\doc\web\99\12\noice.txt Subject: Re: How do YE creationists explain the Greenland ice cores? Date: 1998/07/10 Author: Tim Mitchell Posting History DARNELL Just curious. The ice sheet seems to predate the (creationist) age of the Earth. "The ice sheet "archive" was created as snow fell over Greenland year after year, trapping the gases, chemicals, and dust of the atmosphere, and eventually compressing into ice. The GISP2 core, along with a complementary core drilled by the European Greenland Ice Core Project (GRIP), spans more than 100,000 years of climate history." For details, see: http://www.geo.nsf.gov/adgeo/press/pr9456.htm Mike Darnell MITCHELL Thanks for the question Mike! Let me attempt to give a YE reply... As I understand you, the proposition that you are making is as follows: 'Cores recovered from the Greenland ice sheet include ice 100,000 years old, therefore the Earth is at least 100,000 years old.' As you might expect, I contend with that proposition on the grounds that the cores from the Greenland ice sheet do NOT include ice 100,000 years old. I start by pointing out that I do not dispute the validity of using the Greenland ice cores to study climatic conditions in recent centuries. For example, Etheridge's (1992) study of variations in tropospheric methane provides an excellent example of how such cores may be reliably dated and useful information extracted for the last few centuries. The standard method for dating cores spanning the last few millennia is by using seasonal variations in the macrostratigraphy and the isotopic content of the cores. In Etheridge's (1992) study, the ice from an Antarctic core spanning the last two centuries was dated using seasonal methods, and the dating was independently confirmed using reference horizons, such as a layer of high acidity corresponding to the 1815AD Tambora eruption. When one attempts to date the ice to times prior to the last couple of millennia, one rapidly hits problems... A quote from one of the standard methodological texts on such questions will show that I am not exaggerating: "One of the biggest problems in any ice-core study is determining the age-depth relationship." (Bradley, 1985, p134) Why is it the case that although it is relatively simple to date the uppermost layers of an ice-core, corresponding to the last few centuries, it is that much more difficult to date lower layers? The reason is that in the deeper ice it is not possible to detect annual layers; they can be detected neither in the original macrostratigraphy, nor in the isotopic variations. Reference horizons are limited to the historical period. So the method that is used to date the deep ice cores - whether from Greenland or Antarctica - is glaciological. What happens is that a model of glacier flow is taken, and estimates are made of various parameters that affect the mode of ice movement. It is then assumed that the ice laid down in ages past was laid down in conditions similar to the observed modern conditions. Under this assumption, the model and estimates are applied to the core, and dates are calculated for different parts of the core. Thus one part of the GRIP core will be dated as "50,000" and another as "100,000" years old. So the dating of the Greenland ice cores as "100,000 years old" is dependent upon the assumptions that: 1. The ice was laid down in conditions similar to the present; 2. The glaciological model adopted applies to the Greenland ice sheet. Now YE creationists disagree with both of those assumptions; speaking for myself: 1. The ice was laid down in conditions DISsimilar to the present (it was deposited immediately post-Flood); 2. The glaciological model adopted DOES NOT apply to the Greenland ice sheet (such glaciological models are built on old-earth assumptions). Since I disagree with the assumptions underlying the dating technique, I disagree with the dating (including the dating of part of each core to "100,000" years old). Thus my response may be summarised as follows: 'Cores recovered from the Greenland ice sheet DO NOT include ice 100,000 years old.' I hope that this helps, Tim Subject: Re: How do YE creationists explain the Greenland ice cores? Date: 1998/07/10 Author: mike.darnell Posting History Message segment 1 of 2 - Get Next Segment - Get All 2 Segments > methodological texts on such questions will show that I am not > exaggerating: > "One of the biggest problems in any ice-core study is determining the > age-depth relationship." (Bradley, 1985, p134) > A true statement, but one that doesn't show up "prior to the last couple of millennia." The ice must be fairly old before this becomes a serious problem. Annual layer counting is extremely accurate (within 250 years) within the first 14,500 years. See Hammer, C.U. & Meese, D.A. 1993. Dating ice cores. Nature, 363, 666. > Why is it the case that although it is relatively simple to date the > uppermost layers of an ice-core, corresponding to the last few centuries, > it is that much more difficult to date lower layers? The reason is that in > the deeper ice it is not possible to detect annual layers; they can be > detected neither in the original macrostratigraphy, nor in the isotopic > variations. Reference horizons are limited to the historical period. > No. See above. > So the method that is used to date the deep ice cores - whether from > Greenland or Antarctica - is glaciological. Actually, several different methods were used, all of which correlated fairly well. Naturally, the degree of confidence was worse with the older samples, but all methods gave very old ages. > What happens is that a model of > glacier flow is taken, and estimates are made of various parameters that > affect the mode of ice movement. It is then assumed that the ice laid down > in ages past was laid down in conditions similar to the observed modern > conditions. Actually, the ice cores allow us to detect how conditions in the past differed from current conditions. Analysis of gas in trapped air bubbles, for example, show significant atmospheric and climatic changes Message segment 2 of 2 - Get Previous Segment - Get All 2 Segments > Under this assumption, the model and estimates are applied to > the core, and dates are calculated for different parts of the core. Thus > one part of the GRIP core will be dated as "50,000" and another as > "100,000" years old. > > So the dating of the Greenland ice cores as "100,000 years old" is > dependent upon the assumptions that: > 1. The ice was laid down in conditions similar to the present; Not an assumption. Actually, the cores reveal that past conditions were different from the present. > 2. The glaciological model adopted applies to the Greenland ice sheet. Not relavant, since a "glaciation model" is not the primary dating method. > Now YE creationists disagree with both of those assumptions; speaking for > myself: > 1. The ice was laid down in conditions DISsimilar to the present (it was > deposited immediately post-Flood); > 2. The glaciological model adopted DOES NOT apply to the Greenland ice > sheet (such glaciological models are built on old-earth assumptions). > > Since I disagree with the assumptions underlying the dating technique, I > disagree with the dating (including the dating of part of each core to > "100,000" years old). Thus my response may be summarised as follows: > 'Cores recovered from the Greenland ice sheet DO NOT include ice 100,000 > years old.' > > I hope that this helps, > > Tim > I see your position. If you will review the actual techniques used in dating, I believe you will find your assumptions are mistaken. Mike Darnell -----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/rg_mkgrp.xp Create Your Own Free Member Forum Help | Feedback >> Community: Your community could be featured here! >> Forum: talk.origins >> Thread: How do YE creationists explain the Greenland ice cores? >> Message 11 of 13 Subject: Re: How do YE creationists explain the Greenland ice cores? Date: 1998/07/11 Author: Don Lindsay Posting History 1998/07/11 Author: Don Lindsay Posting History In article <6o5ss0$829$1@nnrp1.dejanews.com>, wrote: >In article <01bdac15$5b8e8740$1f68de8b@avon.cru.uea.ac.uk>, > Tim Mitchell wrote: >> I start by pointing out that I do not dispute the validity of using the >> Greenland ice cores to study climatic conditions in recent centuries. >> Why is it the case that although it is relatively simple to date the >> uppermost layers of an ice-core, corresponding to the last few centuries, >> it is that much more difficult to date lower layers? The reason is that in >> the deeper ice it is not possible to detect annual layers; they can be >> detected neither in the original macrostratigraphy, nor in the isotopic >> variations. Reference horizons are limited to the historical period. If you read http://www.cs.colorado.edu/~lindsay/creation/icecap.html you will discover that direct layer counting has been done to layer 50,000. And, there are multiple evidences that the count is a correct count of 50,000 years, plus or minus 5 percent. For instance, carbon dating of pollen and soot has been done at many layers. I agree that there's some wiggle room in the dating of the bottom of an ice core. But Tim wants the wiggle room to start about 6,000 years ago, whereas in fact the (pun) deep issues are all on the far side of 50,000 years ago. -- Don D.C.Lindsay http://www.cs.colorado.edu/~lindsay/Home.html Home » People » Humanities >> Theology Explore More: Find any book, video, CD SHOP AMAZON.COM! Find great prices on Baby Items! The Ultimate Directory Cool stuff from InfoSpace Classifieds Cool stuff from InfoSpace Price Comparison Cool stuff from InfoSpace 5¢ long distance! Save $$$$$. The Best of ZDNet Delivered to you free! Rate it! Sinbad in Comedians (1=worst, 5=best) Funniness 15 Delivery 15 Originality 15 Persona 15 Compare it to others User Comments Add this rating to your own Web site 5 top rated Comedians 1. Steven Wright 2. Eddie Izzard 3. George Carlin 4. Chris Rock 5. Denis Leary See the full list... Deja Forums Atheism Atheism Atheism Satirical atheism Atheism Deja Communities Orange County Photographer A-Summit Resources candid wedding photography Recycling Weather Watchers Online Start your own community in Theology. My Deja Please login! ratings discussions communities back to search results Help | Feedback >> Community: Your community could be featured here! >> Forum: talk.origins >> Thread: How do YE creationists explain the Greenland ice cores? >> Message 12 of 13 Subject: Re: How do YE creationists explain the Greenland ice cores? Date: 1998/07/16 Author: Siegmar Schleif Posting History Don Lindsay (lindsay@munge.cs.colorado.edu) wrote: : In article <6o5ss0$829$1@nnrp1.dejanews.com>, wrote: : >In article <01bdac15$5b8e8740$1f68de8b@avon.cru.uea.ac.uk>, : > Tim Mitchell wrote: : >> I start by pointing out that I do not dispute the validity of using the : >> Greenland ice cores to study climatic conditions in recent centuries. [snip] : If you read : http://www.cs.colorado.edu/~lindsay/creation/icecap.html : you will discover that direct layer counting has been done to layer : 50,000. And, there are multiple evidences that the count is a correct : count of 50,000 years, plus or minus 5 percent. For instance, carbon : dating of pollen and soot has been done at many layers. : I agree that there's some wiggle room in the dating of the bottom of : an ice core. But Tim wants the wiggle room to start about 6,000 years : ago, whereas in fact the (pun) deep issues are all on the far side of : 50,000 years ago. : -- : Don D.C.Lindsay http://www.cs.colorado.edu/~lindsay/Home.html I invite the readers to have a look on the discussion betweeen mainly D.C.Lindsay and me in September last year. Please use dejanews and search for icecore. In this articles you will find not only pro but also contra arguments and several peer reviewed references. The disput was mainly going about one paper : Alley et al., Nature 362,527 and about checking the dates with volcanic eruptions. In the abovementioned paper the collaboration has counted the annual layers up to 17380 years BP. Deeper in the core - from 17380 BP to 40500 BP - they have counted only 1m of 10 m or 1 m of 20 m. They have then used an iceflow method for the interpolation, a method which I questioned. See Schott et al. Journal of Glac. 38,p. 162 ff., where several problematic assumptions are listed. Before I could ask him where his 50000 year number was/is published he said: "Before you ask where this is published: it isn't. To learn the final count, I had to obtain a preprint from the "in press" GRIP/GISP2 special issue of JGR." Perhaps he means : Meese, D.A., R.B. Alley, R.J. Fiacco, M.S. Germani, A.J. Gow, P.M. Grootes, M. Illing, P.A. Mayewski, M.C. Morrison, M. Ram, K.C. Taylor, Q. Yang, and G.A. Zielinski. 1994. Preliminary depth-agescale of the GISP2 ice core. Special CRREL Report 94-1, US. to which I do not have access. So (unfortunately) you have here to believe D.C.Lindsay's words and credits. The main problem is -if you go deeper into the core- that all the annual layers begin to smear out more and more. The reason is the very high pressure if you go deeper and deeper. This is the reason that there is a thinning of the ice with depth, which makes counting of layers very problematic. So what are the timescales actually used ? See : http://medias.meteo.fr/paleo/icecore/greenland/summit/document/notetime.htm A) Citation: "The Meese/Sowers timescale is the official timescale for the GISP2 ice core, up to and including many of the publications in the GRIP/GISP2 compendium volume of the Journal of Geophysical Research. This timescale was created by combining the original layer-counted timescale of Meese and others (1994), to about 50,000 years, with a timescale constructed using trace gas measurements from the Vostok and GISP2 cores, placed on the SPECMAP marine timescale. See Bender et al. (1994) for details." B) Citation: "....GRIP timescale ss09. This is one of several published depth age scales for the GRIP core. It is based on a Dansgaard-Johnsen (1969) type flow model, with a 1500 m lower shear layer, 13.5% bottom sliding and accumulation rates which are a function of the d18O values: 23.0 cm of ice at -35.2 per mil with 8% and 18% change per per mil at -35.2 per mil and -40 per mil, respectively. The d18O values are given in the file gripd18O.dat. See also the stratigraphic ages by Hammer et al. (1997), presented in the file gripstrat.dat." I think D.C.Lindsay's WWW-pages are in some extend helpful, but on the other hand it is - I think- biased because it cites only literature, which fits good in his world view. For example it cites concerning the dating of icecaps with volcanoes Hammer et al, Nature Vol. 328 pp. 517-519, 6 August 1987 - which dates the Thera-eruption to 1620 BC, but he hasn't given all references, which Don Lindsay knows - from our discussion last year. The paper by Hammer et al. Nature 288, p.230 - 235 (1980) has offered a date which was off by 240 years - the authors say in the 1987-paper that the icecore was corrupted. And concerning the 1620 BC date several criticism were published in: Warren Archaeometry 29,205-211 Warren Archaeometry 30,176-179 Pyle Archaeometry 31,88 Archaeometry is a peer reviewed journal devoted to archeological dating methods. So there is also in the scientific community an overall agreement concerning this issue -as far as I know. Yours sincerely S. Schleif Track this thread for me Subscribe to talk.origins Mail this message to a friend View original Usenet format Create a custom link to this message from your own Web site << Previous in thread · Next in thread >> Search Discussions For a more detailed search go to Power Search Search only in: talk.origins All Deja.com Search for: Search Messages Arts & Entertainment Automotive Computing & Tech Consumer Electronics Health Home & Family Money People Politics & Media Recreation Sports Travel SHOPPING - Long Distance Deals - Free Stuff - Trade with Datek - GET IT NOW @ NECX - Get FREE Health Info@drkoop.com - eBay Auctions - Up to 50% off now at Amazon.com! - BankRate.com-click here! - MTV Video Music Awards - The BEST Music Online Copyright © 1999 Deja.com, Inc. All rights reserved. Trademarks · Terms & Conditions of Use · Site Privacy Statement. 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My Deja Please login! ratings discussions communities back to search results Help | Feedback >> Community: Your community could be featured here! >> Forum: talk.origins >> Thread: P38s, Greenland, and Ice Cores (was Re: Noachian flood ) >> Message 11 of 86 Subject: P38s, Greenland, and Ice Cores (was Re: Noachian flood ) Date: 1998/12/05 Author: Keith Littleton Posting History In message <34fa66b4.428964@news.wn.netlink.co.nz> and on 1998/03/02, Daz Gedye wrote: >What is this YEC? I'm guessing young earth for the ye, >but the c has me stumped. It stands for Young Earth Creationist. It is to distinguish these creationists from the creationists believe that that Earth and universe can be billions of years old, but fail to accept evolution, and the proponents of theistic evolution. The latter are creationists who accept that the Earth and Universe are billions of years old and evolution as either a valid theory or fact. > This is all on my homepage if you are curious. There are plenty of web pages like yours. :-) >I've been given a couple of copies of the journal Creation >ex nihilo. In the august 1997 issue they question the >reliability of ice cores. A squadron of P38s and B17s >that were ditched in Greenland July 15 1942 were recovered >in 1992 75 m beneath the surface. They are unlikely to have >sunk to that depth since a P38 exerts a pressure of 0.18 >tonnes/ square metre, which would only decrease the melting >point by 1/5000 of a degree. That would make the 3000 m >ice core retrieved in Greenland in 1990 possibly only 2000 >years old. The article in "Creation ex nihilo" fails to address two major points. First, the argument that creationists make of the planes not having sunk through the ice is one "whale" of a red herring. It is a stawman claim that is totally irrelevant to the case they are making. As far as I have read, no competent glaciologist or geologist has claimed that the planes sunk through the ice. Any conventional scientist would certainly wondered where such a silly hypothesis came from and readily acknowledge that the planes where buried by snowfall. Finally, any glaciologist can readily point out that the crash site is only about ten miles from the edge of the ice sheet, where both snowfall and melting are very high. Any map showing the precipitation patterns in Greenland will demonstrate that the annual snowfall at the crash site is completely different form the ice core sites. At the ice core sites, the annual average precipitation is comparable to what can calculated from the cores. For example, The planes were found an area which has an average yearly snow fall in the range of 6.5 feet per year. Given that the planes were there about 55 years, which should yield 357 ft of snow, the depth of burial of about 270 feet of snow, rather than ice, is to be expected. If a person was to move inland, the average annual snowfall droRe off dramatically to rates consistent with those calculated from the ice cores. This is like using the rainfall averages for a Brazilian rain forest to estimate how long it would take to fill dry lakes in the outback of Australia. For the details, a person can go to: Putnins, P. (1970) "The Climate of Greenland," in S. Orvig, ed., Climates of the Polar Regions, Elsevier. Benson, C. S. (1962) Stratigraphic Studies in the Snow and Firn of the Greeland Ice Sheet (U.S. Army Snow, Ice, and Permafrost Research Establishment Research Report no.70 (July, 1962). >Similarly Amundsen's camp near the South Pole is now >apparently 40 feet under the ice. Again, precipitation patterns in Antarctica vary as much as they do in Greenland. The missing information here is how the annual precipitation at Amundsen's camp compares to the annual precipitation at the ice core sites. For all we know, the article is ignoring the fact that rates of precipitation at Amundsen's camp are completely different than those at the ice core sites. From what I have read, the annual precipitation rates found at the ice core sites are consistent with the rates calculated from the ice cores. ...... other stuff deleted ...... Key Words: Ice Cores, Creationism, Lost Squadron, P38s, B17s, Greenland, Glacial Gal. Sincerely Yours, Keith Littleton littlejo@vnet.net New Orleans, LA "I further call on all sides to recognize that this is primarily a theological debate. Theology is more fundamental than science; good theology has led to good science, in the emergence of Darwinism from the mainstream of a Christian civilization, and bad theology has led to bad science in the creation scientists' material interpretation of Genesis and their consequent torturing of the scientific facts to construct crazy scientific theories like the 6000 year old earth, that they believe, in genuine sincerity. Seeing that the issue lies not inside science but beyond it might foster the mutual understanding that leads to reconciliation." From an essay was by Dr. Anthony Garrett, a theoretical physicist from Cambridge at: http://www.onthenet.com.au/~stear/abcgarrett.htm