Posted on 10/17/2005 8:57:32 AM PDT by Fzob
Sept. 28, 2005— A supernova blast 41,000 years ago started a deadly chain of events that led to the extinction of mammoths and other animals in North America, according to two scientists.
If their supernova theory gains acceptance, it could explain why dozens of species on the continent became extinct 13,000 years ago.
Mammoths and mastodons, both relatives of today's elephants, mysteriously died out then, as did giant ground sloths, a large-horned bison, a huge species of armadillo, saber-toothed cats, and many other animals and plants.
Richard Firestone, a nuclear scientist at the U.S. Department of Energy's Lawrence Berkeley National Laboratory, who formulated the theory with geologist Allen West, told Discovery News that a key piece of evidence for the supernova is a set of 34,000-year-old mammoth tusks riddled with tiny craters.
The researchers believe that in the sequence of events following the supernova, first, the iron-rich grains emitted from the explosion shot into the tusks. Whatever caused the craters had to have been traveling around 6,214 miles per second, and no other natural phenomenon explains the damage, they said.
They think the supernova exploded 250 light-years away from Earth, which would account for the 7,000-year delay before the tusk grain pelting. It would have taken that long for the supernova materials to have showered to Earth.
Then, 21,000 years after that event, the researchers believe a comet-like formation from the supernova's debris blew over North America and wreaked havoc.
Firestone said they think the formation created superheated hurricanal winds in the atmosphere that rolled across North America at 400 kilometers per hour (about 249 mph).
"The comet (-like event) was followed by a barrage of hot particles. If that didn't kill all of the large animals, then the immediate climate changes must have," said Firestone.
Firestone said smaller animals could have sought shelter more readily, by going into caves or underground.
The findings were presented at last weekend's "World of Elephants" international conference in Hot Springs, S.D.
In addition to the tusk evidence, the scientists said arrowheads from North America's prehistoric Clovis culture, which went extinct around 13,500-13,000 years ago, Icelandic marine sediment, as well as sediment from nine 13,000-year-old sites in North America, contain higher-than-normal amounts of radiation in the form of potassium-40 levels.
Potassium-40 is a radioactive isotope, meaning a molecule that emits radiation.
Magnetic particles also were unearthed at the sites. Analysis of these particles revealed they are rich in titanium, iron, manganese, vanadium, rare-earth elements, thorium and uranium.
These elements all are common in moon rocks and lunar meteorites, so the researchers think the materials provide additional evidence that North America was bombarded 13,000 years ago by material originating from space.
Luann Becker, a University of California at Santa Barbara geologist, told Discovery News she was not surprised by the new supernova theory, since extinction events have been linked to similar comet or asteroid impacts before.
"What is exciting about Dr. Firestone's theory is that it can be easily tested," Becker said, and indicated she hopes future research will yield additional clues from North American and other sediment layers.
Evidence sounds pretty slim.
An event of that magnitude, if it was major enough to leave pits in mammoths tusks, would be marked in the rocks all over the world.
We could probably even figure out where the star was and almost exactly when it happened.
Guest Workers.
That guy's just showing off. And I'm not going to ask how he goes to the bathroom. Or where. ;')
I agree, and for that matter, do the scientists have an explanation for why the ice age glaciers covered nearly half of North America, much of Europe, but almost none of Siberia, when Siberia is colder than the other two places today? I suspect it has something to do with the north magnetic pole being on the Canadian side of the Arctic.
The true ending of "Footfall."
Why would people go to South Dakota to hold a conference on elephants? It makes even less sense than having a scuba diving school in Phoenix, AZ.
This can mean only ONE thing!That"Mother Nature"(under the direction of The Almighty)needs to be INDICTED by The EPA(AlGore)!!!!!!!!!!!!!
The extinction of these creatures is a problem of mammoth proportions.
Didn't you hear, Al Goreghoul is gonna prevent this from happening again? The supernova I mean ... he is the 'global warming cowboy' don'tchaknow.
Look for further developments as Clovis sites are excavated further (they had stopped digging because Clovis was the oldest--in a fine example of circular reasoning) and new finds come to light.
Humans may go back much farther on the continent than previously assumed.
You make a false assumption, that the material of the star would be evenly ejected and have no clumping.
My view is that the glaciations didn't happen (nor will future ones) due to gradualist, uniformitarian causes.
"Humans may go back much farther on the continent than previously assumed."
http://web.archive.org/web/20030508081345/http://www.crystalennium.com/myth/science/man_in_america.htm
may be of interest...
Thanks for the link.
That makes absolutely no sense. A scientific theory is by definition more than an educated guess.
Yes, thanks.
Did Dave Barry ghostwrite this?
Yet the bison in North America, even though they were harassed, were pretty much safe from the Indians.
Until two things showed up here:
Horses and
Firearms
I used to believe the "they were hunted into extinction" idea but it doesn't hold out. There was something more involved, climate change, some sort of catastrophe, whatever...
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