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For people who doubt radiometric dating, layer-counting may provide hard evidence for one or another minimum age of the earth. In its question-and-answer article on how the age of the earth is calculated, the website Biologos.org states:

The annual ice layers in glaciers provide a similar method [to tree-ring dendrochronology] that goes back much further in history. Each year, snowfall varies throughout the seasons and an annual layer is formed. Like the tree rings, this method can be verified by comparison to historical records for weather, as well as to records of volcanic eruptions around the globe that left thin dust layers on the glaciers. Scientists have drilled ice cores deep into glaciers and found ice that is 123,000 years old in Greenland and 740,000 years old in Antarctica. These annual layers go back much farther than the 10,000 years advocated by the young earth creationists. The Earth must be at least 740,000 years old.

"How are the ages of the Earth and universe calculated?" Biologos.org, emphasis added

This doesn't state outright that the annual ice layers go back 740,000 years, but it certainly implies it.

It was in 2005 that the researchers in Antarctica extracted a two-mile-tall plug of ice for historical climate research. While their purpose was to analyze the Earth's climate history by performing chemical analysis of the ice and not to determine the earth's age, it would by no means be impossible to learn something about the age of the earth from such a study.

...a team of researchers from the National Institute of Polar Research in Japan, drilled deep into an ice dome on the east Antarctic ice sheet called Dome Fuji. They extracted a core that spanned more than 700 millennia, including about seven cycles of glaciers warming, melting, and warming again.

The layers in the ice sheets are a lot like the rings in a tree stump: they can tell scientists about the environmental conditions when the layers formed. The presence of dust can indicate dry and windy periods, with gusts strong to blow debris in from South America. And the molecular compositions of the ice tells the scientists whether a layer formed during a warm or cold spell.

The Verge

Besides all of the other work that they accomplished, has this Antarctica team (or any other) provided a layer-counting minimum age for the earth that is 700,000-years-or-greater without any contribution from radiometric dating? And if it's not 700,000+, then how far back is it?

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elliot svensson
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    It's certainly the only reasonable assumption, but I suppose YECs will claim that Noah's flood could put down multiple layers of ice underneath the water, in just 1 year... – hdhondt Oct 10 '18 at 22:57
  • @hdhondt What I've heard them claim is that the layers are freeze and thaw cycles, of which there can be many every year, not just one. It's actually a claim I've never seen tested on this site, so perhaps good for a different question. –  Oct 11 '18 at 00:34
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    Is there a notable claim here? This just seems like a generic Earth science question and not a good fit for Skeptics. – Chris Hayes Oct 11 '18 at 00:53
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    The [Earth Science SE site](https://earthscience.stackexchange.com/) is probably a better fit for this question, since you could easily remove the claim challenge and rewrite the question to something like "How does ice layer counting work" or "Does ice layer counting have a maximum age estimate" and still get basically the same answer you might get here. – Giter Oct 11 '18 at 01:21
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    @fredsbend so we're talking over 100 such cycles per year, every year in the earth's 6000 year "history"? – hdhondt Oct 11 '18 at 04:53
  • @hdhondt I guess. One such guy I heard insisted you could easily get 10 in one day with the right conditions. –  Oct 11 '18 at 05:18
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    Seems trivially provable, if true. It's one of those things that is highly suspect because scientists aren't that stupid. –  Oct 11 '18 at 05:24
  • @fredsbend: Of course, multiple thaw / freeze cycles within one day would add zero to the width of the current layer... – DevSolar Oct 11 '18 at 09:22
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    We seem to be speculating on what Young Earth Creationists think and believe, which is off-topic here. We already have [non-radiometric dating techniques](https://en.wikipedia.org/wiki/Dendrochronology), so speculating that this will change minds is pointless. So what is the actual claim that the OP is doubtful about? – Oddthinking Oct 11 '18 at 11:46
  • @Oddthinking, now I am willing to admit that I already know the answer. Should I put it in comments or write it as an answer? – elliot svensson Oct 11 '18 at 13:44
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    @elliotsvensson this still isn't a valid question for the site. There isn't a notable claim here. – DenisS Oct 11 '18 at 14:41
  • @DenisS, the claim I am forming into a Question is, "apart from radiometric dating, has ice core layer-counting provided a minimum age for the earth of X?" – elliot svensson Oct 11 '18 at 14:42
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    @elliotsvensson that isn't a notable claim, that's you asking a question. You're asking if they've gotten an age greater than 700K years. If your question was "Have they gotten an age of 700K years?" then maybe that would be on topic, but as is right now this question is off topic. – DenisS Oct 11 '18 at 15:04
  • @DenisS, I would honestly appreciate it if you would edit the question into something that you would approve for on-topic, or else provide appropriate phrasing in the comments. – elliot svensson Oct 11 '18 at 15:05
  • @DenisS, oh I get it... re-worded. – elliot svensson Oct 11 '18 at 15:31
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    @elliotsvensson: Have a look at [this Meta question](https://bit.ly/2RJlAsx) for details, but basically if you're asking a question you should be genuinely skeptical about whether or not the claim is true, and that you want to either try to learn the truth or provide a thorough, sourced answer proving/disproving the claim. Otherwise, it can be interpreted as you just trying to spread a view/have a discussion/get feedback, which isn't really the point of a Q&A site. – Giter Oct 11 '18 at 15:31
  • @giter, if this question were not on hold I would provide a thorough / fully sourced answer. – elliot svensson Oct 11 '18 at 15:32
  • @elliotsvensson: You're edits after it was closed definitely bring it more on-topic, since it's more clear what you're challenging and you show why someone might be skeptical of it. My comment was more on why it was probably closed as off-topic in the first place, but now it seems alright.(though I still think the Earth Science site is a better fit, unless you also have some claim saying ice-layer counting *doesn't* work). – Giter Oct 11 '18 at 15:45
  • My problem with this question is that you are continuously asking about more than 700K years. There is nothing, in anything you cited that implies that ice core dating has gone beyond the 740K years found in Antarctica. – DenisS Oct 11 '18 at 17:14
  • @DenisS, I would equally ask whether the study has discovered an age of exactly 700,000 years independently of radiometric dating... but that's trivially answerable as "no, it was 699,999" or "no, it was 700,001". So I'm asking about a value that's equal to or greater than 700,000 years. – elliot svensson Oct 11 '18 at 17:46
  • So are you asking how scientists use the ice cores to get the 700K+ totals? Or are you asking if they've used a method besides radioactive dating to get a 700K+ total? – DenisS Oct 11 '18 at 18:03
  • @DenisS, the second: "have they used a method other than radioactive dating to get a 700K+ total?" – elliot svensson Oct 11 '18 at 18:04
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    OK, I think the problem is that your question is phrased as an answer to the question you're trying to ask. The two links you have in your "question" unequivocally say "Yes, we can use ice core data to get ages older than what YEC say is the age of the earth." If you're trying to go further back than even the 740K quoted in the article, this should be fixed and migrated to EarthScience.SE. – DenisS Oct 11 '18 at 18:10
  • @DenisS, I became skeptical of this claim some time ago and am now able to write a fully-researched answer in the dispositive. – elliot svensson Oct 11 '18 at 18:12
  • Let us [continue this discussion in chat](https://chat.stackexchange.com/rooms/84352/discussion-between-deniss-and-elliot-svensson). – DenisS Oct 11 '18 at 18:17
  • @elliotsvensson I've tossed you some hopefully-useful advice on composition, also in the chatroom. – Ben Barden Oct 11 '18 at 22:09
  • @DenisS, thanks so much for your work reviewing my question. What do you think of the re-working that I have done? – elliot svensson Oct 12 '18 at 15:16
  • "The website Biologos.org, which was provided to inform people who might be inclined to doubt radiometric dating" - that doesn't look like the primary purpose of the site as I read from their self-descriptions, and the text I can see doesn't support it. Do you have a citation for this? – Ben Barden Oct 12 '18 at 17:35
  • @BenBarden, that point was immaterial, so I removed it from my Question. How's that look now? – elliot svensson Oct 12 '18 at 17:39
  • There's also a bit of funny ordering. The pertinent claim you have is the bolded bit - which is at least heavily implying that it has 740,000 years of ice layers. The second quote is potentially useful, but contains no such claim (only saying that the core spanned that time - not how it was determined. – Ben Barden Oct 12 '18 at 17:40
  • Looking pretty good overall, though. I personally think it should be reopened. – Ben Barden Oct 12 '18 at 17:40
  • @Oddthinking could you take another look at this one? – Ben Barden Oct 12 '18 at 17:42

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The counting of layers such as tree rings, glacial varves, and annual ice layers, is a reliable way of establishing a chronology.

As far as the age of Earth is concerned, these methods provide a minimum age for Earth. Scientists do use radiometric dating to calibrate these methods from time to time—C-14 dating of some individual tree rings is an example—but layer counting firmly establishes an annual or seasonal count from the present into the past. With regard to the minimum earth age established by layer-counting, radiometric dating does not come into play.

How many layers have been counted?

Trees have been found having rings showing an age between 4000 and 5000 years, and some of these trees died a long time ago. By matching chemical and environmental qualities among trees at different ages, it is possible to construct a continuous environmental history to between 11,000 and 13,000 years ago.

Radiocarbon and Dendrochronology, Bernd Kromer, 2009

Glacial varves (the layered sediment at lake bottoms near continuously melting glaciers) have been found that clearly show 60,000 layers at Lake Suigetsu in Japan. Below this level, the layers are less distinguishable, but the age could be 150,000 to 200,000 years if you assume a uniform rate of sedimentation.

Lake Suigetsu Chronology, 2012

In 2007, scientists working in Antarctica cut out deep cores of ice from huge ice formations to learn about the climate of the past, providing approximately 740,000 years of history. But I was surprised to read that layer-counting was not done there in central Antarctica, because annual cycles are barely distinguishable. Instead, the history is dated by estimating the snow accumulation rate (together with information about static compression) and by matching various markers to other studies done previously. The researchers were pleased to note that up to 100,000 years, the markers provide excellent pattern-matching with two other Antarctica studies.

Antarctica Pattern-Matching

In 2005, scientists working in Greenland were able to count 42,000 layers back in time, providing a good basis for dates when combined with the other data that they recorded for each layer (and sub-layer to a very high resolution) such as chemical impurities, insoluble dust, and electrolytical conductivity.

Greenland 2006

Bottom line

Only in Greenland and Japan have scientists found more than 40,000 layers; they found 42,000 in Greenland and 60,000 at Lake Suigetsu in Japan. Ages beyond these dates were estimated based on other methods, including the assumption of uniform rate of ice or sedimentation deposition and also radiometric dating.

elliot svensson
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    So, this sentence is true: *"These annual layers go back much farther than the 10,000 years advocated by the young earth creationists."* and this sentence is true *"The Earth must be at least 740,000 years old."* but the implication you drew from those sentences was false? – Oddthinking Oct 15 '18 at 17:30
  • @Oddthinking, it's the expression "must be at least 740,000 years old" that got my attention. What is the implication of "must be"? It cannot simply refer to all our ordinary dates, such as 13.8 billion years (cosmology / Age of the Universe) or 4.5 billion years (meteorites & others / Age of the Earth)... "must be" is talking about evidence that's different from these other methods. – elliot svensson Oct 15 '18 at 17:38
  • @Oddthinking The website in question was notable, and that portion was pretty clearly targeting and attempting to convince young earth creationists. Read from that perspective, the implication is pretty clear, and highly likely to have been intended. It's just that they left enough wiggle room to say "Well, of course that's not what we meant." if someone calls them on it. – Ben Barden Oct 15 '18 at 18:53
  • @elliotsvensson: And you explain that evidence that is different from these other methods: "dated by estimating the snow accumulation rate (together with information about static compression) and by matching various markers to other studies done previously." I am still a little lost about what this is about. – Oddthinking Oct 16 '18 at 03:36
  • @BenBarden: I understand the principle of motte-and-bailey arguments, but I don't see how it applies here. The site provides a raft of evidence that supports an older Earth (notwithstanding the Omphalos hypothesis). – Oddthinking Oct 16 '18 at 03:43
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    Am I right in saying the thrust of this answer is: "The implication from reading between the lines in the claim is that there are 740,000 years of rings disproving a 6,000 year old Earth, but in fact, there are only of 60,000 years worth of countable rings, 150,000 years of accumulation in Japan, 740,000 years of accumulation in Antarctica and billions of years measured with other means, so they haven't actually made their argument at all." Because I think I am missing the point. – Oddthinking Oct 16 '18 at 03:46
  • @Oddthinking, the thrust of this answer is that, with regard to the number of visible layers, we would prefer if the implications in encyclopedic-style articles were aligned with the reports. – elliot svensson Oct 16 '18 at 13:52
  • @Oddthinking, I'm also looking to see if anybody knows better. After all, I only know of English-language articles within my sphere. – elliot svensson Oct 16 '18 at 15:45
  • It is not the one or the other, all methods intermingle, can be used to calibrate and relate each other, taking into account for variations on earth's surface. Counting isotopes is btw. simpler, and not so much subject to errors that happen when things flow over and under each other, thaw and freeze again, get compacted and all that what has to be taken into account when looking at a core of a bore hole. The radiometric age equation isn't exactly black magic: https://pubs.usgs.gov/gip/geotime/radiometric.html –  May 23 '21 at 16:30