Hi Hermione,

I have been "sitting" on this since Mike showed me it in February, and had a few discussions with him on it. You will note that the "Jonny" in the comments section is me, and the points on this article still stand, the most important one being the integrity of the ice core dating, since any correlation with the Mayan calendar requires this to be correct. I repeat them below to contain the argument to this forum to save clicking away to view them. Note that Mike has acknowledged similar concerns in another as yet unpublished article.

Quote

The science does depend upon some crucial assumptions

1) That Ammonia can be formed in sufficient quantities by impact
2) That the ammonia anomalies in question are due to impacts
3) That the ice core chronology is correct.

The first assumption has been demonstrated by Melott to be reasonable, and indeed previously suggested by Baillie as being markers of extra-terrestrial events. Having an ammonium/nitrate signal at AD 1908.5 date in GISP2 implies that such an assumption is strong, since it is estimated that the energy of the Tunguska event generated enough Nitrate to deplete one third the ozone layer.

The second assumption is reasonable, especially to catastrophists. To catastrophists it would seem highly unreasonable to think that out of the 5000 odd years since 3000 BC, we have had only one impact event generating Ammonia/nitrate within the ice cores. Especially when one considers that the impact rate of Tunguska class objects is between 1 every 1000 years (as conservatives believe) or 1 ever 300 years as per catastrophists. There is a chance that some of these signals could be terrestrial events such as large scale biomass burning (which of course could be impact related!). Just because one event is extra-terrestrial does not necessarily mean that others should be, at least not without further lines of evidence.

the third assumption is very important, since the correlation relies upon the integrity of the GISP2 core. There is much debate amongst the chronology community regarding the absolute dating of the ice cores especially with respect to dendrochronological evidences. Even between different ice cores there is difficulty in matching signals in different epochs. For example, Baillie himself advocated that the GRIP core was correctly dated due to its replication, and that there was a problem with GISP2 chronology, but has since changed his mind and argued that there may be flaws in GRIP chronology, and hence GISP2 may correctly dated (which is the raw data presented in the above article), since volcanic markers in GISP2 match historically recorded eruptions back to 44 BC. Before 44 BC in time, the integrity of the chronology may break down, especially given the number of gaps in the ice. So a third option is always that neither GRIP or GISP2 is correctly dated before the 1st century BC.

The major issue is whether the GISP2 ice core data is correctly dated prior to 44 BC. There are a series of gaps in the record, which could introduce errors. However, from 44 BC to around 750 BC there seems to be good dating between volcanic signals and frost rings in bristlecone pine data collected by Salzer and Hughes.. However, from before 1000 BC there seems to be a systematic offset of about 5 or 6 years between bristlecone pine data and volcanic sulphate signals in the ice core data such that the ice cores are 5 or 6 years too young. For example, we have a frost ring at 1089 BC, and Sulphate at 1084 BC, and frost ring at 1628 BC but sulphate at 1623 BC. We also have narrowest ring events in bristlecone pine at 1996, 2148, 2173, with sulphate occurring at 1991, 2143, 2166 BC.

Given that dendrochronological dates are absolutely dated, then it suggests that it is the ice core dates that need to be shifted. Shifting the ice dates 5 or 6 years older will then mean that the ammonia signal occurs around 1149 BC instead, which coincides with a bristlecone pine narrow ring event, as well as being close to the narrowest rings in 1159-1142 BC Irish tree ring event (with the event seemingly beginning with an eruption at around 1161 BC give or take). This to me weakens the argument of the ammonia occurring at 1142 BC, and hence weakens the correlation between ammonia and baktun transitions will also be weakened, though one could still argue that the Mayans based their calendar upon their own numbering system on a poorly remembered date of events. I.e the remembered it was about 1577 years, but it was actually 1580 etc. This could of course be seen as special pleading, but "historical records" do not have to coincide with scientific fact. After all the modern Christian Calendar begins a number of years after the supposed events actually happened.

Jonny

(Edited to insert end quote sign - Hermione)

The path to good scholarship is paved with imagined patterns. - David M Raup



Edited 1 time(s). Last edit at 12/09/2012 12:02PM by Hermione.