"I told you, we were framed!"
Posted on 05/16/2007 3:00:33 PM PDT by Mike Darancette
An extraterrestrial impact 13,000 years ago wiped out mammoths and started a mini-ice age, scientists believe
Margaret Munro CanWest News Service
Monday, May 14, 2007
A comet or some other extraterrestrial object appears to have slammed into northern Canada 12,900 years ago and triggered an abrupt and catastrophic climate change that wiped out the mammoths and many other prehistoric creatures, according to a team of U.S. scientists.
Evidence of the ecological disaster exists in a thin layer of sediment that has been found from Alberta to New Mexico, say the researchers, whose work adds a dramatic and provocative twist to the decades-old debate about the demise of the mammoths, mastodons and sloths that once roamed North America.
The sediment layer contains high concentrations of iridium, fullerenes and other compounds associated with space rocks and impacts, says Luann Becker, a geologist at the University of California, Santa Barbara, who has been analyzing the sediments.
"We have evidence for distribution of impact debris over several thousands of miles over the North American continent," says Ms. Becker, whose group will detail the findings at the American Geophysical Union meeting on May 24.
The sediment layer formed 12,900 years ago and coincides with both the extinction of the animals and the onset of a mini-ice age that lasted more than 1,000 years, say Ms. Becker and her colleagues from several U.S. universities and research labs. They say they are increasingly convinced the impact, extinction and cold snap are all related.
According to their scenario, a comet or large meteoroid generated a shock wave and threw massive amounts of debris, heat and gas into the atmosphere. This set off wildfires that raced across grasslands in southern North America, depriving the mammoths and other grazing animals of food.
The impact and heat also destabilized the ice sheet that blanketed Canada at the time, creating a flood of melt water that poured into the North Atlantic, according to their theory. The pulse of fresh water then shut down the ocean currents carrying heat from the tropics to the Northern Hemisphere, leading to an abrupt cooling. The resulting "mini-ice age" in the Northern Hemisphere, known as the Younger Dryas, lasted more than a thousand years.
Until now one of the leading explanations for the disappearance of the mammoths and other animals is that they were hunted to extinction by the people who arrived in North America from Asia at least 13,000 years ago.
But Ms. Becker and her colleagues doubt there could have been enough people to drive the creatures to extinction with spears. "It would have been a real challenge to slaughter all the animals," she says.
The leading explanation for the mini-ice age has been that melt water slowly built up behind the ice dams as the Earth warmed at the end of the last ice age and then suddenly burst, sending fresh water pouring into the North Atlantic.
Skeptics are not convinced an extraterrestrial impact explains either the disappearance of the animals or the mini-ice age, let alone both events.
Climatologist Andrew Weaver of the University of Victoria says the notion that an extraterrestrial impact caused the Younger Dryas "requires an extraordinarily huge leap of faith." He says there were many climate swings during the last glacial cycle; the mini-ice age was simply the last of them and does not require an extraterrestrial explanation.
Geophysicist Jerry Mitrovica at the University of Toronto is also skeptical. "I'll wait to see the published papers," says Mitrovica, who has studied how the melting ice helped trigger the miniice age.
While the idea of a comet impact may seem far-fetched, Mr. Mitrovica notes that it took almost a decade before scientists accepted geologist Walter Alvarez's evidence that the iridiumrich layer he found pointed to the asteroid impact that killed off the dinosaurs 65 million years ago.
Ms. Becker says the details of their findings will likely be published in the science journals this summer. Meantime, she and her colleagues are expecting a "spirited" debate at next week's AGU meeting.
She says the concentration of the iridium in the sediment layer dating back to 12,900 years is several times higher than normal. It also contains compounds called "fullerenes" with extraterrestrial gases in them, as well as glasslike carbons that require extraordinarily high temperatures to form. "It's a very discrete, well-defined layer," she says.
As for the crater created by the impact, the scientists say it would have formed on the kilometres-thick ice that covered Canada at the time and melted away with the ice.
Entertaining story for physicists on lunch break, but the story has not been completely accepted.
Exactly
I listened to you, mainly because it was a logical, common sense conclusion.
The immensity of it all amazes me sometimes. The Earth has been here for so very long. And yet, we are the first to be able to think and wonder.
A comet expoding over Canada wouldn’t explain the extinctions of megafauna in South America that happened at about the same time.
Here in the Pacific NorthWest we have ample evidence for the floods, up to 120, that created the WA state scablands and deepened the Columbia River. All of the western Montana valleys were full of meltwater, held back by an icedam near Thompson Falls. Periodically it would break, sending cubic miles of floodwater racing to the pacific. Spokane falls is a result of that deluge/gouging action.
Mt Saint Helens happened in 1980, there is ample proof of a 300 foot high wave that hit the Olympic peninsula/Pac NW coast hundreds of years ago, caused by the Cascadia fault. Point : natural forces operate on their own timescale, chicken little algore and his fearmongering has nothing to do with causing it, it’s Mother Nature doing her thing.
I couldn't agree more.
We experience the El Nino phenomena every few years, and scientists still haven't determined its cause. My own theory is that it is caused by a "hot spot" of magma below the crust in the Pacific Ocean. Some tremendous heat source is required to raise the temperature of the ocean by 3-5 degrees.
You might have something there. You know of course about diapurs(not baby diapers) and hot spots. The fixed hot spot out in the middle of the pacific plate causes the hawaiian island chain. Even now the new volcano south of the big island is a third of the way to the surface.
Diapurs are sort of like low 9 cumulonimbus thunderhead clouds of hot rock welling up from deep in the mantle, possibly the outer core/mantle interface. In Hawaii it breaks thru the thin oceanic crust but here, in these 2 warm pools of water, it may not be strong enough to break thru but spread under the crust like that thunderhead.
Easily checked though : measure heat flows directly under these 2 ocean pools of warm water, all the way down to the ocean floor. It is only 2 things, either geothermal or a solar heating gyre that forms in much the same way as the great red spot on jupiter, or the sargasso sea gyre.
Interesting point though, el nino COULD be caused by geothermal diapurs...go LOOK.
But it's amazing what a little common sense, applied to some basic information, can accomplish. It was the awareness of the hotspot forming the Hawaiian Islands that led me this conclusion, plus observation of lava lamps, lol.
I am not familiar with the term diapur, but I am going to investigate this, particularly the information about the area south of the Hawaiian chain.
Thanks.
I have read about the evidence for the Cheetah going through a genetic bottleneck, as well.
It accounts for their extreme photogenic appeal, in that they are virtually identical and make fascinating group photos.
Do you think that members of the transgendered community, which you so negligently failed to mention, are not as adversely effected as those other groups?
Ah yes, HAWAII : spent about 5 winters in a row there as my mother’s companion. For about 20 years(winters)she led a singing group on waikiki beach, sort of an aloha-welcome wagon thing. Ukes, leis, hawaiian dancing on the sun-splashed shore. It REALLY pays off in FEBRUARY when you know back home they are freezing their bippies off.
Yes, unique place and people come from all over the world to be there. I did get to visit the observatory on mauna kea one year. It is in fact the largest mountain on the earth as the base starts 2 miles on the ocean floor, peak at 13,800’. In addition to astronomy they do geotechnical work there as well. They send me periodic announcements.
The activity at the kiluaea crater, on the south shore of the big island, has been tapering off in recent years; the hotspot/diapur lava flow is shifting more to the new volcano to the south. Wait a million years and you’ll see it break thru the ocean’s surface.
Which just goes to show that the earth is doing its dynamic, organic thing; volcanism occurs on venus, mars, jupiter’s moon Io, elsewhere; and those planets never heard of algore and his “we’re the center of the universe” nonsense. Volcanos will continue erupting, earthquakes will continue a-shaking wheather you pray to the earth as a god or see it as fraternal twin to venus that got a lot of lucky breaks, for us.
Funny, even though LAND is limited in HI, the natives wouldn’t even THINK of grinding up fresh lava flow-fields, to make fertile fields, that’s sacred pele’s breath. Hey, you can’t even WALK on that ****, it’s like broken glass. It would take you an HOUR to get 100’ on it. So, folks like that are algore’s natural prey....
Hmmmm.... You’re on to something. You could even drink a Sam Adams with Sam Adams!!!!!
There were some who rejected it, and those still alive may here and there still reject it. But hey, the debate is over... ;’)
Some of my best friends are transgendered and should Halliburton Ice Dam let go again, rest assured that I shall immediately surrender my seat on the rescue helicopter to him/her/it.
The "Out of Africa" thesis rests on a count showing that Africans have many more types than do other groups, and that all types have a source or counterpart (little changed) among Africans.
By conveniently forgetting about this comet which killed off tens of thousands of small settlements and tribes throughout the Northern Hemisphere, the sample got biased.
It's pretty clear that Africans would end up with more types of mitochondrial DNA than others simply because they weren't eradicated by the comet.
In fact, the latest "trail" out of Africa hypothesized by analysts in the field looks more like the outer limit of a blastzone than it does a "trail".
The Sa'ami and Eskimo ability to deal with vast quantities of seal meat and sea mammal fat suggests that at some point the only folks to survive the comet were hidden in caves, or under cliffs, and when they emerged there was nothing to eat but sea mammals.
"In fact, the latest "trail" out of Africa hypothesized by analysts in the field looks more like the outer limit of a blastzone than it does a "trail".
With all the DNA testing that is presently going on, I expect some real suprises in the next few years.
Astrologists and diviners are not scientists, they are charlatans to a man.
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