The source of the graphic is global warming sceptic Prof. Don J. Easterbrook, from an article in
the alt “news” outlet Global research .
http://www.globalresearch.ca/global-coo ... here/10783
Obviously it shows the impact of the YD centering on Greenland and derived from ice cores from various sites including the highest points in the mountains in the centre of that country.
Well, tiompan, thank you very much for that. Since it is an "alt" site likely by global warming sceptics,
now I'll have to check to see if the underlying data is any good.
If that data is from Greenland, then it should reflect the melt water pulses from the North American ice sheet.
The impact there was quite different from that of Asia Minor /Anatolia . E.g. , Gobekli Tepe is nearly 6,000 Km from Greenland , it is over 2000m lower in altitude from the Summit site that produced the data in and is approx 40 degrees nearer the equator. At the most basic level “Plotting Younger Dryas temperature and climate anomalies against latitude shows that climate anomalies increased in magnitude toward the poles “ from “The Younger Dryas Climate Event” A.E.Carlson in the Encyclopedia of Quaternary Science .
If by "impact" you mean the "effects on climate" by two discrete cometary impact events, then we agree entirely.
That said, the 10,850 BCE impact event caused a global dust loading of the atmosphere,
which led to a climate collapse which killed off the mega fauna globally,
including any which lived in the GT region.
Did any mega fauna live there?
Were there any mega fauna hunters?
While I can no longer provide direct citations off the top of my head,
I will state that Native American peoples remembered not being able to store collected foodstuffs
because mega fauna would smell the stores and attack to get at those stores.
As has been mentioned here previously ,
"Change and Stability in an uncertain environment:Foraging strategies in the Levant from the early Natufian to PPNB " :Arlene Rosen .
Small game , the Younger Dryas ,and the transition to agriculture in the southern levant :Natalie Munro .
The role of the younger dryas in the origin of agriculture in west Asia :Offer Bar-Yosef . ) the impact of the YD in Anatolia was nothing like that of Greenland , there is even ample evidence from burial remains from the period and they show no signs of nutritional deficiencies infectious diseases or even trauma .
Fringe attempts to connect GT to the YD are pathetic and those that do make life more difficult for themselves by providing errors elsewhere in their efforts that make the job of refuting that much simpler . The recent Sweatman /Edinburgh Uni effort is a fine example .
Look at the dates for the end of the YD on the graphic and compare with the date of build of GT .
The end of the YD was approx 11,500 BP /9500 BC
tiompan, I do not use the term Younger Dryas, as earlier it was so poorly defined by the paleo climatologists as to be useless.
Some placed it here in time, others there in time, and this behavior continues.
Fletcher and myself work in an area and time of change from hunter gatherers to settled agriculture.
This data provides a very convenient check on near eastern data and hypothesis.
The oldest reliable date from GT is 9314 BC. GT was built after the end YD event in an area where it had much less impact than further north and west.
tiompan, you keep confusing "impact" with "effect".
In my frame of reference, this is like confusing "believe" with "think".
Regarding carbon 14 dating,
note that fast neutrons are produced in large hyper velocity impacts.
I do not know if any comet fragments hit near GT.
I need geologic cores from GT with Platinum Group analysis before I can trust the teams' carbon 14 calibrations.
I also want phytolith sequences firmly established from those cores.
Bones are not phytoliths.
That said, clearly we have not reached the lowest levels of the GT site yet.
In addition to that, I suspect that the first preceding structures may have been made of wood from large trees,
with those wood elements replaced by stone elements
following deforestation in the area.
Lastly, in your analysis,
you have not taken into account the effects of rising sea levels
on people living in nearby marine environments.
Based on data from the Americas,
this range limitation in your analysis is not well founded.
Nor have you faced up to the effect of the global climate collapse at 10,850 BCE.
Finally, it is clear that at GT we are dealing with "magical" thinking of some type.
Right now Flecther and my ow estimate is based on the two plaques,
and the structures themselves.
As a general principle, I always take the lack of data into account when building hypothesis.