Posted on 06/02/2006 11:44:43 AM PDT by cogitator
An apparent crater as big as Ohio has been found in Antarctica. Scientists think it was carved by a space rock that caused the greatest mass extinction on Earth, 250 million years ago.
The crater, buried beneath a half-mile of ice and discovered by some serious airborne and satellite sleuthing, is more than twice as big as the one involved in the demise of the dinosaurs.
The crater's location, in the Wilkes Land region of East Antarctica, south of Australia, suggests it might have instigated the breakup of the so-called Gondwana supercontinent, which pushed Australia northward, the researchers said.
"This Wilkes Land impact is much bigger than the impact that killed the dinosaurs, and probably would have caused catastrophic damage at the time," said Ralph von Frese, a professor of geological sciences at Ohio State University.
How they found it
The crater is about 300 miles wide. It was found by looking at differences in density that show up in gravity measurements taken with NASA's GRACE satellites. Researchers spotted a mass concentration, which they call a mascon—dense stuff that welled up from the mantle, likely in an impact.
"If I saw this same mascon signal on the Moon, I'd expect to see a crater around it," Frese said. (The Moon, with no atmosphere, retains a record of ancient impacts in the visible craters there.)
So Frese and colleagues overlaid data from airborne radar images that showed a 300-mile wide sub-surface, circular ridge. The mascon fit neatly inside the circle.
"And when we looked at the ice-probing airborne radar, there it was," he said today.
Smoking gun?
The Permian-Triassic extinction, as it is known, wiped out most life on land and in the oceans. Researchers have long suspected a space rock might have been involved. Some scientists have blamed volcanic activity or other culprits.
The die-off set up conditions that eventually allowed dinosaurs to rule the planet.
The newfound crater is more than twice the size of the Chicxulub crater in the Yucatan peninsula, which marks the impact that may have ultimately killed the dinosaurs 65 million years ago. The Chicxulub space rock is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide, the researchers said.
Confirmation needed
Postdoctoral researcher Laramie Potts assisted in the discovery.
The work was financed by NASA and the National Science Foundation. The discovery, announced today, was initially presented in a poster paper at the recent American Geophysical Union Joint Assembly meeting in Baltimore.
The researchers say further work is needed to confirm the finding. One way to do that would be to go there and collect rock from the crater to see if its structure matches what would be expected from such a colossal impact.
30 miles wide?!
ouch
No, we got all those in FSU............Florida State Criminoles.......
This impact was before there were dinosaurs.
Penn State 17 the Ohio State U. 10.
Just a pair of cosmic coincidences that two gigantic colliders impacted the earth at two times of massive volcanic upheavals and two mass extinctions?
Maybe the collisions set off the volcanism which caused the climate change.
You forgot to add "against all logic".
A global extinction of all critters bigger than a dog (except for the cold-blooded reptiles which could 'hibernate' through the global winter without having to eat for a year or more if necessary)is not going to be caused by "climate change" or "increased volcanism".
Actually, it was indeed caused by the temporary "catastrophic climate change" caused by the impact of the Yucatan asteroid (According to an Indian scientist, there may have been another simultaneous impact in Asia, presumably from the original object breaking up before impact, but that has not yet been proven as fact...)
If religion did not exist at all, too many in the current crop of self-promoting doofuses, who call themselves "scientists", would make perfect fools of themselves without any help whatsoever, thankyouverymuch.
I think he was referring to the other impact crater, Mike, Chicxulub...
"They" say something enough times and it's fact. You know, like "Teddy is a congressman, Teddy is a congressman, Tedd...." --- oh, well.
This is close:
In Extinction Debate, Dinosaurs and Science Writers are the Losers
Princeton Paleontologist Produces Evidence For New Theory On Dinosaur Extinction
This is from 2003 and I thought I had seen something much more recent. Keller has published more recent stuff, so that may be what I'm thinking of. The jury is still out; I think the Chicxulub impact had to contribute, but how much ?
I have one big problem with that. From what I remember, the K/T iridium layer gets thicker the closer you get to Chicxulub -- and there is only one K/T iridium layer, as far as I know. So if the K/T iridium layer is not due to Chicxulub, why doesn't it thicken in a direction other than toward Chicxulub? I have no idea.
Nancy Pelosi toured the devastated area...
Was she there before or after McCain and Hill toured it and said there was 'devastation as far as the eye could see'?
The Chicxulub Impact and Its Relation to the K/T Boundary
The meeting where these papers were presented was last week, so this is hot off the press.
ping
Obviously, this meteor was cast from one the Flying Spaghetti Monster's Sacred Noodly Appendages!
So let me get this straight -- in post #21, you snottily sneer at the scientists for what you saw as being too much confidence in the dinosaur/meteor scenario, and then after you bothered to read the article you found that they had in fact described it in more qualified terms, then you used *that* as an excuse (in post #24) to snottily declare that it's hard to take them seriously these days, and you even derisively put "scientists" in "scare quotes".
Given that you "found" reason to attack them *both* ways (i.e. for supposedly being certain, then for *not* being certain), which makes it clear that nothing they can say will keep you from saying obnoxious tbings about them, why don't you just come out and admit that you just despise scientists in general no matter what they might say or not say, and leave it at that?
The people who are truly "hard to take seriously" are the folks who inevitably feel a need to pop onto all the science threads to express their knee-jerk feelings about science and the people who work in it. It gets a little old after the 800th time.
LOL! The Scientific Method as taught to me in the 7th Grade is dead.
No, it isn't. But I need a good laugh today, feel free to share with us your "reasons" for saying such a goofy thing.
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