Drilling a Little Deeper: How long has snow fallen in Greenland?

I appreciate Dr. Bull’s response, “Ice Cores and the Flood: A Response to André Reis” to the questions I posed to his articles “Bringing the Real World to Genesis: Ice Cores and Scripture Part I—How Many Years Has Snow Fallen on Greenland?” and “Ice-Cores and Science Part II—Grecian Lead Mining Confirms Ice-Core Chronology”. 

I also appreciate the opportunity Spectrum has given me to fine-tune some of my initial statements. Since my response already dealt with some of the theological and philosophical implications of a compromise between modern geological theory and Genesis, I will now deal with technical aspects of this question.

I’ll start with a clarification. In my essay, “Ice Cores and the Flood: A Response to Brian Bull,” I didn’t mean to say that ice core dating is related to the “survival of the fittest” as Dr. Bull seemed to imply. I did use the terms “evolutionary science” and “uniformitarian geology” somewhat interchangeably because they stem from the same naturalistic worldview, which is clearly unacceptable to the creationists. Below I review some of the methods of ice core dating as explained by the researchers at the Greenland Ice Sheet Project 2 (GISP2), which present problems for Dr. Bull’s conclusions. 

Methods of Ice Core Dating

In his reponse, Dr. Bull states that the dating of the ice cores was done solely by “empirical evidence” and did not involve the principle of uniformity, i.e., that the ice cores should be interpreted as representing uniform precipitation throughout. In fact, the researchers at GISP2 did use a multiparameter continuous count approach for dating the ice core, which includes visual examination, measuring oxygen ratios in the ice, electrical conductivity, laser-light scattering and ion chemistry.[1]

However, there are several problems with the accuracy of this method. First of all, contrary to Bull’s assertion that at a depth of 1836m the oxygen isotopes in the ice can be measured, Meese et al. reveal that after just 300 m, oxygen signature in the ice was rapidly obliterated. At 500m, oxygen isotopes were no longer viable as an annual indicator. Other methods had to be use to detect alleged annual markers at lower depths, which are prone to ambiguous results.

Besides loss of important chemical markers, researchers at GISP2 reveal that from 600-1400m, there was widespread fracturing of cores and that analysis even through laser-light and electrical conductivity was “difficult”. Count in these sections was done by comparison with the upper part of the core. At around 2400m visual analysis is not feasible and layers very difficult to decipher.

To achieve a consistent count of layers all the way down, researchers authors created a sort of template with data from the upper layers, because they expected this would be repeated down the ice core consistently. For several questionable portions of the core, interpolation was done, that is, missing data was filled in based on a range of known markers. This simply means that what occurred in the upper layers was projected to the questionable lower layers. An unverifiable model for layer thinning at the bottom was also applied deeper in the ice.

At deep portions of the ice the laser-light instrument was configured to produce a staggering 500 years per meter (3 ft) of ice! This is not empirical evidence, this is working from biased assumptions. Researchers also applied a “subjective approach” for several (especially the deeper) portions of the ice core; ages were achieved by averaging the count performed by at least two researchers, one of them identifying 20% more layers than the other! Based on this semi-empirical method, researchers were able to predict that the age of the ice at 2800m to would be about 110,000 years , with a predicted, not empirically verified, total age of 161,000 years for the bottom.

But what to say about the lead and volcanic ash signatures in the ice? Don’t they show an exact correlation with other records going back thousands of years, pointing to a consistent annual layer count? To this point, I would say that, besides the fact that such correlation has been disputed recently[2], the problem is that they only go back so far in the ice chronology (perhaps a little more than 2,000 years). Even though the upper annual layer count may be correct, this does not automatically constitute “empirical evidence” of the age of the deeper ice, precisely where the problem lies.

Conclusion

The method for ice core dating used in Greenland is demonstrably semi-empirical, where age of the deeper ice is based on predictions from upper layers and preliminary models, subjectivity, high risk for missing sub-annual events, a bias for overcounting annual layers and uniformitarian assumptions severely impair the objective interpretation of the data. The resulting depth-age of hundreds of thousands of years could be highly overstated starting at least as early as the 1,113 “year” marker where the chemical data in the ice begins to break down severely.[3] Meese et al. state that “There are potential problems with both the GISP2 and GRIP timescales.”[4] I agree.

This appears to contradict Dr. Bull’s assertion that scientists “were certainly not assuming that whatever … they measured in the surface ice would be replicated in the deeper ice. They were not assuming uniformity.” In fact, the Greenland ice core projects were heavily dependent on preconceived ideas and assumptions of what they should find in the ice core when empirical analysis was less reliable or even impossible. If the uniformitarian assumptions projected on purported “annual layers” are removed, the margins of error (1-20%+ throughout) could skyrocket. We could be possibly looking at thousands of seasonal storm layers instead of annual layers.[5]

It appears then that my initial objections to the accuracy of ice core dating have been confirmed by an objective look at the methods and assumptions used. It would appear that scientists need not be believed when they report more than 100,000 annual layers in ice cores.

What does all this mean to believers in the biblical data about a recent Creation and Flood? First, the ice cores do not present insurmountable difficulties to belief in a recent, global Flood, provided one is willing to question the so-called “infallibility” of the claims of geologists. But in order to make a strong case, believers in biblical historiography need to confront science with the ambiguities and inadequacies of its method and conclusions as objectively as possible. “Science is never 100%”, as Dr. Bull said in one of his comments, despite the fact that he has put quite a bit of trust in their theories. Believers in Genesis need to refute science in its own terms, and not simply dismiss the data out of of what may appear to be mere prejudice.

Second, because mainstream ice core dating is fraught with problems, scientists who accept Genesis 1-11 as literal history must continue to offer sensible, catrastrophist models such as the one included here (See diagram). This example shows that while mainstream scientists expect thinner annual layers at the bottom of the ice, the catastrophist model posits much thicker annual layers. This could explain the deep ice sheet (3 km), because thousands of those deeper layers, which GISP2 scientists practically guessed were annual, could actually be massive seasonal post-Flood storms. Nevertheless, the evidence is not definitive for either model.

In Part I, Dr. Bull suggests that: “The disconnect [of the ice core dating] with the time scale implied in Genesis really does exist. A discrepancy of this magnitude will, sooner or later, need to be addressed.” I trust our exchange here on Spectrum represents an important step in that direction.

To answer Dr. Bull’s Urfrage “How many years has snow fallen in Greenland?” I’d say, we may never know for sure, but it certainly need not be 161,000 years.

Once again, thank you Dr. Bull for raising these important questions and for the very positive dialogue.

—André Reis has a B.A. in Theology from the Adventist University in São Paulo, Brazil, a Masters of Music from Longy School of Music and is currently pursuing a PhD in Theology at Avondale College.

Image: Contrary to uniformitarian models, one Christian catastrophist model shows increased glaciation deeper in the ice core. (Source: www.answersingenesis.org).

References:

1. D. A. Meese, A. J. Gow, R. B. Alley, G. A. Zielinski, P. M. Grootes, M. Ram, K. C. Taylor, P. A. Mayewski and J. F. Bolzan, “The Greenland Ice Sheet Project 2 Depth-Age Scale: Methods and Results,” Journal of Geophysical Research 102, C12 (1997): 26,411.
2. Cf. Douglas Keenan, “Volcanic ash retrieved from the GRIP ice core is not from Thera“ Geochemistry Geophysic Geosystems, vol. 4, (2003): 1097-2004; Meese et al., 26,421-2.
3. Cf. Alley, R.B. et al., “Visual-stratigraphic dating of the GISP2 ice core: Basis, reproducibility, and application,” Journal of Geophysical Research 102, C12 (1997):26,367–26,381, 1997.
4. Meese et al., 26,421-2.
5. A similar, “semi-empirical” approach was also applied to the ice cores of central Antarctica. Cf. J. R. Petit and B. Delmonte, “A model for large glacial–interglacial climate-induced changes in dust and sea salt concentrations in deep ice cores (central Antarctica): palaeoclimatic implications and prospects for refining ice core chronologies,” Tellus 61B, (2009): 768–790.