Younger Dryas Impact Hypothesis

[Kacmarek]

The YDIH seems to be a highly polarizing topic in which there are 2 competing theories for significant globalmcooling and megafaunal extinction (as well as the disappearance of the Clovis culture in N America) approx 12,800 years ago.

Younger Dryas Impact Hypothesis : a disintegrating comet or asteroid apprpx 4 miles in diameter broke up in the armosphere over N America, Europe, W Asia leading to enormous temperatures and wildfires. Evidence for this has been found in many locations worldwide including prevalence of shocked quartz, platinum spherules etc

https://martinsweatman.blogspot.com/2022/10/wikipedias-bias-younger-dryas-impact.html?m=1

The YDIH posits that fragments of a large (more than 4 kilometers in diameter), disintegrating asteroid or comet struck North America, South America, Europe, and western Asia around 12,850 years ago, coinciding with the beginning of the Younger Dryas cooling event. Multiple meteor air bursts and/or impacts are claimed to have produced the Younger Dryas (YD) boundary layer (YDB), depositing peak concentrations of platinum, high-temperature spherules, meltglass, and nanodiamonds, forming an isochronous datum at more than 50 sites across about 50 million km2 of Earth's surface. Some scientists have proposed that this event triggered extensive biomass burning, a brief impact winter and the Younger Dryas abrupt climate change, contributed to extinctions of late Pleistocene megafauna, and resulted in the end of the Clovis culture.[4][5]

Content from External Source

There are several issues associated with the validation of the hypothesis :

- Several groups have not been able to replicate the results, leading to papers which claim to comprehensively refute the hypothesis once and for all :

Comprehensive refutation of the Younger Dryas Impact Hypothesis (YDIH)​

• July 2023
• Earth-Science Reviews 247(4):104502

• July 2023
• 247(4):104502

Content from External Source

• https://www.researchgate.net/public...n_of_the_Younger_Dryas_Impact_Hypothesis_YDIH

In addition, individuals lije Graham Hancock have utilised this (prima facie serious scentific hypothesis) to make various extraordinary claims about ancient advanced civilizations

There is a Cometary Research Group (CRG), whose members are seen to be proponents of the hypothesis. Opponents try to portray them as opportunistic and unscientific

Prima facie, careful examination of evidence should lead us to the scientifically rigorous result. But since the publication of the original paper by Firestone et al in 2007 in the Proceedings of the National Academy of Sciences, no less

https://www.pnas.org/doi/10.1073/pnas.0706977104

Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling​

R. B. Firestone rbfirestone@lbl.gov, A. West, J. P. Kennett, +22, and W. S. WolbachAuthors Info & Affiliations
October 9, 2007
104 (41) 16016-16021

Content from External Source

The list of proponents and opponents has continued to grow

Seems to be a genuine scientific controversy

 

[RTM]

From watching some of rebuttal videos on Hancock's recent tv show I got the impression that some scientists aren't necessarily against the idea, the thing about Hancock's claim is that you can have an impact without it wiping out his Atlantis supermen.

 

[Ann K]

From Wikipedia, the competing hypothesis:

It is an alternative to the long-standing and widely accepted explanation that it was caused by a significant reduction in, or shutdown of the North Atlantic Conveyor due to a sudden influx of freshwater from Lake Agassiz and deglaciation in North America.

Content from External Source

The draining of large lakes due to melting of the ice dams that created them is a well-accepted cyclic phenomenon as the temperature rose and fell. Glacial lake Missoula drained west a number of times to create the "channeled scablands" of Washington State, while huge glacial Lake Agassiz drained the other direction, and caused sea levels to rise to the extent that it is believed to be the cause of the submerging of Doggerland on the other side of the Atlantic, and thus the separation of Britain from continental Europe.

But the Storrega slide, an undersea subsidence off Norway that caused a large tsunami, is also believed to have played a part in the destruction of Doggerland. There is no reason why a comet could not have similarly played a part in the Younger Dryas period. It would be naïve to think that a geological event must have one and only one cause. I understand why various researchers might vigorously defend their own pet hypotheses, but major events are rarely that simple.