Age of the Earth Part 1 - Biological Counting Systems Correlations, Calibrations and Consilience
We see many age deniers saying that dating methods are not accurate and are prone to errors. The problem is that these methods all correlate with each other and show remarkable consilience in many rather astounding ways, given that they are based on several very different mechanisms -- unless they are indeed accurate.
To address this issue of correlations, and the consilience of different systems, we will start with age measuring systems that involve direct methods of counting ages due to annual layers. As we move through different methods, we will discusses how those annual layer methods corroborate and agree with each other. We will also discuss how parts of radiometric data and dating methods enter into the mix when appropriate (the methods themselves will be discussed in part 3). In addition, we will discuss correlations and consilience not just with different age measuring mechanisms, but with past climate changes and certain known events or ancient artifacts that occurred in the past, things that show up in multiple records just where they should be if the age measurements are accurate.
I do not ask you to discard your skepticism, I just ask that you temper it with an open mind.
The challenge for the age deniers is not just to describe how a single method can be wrong, but how they can all be wrong at the same time and in the same way to produce virtually identical results (within the margins of error) - when random results or systematic errors in different methods should produce notably different results:
The challenge for old age deniers (especially young earth proponents) is to explain why the same basic results occur from different measurement systems if they are not measuring actual age?
Additional information has become available since the last version of this topic, and I felt it should be combined with the previous version in a new revised and updated thread because it is important to understand the kind of work scientists do to validate their methods. In addition, there are a couple of corrections that I need to make for scientific accuracy, some assertions of a dubious nature have been dropped, and (finally), I am also going to use a slightly different format, starting with the next section on Definitions of Some Terms Used (Message 2). This will be divided into parts to focus of different sets of data. This part covers:
Message 3, The Oldest Known Non-Clonal Trees, with an oldest age of 5,067 years old (in 2017). Message 4, (admin), Message 5, original msg 5, 7 and 8 (hidden), Message 6, (adminphat), Message 7, Dendrochronology Basics, information on dendrochronology basics and how they are constructed. Message 8, The Bristlecone Pine Chronologies, showing the earth is at least 8,307 years old (in 2017). Message 9, Additional Information on Bristlecone Pines, why the rings are annual events. Message 10, The Irish Oak Chronology, confirming the earth is at least 7,305 years old (in 2017). Message 11, The German Oak Chronologies, showing the earth is at least 10,037 years old (in 2017). Message 12, Additional Information on European Oaks, why the rings are annual events. Message 13, Comparing Irish and German Oak Chronologies, how a combined European Oak chronology is formed. Message 14, Accuracy and Precision in Dendrochronologies Compared to Historical Events, ways to test them against benchmark dates. Message 15, Comparing European Oak and Bristlecone Pine Chronologies by 14C Levels, similar to the way that ring widths are used to form the chronologies. Message 16, Anchoring The Floating German Pine Chronology, how it was tethered and then anchored to the absolute European oak chronology, showing the earth is at least 12,477 years old (in 2017). Message 17, Wiggle-matching 14C levels to Anchored Dendrochronologies, how chronologies are tethered or anchored to the absolute European oak/Pine dendrochronology Message 18, Lake and Marine Varve Basics, how they form, what makes them annual varves Message 19, An Introduction to Sediment Deposition Rates, why particles settle at different rates, why clay is so slow Message 20, Cariaco Basin Varves, showing the earth is at least 14,740 years old (in 2017). Message 21, Lake Suigetsu Varves, showing the earth is at least 42,021 years old (in 2017). Message 22, Varve Accuracy and Precision, ways to test the accuracy and precision. Message 23, Radiocarbon Dating and Corrections, how and why dates are calculated, calibrated, and corrected. Message 24, Summary of Part 1 - Biological Counting Systems
As yet, even though several attempts have been made to question individual methods, the consilience of the different methods arriving at the same basic results has not been explained.
Note: all images used on this thread, and subsequent posts that this one refers to with links, may be copied to a mirror site - without any modification or any intent to take credit for them. In every case I reference the original site where they can be viewed in context and verified as needed. The only purposes to copying the images is (a) to include PDF images, (b) to reduce band-width traffic on the original websites when these images are accessed, and (c) to ensure that the images are available in these post should the original sources be changed or removed from the web.
the condition or quality of being true, correct, or exact; freedom from error or defect; precision or exactness; correctness.
Chemistry, Physics. the extent to which a given measurement agrees with the standard value for that measurement. Compare precision (def 6).
Mathematics . the degree of correctness of a quantity, expression, etc. Compare precision (def 5).
In scientific use Accuracy means your ability to hit the bulls eye of a target. If we take a bow and shoot 200 arrows at a target, and all the arrow locations average out to a bull's eye, then the average result is very accurate, the closer they cluster to the bull's doesn't affect the degree of accuracy, even though there may be significant error in any one shot and there may not even be a single bull's eye in the whole group. There could be a fairly large degree of scatter in the data and still have an accurate overall average result.
accuracy; exactness: to arrive at an estimate with precision.
mechanical or scientific exactness: a lens ground with precision.
punctiliousness; strictness: precision in one's business dealings.
Mathematics . the degree to which the correctness of a quantity is expressed. Compare accuracy (def 3).
Again, in scientific usage Precision means the ability to replicate exactly the same results. With our bow and arrow example we now have 200 arrows all clustered very close together, but they may or may not be located near the bull's eye, and their location relative to the bull's eye does not affect the precision. There is very little scatter in this case, so it is highly precise, as the degree of scatter defines the precision.
As you can see these terms are not quite the same, even though there is some overlap. Ideally we would like to have a system that is both accurate and precise.
mutual relation of two or more things, parts, etc.: Studies find a positive correlation between severity of illness and nutritional status of the patients. Synonyms: similarity, correspondence, matching; parallelism, equivalence; interdependence, interrelationship, interconnection.
the act of correlating or state of being correlated.
Statistics. the degree to which two or more attributes or measurements on the same group of elements show a tendency to vary together.
Physiology . the interdependence or reciprocal relations of organs or functions.
Geology . the demonstrable equivalence, in age or lithology, of two or more stratigraphic units, as formations or members of such.
Correlation means taking two or more systems and comparing them to see if they reflect similar results and this is usually shown graphically. Often a "best fit" mathematical curve can be derived to fit the data. A correlation is generally more accurate or precise than concordance.
[kal-uh-breyt] verb (used with object), cal•i•brated, cal•i•brat•ing.
to determine, check, or rectify the graduation of (any instrument giving quantitative measurements).
to divide or mark with gradations, graduations, or other indexes of degree, quantity, etc., as on a thermometer, measuring cup, or the like.
to determine the correct range for (an artillery gun, mortar, etc.) by observing where the fired projectile hits.
to plan or devise (something) carefully so as to have a precise use, application, appeal, etc.: a sales strategy calibrated to rich investors.
Calibration means taking a precise correlation and determining what needs to be done to correct the precise result to obtain more accurate results. This will be discussed in greater detail later.
Another important word applicable to this topic is Consilience(6)
In science and history, consilience (also convergence of evidence or concordance of evidence) refers to the principle that evidence from independent, unrelated sources can "converge" to strong conclusions. That is, when multiple sources of evidence are in agreement, the conclusion can be very strong even when none of the individual sources of evidence are very strong on their own. Most established scientific knowledge is supported by a convergence of evidence: if not, the evidence is comparatively weak, and there will not likely be a strong scientific consensus.
The principle is based on the unity of knowledge; measuring the same result by several different methods should lead to the same answer. For example, it should not matter whether one measures the distance between the Great Pyramids of Giza by laser rangefinding, by satellite imaging, or with a meter stick - in all three cases, the answer should be approximately the same. For the same reason, different dating methods in geochronology should concur, a result in chemistry should not contradict a result in geology, etc.
Consilience means taking two or more systems that have strong correlations and showing how they all point to the same result, thus consilience is stronger than a single set of evidence, or single correlation between systems, in providing evidence of a trend or relationship being correct.
a feeling of trust in a person or thing: I have confidence in his abilities.
belief in one's own abilities; self-assurance
trust or a trustful relationship: take me into your confidence.
something confided or entrusted; secret.
Confidence is a subjective evaluation of how much the evidence is trusted, based on the number of consilient pieces of information that all reinforce the same direction or to the same conclusion, and thus how much the conclusions are trusted.
Please note that denial of evidence that contradicts a personal belief or opinion is not confronting nor refuting the evidence with a skeptical open mind, but avoiding it.
You might think that measuring the age of trees is a simple matter of just counting the rings. In practice it is a bit more complicated. As a starting point we can begin with the oldest non-clonal trees in the world -- all Bristlecone Pines from the White Mountains of the Sierra Nevada:
the "Prometheus" tree(2) (aka WPN-114), with a measured age of 4862 when cut down in 1964 for research, however this is a minimum age because the core of the tree is missing, giving it a minimum germination date of 2898 BCE (but likely older).
the "Schulman's" tree(3) (my name for the tree because Edmund Schulman took the core samples and he was a pioneer in dendrochronology in the area), with a minimum germination date of 3051 BCE
the "Ancient Sentinels"(4) - standing dead trees, as old as 7,000 years, however we have no information on their germination or termination dates at this point.
At this point we don't know from the information available when the ~7,000 year old sentinel trees died -- it could have been last year, 10 years ago, maybe 100 years ago, or more - so they represent a floating chronology, while the still living trees, Methuselah and Schulman's, represent absolute chronologies. Likewise, Prometheus represents an absolute chronology because the year it was cut down (the termination date)is known, so we know the age of the last formed ring.
Unless otherwise noted the ages of these trees were measured by counting annual rings from multiple core samples of the trees. This can lead to some minor inaccuracies, for example from missing sections of partial rings (resulting in an undercount). Cutting down the tree and using the whole cross-section is a different way to determine the age of a tree, and it avoids some of the problems with cores, so they are more accurate. Thus while it is unfortunate that Prometheus was cut down, we can benefit from the confidence gained by comparing the results with cored trees.
Note that these systems are similar so we should expect similar results. The real challenge will be to explain the consilience in results from other more independent systems, which we will get to later. This is just the beginning.
The earth is at least 5,067 years old (2017)
The minimum age for the earth is at least 5,067 years old (2017), based on the accurate and precise tree rings of Schulman's Tree extending back to 3051 BCE, and it is probably older, due to the ~7,000 year old "Ancient Sentinels." This also means that there was no major catastrophic event that would have disturbed their growing on top of these mountains.
Compare this to YEC models (6,000 years for those using Archbishop Usher's assumption filled calculations of a starting date of 4004 BCE), as this chronology extends to 3,051 BCE ... with no flood damage.
2. Please stay on topic for a thread. Open a new thread for new topics.
4. Points should be supported with evidence and/or reasoned argumentation. Address rebuttals through the introduction of additional evidence or by enlarging upon the argument. Do not repeat previous points without further elaboration. Avoid bare assertions.
8. Avoid any form of misrepresentation.
(bold for emphasis)
... because those are just basic honest debate procedures that an honest person will follow on their own.
2. how do evolutionists overcome the issues about the age of the earth (i'm sure you've heard the arguments)
This proposed thread will be about the many ways that we determine age from objective empirical evidence, starting with simple system where layers can be counted. Please read Message 1, Message 2 and Message 3 and message me or ADMIN if you are interested in debate on this thread (you won't be able to reply to this thread until it is promoted).
How do we know that the Bristlecone pine tree rings are accurate annual indicators?
We can compare the data from each of these time anchored trees: the pattern of wide and thin rings is caused by climate variations from year to year. Some years have a longer or wetter growing season, resulting in more tree growth (and thus a wider ring), and some years have a shorter or dryer growing season, resulting in less tree growth (and thus a narrower ring).
Because these trees all grew in the same area (on the same mountain), the pattern of wide and narrow rings should match between the three "absolute chronology" trees ... and they do.
So the growth pattern is not random but a very specific response to climate differences, and we can use those patterns to compare them to other trees growing in the same area and climate conditions.
Dendrochronology is the study of time and climate through the evidence of tree-rings and related data. There are several thousand dendrochronologies currently being used and expanded in the world. Some of these are " floating" chronologies (like the ancient sentinels above, where there is no connection to living trees, so the beginning and end dates are not known, and thus we just know how much time they cover). Some are absolute chronologies that are anchored by a connection to living trees or a tree with a known age datum (when a living tree was cut down, or when it was cored, when a building was built using the wood, etc.).
If a floating chronology can be positively linked to an absolute chronology by matching the ring patterns, then it can become an extension of the anchored chronology. Alternately a floating chronology may be cross-referenced, or tethered to an anchored chronology based on some other shared data patterns. Any change to the tethering reference point/s would affect the dates assigned to the floating chronology and could shift it earlier or later. A tethered chronology is more tentative than an absolute chronology.
More data is being reviewed every year, and the chronologies are being extended, cross-referenced and check by other measures. More floating chronologies are being anchored or tethered, providing more knowledge of the history of wood.
Simply put, dendrochronology is the dating of past events (climatic changes) through study of tree ring growth. Botanists, foresters and archaeologists began using this technique during the early part of the 20th century. Discovered by A.E. Douglass from the University of Arizona, who noted that the wide rings of certain species of trees were produced during wet years and, inversely, narrow rings during dry seasons.
Each year a tree adds a layer of wood to its trunk and branches thus creating the annual rings we see when viewing a cross section. New wood grows from the cambium layer between the old wood and the bark. In the spring, when moisture is plentiful, the tree devotes its energy to producing new growth cells. These first new cells are large, but as the summer progresses their size decreases until, in the fall, growth stops and cells die, with no new growth appearing until the next spring. The contrast between these smaller old cells and next year's larger new cells is enough to establish a ring, thus making counting possible.
Lets say the sample was taken from a standing 4,000 year-old (but long dead) bristlecone. Its outer growth rings were compared with the inner rings of a living tree. If a pattern of individual ring widths in the two samples prove to be identical at some point, we can carry dating further into the past. With this method of matching overlapping patterns found in different wood samples, bristlecone chronologies have been established almost 9,000 years into the past.
A number of tree samples must be examined and cross dated from any given site to avoid the possibility of all the collected data showing a missing or extra ring. Further checking is done until no inconsistency appears. Often several sample cores are taken from each tree examined. These must be compared not only with samples from other trees at the same location but also with those at other sites in the region. Additionally, the average of all data provides the best estimate of climate averages. A large portion of the effects of non-climatic factors that occur in the various site data is minimized by this averaging scheme.
This tells us that we can combine living Bristlecone pines, with the standing dead Ancient Sentinels, some other old wood pieces (some dead wood is lying on the ground in these same areas), and samples from other nearby sites, to form a complete chronology spanning thousands of years -- as long as there are sufficient samples that overlap enough to make a strong correlation based on matching ring thicknesses. Note that more than single matches between two trees are typically used to reduce if not eliminate possible errors. Such errors as do occur, whether from these causes or simple counting errors, would be random rather than systemic and could add or subtract a year from the overall chronology, but should not affect the overall trend significantly.
The fundamental principle of dendrochronology is crossdating (Fig. 1), which is classically defined as "the procedure of matching ring width variations . . . among trees that have grown in nearby areas, allowing the identification of the exact year in which each ring formed" (Fritts, 1976, p. 534). Fritts and Swetnam (1989, p. 121) added that crossdating is a procedure that "utilizes the presence and absence of[ring] synchrony from different cores and trees to identify the growth rings that may be misinterpreted" (Fritts and Swetnam, 1989, p. 121). It is well known that many tree species add one growth ring per year. The problem for dendrochronologists is that in particularly stressful years many tree species will either fail to produce a ring, which leads to a "missing ring," or produce an incomplete, or "locally absent ring," "lens," or "moon ring" (Krapiec, 1999; see Fig. 2).
To complicate matters further, certain tree species may produce a "double" or "false" ring; when the earlywood cells (i.e., those in the ring that are larger, thin walled, and therefore lighter) are being produced during a growing season, and particularly stressful climatic conditions return and lead to a general decrease in the rate of tree growth, a band of latewood cells (i.e., those that are smaller, thicker walled, and therefore darker) will be produced. If and when favorable conditions return during that growing season, earlywood cell production will begin anew, and the normal band of latewood cells will be created at the end of the growing season (Jacoby, 2000a). The key to distinguishing between double or false rings and annual rings lies in the nature of the transition between the latewood and earlywood cells: in a false or double ring the transition is gradual due to the phasing in and out of favorable growing conditions (Fig. 3).
In an annual tree ring, the transition from one ring’s latewood to the next ring’s earlywood is abrupt because ring production actually stopped for some period of time, typically during winter.
The parameters used in crossdating differ depending on geographic and climatological variables and their effects on tree growth, as well as the research questions of interest. Most commonly, crossdating is performed on ring-width variation, but successful crossdating has been accomplished using variations in ring density,
... Crossdating is possible because trees growing in the same (variously defined) regions and under the right conditions record the same climate signal in their rings. Although their growth patterns may differ in absolute size, the relative size of rings in trees from the same stand or region will often be the same, because the climate signal affects them all the same way. Other factors (e.g. competition, insect infestation, accidents, etc.) may have an effect as well.
... Once a number of skeleton-plotted series are compared, all missing and double rings are identified, and the series have been correctly crossdated, a summary master chronology is developed and used to visually crossdate new specimens (Douglass, 1941). ...
... ring-width variations are usually measured with great precision, and sophisticated statistical techniques and computer programs are then used to crossdate the ring-width measurements (Holmes, 1983; see Baillie, 1995). ...
Replication in dendrochronology occurs at three empirical and analytical levels. It occurs when independent tree-ring samples from the same geographic area yield the same ring-width pattern because they record the same climate signal, it occurs when independent tree-ring chronologies can be crossdated (for the same reason), and it occurs when dendrochronologists arrive at the same results, independently, because of the efficacy of the crossdating technique. A classic example of replication at all levels occurred when LaMarche and Harlan (1973), of the University of Arizona, independently crossdated a bristlecone pine chronology from the White Mountains of California, which was then used to calibrate the radiocarbon time scale. ...
Three levels of replication of correlations are used to obtain accurate and precise results. The resulting dendrochronologies are thus accurate and precise, due to identification of both false and missing rings and determining annual rings from numerous samples, and by cross-checking the information on multiple levels. Some species of trees have stronger demarcation of annual layers than others, and this makes some species better for dendrochronologies than others.
It should come as no surprise that the thousands of dendrochronologist working on the chronologies are actually able to discern the difference between rainfall or stress patterns, that could cause false or missing rings, from annual patterns when assembling these chronologies with high levels of confidence.
Part of the challenge for age deniers that honestly question the dendrochronologies is to have some modicum of understanding of the work that has gone into them. Again I note that the real challenge for age deniers will be to explain the consilience in results from independent systems, rather than pick individual systems apart. More to come.
As we saw in Message 3, the oldest known non-clonal trees are all Bristlecone Pines, so they are a logical place to start looking at dendrochronologies.
The first chronology is based on the data Edmund Schulman collected from bristlecone pines in 1954 and ring width measurements he presented for dated series ending (anchored) in 1953. This is the Schulman Master Chronology that covered the period from 800 CE to 1954 CE.
This was updated and extended in 1969 to 5,142 BCE:
... we began, in 1963, to collect material of two types: (I) cores extracted either from the original central portion of standing or fallen snags or from large, eroded remnants of trees, and (ii) entire smaller remnants having the appearance of age and without specific known origin in relation to any tree, living or dead.
... In contrast, more time is required to obtain the multicore sample that is often necessary to reconstruct the entire curvilinear radius characteristic of the unilateral growth of older trees, a technique developed by Schulman (1956) ...
A study (Wright 1963) of the relationshipe between the ring pattern along a single radius and the ring pattern of the cross section of which the radius is a part clearly shows that the cross section is of greater value than a core. While a single radius may contain only 95 percent of the annual rings (that is, 5 percent are "missing"), .... Therefore, remnants are highly valuable in that they provide more surface area for detailed study of the very narrow and often locally absent rings that are critical in chronology building. ....
In certain species of conifers, especially those at lower elevation or in southern latitudes, one season's growth increment may be composed of two or more flushes of growth, each of which may strongly resemble an annual ring (Glock, et al 1965). Such multiple growth rings are extremely rare in bristlecone pine, however, and they are especially infrequent at the elevation and latitude (37°23'N) of the sites being studied. In the growth-ring analyses of approximately 1000 trees in the White Mountains, we have, in fact, found no more than three or four specimens with even incipient multiple growth layers.
In bristlecone pine, problems of crossdating are caused by so-called "missing" rings associated with the extremely slow growth rate of this species on arid sites. ... Such slow-growing wood ... frequently lacks evidence of growth in a large portion of the circuit during a year of environmental stress. ... The location of such "missing" rings in a specimen is verified by crossdating its ring pattern with the ring pattern of other trees in which the "missing" ring is present ...
Table 2. Components of the 7104-year bristlecone pine chronology with the related interval in years ...
TRL specimen number:
(intermediate samples skipped for clarity)
In the summary of the component specimens (Table 2) ... the chronologic data may be converted to the BC-AD time scale by simple subtractions. Values for given years in the AD time period may be derived by subtracting 8000 from the computer time-scale values of 8001 and greater; BC years by subtracting computer values of 8000 and less from 8001.
Thus 9962 - 8000 = 1962 CE (AD), the end of the absolute chronology from sampling a living tree, and 8001 - 2859 = 5,142 BCE (BC), the beginning of this absolute chronology.
Note there is also mention of a "4900-year-old bristlecone pine, reported in the Snake Range of east-central Nevada (Currey 1965)" and LaMarche (1969) "reports a tree in the White Mountains as 4000 years old at the time of its death in AD 1500." Thus the three living trees and "ancient sentinels" mentioned in Message 3 are not the only samples of old trees from this species.
Note also that missing rings are common in single radius cores, and that this means that they are not likely to be found when the number of samples is small (as in the beginning of the series with one or two samples) even when multiple cores of the sample are taken. By contrast multiple ("false") rings are extremely rare, and they were identified when they did occur -- so they were not added to the chronology. If anything, the chronology is under-counting the age due to possible missing rings not being found.
This chronology was again updated and extended in 1972 to 6,291 BCE:
Twenty-one bristlecone pine remnants with all or a portion of their tree-ring record earlier than 4000 B.C. have been dendrochronologically dated. These are summarized in Table 1, ...
TABLE 1. Components of the bristlecone pine chronology prior to 4000 B.C., with the related interval in years B.C., ...
Specimen TRL no.
(intermediate samples skipped for clarity)
508 years (undated)
Note that the last specimen in Table 1 is "floating," because it didn't match up to any of the previous ring sequences and it is not shown in Figure 2. This results in a chronology that goes back to 6,291 BCE by absolute chronology and to at least 6,799 BCE if the floating specimen is added somewhere before the beginning of the continuous chronology. For our purposes only the 6,291 BCE beginning date is useful as an unbroken annual count.
Note that there is only one specimen from 6,291 BCE to 5,951 BCE, two specimens from then to 5,452 BCE, and three specimens from then to 5,005 BCE, so there is a strong possibility that some "missing" rings were not found and the chronology undercounts the actual age of the beginning point.
There is a second Bristlecone pine chronology that was developed independently of the master chronology (and using no common samples), and it provides additional information:
... The final chronology contains 5403 annual values ... ... Year-by-year comparison indicates that the rings dated at 5859M and 5330M are absent from the Campito chronology. Insertion of a nominal value of '0' for the ring width index for each of these years (Figure 6) brings the chronologies into exact synchrony.
A long tree ring chronology for bristlecone pine has been developed independently of previous work. Several lines of evidence show that the growth rings are true annual rings. Evaluation of several potential sources of error in tree ring dates indicates that any uncertainty in calendar dates assigned to annual rings in this series is due to annual rings that may be absent from all samples for a particular year or years. Internal evidence and intrachronology comparison suggest that there are only two such occurrences in the 5403-year Campito record developed in this work. Annual rings for these years are represented in the Methuselah chronology, which has served as the standard for most radiocarbon calibration studies. The Methuselah chronology very probably contains no dating error, at least back to 3435 BC.
The time scale used here is the same "extended scale," where 8000 equals 1 BCE, so 8001-5859 = 2142 BCE and 8001 - 5330 = 2671 BCE. The "M" designates the Master chronology above.
The difference found was that two rings were missing from the second chronology and they matched two rings in the older chronology that were narrow growth rings rather than extra rings. The new chronology did not extend the age of the old chronology, but it did validate and strengthen the Master absolute Bristlecone pine dendrochronology from 1970 CE through 3,435 BCE.
Note that missing rings showed the resulting chronology was too short (under counted). Because of this cross-checking, with only two errors, we can have high confidence that the Master Bristlecone pine chronology is indeed a minimum record of annual tree rings firmly anchored in the present and extending to at least 6,291 BCE.
This is the first test of the consilience between different systems, even though they use the same technique - dendrochronology - and the same species - Bristlecone pines - they were developed independently and were basically identical for the years that overlap, and the new chronology properly counted the intervening years. This is very strong consilience.
The earth is at least 8,307 years old (2017)
The minimum age for the earth is at least 8,307 years old (2017), based on the accurate and precise Bristlecone Pine dendrochronology extending back to 6,291 BCE, and it is probably older, due to the 508 year old "floating" sample that was not linked to the chronology. This also means that there was no major catastrophic event that would have disturbed their growing on top of these mountains or dispersed any dead wood lying on the ground -- ie no massive deluge or catastrophic flood occurred in this area during this time.
This is older than many YEC models (6,000 years for those using Archbishop Usher's assumption filled calculations of a starting date of 4004 BCE), as this chronology extends to 6,291 BCE.
And this is only the start of annual counting methods.
Further evidence of the nature of the growth ring comes from the study of ring development during the growing season. Dendrographic measurements of tree diameter and cambial samples for cell study were obtained from bristlecone pines in the White Mountains during three consecutive summers[Fritts, 1969]. Cambrial activity and resultant ring growth were found to occur in a relatively brief and well-defined growing season, At the elevation of Fritts' study area (3100 meters), ring growth began in mid-June to late June and ended in late July or early August. Cell size decreased more or less regularly from the beginning to the end of the growing season,and there was no pronounced response to the soil moisture replenishment that resulted from a midseason storm during one of the summers. That is, the trees studied formed only one growth ring in each year and did not form intraannual bands, even under presumably favorable conditions.
Another argument for the annual character of growth rings in bristlecone pine depends on recognition of time-synchronous internal markers in growth ring sequences. These include 'critical' rings, which are much narrower than average, and frost damage zones within certain rings. The identification and matching of growth rings constitute a well-established technique known as cross dating. Introduced by A. E. Douglass in the early 1900's[Douglass,1914], it has since been applied to the dating of a large number of tree ring specimens. Comparison of tree ring sequences obtained from living trees in the same area in different years gives a measure of the number of rings formed per year, provided that the sequences can be cross-dated. ... Schulman collected bristlecone pine samples in 1954 and presented ring width measurements for dated series ending in 1953. Plotted ring width measurements from samples obtained in 1971 can easily be matched with Schulman's series, the indication being that most trees have formed exactly 18 rings in the period 1954 - 1971. In a few cases only 17 rings were formed, this result being attributable so the local absence of the ring for 1960 on some of the sampled radii. However, in no case has any of the sampled trees formed more than one ring per year since 1953.
Three things to note: (1) that two independent Bristlecone pine chronologies were compared; (2) that the interval between the chronologies was 18 years and 18 rings were found in most samples in the new chronology, but some of the samples were missing one ring, and (3) none of the samples had an extra ring.
The climate and ecology of the Bristlecone pine is high, dry and cool, with minimal precipitation, most occurring as snow, which occurs even in July. The trees have adapted to the environment by taking advantage of the resources available during that portion of the year that temperatures are above their minimum growth level, a very short growing season:
This difference in soil temperature between substrates is paralleled by a soil moisture difference. Soil moisture content was determined weekly by gravimetric methods at the same two adjacent stations during late summer of 1962. During this period little rain fell. The course of soil moisture at a 20 cm depth in the two soils is plotted in Figure 4. The data show that the dolomite soil remained consistently wetter than the sandstone soil, even though the two sampling sites were under the same climatic regime. ...
... To determine the effects of reduced soil moisture on the metabolism of bristlecone pine plants, measurements of the rates of photosynthesis and respiration were made in the laboratory as the soil dried out.
... Results of these measurements are shown in Figure 7. Photosynthesis was severely depressed at a soil moisture level between 8 and 6%. Since respiration continued without such severe depression, production of photosynthate was curtailed more severely than its consumption. By referring back to Figure 4 it can be seen that at the field site where soil moisture was measured, moisture levels on dolomite were below the wilting coefficient on only two dates, ... It seems then that small site differences in soil moisture could cause large differences in productivity in bristlecone pine, and that such small moisture differences do exist between dolomite and sandstone soils in the field.
... Table 2 shows mean climatic values for a ten-year period (1953-1962) at White Mt. 1 (Crooked Creek Laboratory), a cooperative US Weather Bureau station at 10,150 f t in the bristlecone pine zone (Pace, 1963). Annual precipitation has averaged only 12.54 inches for this period of record. Monthly snowfall and rainfall figures reveal the sharp segregation of precipitation in to winter snow and summer snow and rain. Winter snow comprises the bulk of the precipitation total. ...
Mean monthly temperatures are above 50 F only in July and August, showing the effect of high altitude in restricting summer warming. Winter temperatures are not excessively cold; the record low is -21 F. ...
TABLE 2.-Climatic summary for Crooked Creek Laboratory, 1953-1962 (Pace, 1963)
Ave Mean Temp
Ave Snow H2O
Ave H2O precip.
... Climate is that of a desert mountain range, very dry for forest vegetation, but also cool.
(*) - Note that I replaced the 'Decade' column with a column for annual totals except for the average mean temperature, which is the overall decade average.
Note the only month without snow is August, and the highest rainfall is in July. July would also be when the snow melts, so it would be the wettest month of the year for growing, and mid August would quickly become the driest. In addition, July and August are usually the only months with temperatures over 50°F.
The first impression is that growth would be water limited, and thus there should be a false ring due to the rain late in the summer, but there is another factor that limits growth, and that is temperature:
Korner (34) hypothesized that the upper treeline is created by the temperature limitation of trees' ability to form new tissue (sink inhibition) rather than by a shortage of photosynthate (source limitation). This global model of treeline suggests a narrow range of growing-season temperatures of treelines at different elevations around the globe and supports a common minimum temperature limit of tree growth (35). Recent direct observations of xylogenesis (wood formation) coupled with soil, air, and stem temperatures provide strong corroboration for temperature-limited growth in alpine and boreal conifers (36). The reported critical value of mean daily temperature for the onset of wood formation is 8 to 9°C, a value that usually is not reached until mid to late June at treeline in the White Mountains. Maximum mean daily temperatures at SHP (11°C) commonly are not reached until late July and are only slightly greater than the minimum reported for wood formation. ... Above the transition elevation (~3,320 m to 3,470 m in the White Mountains), ring width is strongly positively associated with temperature and also is weakly positively associated with precipitation. Below the transition elevation, ring width is strongly negatively associated with temperature and also is strongly positively associated with precipitation.
Because the Bristlecone pines grow at such high elevations they have very short periods of growth when the temperature is only slightly higher than required for growth (~47°F). This actually helps ensure that the tree rings are annual without false rings from stress.
This information does not increase our knowledge of the minimum age for the earth, but it does increase our confidence in the Bristlecone Pine chronology accuracy and precision.
Wright, R.D., Mooney, H.A., Substrate-oriented distribution of Bristlecone pine in the White Mountains of California, Amer. Midland Naturalist, vol 73 Nr 2, p 257-284, 1965 http://www.jstor.org/stable/2423454
Salzer, M.W., Hughes, M.K., Bunn, A.G., Kipfmueller, K.F., Recent unprecedented tree-ring growth in bristlecone pine at the highest elevations and possible causes, Biological Sciences - Environmental Sciences, PNAS 2009 106 (48) 20348-20353; published ahead of print November 16, 2009, doi:10.1073
In Baillie, Pilcher, and Pearson (1983) a preliminary review of Belfast dendrochronology was presented as a background to the high-precision calibration. At that time the chronology was not known to be complete but was believed to consist of two major sections, one running from the present to 13 BC, the other spanning ca 200 BC to ca 5300 BC. ...
In 1982 a tentative link existed across the first centuries BC consisting of chronologies from Roman London, Roman Carlisle and Iron age sites, Navan and Dorsey, in the north of Ireland. The 337-yr Carlisle chronology appeared to match with its end year at AD 90. The 246-yr Dorsey/Navan chronology appeared to match Carlisle with its end year at 116 BC and Garry Bog Two appeared to match Dorsey/Navan with its end year at 229 BC. ... In late 1983 a re-working of the Roman London chronologies by I Tyers (pers commun) yielded a chronology (Southwark) spanning 252 BC to AD 255. This chronology linked directly to the established Belfast chronology which extended to 13 BC allowing the link to the long prehistoric chronology to stand independent of the German chronologies.
... Recently an additional chronology was created from timbers from an Iron age trackway from Keenagh in central Ireland. This new chronology spans 446 to 148 BC and acts as an additional link between the long chronology and Dorsey/Navan and shows highly consistent cross-dating with the chronology components covering that date range. All available evidence thus suggests that the internal logic supporting the continuous British Isles chronology is correct.
Once the Belfast chronology was complete, work started on archiving the primary data and rebuilding the chronology as a single continuous sequence. In the process each individual tree in the chronology has been checked and only those samples with high quality cross-dating are included. So far, 658 trees have been included in the sequence spanning 5289 to 116 BC. The distribution of samples with time is shown in Figure 3. As can be seen, there are only two points where replication falls below 10 trees-at 950 BC and at 2500 BC. The former point is bridged by six long-lived individual trees and the latter is one of the two depletion periods discussed in detail in Baillie, Pilcher and Pearson (1983). The other weak point described and justified in the 1983 article can still be seen at 1900 BC.
This chronology runs in two parts, one a floating chronology from 5,289 BCE to 116 BCE (estimated dates) and the second an absolute chronology from 13 BCE to the present (1986).
Secondly, we approached archaeological and tree-ring colleagues excavating or working on Roman sites in England—specifically Carlisle and London—to provide timbers or chronologies for the centuries between AD 200 and 200 BC, in the hope of using these to link across the 1st century BC gap. This approach led to the construction of a Roman chronology for Carlisle in northern England that spanned 247 BC to AD 90. This Roman section was well replicated by a chronology from Roman London (kindly supplied by Jennifer Hillam, Cathy Groves, and Ian Tyers) that spanned 252 BC to AD 255.
Thirdly, we got lucky. Within the north of Ireland, the discovery of oak timbers at 2 Early Iron Age sites—Emain Macha (the ancient capital of Ulster at Navan Fort, County Armagh) and The Dorsey (an important banked enclosure related to the linear earthwork called the Black Pig’s Dyke, County Armagh)—provided a 246-yr chronology that linked with and extended the Garry Bog II chronology forward to 116 BC (later this would be extended further to 95 BC, but that is not relevant here), partially closing the 229 BC to 13 BC gap. Similarly, the chance find of a large heap of bog oaks at Swan Carr, in northeast England, provided a 775-yr chronology that linked across the gap between the Long Chronology and Garry Bog II. Just to keep the "lucky" nature of this exercise going, the "gap" between the 2 Irish chronologies turned out to be a single year. (We now know that the Swan Carr chronology spanned 1155 to 381 BC and the LC/GBII gap was between 949 and 947 BC[Baillie et al. 1983].)
So the floating chronology was connected to the absolute chronology into a master absolute chronology running from 5289 BCE to the present.
While this does not extend to an earlier date than the Bristlecone pine chronology, there is consilience for the fact that tree ring data demonstrates an age of the earth that is older than many YEC models (6,000 years for those using Archbishop Usher's assumption filled calculations of a starting date of 4004 BCE).
This confirms earth is at least 7,305 years old (2017)
This confirms the minimum age for continuous growth of at least 7,305 years old (2017), based on the highly accurate and precise Irish oak dendrochronology extending back to 5289 BCE, also means that there was no major catastrophic event that would have disturbed the growth of any of the overlapping trees -- no catastrophic flood occurred in this time.
This is also older than many YEC models (6,000 years for those using Archbishop Usher's assumption filled calculations of a starting date of 4004 BCE), as this chronology extends to 5,289 BCE.
In addition to the Bristlecone pines and Irish Oak dendrochronologies, there is a third long absolute chronology of interest in measuring the age of the earth by counting annual tree rings: the German oak chronology.
Because of the remarkable length of the chronology and the great number of integrated tree-ring patterns, a detailed discussion of all the subsequent linkages would exceed page limitations. Thus, I will demonstrate the reliability of the chronology by presenting the replication of the Holocene master curve. The only valid proof of an absolute dendrochronology is the external replication by significant cross-dating of independently established tree-ring chronologies. In the case of the Hohenheim oak dendrochronology, this can be shown by cross-dating between the Rhine-Main-Danube river oak series, and by comparison with the Irish oak chronology.
... Following the completion of the US bristlecone pine series (Ferguson 1969), research was begun in Ireland and Germany to construct super-long chronologies. After two decades of intensive field collection and laboratory analyses, three European Holocene oak series have been established:
Irish oak, Belfast: Present-5289 BC (Pilcher et al. 1984)
German oak, Gottingen: Present-6255 BC (Leuschner & Delorme 1988)
German oak, Hohenheim: Present-8021 BC
The Belfast group collected subfossil oak trunks from peat-bog deposits, whereas the Hohenheim Laboratory focused on subfossil river oaks from gravel deposits. Researchers from the Gottingen Laboratory used both river and bog oaks for their oak record. Two series, the Belfast Irish oak and the Hohenheim German oak chronologies, became important for radiocarbon age calibration.
The river oaks of the Hohenheim Laboratory were collected in gravel pits along the upper Rhine, Main and Danube Valleys, and from minor tributaries, such as the Neckar, Iller and Tsar Rivers. The subfossil trunks are remnants of riparian Holocene oak forests (Quercus robur, probably also Quercus petraea). The trees were washed into the rivers by undercutting of meander banks and by erosion of larger river channels during floods. The eroded trees drifted into oxbow lakes, or were immediately deposited in river-channel gravels. Tree-trunk horizons of alluvial terraces were preserved below the water table for >10,000 yr (Becker 1982).
Growth ages of the riparian oaks are surprisingly short; 95% of the trees consist only of 150-400 tree rings. This is related to flood frequency on the alluvial plains. Regularly occurring floods, especially those with drifting ice during the spring, often must have destroyed floodplain forests. Evidently, Holocene river oak stands seldom grew longer than 300-400 yr without disturbance. This explains why >5000 subfossil tree trunks were needed for a continuous Holocene river oak chronology.
The first linkage of the middle Holocene chronology was again achieved in a cooperative project between the Koln and Hohenheim laboratories. As a result, the absolute German oak chronology was extended continuously back to 7237 BC (Becker & Schmidt 1990).
In 1988, the German Holocene oak chronology was extended by very early oaks of the Main, Rhine and Danube Rivers, which date from the beginning of the Boreal period. This extension of the Boreal oak chronology extends the absolute German oak chronology to 7938 BC. During 1991 field sampling, we found three older oaks from the Main River floodplain, which cross-date with the beginning of the master, and extend the entire absolute master chronology to 8021 BC.
We will discuss the German pine connection and duration later, in Message 16, Anchoring The Floating German Pine Chronology, here we are only interested in the oak chronology, extending back to 8,021 BCE. and the consilience with the Bristlecone pine and Irish oak chronologies.
The earth is at least 10,037 years old (2017)
The minimum age for the earth is now at least 10,037 years old (2017), based on the highly accurate and precise German oak dendrochronology extending back to 8,021 BCE. This also means that there was no major catastrophic event that would have disturbed the growth of any of the overlapping trees -- ie no catastrophic flood occurred in this time.
This is significantly older than many YEC models (6,000 years for those using Archbishop Usher's assumption filled calculations of a starting date of 4004 BCE), as this chronology extends to 8,021 BCE.
And this is still only the start of annual counting methods.
My first encounter with dendrochronology involved oak trees in Europe, where they had set up a database of oak tree sections from archaeological sites and matching different sections that overlapped in time to build a complete lineage of tree ring dates.
The common name for this species is "Post Oak" due to its natural resistance to rot thus making a good material for posts in ancient constructions. This also means that there are a lot of samples that are referenced to and associated with archaeological finds, finds that can be dated by other means, including historical documents as far back as the history goes. Oaks are also considered one of the best species for dendrochronology.
Oak is a highly preferred species to use in dendrochronology - in fact, the longest continuous tree-ring chronology anywhere in the world was developed in Europe and is currently about 10,000 year in length. This chronology is providing scientists new insights on climate over the past 10,000 years, especially at the end of the last Glacial Maximum.
Because ring-porous species almost always begin annual growth with this initial flush, missing rings are rare in such species as oak and elm. In fact, the only recorded instance of a missing ring in oak trees occurred in the year 1816, also known as the Year Without a Summer. A volcanic eruption in the year 1815 caused much cooler temperatures globally, thus causing oak trees to remain dormant. Therefore, no clear annual ring was formed in 1816 for certain locations in Europe.
... The earlywood is marked by large vessels used in conducting water. Latewood appears darker, marked by smaller vessels. Occasionally, offsets in oak tree rings can be problematic when trying to crossdate the rings. Dendrochronologists therefore must be careful when working with oak species, as these rays can cause a misdate of one year.
Note that sources of error are identified and accounted for and that we have a record of an historical event in the tree-ring chronology for 1816. This confirms that harsh climate results in narrow growth rings, and it demonstrates that annual rings are involved and that the chronology is accurate and precise.
Unlike the Bristlecone pines the Irish oak is not environmentally challenged:
The seasonal variation of rainfall in Northern Ireland is less marked in the drier southern and eastern areas than in the wetter areas, but in all areas the wettest months are between October and January. This is partly a reflection of the high frequency of winter Atlantic depressions and the relatively low frequency of summer thunderstorms in Northern Ireland. For example, at Armagh, thunder occurs on an average of less than 4 days a year, compared with 15 to 20 days at many places in England. Only in a few locations, mainly away from the coast, does the frequency of thunder exceed 5 days a year.
Over much of Northern Ireland, the number of days with a rainfall total of 1mm or more ('wet days') tends to follow a pattern similar to the monthly rainfall totals. In the higher parts, over 55 days is the norm in winter (December to February) and over 45 days in summer (June to August). In the driest areas around Lough Neagh and eastwards to Strangford Lough, less than 45 days in winter and about 35 days in summer are typical.
The Irish chronology is built with bog oaks -- oaks that grew on the extensive bogs in Ireland -- so they were certainly not water limited. Like the Bristlecone pines, however the bogs were nutrient poor, and this resulted in thin growth rings and long lives compared to other oaks (over 300 years).
The German chronology was built with oaks that grew along riverbanks, so they too were certainly not water limited. Their rings are wider and they were generally shorter lived than the Irish oaks.
From these rainfall data sheets we can see that the climate in Ireland and Germany differ from each other and from the Bristlecone Pine climate discussed earlier. The Irish oaks are found in low elevation temperate climate peat bog ecologies with lots of moisture, and the German oaks are found in similar low elevation temperate climate riverside ecologies, again with plenty of moisture. Because these ecologies do not limit tree growth and these trees are deciduous, we can have high confidence that the Irish oak and German oak tree rings are annual layers and do not contain "false" rings due to environmental stress factors.
Unlike the Bristlecone pine chronologies, the oak chronologies are not built up from samples all in one location, but were assembled from site chronologies from several locations. The Irish chronology was built up from chronologies from several different bogs, and some archaeological sites. The German chronology was built up from chronologies from different sites and from different labs.
There were two oak chronologies that could be compared similar to the way the two Bristlecone Pine chronologies were compared.
The chapter treats the final stages in the completion of the first long oak chronologies in Europe. This took place between 1981 and 1984 with the resolution of some of the problems which had seemed insuperable in 1980. The power of dendrochronology to date things precisely opens up a whole new window into the past and so significant are the results destined to be that it is important to see how the chronologies were constructed in the first place. The final section reviews progress with the construction of a second-generation oak chronology, i.e. one which is not independent in the sense of the original Irish and German chronologies but derivative in that the chronology sections are placed in time by cross-dating with the established chronologies. This is the way most European chronologies will be constructed in the future and it is interesting to see just how rapidly a long, c. 5000-year chronology can be put together when there are neighbouring chronologies against which to cross-date.
... However, the essence of the exercise was that almost immediately Schmidt was able to demonstrate a long section of consistent cross-dating between one of his north German chronologies and the Irish chronology. This agreement was sufficiently good to imply that our whole 5061-year chronology ended in 158 (Fig. 2.3). If correct, this direct link to the absolutely dated German chronology should have bypassed the problems in the first centuries BC, and in theory the arrival of Schmidt’s telex with the news of the match should have marked the ‘eureka’ finish to the whole long chronology programme. Unfortunately, as outlined above, the Southwark to Carlisle to Navan/Dorsey to Garry Bog 2 logic-chain suggested that G132 ended in 229 BC! We had no evidence to support a 158 BC end-date for Garry Bog 2.
... by this time we knew that the high-precision calibration work was demonstrating a broad agreement between Pearson’s work on Irish oak and Suess’ original bristlecone calibration. Indeed the calibration performed on the old Long Chronology showed sufficient agreement with the Suess curve, by way of a ‘wiggle match’ (see Chapter 4), to make it likely that the 4341-year chronology ended ‘within 10 years of 940 BC’ (Pearson 1980; Baillic 1983a). Such a placement, if correct, implied that the end of the 5061-year chronology might be within 10 years of 220 BC. So radiocarbon evidence tended to support the Belfast ‘229 BC’ placement rather than the ‘158 BC’ German placement.
Looking at this situation with hindsight it is possible to see just how weak a link KSB represented in the overall German chronology. Here was a somewhat dubious chronology .... So the answer to the Belfast problem presented itself as follows. Since Hollstein could only search for matches between KSB and the existing master, then, if the true position was ‘off the end’ of the master any match found would have to be spurious (this is the dendrochronologists’ dilemma). ... Analysis of the relevant overlaps using Hollstein’s published data and the Belfast GROS program suggested that Hollstein’s matching position was not supported by consistent t values and might well be spurious.
... At around the same time Becker published an article indicating that the only point in the south-central German chronology nor independently replicated was between 600 BC and 400 BC. He also noted that, when two of the German prehistoric oak chronologies were radiocarbon wiggle matched against the bristlecone calibration, their calibrated dates differed from their tree-ring dates by 73 and 67 years respectively (Becker 1983). Within months all concerned had accepted that the German complex had to be broken at 500 BC and the older section moved back by 71 years (Pitcher et al. 198, Schmidt and Freundlich 1984).
... Just when it was needed, and unknown to any of the Belfast, Koln or Stuttgart workers, Leuschner and Delorme, at Gottingen, published a note on their completion of a separate German chronology from AD 785 to 4008 BC (Leuschner and Delorme 1984). Here then was the opportunity for an independent test of the Belfast chronology. In the spring of 1985 Hubert Leuschner kindly made available to us a continuous German chronology running, by that time, from AD 928 to 4163 BC. The results of running the various sections of the Belfast prehistoric chronology against the independent Gottingen chronology confirmed that both prehistoric chronologies were in precise synchronization. Despite the distances involved, the original Long Chronology gave t = 8.8 at 949 BC, Swan Carr gave t = 8.45 at 381 BC and even Garry Bog 2 gave t = 3.6 at 229 BC (Brown et al. 1986). ... So the Gottingen chronology provided the ultimate tertiary replication necessary to prove the European oak complex. In the overall scheme of things it is remarkable that the independent announcements of the completion of long oak chronologies should have appeared in the same year!
... However, as noted above, dendrochronology is not static. Already by 1985 fresh Irish material, from a major bog roadway at Corlea, Co. Longford (see Chapter 4), provided a chronology spanning 446-148 BC. This chronology confirmed all the main links in the original Belfast logic-chain. The Dorsey/Navan chronology has been extended and now spans 95-575 BC, confirming the original link to Garry Bog 2.
Initial comparisons showed there was an error in one or the other chronology, and it was resolved by finding additional new samples that covered the time in question. The final result is a combined Irish and German Oak chronology with a high degree of confidence in the accuracy and precision of this European Oak Chronology. This gives us an idea of the amount of work that goes into verifying the data and the conclusions that can be reached.
Two things to note: there is reference to "t" values for matching dendrochronologies by their ring patterns, and to "wiggle-matching" for use with 14C values.
The t-values are a measure of how precisely two different sample match on the tree ring patterns. There are often minor variations due to specific ecology surrounding the tree (amount of light and water available) and also to micro-climate differences between nearby sites. That the German oaks could be matched by ring patterns to the Irish oaks is a little astounding in retrospect -- their annual climate patterns are rather different, as shown previously in Message 12, Additional Information on European Oaks.
Whilst the principle behind tree-ring dating is a simple one, the determination of what is an actual match is much more involved. When an undated sample or site sequence is compared against a dated sequence, known as a reference chronology, an indication of how good the match is must be determined. Although it is almost impossible to define a visual match, computer comparisons can be accurately quantified. Whilst it may not be the best statistical indicator, Student’s (a pseudonym for W S Gosset) t-value has been widely used amongst British dendrochronologists. The cross-correlation algorithms most commonly used and published are derived from Baillie and Pilcher’s CROS programme (Baillie and Pilcher 1973).
Statistically, t-values over 3.5 should be considered to be significant, although in reality it is common to find demonstrably spurious t-values of 4 and 5 because more than one matching position is indicated. For this reason, dendrochronologists prefer to see some t-value ranges of 5, 6, or higher, and for these to be well replicated from different, independent chronologies with local and regional chronologies well represented. To give some idea of how good a match can be expected, two timbers from the same parent tree will often give a t-value of 10 or higher. ...
Therefore, when cross-matching samples between each other, or against reference chronologies, a combination of both visual matching and a process of qualified statistical comparison by computer is used. The ring-width series were compared on an IBM compatible computer for statistical cross-matching using a variant of the Belfast CROS program (Baillie and Pilcher 1973). A version of this and other programmes were written in BASIC by D Haddon-Reece, and latterly re-written in Microsoft Visual Basic by M R Allwright and P A Parker.
The t-values mentioned for the dendrochronological match between the Irish and German oak chronologies is better than the minimum mentioned here, and because they are comparing two anchored chronologies (rather than assembling the chronologies) this gives us high confidence in the construction of both chronologies -- if any errors in placing samples in either chronology had occurred then they would not match to such a high degree in comparison.
The wiggle matching is used to match the variations in 14C levels between different data sets in a manner similar to the way tree rings are matched by their pattern. It was originally used to help form the overall chronology, but it was later discarded when the additional tree sections were found to fill the gap. This method of comparison will be discussed in greater detail later in Message 17, Wiggle-matching 14C levels to Anchored Dendrochronologies.,.
This information does not increase our knowledge of the minimum age for the earth, but the consilience between these independent systems does increase our confidence in the combined European Oak chronology accuracy and precision.
Remember: The challenge for old age deniers (especially young earth proponents) is to explain why the same basic results occur from different measurement systems if they are not measuring actual age?
Baillie, M.G.L., A Slice Through Time: Dendrochronology and Precision Dating (paperback), (c) 1995 (Jun 2, 1997), Routledge, ISBN 0 7134 7654 0(download book here)
Accuracy and Precision in Dendrochronologies Compared to Historical Events
Accuracy and Precision in Dendrochronologies Compared to Historical Events
Tree rings and dendrochronology are one of the most accurate and precise annual measuring systems available to both scientist and the layperson: it is fairly easy to count rings in a cross-section or coring of a tree. Once the problems of false rings and missing rings are identified it becomes possible to identify these in the chronologies, and thus correct them for such errors. This is well documented in Message 7, Dendrochronology Basics.
Note that carbon-14 (14C) measurements and age calculations based on 14C measurements are NOT discussed yet, as the focus is on the accuracy and precision of the tree ring chronologies.
As seen above the ecology and local climates in Ireland and Germany differ from each other and from the ecology and local climate for the Bristlecone pines.
This means that a direct comparison of tree ring widths would not be likely -- there is too much variation in the local (micro) climates for the overall patterns to be similar -- except where the sites are relatively close, and of course, for extreme incidents that affect the climate of the whole earth, such as the "year without a summer" (1816 CE) mentioned in Message 9, Additional Information on Bristlecone Pines.
The two Bristlecone pine chronologies correlated with such high accuracy and precision because they came from adjoining sites.
The two Oak chronologies correlated as accurately as they did because they shared a common basic European climate pattern, even thought they had individual microclimate differences.
However, there are several additional historical incidents of note that do show up in the tree chronologies:
The extreme weather events of 535–536 were the most severe and protracted short-term episodes of cooling in the Northern Hemisphere in the last 2,000 years. The event is thought to have been caused by an extensive atmospheric dust veil, possibly resulting from a large volcanic eruption in the tropics, or debris from space impacting the Earth. Its effects were widespread, causing unseasonal weather, crop failures, and famines worldwide.
Tree ring analysis by dendrochronologist Mike Baillie, of the Queen's University of Belfast, shows abnormally little growth in Irish oak in 536 ...
So there is consilience between history and the Irish oak chronology: 100% accuracy and precision at 1816 CE and 536 CE, from independent sources of information with the same values. Thus we can test dendrochronologies with historical events, and we can look at this aspect in greater detail here:
Frost damage to the wood of mature trees is a rare phenomenon caused by temperatures well below freezing at some time during the growing season, when secondary wall thickening and Iignification of immature xylem cells in the annual ring is not yet complete. Freezing promotes extracellular ice formation and dehydration which result in crushing of the outermost zone of weaker cells, leaving a permanent, anatomically distinctive record in the wood. ...
Frost-damage zones have been produced in the annual rings of subalpine bristlecone pines ( Pinus longaeva D. K. Bailey and P. aristata Engel.) at intervals of a few decades to a few hundred years for at least the past 4,000 yr. They are observed at localities ranging from California to Colorado, a distance of some 1,300 km. In the course of tree-ring chronology development, the presence and type of frost damage in dated annual rings from living trees[10-12] and sub-fossil wood[13,14] was routinely noted. ...
... Wexler's basic premise seems to be supported by Lamb's observation of southward displacement of the sub-polar low-pressure zone in the North Atlantic sector in the first July following a great eruption, and continuing in some cases for 3 - 4 yr. ...
... Synoptic situations more typical of winter may be expected to occur in late spring and in early autumn. Such a scenario seems to have been followed in the frost-ring year of 1884, ...
We can see the evidence of frost-rings for 1817 (following the "year with no summer"), and for 1884, after the eruption of Krakatoa in 1883. There are several other notable events shown going back to 1601 CE, however there was no frost-ring for 1785 when one of the highest DVI's was recorded.
Such effects may not occur in all locations, due to weather patterns, and thus may not affect all three chronologies, but effects can still be found in many wide spread localities. Frost rings are reported in pines in Sweden for example. Similar correlations can be found for other volcanic eruptions, demonstrating that these events can affect the tree-ring growth in a way that can provide accurate information of the interaction of eruptions with climate.
We will employ tree rings and carbon-14, but not in the way readers may be accustomed to seeing. We will not use carbon-14 to determine an age at all. We will simply measure how much carbon-14 is currently found in each tree ring. Carbon-14 decays with time, so if each tree ring represents one year of growth, we should see a steady decline in the carbon-14 content of each successive ring. Figure 5 shows tree-ring carbon-14 data from living trees extending back 4000 rings. ...
If additional confidence in this data is desired, it may be helpful to note that the amount of carbon-14 found in a timber from a tunnel in Jerusalem thought to have been built by Hezekiah is approximately the same as the amount found in tree ring number 2700, which places its ring-counting age where expected from Biblical records if each ring equals one year. Even better, consider the Dead Sea Scrolls – the book of Isaiah in particular. ... The amount of carbon-14 in the Isaiah scrolls is equal to or less than the amount in tree ring number 2100, meaning carbon-14 confirms its before-Christ historicity.
This graph appears to start with year 2000 CE (rather than 1950). This adds 2050 BP (100 BCE) and 2650 BP (700 BCE) to the list of correlations of historical artifact to dendrochronological age by 14C content.
Then there is consilience with Egyptian history and the dating of various finds (artifacts), for example:
... Radiocarbon dating, which is a two-stage process involving isotope measurements and then calibration against similar measurements made on dendrochronologically dated wood, usually gives age ranges of 100 to 200 years for this period (95% probability range) and has previously been too imprecise to resolve these questions.
Here, we combine several classes of data to overcome these limitations in precision: measurements on archaeological samples that accurately reflect past fluctuations in radiocarbon activity, specific information on radiocarbon activity in the region of the Nile Valley, direct linkages between the dated samples and the historical chronology, and relative dating information from the historical chronology. Together, these enable us to match the patterns present in the radiocarbon dates with the details of the radiocarbon calibration record and, thus, to synchronize the scientific and historical dating methods. ...
... We have 128 dates from the NK, 43 from the MK, and 17 from the Old Kingdom (OK). The majority (~75%) of the measurements have calibrated age ranges that overlap with the conventional historical chronology, within the wide error limits that result from the calibration of individual dates.
The modeling of the data provides a chronology that extends from ~2650 to ~1100 B.C.E. ... (red lines added)
The results for the OK, although lower in resolution, also agree with the consensus chronology of Shaw (18) but have the resolution to contradict some suggested interpretations of the evidence, such as the astronomical hypothesis of Spence (24), which is substantially later, or the reevaluation of this hypothesis (25), which leads to a date that is earlier. The absence of astronomical observations in the papyrological record for the OK means that this data set provides one of the few absolute references for the positioning of this important period of Egyptian history (Fig. 1A).
("OK" refers to the "Old Kingdom")
Note that there are several other sample dates with similar correlation of 14C measurement to dendrochronology correlations, here it is the earliest/oldest set that is of interest as a measure of accuracy and precision. The dendrochronology correlation is shown as two lines in Fig 2 (+1σ and -1σ ) -- I added the red lines in the image for discussion:
The earliest/oldest dates in Fig 2 are shown at ~2660 BCE, with 7 samples placed together (with two more placed nearby). There are several possible matches for each of these samples, running from 2580 BCE to 2860 BCE -- due to the wiggle of the 14C amounts in that portion of the graph -- I get 5 possible matches for the lowest point with an average age of 2693 BCE, 8 possible matches for the next point with an average of 2660 BCE, 6 possible matches for the third point for an average of 2702 BCE, 12 possible matches for the fourth point for an average of 2733 BCE, 9 possible matches for the fifth point for an average of 2754 BCE, 6 possible matches for the sixth point for an average of 2750 BCE, 8 possible matches for the seventh point for an average of 2771 BCE, 8 possible matches for the eight point for an average of 2787 BCE, and 6 possible matches for the highest point for an average of 2788 BCE. Assuming these points all represent the same age, the overall average age is ~2740 BCE with σ of +/-88 years (2827 BCE to 2651 BCE).
Shaw's date for the tomb is 2660 BCE, so this falls inside the margin of error and thus is in close agreement with that dating.
Note that +/-88 years in over 4,700 years of tree ring chronology is an error of +/-1.9%. The error is partly due to the two stage process of using 14C data to convert to dendrochronological calendar age, but it is mostly due to the wiggle of the 14C levels that match these sample data points to several different times.
Note that this conversion to dendrochronological time does not depend on the calculation of 14C 'age' (which is a purely mathematical conversion of the measured amounts of 14C in the samples as a fraction of the 1950 standard amount), but to comparing the measured 14C/14C(1950CE) ratios to ones found in the tree rings to find the best match to the tree rings. Using 14C levels to match chronologies introduces an error due to the number of different rings that match those levels inside the +/-1σ margins of error.
So we have another historical calibration date of 2660 BCE with 98% consilience between history and European oak chronology. This chronology extends back to 12,410 cal BP (before 1950), or 10,460 BCE, and ~40% of its length is consilient with documented historical events\artifacts.
This high consilience between these dendrochronologies and historical dates gives us high confidence in the accuracy and precision of these dendrochronologies.
Remember: The challenge for old age deniers (especially young earth proponents) is to explain why the same basic results occur from different measurement data sets if they are not measuring actual age?
Comparing European Oak and Bristlecone Pine Chronologies by 14C Levels
Comparing European Oak and Bristlecone Pine Chronologies by 14C Levels
As noted for the Bristlecone pines and European oaks, crossdating between many trees in a location is one method to check for errors. Another is to compare two or more independent chronologies from different locations, as was done with the two Bristlecone pine chronologies and the German and Irish oak chronologies. However the climate differences between Europe and the White mountains in California are too different to use dendrochronological methods to compare the oaks to the pines. We have indirect comparisons through the historical events that show up in these chronologies, but these are limited to the historic period.
Another comparison can be done, however, using 14C quantity measurements as alternate "ring" data: the generation of 14C changes year to year, so there is a pattern of 14C variation in the atmosphere similar to tree ring climate patterns, and these can be matched in a similar manner. Because the atmospheric levels are essentially the same around the globe (there is some difference between north and south hemispheres), we can compare the Bristlecone pines and European oaks by their 14C level patterns.
For an initial idea of the accuracy of the data and the amount of error involved we have this piece of evidence:
In a recent series of papers studying annual tree rings, Miyake et al. (2012) reported on the existence of excursions in the radiocarbon record at A.D. 774 – 775, followed by a less intense event at A.D. 993 – 994 ( Miyake et al., 2013). The A.D. 774 – 775 "spike" is observed as a change in Δ14C of ~12 – 15‰ in a 1 – 2 year period. Apart from the event at A.D. 993 – 994, there are no other reported excursions of this magnitude in the last several thousand years ( Usoskin and Kovaltsov, 2012). The initial work of Miyake et al. (2012) on the A.D. 774 – 775 event was based on annual rings from Japanese cedar trees. The first event has been independently confirmed by other investigators on European oak trees ( Usoskin et al., 2013), with a change in Δ14C of~15‰.In addition, Güttler et al. (2013a, 2013b) report on a record from the Southern Hemisphere using Kauri wood from New Zealand. This Kauri record shows the same amplitude in Δ14C but with a small offset due to the Southern Hemisphere regional effect. Liu et al. (2014) have recently reported on a similar excursion in Δ14C determined from dated corals in the South China Sea.
In a recent paper, Liu et al. (2014) proposed that the 14C increase at A.D. 774 – 775 was caused by a cometary impact into the Earth’s atmosphere. ... They also cited Chinese historical records from A.D. 773 that described a major atmospheric disturbance at the time, including a significant dust event (e.g., Napier, 2001).
We have confirmed the A.D. 774 – 775 event in the 14C record at two additional locations, in the western United States and Russia. The amplitude of the event is very similar to previously reported results from Japan, Germany, and New Zealand. ... The fact that the 14C signal is observed in five very different locations with exactly the same amplitude is remarkable in itself. The exact cause of the event is unclear, although a number of mechanisms have been proposed, all of which require an extraterrestrial origin. ...
The consilience displayed with these independent dendrochronologies is remarkable: if any one of them were off by 1 year it would be an 0.13% error. Thus this consilience is good confirmation that the tree ring chronologies are both accurate and precise this far back in the chronological record.
Two studies look at the accuracy and precision between these chronologies, first:
High-precision measurement of dendrochronologically dated Irish oak at bi-decade/decade intervals has continued in the Belfast laboratory, extending the 14C data base from ca AD 1840 to 5210 BC. The dendrochronology is now considered absolute (see Belfast dendrochronology this conference) (Brown et al, 1986) and a continuous detailed curve is presented, showing the natural variations in the atmospheric concentration of 14C over >7000 years. Each data point has a precision of <2.5 ‰, and some 4500 years have now been compared with Seattle, giving excellent agreement.
It has been shown above that it is now possible by combining Seattle and Belfast data to provide an internationally acceptable calibration curve within a 1σ envelope of ca ± 14 years, covering a time period of some 4500 years. The remaining Belfast curve from 2500—5210 BC would be valid using an error multiplier of 1.23 to give an average calibration band-width of <± 20 years.
Note that the "‰" symbol is "parts per thousand," so this is <0.25% error in the measured 14C levels in all the samples. At 5210 BCE (7160 BP) an error of 0.25% in ~7200 years would be a error of +/-18 years, very precise and accurate.
The availability of absolutely (dendrochronologically) dated German oak has allowed the Belfast laboratory to extend its published high-precision 14C measurements of Irish oak (Pearson et al. 1986) by 2680 yr. The samples were selected at contiguous 20-yr intervals, following a precedent adopted and considered satisfactory in previous publications. All samples were measured for at least 200,000 counts within the 14C channel. The statistical counting error, together with the error on standards, backgrounds and applied corrections, give a realistic precision quoted on each sample of ± 2.5%o (± 20 yr). This error is considered high-precision for sample ages of 7000-8000 BP.
To help justify a claim to accuracy, and at the same time, help to determine a laboratory error multiplier, both replicate analysis and interlaboratory comparisons are necessary. We measured six contiguous samples to give an overall precision of ± 20 yr on each sample. They gave a mean age difference of ca. 13 yr, when compared to the same samples (some already duplicated) measured some 8-11 yr before (Table 1). This difference is considered reasonable, although just at the acceptable limit of statistical expectation. We compared recent replicate analysis of Irish oak samples from 5170-5090 BC to German oak, and the mean values differed by <10 absolute.
The mean difference between the Irish Oak Chronology and the German Oak Chronology was <10 years over ~8,000 years, based on matching 14C levels, or 0.13%. This compares to the 0.48% for the Bristlecone Pines.
For a final idea of the accuracy of the tree ring data and the amount of error involved in just the dendrochronologies, we have this:
For inclusion in the calibration data set, dendrochronological dating and cross-checking of tree rings is required. ...
The Holocene part of the 14C calibration is based on several millennia-long tree-ring chronologies, providing an annual, absolute time frame within the possible error of the dendrochronology, which was rigorously tested by internal replication of many overlapping sections. Whenever possible, they were cross-checked with independently established chronologies of adjacent regions. The German and Irish oak chronologies were cross-dated until back into the 3rd millennium BC (Pilcher et al. 1984), and the German oak chronologies from the Main River, built independently in the Gottingen and Hohenheim tree-ring laboratories, cross-date back to 9147 cal BP (Spurk et al. 1998).
Due to periodic narrow rings caused by cockchafer beetles, some German oak samples were excluded from IntCal98. Analysis of these tree rings, with an understanding of the response of trees to the cockchafer damage, allowed some of these measurements to be re-instated in the chronology (Friedrich et al., this issue).
The relation between North American and European wood has been studied using bristlecone pine (BCP) and European oak (German oak and Irish oak), respectively. Discrepancies have become evident over the years, in particular when the German oak was corrected by a dendro-shift of 41 yr towards older ages (Kromer et al. 1996). Attempts were made to resolve the discrepancies by remeasuring BCP samples, measured earlier in Tucson (Linick et al. 1986). The University of Arizona Laboratory of Tree-Ring Research provided dendrochronologically dated bristlecone pine samples to Heidelberg (wood from around 4700 and 7600 cal BP), Groningen (around 7500 cal BP), Pretoria (around 4900 cal BP), and Seattle (around 7600 cal BP). The replicate measurements have a mean offset of 37 +/- 6 14C yr (n = 21) from the Tucson measurements. ... Because of this offset, the IntCal working group has decided not to include the BCP record in IntCal04.
Uncertainty in single-ring cal ages for dendrochronologically-dated wood is on the order of 1 yr for highly replicated and cross-checked chronologies and is therefore ignored in the analysis. …
The Bristlecone Pine was not included in the calibration data for INTCAL04 because it was 37 years younger than the two oak chronologies at 7600 BP (before 1950). This indicates that the Bristlecone pine chronology is likely missing rings, especially in the more ancient rings where the number of samples is small and where the offset is noticed. Even so, this is an error of only 0.48% at 5650 BCE, which is still very high accuracy.
The combined information from these chronologies now extends back to 7980 BCE, or 9930 BP (before 1950), slightly longer than the Bristlecone Pine chronology. The significant point though, is not the extension of the chronologies, but the consilience of the data and their ability to match each other with very small error.
So the data from all three dendrochronologies is consilient with 99.5% accuracy and precision and the German oak and Irish chronologies back to 7980 BCE with 99.9% accuracy and precision. This results in very high confidence for the accuracy and precision of the dendrochronologies.
This high consilience between these independent chronologies gives us high confidence in the accuracy and precision of the Irish oak chronology, and increases our (already high) confidence in the Bristlecone pine chronology.
Remember: The challenge for old age deniers (especially young earth proponents) is to explain why the same basic results occur from different measurement systems if they are not measuring actual age?
Jull,A.J.T., Panyushkina,I.P., Lange,T.E., Kukarskih,V.V., Myglan,V.S., Clark,K.J., Salzer,M.W., Burr,G.S., and Leavitt,S.W., (2014), Excursions in the 14C record at A.D. 774 – 775 in tree rings from Russia and America, Geophys. Res. Lett., 2015 41,doi:10.1002/2014GL05[2015, March 01] http://www.geo.arizona.edu/....arizona.edu/files/JullAGU.pdf
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