Posted on 08/01/2013 3:35:01 PM PDT by NormsRevenge
New data from Greenland ice cores suggest North America may have suffered a large cosmic impact about 12,900 years ago.
A layer of platinum is seen in ice of the same age as a known abrupt climate transition, US scientists report.
The climate flip has previously been linked to the demise of the North American "Clovis" people.
The data seem to back the idea that an impact tipped the climate into a colder phase, a point of current debate.
Rapid climate change occurred 12,900 years ago, and it is proposed that this is associated with the extinction of large mammals such as the mammoth, widespread wildfires, and rapid changes in atmospheric and ocean circulation.
All of these have previously been linked to a cosmic impact, but the theory has been hotly disputed due to lack of clear evidence.
New platinum measurements were made on ice cores that allow conditions 13,000 years ago to be determined at a time resolution of better than five years, report Michail Petaev and colleagues from Harvard University. Their results are published in the journal Proceedings of the National Academy of Sciences.
A 100-fold spike in platinum concentration occurs in ice that is around 12,890 years old, at just the same moment that rapid cooling of the climate is indicated from oxygen isotope measurements, at the start of a climatic period called the "Younger Dryas".
(Excerpt) Read more at bbc.co.uk ...
“It has been suggested that debris thrown into the atmosphere in an impact tipped the Earth into global cooling at a rate as rapid as the global changes in climate in the reverse direction seen in the last century.”
I call a greentard BS alert.
The Cycle of Cosmic Catastrophes:
Flood, Fire, and Famine
in the History of Civilization
by Richard Firestone,
Allen West, and
Simon Warwick-Smith
Interesting time frame...hmmmm...
——— no impact site has been identified.———
Then there is that statement.
The theory is interesting and something apparently did in fact happen but........ no smoking gun
I read somewhere that we get a major hit about once every 10,000 years (on average) and that is has been almost 13,000 since the last major one
All these recent hits have me a bit worried- we could be going through a ‘patch’ of space that has a bunch- we DID just cross the galactic plane, after all.
would something that size leave much of a crater if it was an ocean hit?
Don’t you watch the doomsday movies. We are fortunate to have Bruce Willis on hand to go up in space and destroy any nasty asteroid that bothers us.
Well, Bruce is getting a little up in years, but Mark Wahlberg is almost ubiquitous in the movies these days so we should be in good hands. Give him a giant laser sniper rifle and a space station to fire from and we’re good.
A collection of links to related FR topics:
A very on-the-nose 45 minute documentary treatment of Barringer Crater (a.k.a. Meteor Crater) with discussions of Sudbury Crater in Ontario, Chicxulub, the Tunguska blast of 1908, and the Clovis-ending event.
Barringer Meteor Crater in Arizona Documentary | Howardites Meteorites | Published on July 19, 2014 | YouTube
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.