8.2 ka climate event in Catal Höyük

[bicicleur]

http://www.sciencemag.org/news/2018/...man-prehistory

These clay pots were used to store meat, and researchers found relatively well preserved animal fat residue soaked into the porous, unglazed sherds. Extreme drought brought on by the 8.2-kiloyear event would have frizzled feed crops and grazing lands, and cooler winters would have increased animals’ food requirements. The combined effect would have been leaner, thirstier livestock, and their fat may have recorded chemical echoes of that dietary stress, the researchers reasoned.

The team used a technique known as gas chromatography–mass spectrometry to identify elemental variants known as isotopes. When the researchers looked at the fat deposits’ hydrogen isotopes, something interesting jumped out: In sherds dating to about 8200 years ago—and only those sherds—the ratio of the isotope deuterium, or heavy hydrogen, rose by about 9% in relation to other hydrogen isotopes from the samples. Previous research on the region’s climate and plant chemistry has shown that lower precipitation rates correlate with higher ratios of heavy hydrogen, which the livestock would have consumed as they grazed during the drought.

The isotopic signature was thus likely caused by the 8.2-kiloyear event, the researchers report today in the Proceedings of the National Academy of Sciences, the first direct archaeological evidence of this phenomenon. By analyzing other fat-soaked pot sherds from sites around the world, the team adds, scientists will for the first time be able to accurately recreate climate conditions for other ancient societies.

[Angela]

Very interesting.

I also noticed this:

"Additional finds from Çatalhöyük reveal how the farmers adapted to the cooler, drier conditions. Animal bones from that time have a relatively high number of cut marks, suggesting they were butchering for every last edible bit. Cattle herds shrunk while goat herds rose, the authors note, perhaps because goats could better handle drought. Çatalhöyük’s architecture changed, as well, with the site’s iconic, large, communal dwellings giving way to smaller houses for individual families, reflecting a shift toward independent, self-sufficient households.Although these changes underscore humans’ historical resilience in the face of capricious conditions, they also show how even relatively minor climate shifts can fundamentally alter a society, Evershed says."

[Jovialis]

Significance

This study reveals that animal fats preserved in pottery vessels from the United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage site of Çatalhöyük recorded the abrupt 8.2-thousand years B.P. climatic event in their hydrogen isotopic compositions. In addition, significant changes are observed in the archaeology and faunal assemblage of the site, showing how the early farming community at Çatalhöyük had to adapt to climate change. Significantly, this contribution shows that individual biomolecules preserved in ancient animal fats can be used to reconstruct paleoclimate records and thus, provides a powerful tool for the detection of climatic events at well-dated onsite terrestrial locations (i.e., at the very settlements where human populations lived).

Abstract

The 8.2-thousand years B.P. event is evident in multiple proxy records across the globe, showing generally dry and cold conditions for ca. 160 years. Environmental changes around the event are mainly detected using geochemical or palynological analyses of ice cores, lacustrine, marine, and other sediments often distant from human settlements. The Late Neolithic excavated area of the archaeological site of Çatalhöyük East [Team Poznań (TP) area] was occupied for four centuries in the ninth and eighth millennia B.P., thus encompassing the 8.2-thousand years B.P. climatic event. A Bayesian analysis of 56 radiocarbon dates yielded a high-resolution chronological model comprising six building phases, with dates ranging from before 8325–8205 to 7925–7815 calibrated years (cal) B.P. Here, we correlate an onsite paleoclimate record constructed from δ2H values of lipid biomarkers preserved in pottery vessels recovered from these buildings with changes in architectural, archaeozoological, and consumption records from well-documented archaeological contexts. The overall sequence shows major changes in husbandry and consumption practices at ca. 8.2 thousand years B.P., synchronous with variations in the δ2H values of the animal fat residues. Changes in paleoclimate and archaeological records seem connected with the patterns of atmospheric precipitation during the occupation of the TP area predicted by climate modeling. Our multiproxy approach uses records derived directly from documented archaeological contexts. Through this, we provide compelling evidence for the specific impacts of the 8.2-thousand years B.P. climatic event on the economic and domestic activities of pioneer Neolithic farmers, influencing decisions relating to settlement planning and food procurement strategies.

http://www.pnas.org/content/early/2018/08/07/1803607115

[Maciamo]

I have merged the two threads.

That climatic event is probably the reason why Anatolian farmers starting expanding to Southeast Europe 8200 years ago.

[bicicleur]

I have merged the two threads.

That climatic event is probably the reason why Anatolian farmers starting expanding to Southeast Europe 8200 years ago.

the farmers expansions into Europe had allready begun 400 years prior to 8.2 ka
but the 8.2 ka climate event seems to have triggered farmers and herders expansions to Tanscaucasia, Central Asia and Northern Africa

[bicicleur]

Very interesting.

I also noticed this:

"Additional finds from Çatalhöyük reveal how the farmers adapted to the cooler, drier conditions. Animal bones from that time have a relatively high number of cut marks, suggesting they were butchering for every last edible bit. Cattle herds shrunk while goat herds rose, the authors note, perhaps because goats could better handle drought. Çatalhöyük’s architecture changed, as well, with the site’s iconic, large, communal dwellings giving way to smaller houses for individual families, reflecting a shift toward independent, self-sufficient households.Although these changes underscore humans’ historical resilience in the face of capricious conditions, they also show how even relatively minor climate shifts can fundamentally alter a society, Evershed says."

yes, but the 8.2 ka climate event wasn't a relative minor climate shift
temperatures probably dropped by abt 3°C in a very short time

[holderlin]

I have merged the two threads.

That climatic event is probably the reason why Anatolian farmers starting expanding to Southeast Europe 8200 years ago.

Yes, more reliable rain/river levels in general is probably what catalyzed the initial movements North from closer to the Levant as well. Europe has always been very wet compared to where farming originated, which is probably why in 5000-6000BC the largest cities in the world were Balkan farming complexes. An exceptionally dry spell would surely have pushed them further North as word spread.

When did the Mediterranean empty into the Black Sea? I know there's a fringe element that tries to make this event into something that it wasn't, but it surely had to have some effect. I haven't looked at the hard data. You think there would have been some clear myth surrounding such an event, but all we have is a flood that doesn't seem to be associated with such a singular catastrophic event. I'm pretty sure the flood stories talk about rain and rising river levels, which is probably older than Black Sea Deluge when the glaciers started melting catalyzing a wet trend.