
Good gosh, it shouldn’t all be so confusing should it?
I found an accumulation graph and O18/ratio graph developed from the ice cores at Quelccaya showing the LIA and showing “warmer” in the past then at present.
It’s an educational slide too. It seems to focus on the LIA only not the warming bits LOL.
NOAA
Credit Line: Courtesy National Oceanic and Atmospheric Administration South America; Peru; Altiplano; Quelccaya Ice Cap
Latitude: -13.93 / Longitude: -70.83
“The period of the Little Ice Age stands out clearly as an interval of colder temperature (lower 18O) and higher accumulation. Such evidence demonstrates the Little Ice Age was a climatic episode of global significance. From World Data Center for Paleoclimatology (educational slide set).”
Here is the graph:
http://tinyurl.com/zyad9
Re; #25
In looking at that graph, I have to ask how they can say it’s “warmer now since ice covered the plant 50,000 years ago” as all the current articles in the media or on websites say?
Sorry, just one more bit here on a volcano site:
“The most useful objective morphological criterion we have used is evidence of eruptive activity which post-dates the last major glaciation in the Central Andes. It has been known for many years that the central Andean volcanoes were extensively glaciated down to altitudes of ~4,300 m (Hollingworth & Guest 1967; Clapperton, 1983). Only one detailed radiocarbon dating study of the timing of central Andean glaciation has been carried out, on the Quelccaya ice cap in southern Peru (Mercer & Palacios, 1977). This ice cap is some 250 km from the nearest volcano that we have studied, but provides a vital frame of reference for our geomorphological observations (Figure 9). Mercer & Palacios’ critical observations are firstly that after a major re-advance about 11,000 yr BP (Huancane II stage), *** the Quelccaya ice cap shrank rapidly until by 10,000 yr BP it was little, if any, larger than at present***; and secondly that there was a further minor readvance between 600 and 300 BP corresponding to the world-wide “Little Ice Age” (Grove, 1989, Thompson et al. 1986).
http://volcano.space.edu/cvz/criteria.html
***added for emphasis
geology, geology, geology ! 😉
Something just occured to me that I haven’t seen mentioned yet. Since we are talking about altitude and how high is the maximum elevation plants can grow etc, I was wondering if anyone knew or took into account the uplift or subsidence rates of the various locations where samples were collected around Quelccaya?
Seems like this might really matter, especially for the older sample, the 50,000 year sample. One could assume an uplift rate of say one meter per thousand years (=1mm/yr), more if the uplift rate is rapid. In 50 thousand years thats at least 50 meters elevation change, possibly 2-5 times that depending on actual measured area uplift or subsidence rates.
It seems mosses can grow on rocky areas in the middle of glaciers or ice fields. Maybe this could help explain some of the confusion.
re: 29. Ooops. I guess it has been established that the peat is not growing above 5100 M. Sorry for the stupid comment.
In my many treks into the areas above the current timber line, I have indeed encountered boggy areas that might lead to peat formation. I’ve seen lichens and moss like organisms well above timberline at the margins of filled in tarns that have become swamps. At this latitude, things like this are typically in the 9 to 10K foot range.
Uninformed amateur’s question here;
Why does the assumption seem to be that what makes this ice cap shrink or expand is solely temperature? Isn’t it possible that precipitation patterns and local conditions are just as likely to effect the size of a particular ice cap as global temperatures?
32: Yes, good point.
re: #32,
And as you may have noticed, Steve M has just started a new thread which seems to have that as its very point.
Yeah, I saw it right after I posted.
Am I missing something? Pretty much this tells me that this area has been under ice for >5,000 years.
Can anyone (skeptic) tell me why during the supposed warmer MWP these plants weren’t exposed? And the idea that they were and some how didn’t decay is silly IMO.
First, decay rates in high cold areas are very very slow. You need to do more than arm-wave through the possibility of exposure without decay. Second, the peat could have been covered by till and then had the till bulldozed by the LIA glacier expansion. This phenomenon is observed elsewhere – that’s why you need stratigraphy. Third, the various dates prove too much, there is ajumble of miscellaneous dates. Right now promoters of this date need to show in detail how a sequence of glacier advances and recessions explains the various finds. If you’re using this informaiton for policy purposes, you have to do the details to ensure that there is some sequence which both makes sense of the observed plant deposits and permits continuous glaciation in the 5000-year spot. I’m not convinced that it’s possible. No one has done it yet. Thompson’s pamphlet is a joke as a geological report and no responsible panel should use it.
Can you explain away all of the studies that confirm a MWP that was warmer than now (the studies cover the globe pretty well, BTW).
We need to bring Art Sylvester back from retirement so he can teach some of this folks strat. (And in general, thinking skills!)
This > these …. oops!
bender: You may be interested in this paper summary, since it addresses uncertainties.
Anybody know what the uplift rate is for that part of the Andes? It may help.
Again, if Thompson is correct, and the one sample is 110,000 years old, uplift rates will make a huge difference, 1mm per year equals 100m, but 5mm/yr = 500 meters, thats huge as far as elevation differences go.
42, 43:
Here.
Best,
D
Dano, either you blew it or had an agenda. You Googled on isostatic rebound not tectonic uplift. The question is what is the tectonic uplift of the Andes. I’ll give an upside indication. In small scale obductive compression zones in Ventura County, CA, near Rincon Point. There are non fossilized clam shells, embedded in partially consolidated marine shales, at ~ 1000 ft elevation in impacted areas. I seem to recall Holocene dating of them.
Re:#45
Well, the Moche civilization at the coast of Peru had to keep remodeling/rebuilding their amazing long-distance aqueduct system due to tectonic uplift. IIRC this was over a multi-decade/few-hundred year timespan.
http://www.bu.edu/jfa/Abstracts/O/OrtloffC_12_1.html
RE: #46 – that’s right in the same ball park alright – pretty impressive rates. I guess that would explain that megathurst quake back in ’60, no?
I was trying to find the uplift rates with no luck but I did find a list of papers regarding “LICHENOMETRY” on a university site for required course reading :
Beschel, R.E. 1957. A project to use lichens as indicators of climate and time. Arctic 10:60.
Beschel, R.E. 1961. Dating rock surfaces by lichen growth ant its application to glaciology and physiography (lichenometry). pp.1044-1062 IN Geology of the Arctic (G.O. Raasch ed.) Univ. Toronto Press.
Burrows, C.J. and Lucas, J. 1967. Variations in two New Zealand glaciers during the past 800 years. Nature 216:467-468.
Calkin, P.E. and J.M. Ellis. 1980. A lichenometric dating curve and its application to Holocene glacier studies in the central Brooks Range, Alaska. Arctic Alpine Res. 12:245-264.
Calkin, P.E. and J.M. Ellis. 1981. A cirque-glacier chronology based on emergent lichesn and mosses. J. Glaciology. 27:511-515.
Carrara, P.E. and Andrews, J.T. 1973. Problems and application of lichenometry to geomorphic studies, San Juan Mountains, Colorado. Arctic Alpine Res. 5:373-384.
Good old school stuff maybe? The last one sounds very appropriate.
I googled “radiocarbon moss” and radiocarbon peat. The abstract for an oldish article MacDonald et al Geology 1987 Geology: Vol. 15, No. 9, pp. 837–840, Comparative radiocarbon dating of terrestrial plant macrofossils and aquatic moss from the “ice-free corridor” of western Canada
G. M. MacDonald, R. P. Beukens and W. E. Kieser AND, D. H. Vitt, said that radiocarbon dates for moss ran high relative to macrofossils. I don’t know whether that is still regarded as a potential issues.
Here’s a more recent article on radiocaron dating of peat:
“Critical examination of many Holocene peat palaeoclimate records shows that the maximum
possible errors involved in age estimates are often much larger than we routinely
acknowledge. Age estimates for events within profiles are usually based on a combination of
statistical techniques and subjective assessment using current understanding of the peat
forming system. When a range of plausible age-depth models are applied to estimate ages of a particular horizon in typical records, there may be considerable variability between the central age estimates of 200-400 cal yrs. Inclusion of 2à?Æ’ error ranges might increase this to as much as 400-600 cal yrs. We might have more confidence in the central age estimates from a particular model for good ecological reasons, but we will inevitably be left with some
uncertainty over any such conclusion. When we begin to ask searching questions about the
synchronicity of events in different profiles and different proxies, it rapidly becomes apparent that our conclusions are limited primarily by the quality of our chronologies.”
http://www.bio.uu.nl/~palaeo/Congressen/ Holivar/PDF/18%20D.Charman.pdf
Oh that’s interesting SteveM and James Lane.
I was wondering something similar too.
Since this is a “pamplet” is it ok to leave out all the steps that are found in most papers? ex: if they are using mosses for dating, they’d cite a paper that established the dating method they were using and even the problems too, or at least reference it? Like in a court case ; ref other verdits from similar cases (that could have estabished a law too).
Well, sheesh isn’t that how science works? ( I know I know, we are talking about climate papers)
Bender: Weren’t you questioning the problem of dating errors?
I think the interesting issue in these papers as applied to Quelccaya is the dating of the 270BP sample “entrained” in the H1 moraine. It seems that the uncertainty might be much larger than the estimated range itself. Goodman et al used the sample to date the moraine itself to about 300BP.
Not that there’s necessarily anything important to be concluded from that, but it’s a good example of the “uncertainty cascade” that bender has alluded to elsewhere.
Teh 270 yo [peat was foudn under a terminal moraine, that is clearly fro tthe ice cap – whether you want to call it as Steve does an “outlet glacer,’ it did nto cascasde down a valley, it is perpendicular to the current outlet glacier, it is essentially parallel to the current ice cap, and it seems to be part of a system of moraines the circle the ice cap at a distance of about 1 km down to quite close.
It looks to me like a reasonable interpretation is that the moraine ‘system’ of which one part covered teh 270 sample corresponds to the maximum ice cap expansion during the LIA, consistent with the peat dating. Yes, there is uncertainty in the date, but given the climate history we know, this makes sense.
Re #52
No. Not me.
re: #54 Lee,
I assume you can read contour maps. Just look at the two renderings of the area around #14 carefully. It’s quite clear that there’s a valley there leading from the icecap to the little lake shown. The second map only gives contour lines for every 200 meters, but the first map has them every 100 meters. Look at the moraine at 14. It rises to the 5200 meter contour on both ends. But where the peat was sampled it was almost exactly at the 5100 contour. This is a valley of about 300 feet depth. This can’t be ignored. The glacier, not I think what should be called the ice cap, must have been about 300 feet in depth (+_100′?) in order to have had a more or less linear moraine.
Now the sample may well have been “under” the moraine in some sense or another, but I can’t imagine it was under very much. The researchers weren’t AFAIK drilling for samples but finding samples near the surface. So whether it was scooped up and moved some distance downhill or just got covered with mud or falling debris, it ended up being easy to discover.
Now none of this means a whole lot, but as long as you’re making a big issue about it, I feel I have to respond.
Dave, it may be my monitor, but I’m having a devil of a time seeing the contour lines – I get incomplete and broken contours on my screen ,and am having to interpolate. I’m going to try to print them tomorrow, when I have access to a good printer.
My point about the moraine, whether we call it a glacier or ice cap, is that it was along a more-or-less continuous line marking the extent of the ice cap. Even in that little valley, it did not appear to extend a glacial ‘tongue’ down the valley, just a bit of a bulge in teh cap margin. Look at that moraine, and the similar moraines flanking the ice cap as one continues around the cap.
To me, given that we know the glacier is retreating from presumably-LIA boundaries, and the date of the sample, a reasonable first interpretation is that those moraines mark the extent of LIA expansion of the ice cap. The fact that part of that is in a valley doesnt much alter that idea, especially since there wasnt much of a glacial tongue in that valley.
re: #57
Whatever. I think you’re just backfilling but it’s not important. I agree that the moraine is the maximum of the ice from the LIA. That it occurred 270 years ago or possibly less (if the peat was already dead when covered), is not a problem. We already know things were warming up 150 YO in NA.
Re # 37
Wow , why am I the one doing the hand waving? You want me to believe this plant got compressed flat like a pancake, had the glacier recede and expose it for what would likely be decades if not hundreds of years, then this herbaceous non-woody plant survives the elements for years on end intact but no new ones grow in its place for some reason, then it gets recovered by the glaciers a second time WITHOUT getting bulldozed down the hill into a moraine and uncovered again still rooted in place and is the only plant around because all the newer plants got bull dozed away but yeah they were growing there..probably…based on your hunch..99% likely but they just all got washed away while the 5,000 year old plants survived two coverings and one bulldozing. Oh yeah…I’M a hand waver!!!
I’m not talking about the peat. I’m talking about the 5,000 year old plant rooted in place and recently uncovered with no apparent newer material in the area. It’s the furthest thing up the hill so it’s likely been covered the longest…..how’s it go?.."the ice keeps what it takes"
Uh? How many dates are there in the most recently exposed areas? I think only one ~ 5,000. ( Well not counting the 50,000 year old peat). All the other stuff is down hill and apparently uncovered long ago-ish. And thus immaterial…obsfucatory if you will.
I don’t think so. I think your position needs to find newer material recently uncovered. Your Medieval forest need to come uncovered and soon. [snip – no creationist talk on this site]
Condescend on Thompson all you want but he is a great and amazing fella. Incredible his life’s work. I think you hate his facts as much as his uncrossed t’s and undotted i’s.
Re:#56
Dave, I got the oppposite impression. From the table wording in describing samples, it looks to me as though they dug/cored through moraines in order to access (what is left of) the pre-moraine ground level.
Re # 38
Yeah all those studies are trash and must be wrong if you can’t come up with some medieval plant material from the currently…i said CURRENTLY…. receding glaciers.
Your studies are like information from a friend of a friend who has a sister who knows this guy…..the glaciers and the plants they release are the very books of nature…they are first hand knowledge.
Are you all missing the good old days when you could machinate and obfuscate all day long about Mann, the Hockey team and statistical felonies they committed? Boy…back in the day…it used to mean something…..it’s all so long ago now….we don’t even talk in terms of a 1,000 years anymore….we’re talking 2,000…5,000…50,000 years…..
George, try to keep up. 2760 BP material was found at the margin of the ice cap in 1977. At 5180m it is the highest sample yet found.
Of course, Thompson doesn’t bother to tell us the location or altitude of his sample.
But, George, we’ve… moved on!
Re 64
Oh so you now realize it is warmer then its been in over 2,760 or 5,000 years. And the Hockey team was right by a long shot..a slap shot if you will…..good for you…now what?
As they say, don’t feed the trolls. Bye George.
James, I find it funny that George got his head chopped off (metaphorically) yesterday and today we find him running around like a chicken….
This stratigraphic work we are assessing and doing here is driving the warmers into a tizzy. I wonder why?
Re # 67
My heads still here. And there still exist no explanation of a sustained TOA (top of the atmosphere) forcing of 6 W/M2 as would be required to explain Mr Hoyts very low climate sensitivity numbers.
Likewise we now have two sites , here (Quelccaya) and the tree stumps from Alberta’s Saskatchewan Glacier that you, Steve and others are trying to turn logic on its head to convince yourselves that the newer stuff that would show a warmer MWP must have been lost in the repeated advances and retreats of the glacier yet some how the old stuff survived. How many sites can we find like this and how long will you guys attempt to use stratiography like you use statistics to obfuscate the obvious……no it’s not me missing my head….your position is the one that is unsupportable in spite of your best efforts to convince yourself to the contrary.
Re 68
Steve,
Sorry but you are wrong. There’s a picture up above that shows Lonnie Thompson and University of Texas botanist Blanca Leon looking at a recently uncovered 5,200 plant buried while still rooted.
I’m looking at the picture and I don’t see any MWP plants in the picture…the authors don’t mention any MWP plants…that’s because they never grew there because it has been covered in ice continuously for 5,200 years only finally melting in todays anomalous warmth.
Statistics won’t save you and stratiography won’t save you….you need some young plant material to start showing up from beneath the melting glaciers and melting ice caps and you need it to show up soon. Unfortunately it looks like its just older and older stuff showing up with each years melt.
RE: #70 – I am simply characterizing your behavior. You and others of your ilk are like a fly to a picnic here. This topic is one of your hot buttons. I wonder why? I’ll answer – this approach somehow threatens you and your agenda.
re: #70. How do you know the plant is rooted? Certainly the caption of the picture doesn’t say it was. If it was in the text, could you please provide a quote of how it was stated? Mosses, BTW, generally have very shallow roots. Those I’ve observed could always be pulled off with a fraction of an inch of roots,whether on soil or rocks. I’d think it’d be a fairly technical process to prove that a given sample of moss was rooted where it was found.
Re# 71
Absolutely, my agenda of the truth is threatened by the powers that be which control oil markets, politicians, public policy, the media and gullible people like yourself. Ultimately history shows the truth wins out except when those in control become powerful enough to burn books and jail intellectuals.
Touche: My agenda of the truth is threatened by the powers that be which control the media, the research funds, politicians, public policy, and gullible people like yourself. History will show the truth, regardless.
Re # 72
He states it both in the abstract and on page 10541 of the PNAS article;
Re # 74
But Jae we can’t both have separate truths. There is only one truth. And the glaciers and their 5,000 year old plants have spelled it out for you. So cease-and-desist your agenda because you seek the truth and because you don’t want to be an instrument or a tool if you will of those who have an agenda to hide the truth in favor of their record profits. Do you want the truth to be what you want it to be Jae? Or do you want the REAL truth..unbridled? Now before you answer that question get a mirror….or better yet stand in front of a mirror….grab the guy you see there by the front collar…pull it tight…shake him a little bit…no shake him hard…look into that guys eyes and ask him…DO YOU WANT THE TRUTH??….If he looks away shake him good..smack him across the face if you need to and ask him again DO YOU WANT YOUR TRUTH OR THE TRUTH…Make sure he doesn’t lie back to you. Look him in the eyes and see into his heart…that’s the only way you’ll know if he’s lying to you….
Good luck with that!
gbalella – yet another bold and brave revolutionary, fighting against “the Man” (e.g. the big bad oil companies, the “establishment” and all o’ dem bourgeois types …. yeah, yeah, yeah … same old song and dance. To the barricades mon ami! 😉
76: Man, you are coming unglued. Take your meds.
68:
This stratigraphic work we are assessing and doing here is driving the warmers into a tizzy. I wonder why?
o If your marginalization wurd ‘warmers’ means to categorize ‘scientists’, no you’re not.
They don’t read this blog’s comments. Thus, no tizzy.
(Who could blame them for not reading these, what with the typical ‘stratigraphic worker’ here commmonly using marginalization phrases and whatnot).
o If your marginalization wurd ‘warmers’ means to categorize ‘laypeople who reject your ideology/POV’, well, you aren’t assessing anything or doing any work (I see no submissions coming from these comment threads), so there must be something else causing the tizzifying. Mabye the preening causes tizzyfication. Maybe you should ask rather than conclude.
HTH,
D
#79 Geez Dano, how special are you really? Don’t hold back now, we can take it. I know that might be hard to imagine with us so lowly and poor, and dumb around here.
I can forward your comment to my husband so he can pass it on to “those in the business” so they know you are doing such a good job protecting the knowlege, if you’d like me too. Must be so stressful to wade through all this by yourself.
holy cow. LMAO
RE: If your marginalization wurd “warmers’ means to categorize ‘scientists’, no you’re not.
Why are you being such a snake? RE: “warmers” = “scientists?”
That’s your meme, not mine.
Back when I was out there mapping the column out at Piru Lake, I never would have dreamt that stratigraphy would be capable of stirring such passion …. 😉
81:
There are two conditional choices, see – it’s the ‘if’.
HTH,
D
Hey, Dano: AGAIN: PLENTY OF SCIENTISTS DON’T AGREE WITH YOUR SCIENTISTS. BTW, where is your “deconstruction” of even ONE of the Idso’s summaries?
RE: #83 – That’s your problem, not enough choices. One of the ones you forgot was “warmers” = “scientists who have a revolutionary agenda and think their elder and mentor scientists, not to mention certain of their contemporary scientists, should be ignored”
85:
It’s the same.
No scientist gets their science from blog comments, whether or not commenters tack on widdle marginalization phrases to a description.
HTH,
D
87: I will bet you a case of your favorite brew that many scientists get IDEAS and INPUT/FEEDBACK from the blogs. I know I do, and I have learned a lot from blogs (I am a scientist, although not a climate scientist). They are good sounding boards, Dano.
Dano shall we call you “Dodge prime?” You completely dodged my #85. You failed to confront the issue of a newer breed of scientist who is part of some sort of counterculture within the more traditional scientific community. Let us face the facts. 100 years ago, there were only the basic disciplines. Now we have all these things like “Stream Ecology” and “Sustainability” – all of them developed when influences such as Amory Lovins and Stewart Brand made their mark. Without the 1960s “revolution” I seriously doubt something like Real Climate would ever be able to stick. I know well of this. I witnessed a split within a promonent geology department between those who focussed on pure geology, and those who were into geology because they saw it as an opportunity to work in a field where they could go out and worship Mother Earth. At the extreme, the latter group might let ideological pressures exert influence on their practice of the Scientific Method (or lack thereof). You cannot claim that this split does not exist.
Oh and by the way, here’s a challenge, guess which side of the “split” I was on at the time!
88:
Dano shall we call you “Dodge prime?” You completely dodged my #85
If we go back to 79, we’ll see that the italicized is irrelevant to my point. That is: you are distracting away from the point that no scientists read this blog’s comments, regardless of the widdle namie-names you use or your attempts to marginalize with capitalized wurdz.
HTH,
D
RE: #90 – Are you a scientist?
91:
Applied, not research.
Best,
D
RE: #92 – But nonetheless, you are a scientist who reads this blog. And based on the names I see here, you are not the only one. So, indeed, scientists do read this blog. I am a science degreed high tech manager myself. Had I instead gone to work for the USGS or academia, I’d be just a plain old scientist reading this blog. Etc.
82: I thought it was Pyramid Lake with Boles in Sed Pet. Were you a geofizzie grad in’82 and lived on diablo as a freshman? Are you really that Steve???
RE: #94 – you’re warm but not that warm. Man there sure are a lot of Gauchos out and about, eh?
93:
The point I should have expressed mo’ bettah (and that I’ll talk to my editor about its lack of clarity) is I don’t get my science from comment threads on blogs. Not here, not RC.
That is: comment threads are for opinion and extrapolation (eg Curry at RC, others at RP Jr’s), not reference or citation. The conclusions arising from blog comments aren’t cited. The conclusions arising from blog comments aren’t science.
Best,
D
RE 95: Too bad, that Steve was a genius.
What I think Dano meant was that real scientists do not pay attention to blog comments, just us gray-haired pebble-pimps between field jobs.
Steve M: Thanks for providing a most interesting blog where geologists are praised: Cheers! I think Twains definition of a mine is appropriate to climate science: A Fool at one end (Gore) and a Liar at the other (Mann)
RE: #96 – I agree
RE: #97 – well, nothing bad about having possibly crossed paths with both you and that Steve.
More of the same….stumpy
Nice cite, George. Let’s look at the rest of it:
Not sure about the AD 1300 reference to the LIA. Maybe they meant AD 1700?