Lake Suigetsu and the 60,000 Year Varve Chronology

Do places on Earth exist where annual records have been stored for tens of thousands of years and can be accessed today? Ice-cores and tree rings can preserve long records of yearly events but some of the best records come from layers of sediment underlying some lakes which,  if formed under the right conditions, can be read like the annual rings of an oak tree. These alternating layers of sediments and sometimes organic material are called varves and by counting each varve sequentially a varve chronology can be constructed.   Varve chronologies are a window to the past and have been used to study past climate conditions, the periodicity of volcanic eruptions and as an independent test of radiocarbon (C14) dating methods.

One place were varves have been studied for decades is below a deep lake in Japan: Lake Suigetsu.  Here a varve chronology stretching back well over 50,000 years has been established.

An important summary of the significance of this varve chronology can be found in an open access article from Science here with a summary from Nature magazine here.   For several decades,  varve chronologies  have been featured as clear evidence of an ancient Earth. The evidence from varves presents a formidable challenge to young-earth creationists  (YECs) and their assertion that scientific evidence, properly interpreted, points to a young earth.   Though a well-worn example, this recent work pushing the varve chronology to close to 60,000 year bears reviewing in light of how YECs have responded in the past to this challenging data.

Below I introduce you to the varve deposits in Japan and then review how young earth creationists have responded.

Why is Lake Suigetsu a good place to examine varves?

Lake Suigetsu is one of five lakes that were formed from volcanic eruptions.  The reason this lake was targeted for study is because scientists are fully aware of the potential errors that may occur when assessing whether the varves they see truly represent annual layers. This lake has all the features that one could hope to find in a location to avoid those problems.   Annual varves are the product of changes in the composition of sediments and organic material deposited in spring and summer vs the fall and winter.

To avoid the problem of  false layers – non-annual rings – produced by floods or inconsistent seasonality, a location that is protected from large sediment influxes and exhibits a strong seasonal signal is ideal.   Lake Suigetsu fits those requirements exceptionally well.  For example, the Hasu River enters Lake Mikata where the sediments suspended in the river, even during a large flood, will fall out of the water column.  The sediment-depleted water then flows through a narrow but shallow channel into Lake Suigetsu which is surrounded by high cliffs on all sides and has almost no input of water from the surrounding area.  The result is that the waters of Lake Suigetsu have little suspended sediment and the surrounding walls limit the wind on its surface so the waters are not disrupted.  Thus the center of the lake is extremely stable and unlikely to be disturbed by floods, large storms, etc…

New input of sediments to the lake floor is derived primarily from material falling into the lake from the air (leaves, pollen, volcanic ash, dust) or from differential growth of organisms (algae) over the year. What is amazing about most of the varves of Lake Suigetsu is that as one moves down the cores retrieved from below the center of this lake, the varves formed in the past several hundred years for which climatic and lake-conditions are known look similar to those formed 10s of thousands of years ago. This provides researchers with increased confidence that the varves represent annual years and that the climatic influences on this lake in the past have been very similar to those of the present.

How do varves form in this lake?

There is strong seasonality in the this portion of Japan.  Greater precipitation in the winter along with very cold water and decaying plant material and algae results in deposition of a distinctive set of organic and inorganic material during the winter months.  In the summer, pollen, algae (especially diatoms, see: Life in a Glass House: Diatoms Shatter Young Earth Flood Geology) – fall to the lake bottom.  The result are annually alternating bands of material. These layers are very thin because in the very middle of this lake, were the cores were obtained, the total amount of material that settles to the bottom of the lake amounts to less than 1mm per year.   I want to stress here that climatologist and biogeochemists have spent a considerable amount of time documenting the layers from multiple cores drilled out of the bottom of this lake. They have counted these layers by multiple methods

including  by eye and by computer assisted techniques and more recently by various scans of the cores using other methods of imaging which highlight differences in organic content which can accentuate the winter season layers making the reads more accurate.   Careful, independent counts of the annual varves have been performed and more than 800 samples of leaves and other organic content (pollen grains etc..) have been selected from the cores for carbon 14 dating.  In addition, 40Argon/39Argon dating has been performed on tephra (ash) layers found in the cores sections (see picture to the right for an example) and two other types of dating methods have been performed on the cores. See the Science article for details. In addition, papers about varves and chronology around the world can be found in this issue of Quaternary Science Reviews.

So many different tests of the annual nature of the varves have been conducted here because these varves play a critical role in calibrating the radiocarbon (C14) clock. The methods and results published in dozens of papers have been scrutinized by hundreds of other scientists and the varves counts continually remade to test their accuracy.  As a result of this high level of scrutiny the scientific community is confident that  the varve counts have a high degree of accuracy and they represent individual years.

What are the data derived from Lake Suigetsu?

Initial studies in the early 1990s from the first cores below this lake found a tight correlation between varve count date (the number of varves) and radiocarbon derived dates of organics in the layers stretching all the way back to 40,000 varve years.  As you would expect, there is also a strong correlation of age with depth of the column (see figure to the right).   The most recent analysis reported in Science expands the varve counts back to more than 50,000 years.   Over 800 samples of organic material have been C14 dated and each of those has been sent to at least two – and sometimes 3! – radiocarbon labs for independent verification of the C14 dates. The incredible rigor in selecting samples for C14 dates and blind testing at multiple labs has been undertaken because one of the primary goals of the Suigetsu varve counting group is to confirm the accuracy of and calibrate the C14 clock.

Volcanic activity recorded in the cores provides an additional independent test of the varve chronology

Consider also that there are more than 30 visible ash layers which form discrete almost pure glass crystal layers that lie between varve layers.   These would have formed from airborne ash from volcanoes in the area. That ash would have fallen directly into the lake surface and settled quickly to the bottom. Had this ash been brought in by the river it would have been mixed with other sediments.  These ash layers further attest to the fact that this lake had clear undisturbed waters during the whole period that these varves formed.  In addition to the 30 visible layers there are at least 100 additional ash deposits that are so fine that they can only be identified by microscope. These represent ash from very distant or small volcanic explosions that brought a very small amount of ash fallout to the lake.

The advantage of having ash deposits in the varve cores is that it is possible to radiometrically date them (Smith et al. 2013) and those dates can be compared to the varve counts.  If either radiometric dating or the varve counts were inaccurate measures of the time – ie. a bad chronometer – then the two dating methods should yield inconsistent results.  Multiple ash layers in multiple cores have been dated by several radiomentric dating methods and those dates are consistent with the varve counts. For example, an ash layer found at varve count 9000 yields a radiometric date of around 9000 years.  This correlation of varve counts with radiometric dates represents yet another independent verification that both the varve counts accurately reflect the passage of time as annual layers.

Over the years there have been multiple cores taken from the lake bottom which have had their varve layers counted multiple times by multiple methods by multiple investigators.   C14 dating has been performed by independent groups over the same time. If we combine these data with data from varves from other locations and tree ring data, a very compelling and consistent chronology of Earth’s history can be observed extending back a minimum of 50,000 years. Below is a composite figure showing the relationship of tree rings, varves and C14 dates compiled from multiple studies from different locations in the world. What we see is an amazing correlation of these data points.

Creation Science response to the Lake Suigetsu varve chronology

Varve chronologies have been used to challenge the young earth creationist’s understanding of earth history for 30 years.  It is remarkable that the creation science community has produced so little literature in response to what is a serious challenge to their young-earth thesis.   A few experiments have been performed in an attempt to recreate something that look like varves (for example, Berthault, 1988). These were performed solely with sediments and thus lacked the  organic material for which most of the important varve chronologies, like Suigetsu, are based.  Dr. John Reed, who has a PhD in geology, provides the standard response to varve chronologies  in a paper entitled,  Toppling the Timescale Part III: Madness in the Methods in the Creation Research Quartarlyin Summer of 2008.  Despite significance of varve chronologies to climate studies and C14 dating methods there is only this one mention of varves in this paper:

“Like varves or ice layers, geologists simplistically assume that the target sediments  were deposited slowly, uniformly, and in response to regular climatic variables. Remove those assumptions and  the whole theory crumbles, as has been  shown for both ice layers (Oard, 2005) and varves (Oard, in press).”

Dr. Reed simply asserts that rapid sedimentation can cause the appearance of varve like layers which could be mistaken as annual years when they really represent catastrophic deposition over a very short period of time.  He also reports in several other articles examples of lakes and other fossil varve sites (ancient preserved lakes with varved rock such as the Green River Formation) where there is evidence of multiple varves produced in a single year.  This defensive strategy employs redirection.  By either implicitly or explicitly that because known exceptions of varves representing individual years can be identified, then all reports of annual varves should be discredited.

These responses are nothing more than accusations that the assumptions are incorrect and that scientists are unwilling to consider alternative means by which these tens of thousands of layers could have been formed.  But, this is exactly why the  Lake Suigetsu cores have been scrutinized by so many scientists.  Scientists are well aware of that annual varves require specific condition to form. They picked this location because the conditions there do not violate any of those conditions.  They have used multiple methods to test for annual periodicity. They have assumed nothing and only after passing all the tests have they stated that the varves under this lake represent annual varves.

A more recent example of the young-earth response to the Lake Suigetsu varves is found in the article “Long-age geology or Genesis” again by John Reed published on Creation Ministries International’s web site.   Dr. Reed writes a short response to an article written by a group of eight Christian PhD geologists entitled “PCA Geologists on the Age of the Earth.”  Those geologists explored multiple methods of determining the age of the earth and concluded that the evidence overwhelmingly points to an ancient earth.   Dr. Reed provides a quick rebuttal to one of those methods which involved varve counts from Lake Suigetsu :

“The first example is the “varved” (finely layered) sediments of Lake Suigetsu in Japan. Apparently, the varves present a “record” of 100,000 years, reinforced by C14 dating and dendrochronology. And of course, once the lake sediments have blown away the creationist position, the authors can then point to the rock record beneath the lake as “proving” millions of years.

Like any other interpretation, this one is a combination of data and assumptions. There is no attempt to consider a serious Flood alternative; it is simply a matter of PhD condescension towards the ignorant peasants who give the elite accommodationists a bad name in the eyes of the world. If the sediments are annual varves … if C14 dating is accurate … if dendrochronology is accurate … etc. If, if, if. Unfortunately, none of these can be demonstrated, as shown by the links above. Another good resource is Rock Solid Answers, where Mike Oard has a good chapter on varves.”

This is a short response by Dr. Reed. However, he also produced a longer more technical-sounding line by line response to the same article.  I don’t really need to review that response because it doesn’t provide any new responses.  He simply throws out the same doubts about c14 dating and varves and claims that these scientists haven’t been willing to consider alternatives.    But what alternatives does Dr. Reed provide?  He asserts that links to other articles provide demonstrations that varves and c14 doesn’t work.  But is this true?

His linked article that presumably demonstrates that varves are not valid is to a paper by Michael Oard. But that paper doesn’t have anything to do with the Suigetsu varves or the type of varves that are found there.   I’ve read all of Oards’ refutations of varves and they have little to do with reality. Rather they include the same hand-wavy assertions that Reed uses:  one lake has layers that aren’t annual years that this casts doubt on all other layers in other lakes around the world.    Does he really think that scientists are so ignorant of these assumptions and are unaware of variables that can cause varves to be unreliable?  Scientists have found many varve records to be unreliable chronological markers, precisely because they really do understand that there are conditions that must be met to reliably interpret varves as annual layers.

Dr. Reed wrote yet a further response to the same old-earth article (see references).  In it he provides no further evidence that the Suigetsu varves are invalid than he does in his article from 2008.   I find it very difficult to find much charitable to say about Dr. Reed’s responses and attitudes.  Of course he is upset that his beliefs about a young earth are being challenged but he is supposed to be a PhD geologists capable of critically analyzing and demonstrating the faults in interpretations of old earth geology. What we get instead is nothing but name-calling rhetoric.  He faults scientists including other Christians for not considering the alternatives and yet provides no other alternative himself other than a generic appeal to a global Flood without offering any mechanism that could explain the observed facts.

I have spent many hours reading the original literature about these varves.   These article include extensive discussions by the authors about why they believe the varves represent annual layers and not just individual events layers as are seen in some other lakes in other parts of the world.   What has Dr. Reed done to respond to the Christian geologists who have used the Lake Suigetsu varves as evidence of an old earth?  Apparently he hasn’t done them the courtesy of reading the original literature himself. Rather he responded with generic arguments that apply to some varves but not the ones that are being held up as the specific challenge. Yet he confidently claims they must be wrong!

Does Dr. Reed or Michael Oard address how discreet bands of ash can be found between 10s of thousands of fine bands they believe must have formed in a matter of months or just a few years?  I haven’t even seen Dr. Reed even acknowledge to his audience that such bands of ash exist in these varved layers!   His strategy, like so many other creation scientists, seems to be to simply proclaim as loudly, as boldly and as confidently as he can that there is an alternative and to make fun of scientists for not being able to see the real truth that he sees.   It’s all preaching to the choir. He has no interested in providing a reasonable alternative explanation for the data. Rather he only wishes to provide enough doubt in his audience’s mind that they will not explore the evidence any further.  Young earth creationists have had 30 years to construct a plausible hypothesis to explain these and other annual varves. The fact that they are still just waving accusations and vague generalizations around is a clear sign that they know that there is no alternative.   What we are seeing here is reminiscent of observations that I made in my post:  Having Faith in Flood Geology: Dogmatic Assertions of Evidence.

Summary:  Varved sediments underneath lake Suigetsu provide powerful confirmation that this lake has existed for 10s of thousands of years in a state very similar to what we observe today.   A recent global flood does not provide a viable interpretation of the same evidence.

Addendum 8/19/2016:  The 60,000 from the title came from popular reporting from when this research was first reported. The reported varve counts, which are considered reliable annual varves, only go back to just over 53,000 years.  But there are varves potentially reaching back to 150,000 years below this lake but the lower layers can’t be read with the same accuracy as the upper 50,0000.

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Berthault, G., Experiments on lamination of sediments, CEN Technical Journal 3:25-29, 1988.

JK. Reed. A response to the Old-Earth advocacy of Campell et al., PCA geologists on the antiquity of the Earth.  Published in Answer in Depth at the Answers in Genesis website.

Below are just a few of the more than 100 articles that have published which examine all aspects of these varves.  For a list of other articles please visit:  http://www.suigetsu.org/embed.php?File=publications.html  

Nakagawa, Takeshi, Katsuya Gotanda, Tsuyoshi Haraguchi, Toru Danhara, Hitoshi Yonenobu, Achim Brauer, Yusuke Yokoyama et al. “SG06, a fully continuous and varved sediment core from Lake Suigetsu, Japan: stratigraphy and potential for improving the radiocarbon calibration model and understanding of late Quaternary climate changes.” Quaternary Science Reviews 36 (2012): 164-176.

Schlolaut, Gordon, Achim Brauer, Michael H. Marshall, Takeshi Nakagawa, Richard A. Staff, Christopher Bronk Ramsey, Henry F. Lamb et al. “Event layers in the Japanese Lake Suigetsu ‘SG06’sediment core: Description, interpretation and climatic implications.” Quaternary Science Reviews 83 (2014): 157-170.

Smith, Victoria C., Richard A. Staff, Simon PE Blockley, Christopher Bronk Ramsey, Takeshi Nakagawa, Darren F. Mark, Keiji Takemura, and Toru Danhara. “Identification and correlation of visible tephras in the Lake Suigetsu SG06 sedimentary archive, Japan: chronostratigraphic markers for synchronising of east Asian/west Pacific palaeoclimatic records across the last 150 ka.” Quaternary Science Reviews 67 (2013): 121-137.

Staff, Richard A., Takeshi Nakagawa, Gordon Schlolaut, Michael H. Marshall, Achim Brauer, Henry F. Lamb, Christopher Bronk Ramsey et al. “The multiple chronological techniques applied to the Lake Suigetsu SG06 sediment core, central Japan.” Boreas 42, no. 2 (2013): 259-266.