Antarctic Blast Made Australia, Room For Dinosaurs 122
Agent Provocateur writes "Posted on the Science Daily site is a story from Ohio State University about a massive Antarctic blast that may have contributed to the Permian-Triassic extinction." From the article: "Its size and location -- in the Wilkes Land region of East Antarctica, south of Australia -- also suggest that it could have begun the breakup of the Gondwana supercontinent by creating the tectonic rift that pushed Australia northward. Scientists believe that the Permian-Triassic extinction paved the way for the dinosaurs to rise to prominence. The Wilkes Land 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 meteor is thought to have been 6 miles wide, while the Wilkes Land meteor could have been up to 30 miles wide -- four or five times wider."
hollywood disaster movies (Score:2, Interesting)
Re:hollywood disaster movies (Score:3, Informative)
Re:hollywood disaster movies (Score:2, Informative)
Even bigger than you think. Current theory (speculation/whatever) says that the Earth-Moon system was created a few billion years ago when something the size of Mars smacked into the (pre) Earth. And it still wasn't destroyed - just changed a bit.
Of course, if that happened now even the bacteria would be *severely* upset about it.
Spelling Nazi alert: You mean "physically".
Re:hollywood disaster movies (Score:2)
Of course, if that happened now even the bacteria would be *severely* upset about it.
I for one would be slightly pissed as well.
This is my home too.
Re:hollywood disaster movies (Score:5, Funny)
Double-Edged Disasters (Score:3, Informative)
This is the Caloris Basin and, on the opposite side of Mercury, some very strange topography that is usually called "weird terrain".
The explanation is the the shock waves from the impact that created Caloris converged on the opposite side of Mercury and tore the landscape to pieces.
Well, Mercury is small and internally much cooler than Earth, so Mercury has a thick crust while the Earth's c
Re:Double-Edged Disasters (Score:2, Interesting)
I think the two areas were (approximately) at quadrature - 90 degrees apart, not in opposition.
More evidence for this sort of Double Disaster comes from the Chixulub impact, which, when it happened, it is known that India was on the opposite side of the world, and the "Deccan Traps"
OAQ (Score:1)
That may be true, but the bacteria didn't pay for it, now did they?
Re:hollywood disaster movies (Score:2)
Re:hollywood disaster movies (Score:1)
Forget the bacteria. It's the mice that would be absolutely FURIOUS about such a monumental cock-up.
cya,
john
Re:hollywood disaster movies (Score:2)
Re:hollywood disaster movies (Score:2)
Re:hollywood disaster movies (Score:2)
Re:hollywood disaster movies (Score:2)
Re:hollywood disaster movies (Score:2)
Perhaps true; on the other hand, the P-T extinction event wiped out better than 90% of sea species, and 70% of land species. It didn't kill the planet, but it came closer than anything since the formation of Luna.
On the gripping hand, getting rid of the extremophile bacteria as well would pretty much requires re-liquification of the entire planetary crust for a multi-century timescale.
Antarctic Blast Made Australia, Room For Dinosaurs (Score:2, Funny)
Wow, I knew some dinosaurs were big, but I didn't realize they were that big!
Re:Antarctic Blast Made Australia, Room For Dinosa (Score:3, Funny)
You know Clippy, that sort of non-sequiter was why we kicked you out of the Office help system. Don't make us do it again...
Re:Antarctic Blast Made Australia, Room For Dinosa (Score:1)
Re:Antarctic Blast Made Australia, Room For Dinosa (Score:1, Informative)
Age of impact (Score:3, Insightful)
They are guessing that it was in the last 250 million years because they can still detect a mass concentration. I wonder if it is possible to drill to the bottom of an ice cap and then drill into the underlying crust. Doing that may make it possible to accurately date the impact.
Ice drills in my experience melt a hollow cylinder of ice and then extract the core. Presumably they would have to do this down to the surface and send a traditional drill down.
Re:Age of impact (Score:1, Funny)
1. Melt Ice caps.
2. Do research.
3. Profit!
Re:Age of impact (Score:1)
Re:Age of impact (Score:1)
One does not have to beleive that Gore is completely altruistic and all Republican self-serving ignoramuses, to believe that Gore is somewhat (relatively to the population of politicians) altruistic, and the current Reublican leadership are self-serving ignoramuses and/or sociopaths .
Just because they're both shades of
Re:Age of impact (Score:2)
Re:Age of impact (Score:3, Interesting)
It may in fact end up being simultaneous with Chicxulub which by most recent estimates was not enough in itself to kill of the dinosaurs. Something else helped it.
So the "mummy dinosaur says to toddler dinosaur: what goes around comes around" joke will have to wait for now.
Re:Age of impact (Score:1)
Re:Age of impact (Score:4, Interesting)
It's been done in the Arctic Ocean, Nature reported recently. [nature.com]
"The results are unexpected. Not only did the Arctic heat up to an extent that is inexplicable by current climate models, say the researchers, it also seems that the North Pole began to cool at about the same time as the Antarctic. This timing suggests that climate was being driven by a global factor, such as atmospheric levels of greenhouse gases, rather than something more local, such as geological upheaval."
Re:Age of impact (Score:2)
Problems with drilling (Score:3, Informative)
One of the problems is that the ice is not lying still during the time that you are drilling, the ice creeps. That is once of the reasons why all the major drillings through ice are done on the top of the ice sheets where the movements are the least there.
The problem with Ice creep is pretty big, it is for example not possible for scientist to come back to the hole's they drilled before, like you do with holes in the earth, the holes shut
Re:Problems with drilling (Score:2)
Its not easy, I agree. Glaciologists I used to work with would drill a hole then drop instruments down it to measure differences in ice flow at different depths. I am sure that eventually a hole would become unusable as shear forces moved it away from vertical.
The RTG powered "mole" devices being planned for Europa might work in this environment. It would certainly be a good test, but developing something like that can take > 10 years.
Re:Age of impact (Score:1)
Re:Destroying or creating life? (Score:4, Interesting)
The conditions we currently think led to abiogenesis (the pre-evolutionary formation of life) weren't cataclysmic, they were merely improbably chemical reactions that might have arisen on the primordial earth - just a matter of something with a low probability having a few hundred million years to occur by chance in, in an environment with no pre-existing competeing lifeforms and plenty of potential habitat.
Now mind you, any major change in the ecology will open up new niches for creatures to evolve into, so in that sense an impact "creates new life", but that is exactly what the article is talking about. The mass die off precipitated by such an impact let the dinosaurs get started. The cretaceous die off got rid of the dinosaurs in turn, and let mammals take the top spot.
Re:Destroying or creating life? (Score:2)
Great. I'm baked out of my mind and paranoid that we're all next.
Thanks a lot.
Re:Destroying or creating life? (Score:2)
Re:Destroying or creating life? (Score:2)
Yeah. Like you were there.
Re:Destroying or creating life? (Score:3, Interesting)
It wasn't quite like that. The die-off simply got rid of most large animals (probably the ones that couldn't burrow or hide in some way to avoid several hours of intense heat after the impact). Some small dinosaurs carried on fine - today we call them birds! Also, for some periods in wasn't mammals that took the top spot - large birds have often been the major predators. Things are far, far more interesting that s
Re:Destroying or creating life? (Score:2)
But OTOH, it's been a long time since I was learning this, so new evidence might have emerged since then, or my memory could be wrong.
Re:Destroying or creating life? (Score:2)
It is still very much debated, but my impression is that birds are basically therapod dinosaurs - the bone structures are very close. There is considerable evidence that dinosaurs has warm blood as well.
My interpretation i
more importantly (Score:1, Funny)
Re:more importantly (Score:5, Funny)
Mr. President, shouldn't you be working on a plan to get us out of Iraq, rather than posting on slashdot?
Bullshit. (Score:4, Funny)
Re:Bullshit. (Score:2)
"I never said Thou Shalt Not Think."
Re:Someone to study it (Score:2)
~X~
not as clear-cut as the article makes it out (Score:4, Interesting)
But the situation is much murkier with the Permian extinctions. Last I'd heard, we have yet to find clear evidence of an impact in the form of iridium, a dust layer or shocked quartz. So that sheds some doubt on the idea of an impact. Even if this is an impact crater, we don't know for certain that it dates to the time of the end-Permian mass extinctions: obviously, if it didn't occur at the same time as those extinctions, it couldn't have caused them. Given that the researchers are using radar and gravitometry, how do they know how old it is? You need to either do radiometric dating or look at the fossils to tell how old the underlying and overlying rocks are.
There is also some evidence that the Permian extinctions may have been drawn out, with several bouts of extinction occurring over the course of a million years or so, again that doesn't fit with an meteorite/comet impact. Anyhow, it might have been an impact, and it might not have been. It's still a mystery and probably will be for quite a while.
Re:not as clear-cut as the article makes it out (Score:5, Informative)
Xu and Yang, 1993 and Yang et al. 1995 have reported Iridium spikes and Stishovite microspherules in non-marine P/T sediments in Australia and Antarctica. There's no Permian oceanic crust left since all of it has been subducted, and the Iridium and Stishovite levels are an order of magnitude smaller than C/T sediments, but it is still evidence of some type of major impact.
Re:not as clear-cut as the article makes it out (Score:2)
Re:not as clear-cut as the article makes it out (Score:2, Informative)
Re:not as clear-cut as the article makes it out (Score:2)
No, it's not. It's pretty clear that there was a significant impact that coincided with the decline of the dinosaurs, but coincidence is not the same as causality.
The asteroid did not cause the continents to continue their drift, widening the gap that would become the Atlantic Ocean. It did not cause the drainage of the shallow inland seas that enhanced a dinosaur-friendly climate. The asteroid did
Re:not as clear-cut as the article makes it out (Score:2)
Dinosaurs are not so easy (Score:2)
Toss in a few things like Coelacanth [wikipedia.org] and dinosaur ages start to get seriously murky. A friend of mine accidentally bought one of those in an Indonesian fish market, it was on the table with everything else and (apparently) often is, there.
Then we have this new crash-bang which would be difficult to label a non-meteor, and b
Thanks (Score:1)
Prehistoric Math (Score:1)
It bothers me that that calculation isn't quite as definate as it should be. I've yet to see 30/6 = 4.
Re:Prehistoric Math (Score:2)
Re:Prehistoric Math (Score:1)
Re:Prehistoric Math (Score:2)
Re:Prehistoric Math (Score:1)
Re:Prehistoric Math (Score:4, Funny)
Obligatory Anime Reference. (Score:5, Funny)
Re:Obligatory Anime Reference. (Score:1, Funny)
Re:Obligatory Anime Reference. (Score:2)
Never mind Asuka. She'd done her bit: chopped up all nine Mass Production Evas and run out of power. Nothing she could have done against a spear out of nowhere.
Now Shinji, on the other hand... he finally gets into EVA-01, comes out of HQ in a massive explosion taking out the entire top of the pyramid - and proceeds to just stand there screaming. Doesn't lift a finger to even try to stop the Evas skewering him and in
Re:Obligatory Anime Reference. (Score:2, Funny)
I never got it (Score:1)
What did it kill to pave the way for the dinosaurs? Orcs? Oompah Loompahs?
Do the chickens have large talons?
Boy, I didn't understand a word you just said.
Ecological niches (Score:3, Insightful)
Re:I never got it (Score:2)
September 13, 2000 (Score:1)
Re:September 13, 2000 (Score:1)
March 30 2001 (Score:1)
Thank you! (Score:5, Funny)
Thank you for for adding that! Saved us all the trouble of pulling out slide rules to work out that ugly divison problem ourselves!
-
Re:Thank you! (Score:2)
(seriously though, 30 miles sounded more interesting than 24 miles, so they used the bigger number?)
Re:Thank you! (Score:3, Informative)
In other words, if it hit at anywhere close to the same speed, this one was A LOT more destructive.
Re:Thank you! (Score:1)
Re:Thank you! (Score:1)
Nope, Malor specified "six times as wide", which leads to 216 times as massive, ceteris paribus.
Re:Thank you! (Score:2)
Re:Thank you! (Score:2)
Re:Thank you! (Score:1)
My sliderule which is made of bamboo, I might add, not your shitty plastic substitute. No, alas, it's not a Versalog.
Notes (Score:3, Informative)
http://en.wikipedia.org/wiki/Chicxulub_Crater [wikipedia.org]
Re:Notes (Score:1)
30 miles = 48.28
Re:Notes (Score:2)
First Impact (Score:1)
A scientific organization named GHERIN has established a base in Antartica to study the phenomenom that they call "the first impact".
Is gravimetrics really this efficient? (Score:3, Interesting)
As far as I know from my the few classes I have had on gravimetric data without the help of other data you are usually pretty lost. It would be very difficult to say how deep, what size and what weight anamoly the gravimetric anomily has and even more make out it's shape.
Furthermore with these gravimetric data taken from a satelite and not from the surface you get even more "meaned data" (less precise) being further away from the anamoly I can figure, of course they probably have a huge data set and also extremely precise instrumentation at the satelite in space, maybe that makes up for the distance in some ways, but for now I remain very sceptical.
Another thing that makes me wonder is why they don't talk about doing seismic or seismologic checks to confirm their theory. I actually thought that there was a few seismic stations places in this region, if this anamoly is as huge as the article suggests then I would think it should be pretty clearly visible in the seismic data.
Anyhow gravimetrics is certainly not my area of expertise. I would if someone out there is able to show me where I go wrong if that is the case, then I'd be grateful.
Re:Is gravimetrics really this efficient? (Score:2, Insightful)
it missed... (Score:2)
Re:it missed... (Score:1)
Freudian slip from an evil scientist with scary plans? Time to sell my Ohio real estate.
Thinking.... (Score:1)
didnt a "explosion" happen due to the first angel?
OH NO!! build EVAs!!
Flash of light (Score:3, Interesting)
Comparing the widths of the meteorites is a lot less interesting than realizing that the mass ratio is about 125:1. Actually I suspect that the mass was estimated first from the size of the crater and then the diameter calculated, converted from metric to American, and the word "diameter" changed to the more easily understood "width".
Re:Flash of light (Score:3, Informative)
If we're going to be pedantic, something is a meteorite only if it strikes the earth. A meteor is merely an object from space (man-made satellites usually excluded) that enters the Earth's atmosphere, and may or may not become a meteorite--most meteors are too small and completely burn up/disintegrate before hitting land.
Link to OSU research (Score:4, Informative)
If you want to "experiment" with results of various impacts, Arizona State has an online calculator [arizona.edu].
Math Whiz (Score:1)
What A Wonderful Time It Was To Be Alive ... (Score:3, Interesting)
A couple of years ago an entirely different impact crater was discovered in Australia [ucsb.edu], with preliminary dating indicating that it happened at about the same time as this one. It, too, is huge -- not as monstrous as this here Antarctica sockdollager, but apparently about as apocalyptic as the one that reputedly KO'd the dinosaurs. Considering the history of our Solar System, I don't think that a multiple-impact armaggedon is at all out of the question. Hell, maybe we'll find even more impact craters, and have to come to the conclusion that it was some kind of supersized rain of fire that reset the planetary ecology switch.
And then, of course, we shouldn't forget about the largest volcanic eruption in the history of the planet [le.ac.uk] that sparked up at just about the same time, too. An area roughly the size of Scandinavia simply melted into a mass of sulfurous, poisonous, volcanic goo for a couple of million years before settling down. I'm not terribly firm on my Permian Era geography, but I'd be willing to bet that the Siberian Traps event was pretty close to the opposite side of the planet at the time of the impacts.
Re:What A Wonderful Time It Was To Be Alive ... (Score:1)
What about my Hummer theory? (Score:2, Funny)
Bushveld Complex (Score:2)
Erwin's book Extinction (Score:2)
Danny.
Re:Four or five? (Score:2)