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End of the "Lone Asteroid" Theory?
hussar writes "This BBC article reports on research that suggests the dinosaurs were not killed off by the Chicxulub asteroid's immediate effects but ultimately fell to evironmental stresses caused by a second asteroid that hit about 300,000 years later. The second impact may have been in the Indian Ocean."
Gerta Keller's conclusions are being strongly refuted by Jan Smits, one of the researchers that got funding for the core samples used in the study. He said in this NPR clip that he is really upset that Keller's research passed peer review without catching the obvious mistakes.
Remember... ZG9uJ3QgZm9yZ2V0IHRvIGRyaW5rIHlvdXIgb3ZhbHRpbmU=
Back when I took astronomy the standard theories were carted out before us for our own inspection and consideration.
I've not been convinced climatic change did them in as most theories seemed predisposed to a direct impact on the dinosaurse themselves. i.e. the earth passed through the tail of a comet and the atmosphere cooled and they died off. I'm more inclined to some environmental change which impacted the low end of the food chain, plants in particular, but it still doesn't explain why aquatic dinos went, too.
I'm looking for a theory that says the earth was a warmer place with most of that fossil fuel carbon still on the surface (where we're presently putting it again, one study observed plants are taking up the extra carbondioxide in the air, what's the long term impact of that?) As the carbon became buried (ever think about how much green stuff it took to make pertroleum deposits or coal seams?) the food changed and those at the bottom of the chain adapted or perished. Perhaps dinosaurs were really hugely inefficient creatures and require large amounts of energy, whereas mammals and birds are quite efficient.
Anyway, that's my two cents. Anyone who can point me toward some theories which follow that logic, as opposed to the big-exciting-asteroid-or-comet theories much appreciated. I think in extinction theories, the ones involving some violent cataclysm get too much press, probably due to the sensational value.
A feeling of having made the same mistake before: Deja Foobar
This brings back memories.
I remember having a beer at my buddy Vijay's place in India (he was an outsourced Fern & Brush Maintainer for the Pangea Shrubbery Co. in the Late Cretaceous) Anyhow, I was working on my tan as the sun's light had only recently begun shining through to the Earth's surface thanks to the Chicxulub hit years before.
Vijay had just finished telling me a great joke about his dog having no nose when we saw a massive asteroid coming down. Vijay just muttered "Oh bugger, not again." The sad part of the whole thing was that I had tanned lying on my stomach that morning. My face and frontside were ghostly white for ages.
I was a laughing stock for most of the Tertiary period..
Trolling is a art,
We all know there was an asteroid that came from the grassy knoll.
If only Bruce Willis had lived back then...
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
THIS will be going around the religious channels like wildfire. They will be pointing out how foolish the "scientific community" has been for the past 100 years of this theory and show how the bible forsaw "a deluge of heavenly matter from above". This will be going on for centuries from now. Cataclysmic, to be sure.
"from the this-changes-everything-and-nobody-cares dept."
I'm thinking maybe the dinosaurs involved cared just a little...
dinosaur comics
Obviously it was the second asteroid on the grassy knoll!
It may just be scientist ruffling their feathers at a new theory, or there may very well be serious problems with the evidence. It's certainly not a final answer yet.
The second impact may have been in the Indian Ocean
I'm checking my notes now, but as I recall, the 'Indian Ocean' wasn't there when the second one augered in. Who writes this stuff....
Hmm...I suppose that would make Mars the grassy knoll, right?
I have discovered a truly marvelous
Dont be a fool. Religious fanatics dont believe in dinosaurs.. first of all, to them earth is only 10,000 years old, second, dinos arent mentioned in the bible.. its all a conspiracy by satan.. the bones we find are just mixes of elephants and alligator bones.
When the K-T boundary impact finally came, it hit an already stressed community... almost anything could have wiped them out at that point
Actually, they couldn't reproduce anymore because they couldn't afford all the license fees to copy their genome ...
The Tao of math: The numbers you can count are not the real numbers.
Indian Ocean eh?
............
I presume these Indians had something to do with the massive extinction of US Tech jobs as well?
First the poor dinosaurs, and now poor US geeks..
And yes, I am Indian, the real deal, the kind Columbus went searching for..thankfully never found.
Rapid Nirvana
The second impact may have been in the Indian Ocean.
I always though the Second Impact was caused by one of the Angels...
No wonder I was so confused by the end.
This sig is only here so people stop skipping the last lines of my posts.
Kellers findings are pretty well founded. The idea is that the Chicxulub impact occurred during this warming period with severe environmental effects but the extinction of the dinosaurs - When the second impact finally occurred, it hit an already stressed community which was the straw that broke the camel's back. Almost anything could have wiped them out at that point. Jan Smits doesn't refute this very clearly - but I would accept that the theory is less sensational that it appears from the headline.
Please help publicise swpat.org - the software patents wiki
Ah.... The great K-T extinction debate continues....
For those interested in reading about the supporting data and possible causes of the K-T extinction,
here's a good discussion" by Dewey M. McLean of the Department of Geological Sciences,
Virginia Polytechnic Institute and State University.
See? The dinosaurs fell victim to outsourcing to india.
Hmmm ... Kangaroos weren't mentioned in the bible as well. Nor was Australia. Probably the evil non-believers invented australia to hide the fact that earth really is flat :-)
The Tao of math: The numbers you can count are not the real numbers.
The obviousness of this question makes me suspect it is a dumb one to ask but maybe someone can clarify for me. Why is it so strongly believed that some kind of environmental change wiped out dinos and not some kind of disease/virus?
... is that practically all dinosaurs that lived after the first impact were dead before the second hit earth ;)
Well actually, some of them believe the dinos got wiped out by the Great Flood. To think that all those jews before Noah had to go around dodging dinosaur feet..
The second impact may have been in the Indian Ocean.
I had always thought the Second Impact was in Antarctica when Adam got pissed and melted the entire continent.
I know I'd be stressed if I lived to be 300,000 years old.
The article doesn't seem to make any clear connection between the climatic stress - warming - supposedly caused by the eruptions that created the Deccan Traps and any meteorite. The accompanying graphs show a steady climatic cooling trend in the late Cretaceous and that curve doesn't appear to be affected by the iridium yeilding event. The biological diversity however correlates pretty muc exactly in geological time. So, where are the linking data that make sense of this article?
That the climate change that killed off dinosaurs was caused by greenhouse gasses from American SUVs.
Remember, Jesus taught us to love all of God's children. Those pesky Asians couldn't possibly be God's children if the Old Testament is an accurate account of history. Noah's flood must have wiped out all of those destable foreigners, except that the Chinese had a society at the time with written history that has no details of an unusual flood.
Even more eye-opening is the fact that literal interpretations of the Bible are extremely new. Such intellectual hobbling wasn't popular until the 19th or 20th century - for almost 2000 years Christians realized what the purpose of the Bible was, only recently did some of them shut off their God given faculties and prescribe to a system of belief founded on utter and incredible ignorance.
I was only kidding about the Australians - forgot to add that as a PS on the last post. Kangaroos definitely do the bidding of the Prince of Darkness, though.
Do we seriously have to believe that this one asteroid entered the neck of Tyrannosaurus Rex, pierced the left lung of Triceratops and then PAUSED IN MIDAIR to hit a pterodactyl in the eye? I say NO gentlemen. There had to be a second asteroid posted on the grassy knoll.
In your heart you know it's flat (This appeals to the Discordian in me.)
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
There must have been a second asteroid.
After all, everyone knows that the JFK 'Second Gunman' Theory is 100% accurate.;-)
Been decades, wasn't the worldwide commonality of stories of an unusual flood one of Velikovsky's data points?
Ah, good old mindless Christian(ity) bashing...made especially amusing since other scientists are already disputing this theory. (Check a few posts up ;) To be blunt, many theories that have come out of scientific circles are at least as stupid as the theories that you are "presenting". Quit whining, Christians don't have a lock on being morons.
I think some of you need to do a better job of keeping up with what the religious fanatics believe. Do you really think your arguments trying to make pinprick holes in their belief system haven't been answered countless times before?
There is an answer to multiple races.
There is an answer for the dinosaur extinction.
They do believe dinosours existed.
Please don't make yourselves look like fools talking about stuff you don't know anything about. Keep your reputation high by talking about geek stuff which you know best, not religion. Your arrogance is amusing.
Of two meteors, one near-extinction level, the second not-quite-but-enough-to-finish-them-off level, within 300,000 years?
Personally I say slim and none. 300,000 years is a fucking long time. Remember where humanity was 300,000 years ago (hint: not exactly homo sapiens sapiens). Whatever near-cataclysmic damage the first meteor did, nature would have moved on. If the first meteor didn't wipe them all out, the ones that did survive would also have been those with the best odds against the second meteor. So, it doesn't really make sense.
Kjella
Live today, because you never know what tomorrow brings
There seems to be a popular opinion that humans are the most evolved of all species... that statement is totally bogus for a number of reasons, but if you define most evolved as best adapted to surviving whatever its environment throws at it (the galactic environment you could say), you just can't beat single celled organisms. The more adapted you are, the more you depend upon the situations and circumstances that make those adaptations beneficial. If we have a true Armageddon, I'm voting for the bacteria that live in deep sea volcanoes... it doesn't even need the Sun's light to survive.
Am I the only one that saw this and thought for a second that the dinosaurs might have been wiped out by an asteroid named Chixclub?
I Am My Own Worst Enemy
Check out his reply to the original article.
There's a picture of the soil sample he's talking about, too.
"The best evidence in favour of a single impact, I repeat, is in the K/T record from the US western interior. In numerous outcrops from Alberta in Canada, through Dogie Creek in Wyoming to the Raton Basin in New Mexico an iridium-enriched clay layer occurs in coal swamp deposits at the palynological K/T boundary. This clay layer has a dual nature (Izett, 1990), and consist of two layers: a lower layer that contains spherules (best seen in Dogie creek (Fig. 7) morphologicaly indistinguishable from the Chicxulub spherules from the Gulf.
The upper layer is strongly enriched in iridium and shocked minerals, such as quartz, feldspar and zircons. The shocked zircons are shown (Krogh, 1993) to have the isotopic properties (Sm/Nd) of the pan-African basement of the Chicxulub crater. In all the mentioned localities the two layers are in contact with each other, without an intervening layer. Not even a single layer of one fall season of leaves or plant material occurs between the two layers. If the upper, iridium-rich, layer is from another impact than the Chicxulub impact, they have to be simultaneous, and have to occur on the same pan-African basement - in itself highly unlikely, but not impossible. A 300Ka separation between the two layers in all the localities, as Keller posits for the separation between the Chicxulub impact and the iridium producing impact, is therefore excluded - barring a miracle."
Yeah, if you can't explain everything with the theory of ONE asteroid, TWO may be the solution!
Add asteroids until it works!
Could it be that this second meteorite was rich in poisonous metals, tainting the soil world-wide for years to come? This article is interesting, but I have not seen mention of the theory elsewhere.
I'd be the last to propound a literal interpretation of the Bible, but I believe the traditional interpretation of Genesis is that all of humanity is descended from Noah's children. Asians are presumed to be the descendants of Shem. You'll have to look for the origins of racism elsewhere.
The abiotic theory on the origin of oil, while politically convenient to certain groups due to it's consequence of almost unlimited oil reserves, is still highly controversial. It is not reasonable to expect it to be taught as fact in textbooks for a long time, if ever.
He has one of the samples of this study was based on (and (acording to above mentioned radioshow) the who divided up the original). In the end of the radiointerview he sugests letting all the original drill samples be tested by a third party for magnesium or calcium to prove if what Kellar has found are actual organism or just cristaline structures (as Smit seem to think). Sounds good to me, but then IANAPaleontologist.
We're talking on a scale of millions of years. I really would leave a puny 300,000 year figure up to error.
Innocent until proven guilty, my friend. If you want to refute them, post evidence. Otherwise, you're doing the same thing that they are.
... (including the Bible). Say something, offer no proof.
I also vehemently profess, that Jesus was a woman, smoked pot, and lived to bear 18 children, the bloodlines of which are present in all of our governments' heads.
People believe that, too. I swear, it's true. Don't belive me? Look it up yourself.
It's the oldest trick in the book
Oh, hell no. This is a perennial windmill to be tilted at. There's an alternate hypothesis presented every year or so, and not because the most widely accepted hypothesis doesn't do a good job of explaining the data. It's one of those unanswerables that you can make your professional mark on by going up against it. As in boxing, you don't have to win against the champ, you just have to last enough rounds.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
What has bothered me for a long time about the Chicxulub theory is that nobody ever provides evidence linking the impact to the extinction. Every time new evidence appears indicating that there was an impact, it's reported as being new evidence that the dinosaurs were wiped out by it. Actually, all it shows is that there was an impact of some sort.
Years ago I read Robert Bakker's book, 'The Dinosaur Heresies". In it he claims that the fossil evidence shows that the dinosaurs were in decline long before the KT boundary and the appearance of its famed iridium layer. Furthermore, many species survived the extinction, and some of those species (such as amphibians) were ones that you might expect to be particularly susceptible. So although the impact might have contributed to the mass extinction, it's not likely to have been the root cause.
Lost: one sig, witty, 120 chars, sentimental value. Reward offered.
In America, even extinction is outsourced to India.
NMG
For the last time, Linux is not a derived work of BSD or any other "Unix". You SCOG astroturfers make me ill.
When I was an undergrad geology student 20 years ago, the prevailing theory of how dinosaurs went extinct involved an asteroid hitting the Earth on the Atlantic Ridge system. The target location would be the present-day island of Iceland. The evidence used to support the conclusion included iridium-soaked sediments ringing Iceland dated right at the Mesozoic/Cenozoic (K/T) break, the high concentration of ultramafics at the surface, etc. etc.
The problem for this theory was (is!) the chain of events that would have led to a mass extinction. The theory assumed that the explosive force of the impact would have kicked up large amounts of dust and moisture, which would reduced solar activity and stunted or halted sufficient production of vegetative matter. That would have led to the die-off of herbivores, which in turn would have led to carnivore die-off. The hitch? Insufficient evidence of mass flora extinction at the K/T boundary.
Some years later, the location of the impact changed to Mexico, but the mechanics stayed the same. But there is still a huge lack of vegetative data to support a mass extinction.
So now there are several asteroids hitting the Earth. Did that change the fundamental assumptions?
Nope.
I'm glad the debate is still alive. Nothing bothers me more than a theory that attempts to tie everything together in a neat package.
"Rocky Rococo, at your cervix!"
Turtles and crocodiles seem to have survived the mass extinction(s) of the dinosaur age quite well. Both are ectotherms, neither migrates especially far. The general "coldbloodedness = vulnerability to the extinction" correlation just plain isn't there. The major case we're talking about, the dinos, is an open question to start with -- cold-blooded? Endotherms? Somewhere in between? Varying by species?
Something on the scale of the impact we're talking about would have all sorts of indirect effects. Mass extinctions, too, are going to be complex events, which is one big reason to be skeptical of any single-impact idea. For my money, what we have is a correlation -- not a causal link we can describe in concrete ways.
The model I always think of is Krakatoa's eruption in 535 AD. Global climate change kicked in just after that -- years without any harvest in Europe, extreme volatility. There are people who think that eruption changed human history: ushered in the "dark ages," partly caused or influenced the rise of Islam, destabilized governments, and so on. Maybe so -- but this is an event well within recorded human history, and it's still pretty doubtful trying to connect all the causes with their effects. That's if we accept the volcano -> weather changes link to start with.
Simple biological example: take ammonites and nautiloids. Similar chambered-shell mollusc floaters, right? Why did ammonites die out after the crateceous event, while at least a few nautiloids didn't? Ammonites were by far the more dominant critters before the extinction. Were there differences in their reproductive strategies, so that Nautiloids could "wait out" a bad phase better? What? It just ain't that simple.
(As far as mammals eating sleeping dinos at night, there were early mammals for a long time during the age of the dinosaurs. The jurassic, at least.)
"Fundamentalism" isn't about divine morality. It's about human authority.
Now their stealing our asteroid collisions too!
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg
Too bad that many major scientists think that this conclusion is totally wrong given the evidence presented. (At least according to some NPR program I listened to).
The only thing I really have trouble with is the Carl-Saganish misuse of probability. The fact that something happened once doesn't make it any less likely to happen the next day. The odds remain the same.
The second misuse of probability here is the assumption that there's no causal relation between the two events. They are simply treated as random occurrences, which fact is not in evidence. For all we know the two meteors could have been parts of the same original object on the same orbital path.
"Is this Winkhorst a nova criminal?" "No just a technical sergeant wanted for interrogation."
Extinctions on the continents
The only groups for which a detailed record of change has been established are terrestrial and aquatic vertebrates and plants, to which discussion must accordingly be confined. However, it is worth noting that for the extremely important and diverse insect faunas, for which the fossil record has improved considerably in recent years, there are no indications of any significant change across the K-T boundary (Labandeira and Sepkoski 1993). Nor is there any good evidence of an extinction event among birds (Chiappe 1995).
Vertebrates
Although they attract the greatest popular interest, dinosaurs are one of the least satisfactory groups for this kind of study, because of the paucity of suitable stratal sections and the comparative scarcity of fossil material. Virtually all the conclusions that have been drawn about the final dinosaur extinction episode derive from a few sections in the North American Western Interior, arguably the only complete succession of vertebrate-bearing strata across the K-T boundary, with the best sections being in eastern Montana. For all we know, the group might well have gone extinct in other parts of the world before the end of the Cretaceous, or even locally have persisted into the Palaeocene. In any case, too much has been made of the end-Cretaceous dinosaur mass extinction as a unique event. In fact, as Padian and Clemens (1985) have pointed out, the dinosaur generic turnover rate was exceptionally high throughout the group's history, and the most unusual feature of the end-Cretaceous event was the failure of a new replacive group of dinosaurs to emerge. The implication of the high generic turnover rate is that dinosaurs were always relatively vulnerable to extinction throughout their long history, and that no environmental event of exceptional magnitude need necessarily be invoked.
Mass Extinctions and Their Aftermath, A. Hallam and P.B. Wignall
Second of all, the Chinese have had a continuous history and civilization for thousands of years -- it predates the flood of the Old Testament. You can find a reference for that yourself. They are abundant.
You may find my arrogance amusing, but that's only possible because Christian fanatics forcibly inject all sorts of negative personality traits into people with half a clue - jealousy, evilness, arrogance, take your pick. There's no arrogance on my part, only rational conclusions, many of which are based on the Bible. There are countless irrational explanations for Chinese people and only one rational one. It takes an irrational conclusion to support the Old Testament's claim of a global flood, and yet another to declare that Chinese people are not some sort of abomination of God.
The alternative is the stunning realization that the Bible was not, is not, and never will be a history book. That was obvious to Christians from the years 100 through the late 1800s. Christian fundamentalism sprouted primarily in America, among people horribly unqualified to debate theology, and only in the last 100-150 years. And to the halfwits, everybody who laughs at them will appear arrogant.
It's either a fact that Noah's flood was not global, refuting the Bible; or a fact that Chinese written history is a fraud, refuting the legitimacy of any ancient written document such as the Bible. The only thing that separates the Bible from other ancient texts is the belief that it was authored by God which is an obvious fallacy. Take Old Testament 101 in any college and you'll spend a great amount of time studying the ample evidence that the OT has been edited, by whom, when, where, and how many times.
And as I've said elsewhere, even the notion that the Bible is a historically accurate document is brand new - less than 150 years old. The idea itself is not consistent and can only be supported by countless leaps of "faith", known to educated people as "pseudo science", "fallacy", and "make believe".
The Bible is an infinitely valuable document and an irreplaceable component of many people's spirituality, but a history text it is not.
Astronomical events happen on astronomical timescales, so if you accept the argument that even one dinosaur killer asteroid managed to get its orbit disrupted sufficiently to head our way, then there would most likely have been a few more disrupted by whatever caused that disruption, and/or by consequent events.
Now you put a large enough asteroid in an earth intersecting orbit, and ask yourself just how long it will take to either collide, or have its orbit further disrupted by a sufficiently near miss, and, I suspect, estimates of the order of hundreds of thousands of years would not be unreasonable. There is a lot of space out there.
(I still like the notion that there might have been a brief flourishing of technological dinosaur society which decided that the best way to benefit from the resources in the asteroid belt was to move some nearer to earth, but can't seriously imagine that there would be no other surviving evidence of such a society.)
One more reason to go back to the moon permanantly is so we can do a proper age census of significant craters where the archive isn't subject to plate tectonics.
-- Our systemic servants do not good masters make.
Not wrong.
You assume in your attack that there was a "North America" and and "India" during the K/T time frame.
A cursory inspection of the plate movements and alignments during this period of time reveals that your debris track would have collided with Africa as well.
Do the authors indicate that there were massive forest extinctions, or just massive forest fires? Which mechanism caused the decline of the dinosaurs? Was the extinction just in North America?
Problems, problems......
"Rocky Rococo, at your cervix!"
Here is a nice Nature article on point.
/. noise.
To summarize: oil can definitely form non-biologically. However, chemical analysis indicates that most oil is formed biologically.
I unfortunately don't have time right now to sift through the UCLA paper linked to in the article, but note that the date of review is in 2002. This is not settled science, so it is very reasonable that schools would still be teaching the more established theory. (Granted, the idea coal or oil comes from animals rather than plants is silly. I hope very few people are actually teaching that.)
Also, if you're going to debunk theories, post links to reputable sites. Otherwise, it's hard to distinguish from the