Just published online today for open discussion while it undergoes peer review, is this paper by Mike Baillie and myself, in which we argue that the ice core dating in the 6th and 7th centuries AD (and likely before), are too old by 7 years. We do this by comparing the spacings between frost ring events in American bristlecone pines and spacings between volcanic acidities dates measured by the European ice core workers, in various ice cores taken from Greenland (and amalgamated into their Greenland Ice Core Chronology GICC05). Further more, we show that claimed independent ice cores from Antarctica (which are linked to the GICC05) are also wrongly dated.
There are some big implications for this. First up, is that the acid and tephra that the ice core workers believe belongs to Vesuvius AD 79, is likely not due to Vesuvius.
The main implication though is that it identifies the potential cause of the severe environmental event in the mid 6th century. To put it simply, we show that the two stage downturn event at AD 536 and AD 540 is due to two eruptions around this time. GICC05 only has one eruption at around AD 535, and blame effectively 10 years of climatic downturn on this one supposed event. Furthermore, by showing that there is a volcano at around AD 540, it reduces the need for there to be a cosmic impact at this time a la Occam's razor (the cosmic impact was hypothesised by Mike Baillie in 1995 due to lack of volcanic evidence for the environmental downturn). This does not mean that some cosmic event did not occur around this time, but it does negate the need for for one to have occurred.
The full paper can be downloaded here [
www.clim-past-discuss.net]
Jonny
The path to good scholarship is paved with imagined patterns. - David M Raup
Edited 1 time(s). Last edit at 04/15/2014 03:06AM by JonnyMcA.