A team of scientists say that a large comet exploded over eastern Canada almost 13,000 years ago, causing mass, near-instant extinctions of 35 genera of animals and killing 70 percent of human beings in North America, thus snuffing out the Pleistocene Clovis cultures practically overnight.
Science News Online reports, 
But did the stories of the remnant remaining survive to this day? Perhaps:
Evidence unearthed at more than two dozen sites across North America suggests that an extraterrestrial object exploded in Earth's atmosphere above Canada about 12,900 years ago, just as the climate was warming at the end of the last ice age. The explosion sparked immense wildfires, devastated North America's ecosystems and prehistoric cultures, and triggered a millennium-long cold spell, scientists say. ... Heat from the event would have set off wildfires across the continent, the scientists suggest. The heat and shock from the explosion probably broke up portions of the ice sheet smothering eastern Canada at the time, they add. The flood of fresh water into the North Atlantic that resulted would have interrupted ocean currents that bring warmth to the region, and thick clouds of smoke and soot in the air would have intensified cooling across the Northern Hemisphere.It's been recognized for a long time that at this time the glaciers were in retreat, but that this warming period was followed by a 1,000-year-long mini-ice age, referred to as the Younger Dryas. New Scientist reports
But by 12,900 years ago, the ice had retreated sufficiently from the northern Atlantic coast to let meltwater rush suddenly eastward. As an estimated 9500 cubic kilometres of fresh water poured into the Atlantic, it switched off the ocean's salinity-driven "conveyor belt" current, shutting down the Gulf Stream that carries heat from the tropics to eastern North America. It was this that triggered the Younger Dryas cooling, say many palaeoclimate experts. However, some of the comet proponents now propose a different trigger for the cold spell. The massive airbursts over Canada could have destabilised the continental ice sheet, opening new drainage channels to the east. Additionally, dust and debris from the explosions may have darkened the ice, absorbing solar heat and accelerating melting.But the worst consequence of the cataclysm was the mass extinctions of the late Pleistocene that have heretofore been attributed to overhunting by the Clovis peoples of the continent. The extinctions were additionally blamed on the Younger Dryas. The new impact theory, though, says that the comet's multiple explosions (caused by its breakup in the high atmosphere) themselves caused the extinctions: "at least 35 genera of the continent's mammals went extinct – including mammoths, mastodons, camels, ground sloths and horses." That's 35 whole genera, not just species, that died out. Just at the time of the extinction the researchers found a significant band of soot in sediments from widely-separated sites.
[T]eam members say this suggests the cometary explosions ignited wildfires that swept across much of southern North America, wiping out large populations of animals. "I don't want to sound catastrophic here," he says, "but this is wild stuff. There is significant evidence of massive biomass burning."That is, the genera that perished were burned alive. Based on this and other archaeological evidence, researchers say that 70 percent of the human beings in North America were killed as well. The Clovis cultures disappeared.
But did the stories of the remnant remaining survive to this day? Perhaps: The Ojibwa of the upper Great Lakes region had a story about Genondahwayanung, which meant "Long Tailed Heavenly Climbing Star." During the 1980s, Thor Conway visited the Ojibwa and talked to Fred Pine, an Ojibwa shaman. Pine's story about the creation notes that Genondahwayanung was a star with a long, wide tail which would return and destroy the world someday. He said, "It came down here once, thousands of years ago. Just like a sun. It had radiation and burning heat in its tail." The comet was said to have scorched the earth so that nothing was left, except the native Americans, who were warned ahead of time by Chimanitou, a Holy Spirit, and had gone to a bog and rolled themselves up in the mud to protect themselves from the heat. Pine continued, "It was just so hot that everything, even the stones, were cooked. The giant animals were killed off. You can find their bones today in the earth. It is said that the comet came down and spread his tail for miles and miles." Thereafter, all comet and meteors were treated as serious omens which required the interpretation of the Ojibwa shamans. There are other stories of a great fire coming from the sky and destroying everything except for certain native American tribes. In some cases the tribes claimed they were warned, while others claimed they just ran for the nearest bodies of water.The Indian legends are congruent with the comet theory, especially in the suddenness of the destruction.
That was not in the bible.
Your point being . . . ?
Fifteen years ago I went camping with a glaciologist near Mount Katahdin, in Maine. We talked late into the night about the [then] mystery of the Younger Dryas period, during which we witnessed a once-in-a-lifetime observation of a meteoric fireball traveling from one horizon to the other. How marvelous it's been to follow the story all these years and to then learn of clues from a similar, heavenly bombardment!
I have to admit I'm sort of disappointed the asteroid will miss Mars. Better luck (?) next time.
Who says nothing exciting ever happens in Canada?
Do I have to say anything about how this latest research gives us another push towards building space infrastructure as soon as possible?
The more advanced technology gets, the more interconnected it gets, the more vulnerable humanity gets to an event like that. We need another basket for our priceless eggs.
Interesting. Also note, that the Younger Dryas climatic down-turn is often cited as a "push" that helped cause the origins of agriculture in what's now Israel, Lebanon and Jordan.
This begins to sound a bit like Deus ex machina. It does not explain the extinction of most large mammals in Australia shortly after the arrival of humans.
Here in North America pretty well everything bigger than 100 kg disappeared, except the animals that followed us across the Bering land-bridge from Siberia (elk, etc) who had already learnt to be afraid of humans.
It doesn't require a comet.
As for the ice ... do you know how long it takes for a campfire to melt the ice on a pond? Duration is a key issue. Tungaska (1908) was probably a small comet. It knocked trees down but didn't even burn the trunks.
Melt 3 km of ice? Probably not, eh?
FWIW, my first two degrees are in geology, and I'm even more skeptical about this than "global warming," which is going some.
Bart;
I'm a Hall too, but I read all the words. "Broke up portions of the ice sheet" to create a few channels does NOT equal "melt 3 km of ice".
And what does the entry of humans into Australia 40,000 years ago have to do with this? Nada. Whole different issue, having to do with desertification accelerated by burning off ground cover to hunt animals, etc.
What Australia has to do with North America is that in every documented case of human arrival in a new area the mega-fauna have been hammered into extinction within a geological instant.
In North America the persisting mega-fauna were all of Asian origin and were familiar with man. Odd that the putative comet didn't kill any of them off.
",,, mass extinctions of the late Pleistocene that have heretofore been attributed to overhunting by the Clovis peoples of the continent,,,"
Jared Diamond blames overhunting but I am unaware that he has much support for that view.
Correct me if I am wrong.
Africa's Megafauna are still around. Just saying.
"Jared Diamond blames overhunting but I am unaware that he has much support for that view."
I'm aware of alot of support for many of Jared Diamond's views, but I'm not aware of any factual evidence for them.
But they do have alot of support.
It has been my experience that it takes about 5 seconds for animals to be wary of humans. At least, I have a hard time getting a second shot off.
I'm not sure how much anthropological weight you ought to give to the stories of a shaman named Fred Pine dating from the late Carter administration. That's way too late for oral traditions to not have been contaminated by SF and Fantasy tropes. Lucifer's Hammer had just come out, for one thing.
Seriously, in all seriousness, we should build a time machine so the blazing thing lands in 2008, unless Ron Paul is elected - which might save us anyway, but if not, drop it in washington while american president x is having his/her breakfast.
What a good story. In the old days my elders remembered a story that was told of the days before the sun shined not as brightly. Now the sun shines bright. It is global warming.
as long as it's painless, i'll be fine
How to blame Bush for it will be the biggest question. In fact the universe is expanding at an astonishing rate and I'm sure that's his fault.
Mr. Hall cites the Tunguska comet, and its lack of trunk burning, as one reason to question the North American theory. However, the altitude of neither comet can be deduced accurately after the fact. The Tunguska comet has been generally thought to be a high altitude burst--with the concussion being the main force to hit the trees. The lower the explosion, the more direct heat release. The comet's burst itself could be responsible for the melting/fragmentation in N. America--without relying on an agreeably dubious theory that wildfires melted glaciers.
The Tunguska event does not seem to be an impact event, it may have been a tangent shot with a main body bounced back out of the gravity well. A methane, CO, and CO2 slush ball of 2 to 3 Km in size, calved into many 300 meter daughters, either, slammed or bounced into the ice sheet, would have both impact E_sub_K and a fair Fuel_Air munition component as well, might have left a soot remnant of ultra fine carbon and other ash. Should a ice/gas ball lodge deep in the ice, the outgas zone might persist as a methane fire for some long time while super chilling the water ice as it melts and burns. OR. the slush, at impact, gases, and is flamed in the shock wave as it encounters free O2.
Responding to comment #9- Why are only the human-familiar animals still extant, that is, those from Asia who have experienced man's depredations? Perhaps only those large animals which lived in Eur/Asia could repopulate the N. American continent after the destruction of all large native fauna due to widespread conflagration. European bison, reindeer, elk, moose may have had an opportunity to cross the Bering Strait after the land grew up lush and before the ice age was over globally, closing off their access to the new world. Mankind also could have repopulated the New World though the Clovis culture was destroyed for ever.Endemic species- ground sloths, short faced bears, dire wolves, which were not represented elsewhere, were lost for all time.
Please respond-
Scienceblogs suggests that overhunting may have been true, but can't explain key extinctions from that area because of lack of overlap between human and megafauna territories.
So, yeah, humans can be kind of pestilential once they arrive in an area, but no, that doesn't seem to explain this particular event.
If a laymans hypothesis is worthy of any consideration you'll find a discription of the blast structure at
http://theholocenecomet.spaces.live.com
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