Asteroid Impact, Not Volcanic Activity, Killed the Dinosaurs, Study Finds (space.com) 62
Scientists have gone back and forth over exactly what caused a mass extinction event 66 million years ago, which destroyed about 75% of all life on Earth, including all of the large dinosaurs. Some have thought that volcanic activity could be to blame, but one new study shows that a giant asteroid impact was the prime culprit. Space.com reports: In a new study, researchers from Imperial College London, the University of Bristol and University College London have shown that the asteroid impact, not volcanic activity, was the main reason that about 75% of life on Earth perished at that time, and it did so by significantly interfering with Earth's climate and ecosystems. To come to this conclusion, the researchers modeled how Earth's climate would be expected to respond to two separate possible extinction causes: volcanism and asteroid impact. In these mathematical models, they included environmental factors including rainfall and temperature, which would have been critical to the survival of these species. They also included the presence of sunlight-blocking gases and particles and carbon dioxide, a greenhouse gas. With these models, the team found that the giant asteroid hitting our planet would have released tremendous amounts of gas and particles into Earth's atmosphere, blocking out the sun for years on end. This effect would have created a sort of semi-permanent winter on Earth, making the planet unlivable for most of its inhabitants.
Now, while the team found the asteroid impact to be the major factor in making Earth unlivable for most animals, they also found that volcanic activity could have actually helped life to recover over time, a conclusion that scientists have drawn before. They found that, while volcanoes do release sunlight-blocking gases and particles, which would have helped to block the sun in the short term, they also release large amounts of carbon dioxide which, because it's a greenhouse gas, would have built up in the atmosphere and warmed the planet. So, as the researchers suggest in this work, while the devastating winter caused by the asteroid killed off most life on Earth, over time, the warming effect created from the volcanic greenhouse gases could have helped to restore life to habitats. The study has been published in the journal Proceedings of the National Academy of Sciences.
Now, while the team found the asteroid impact to be the major factor in making Earth unlivable for most animals, they also found that volcanic activity could have actually helped life to recover over time, a conclusion that scientists have drawn before. They found that, while volcanoes do release sunlight-blocking gases and particles, which would have helped to block the sun in the short term, they also release large amounts of carbon dioxide which, because it's a greenhouse gas, would have built up in the atmosphere and warmed the planet. So, as the researchers suggest in this work, while the devastating winter caused by the asteroid killed off most life on Earth, over time, the warming effect created from the volcanic greenhouse gases could have helped to restore life to habitats. The study has been published in the journal Proceedings of the National Academy of Sciences.
Iridium anomaly (Score:3)
How is this news? The iridium in the ash deposit at the KT boundary established decades ago that it was an asteroid impact.
Iridium anomaly [wikipedia.org]
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There were some interesting theories that the meteor impact triggered volcano activity elsewhere on Earth. There was an article in Discover magazine at https://www.discovermagazine.c... [discovermagazine.com] about the idea.
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Two birds with one stone, so to speak.
Always recommended, if you have the means.
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Hmm... I can see why being two people would be a concern, but it's a much wider thing than a vote. [twincities.com]
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You were expecting the Palm Beach Supervisor of Elections to test you with questions about the Holocaust?
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Two birds with one stone
Except that, ironically, it was the birds who survived.
Re:Iridium anomaly (Score:5, Interesting)
If the impact triggered volcanoes, they would have likely been mafic volcanoes spewing out molten basalt. Mafic volcanoes generate much less ash and dust than felsic volcanoes.
They also produce wide basalt shields like the Siberian Traps [wikipedia.org] which occurred at the PT boundary 180 million years earlier. So where is the basalt shield? Where is the layer of basaltic ash? It should be sitting right on top of the iridium, but it isn't there.
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Mafic volcanoes ... felsic volcanoes
Found my next band name, and the name of the first album
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Well, the impact and subsequent major vibrations would not have triggered volcanoes they would have triggered substantively accelerated tectonic plate movement and that plate movement with association with altered magma flows, would have triggered extra volcanoes, and due to chaos, they would have been all over the place. Sort of like hundreds of thousand of years of tectonic plate movement compressed over several months, with the most acceleration in the first few days. A wobbly plate of jelly in slow moti
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Deccan Trapa [Re:Iridium anomaly] (Score:3)
...the Deccan Traps... basically antipodal to the impact site...
Not really antipodal-- Deccan traps are 17–24N, 73–74E, Chicxulub impact structure is 2124N 8931W.
That's about 40 off the antipode-- not very close.
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Even with intermediate steps over the course of a few months, I would call that "triggered by the asteroid strike". It wouldn't have occurred without the asteroid strike.
Like system failures triggered by a software update. the causality doesn't have to be immediate and may not be specifically predictable before the trigger event.
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Fox news has all the information you'll ever need, right?
WP [Re:Iridium anomaly] (Score:2)
Wow you believe Wikipedia. how gullible are you?
Nice thing about Wikipedia is that they cite references.
Unlike most slashdot posters.
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How is this news? The iridium in the ash deposit at the KT boundary established decades ago that it was an asteroid impact.
The correlation is evident. The precise causation is often questioned. Remember that even thin layers are smeared out over quite a large time period, so the order of events isn't so clear.
I thought there were a number of theories that the dinosaurs were nearing extinction already, and the asteroid just finished them off. Has that fallen out of favor?
Sharp anomaly [Re:Iridium anomaly] (Score:3)
The correlation is evident. The precise causation is often questioned. Remember that even thin layers are smeared out over quite a large time period,
Always something to worry about, but in this case, the iridium-rich layer is remarkably thin: 3-4 cm. http://hyperphysics.phy-astr.g... [gsu.edu]
And it is precisely correlated with the extinction of a large number of foraminifera species. Unlike, say, large animal fossils (like: dinosaur bones), which are rare and can straddle multiple layers, the microscopic foraminifera are abundant and small, a pretty clear marker of the extinction https://pubs.geoscienceworld.o... [geoscienceworld.org]
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But it doesn't establish how near extinction dinosaurs were at the time. Those were the theories I was talking about.
Re: Iridium anomaly (Score:2)
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The interesting thing about Science, is it isn't fixed. It will constantly re-look and re-evaluate their hypothesis's and even give a theory an other shot, if they find some new data that make put it into question.
If in 100 million years archeologists look at our evidence. They may come up with rational but inaccurate hypothesis of what our time period was like. A large amount of rare minerals out of place, Nearly pure Iron and Carbon layers in some spots. They may see it as some sort of Super Volcano t
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I think it's great when there's new evidence, new calculations, new discussion etc. even on what seems like largely settled science, but it is not all that clear what's new this time. For a while it's been the censensus (as I understood it) that ecosystems were already in distress from volcanic activity but the meteor impact was major factor, with some minor disagreement as to the relative contributions of those two causes.
Cue climate change deniers (Score:2)
OK, lets see how long before climate change deniers get here. Concluding that "see, carbon dioxide is good" (one step after "it's not happening" and "we are not causing it").
Which is certainly true, that CO2 is good - it's rather essential for both a suitable climate and as a part in photosynthesis. But that doesn't say anything that *more* CO2 is better, and specifically nothing about whether a rapid increase in CO2 is good for us humans, our habitats and our food and water supply.
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Deniers aren't skeptics [Re:Cue climate change...] (Score:2)
Uh oh, it looks like an unreasonable "Greta" modded you down
Nobody modded him at all; anonymous coward posts start at 0. You're apparently posting in anticipation that somebody is going to down mod him.
for being a climate change heretic because you made a reasonable comment about considering all sides and drawing you own conclusion
How about, instead of "consider all sides," switch to "pay attention to the actual science, not the hype."
There are a few actual skeptics out there, but they tend to get drowned out by the deniers. The deniers look for any excuse to not read any of the actual science.
I'll propose starting with Climate Change: the Physical Science Basis [www.ipcc.ch] as a starting point, and
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"I do not know what is true in this case. I am no expert and I have no way of deciding who is an actual expert without an agenda."
Yet you're still sitting on the fence despite 99% of man made climate scientists who are experts and can decide citing it as real. Sounds to me like you've made your mind up but don't want to admit it.
"Go fix academia. Fix science."
There's nothing wrong with either of them except in your mind. What do you think needs "fixing" about science? Wait, let me guess, because science doe
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"Every documentary produced about a scientific subject over the last few decades is pocked with scientists saying "boy, where we wrong.""
Really? Name a few. Sure, there are cutting edge areas such as cosmology and various parts of biology where theories abound and evidence scant. With climate change however there is one theory and plenty of evidence in the form of temperatures going up in line with CO2 concentration.
I wonder if people like you if told you had cancer would say "Hold on, I'm not having that t
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Really? Name a few. Sure, there are cutting edge areas such as cosmology and various parts of biology where theories abound and evidence scant. With climate change however there is one theory and plenty of evidence in the form of temperatures going up in line with CO2 concentration.
Science is a liar sometimes [youtube.com]
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Yet you're still sitting on the fence despite 99% of man made climate scientists who are experts and can decide citing it as real. Sounds to me like you've made your mind up but don't want to admit it.
Assume 100% it's real. Now what?
All of the methods proposed to reduce carbon emissions require fundamental restructuring of the global economy. For some reason, Western countries are supposed to shoulder a larger burden than developing countries. Based in some kind of political get-evenism for historical wrongs, I suspect. And never spoken about is advancing our nuclear generation technology, which is ridiculously clean compared to green technologies that require huge battery stores.
This is the real argumen
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"All of the methods proposed to reduce carbon emissions require fundamental restructuring of the global economy."
Not true.
https://www.theguardian.com/bu... [theguardian.com]
"And never spoken about is advancing our nuclear generation technology, which is ridiculously clean compared to green technologies that require huge battery stores."
Nuclear is certainly part of it.
No argument [Re:Cue climate change deniers] (Score:2)
This is the very model of a disingenuous argument
There are indeed people who, as you say, think "all of the methods proposed to reduce carbon emissions require fundamental restructuring of the global economy" and "this will be a large burden to western countries." And as a result, they argue "The science isn't real! It's a hoax! Or, maybe it's not a hoax, but it's not settled! Or maybe it's true but the models are too catastrophic! One way or another, it's all wrong!"
What they are not arguing is "it wo
a few more comments [Re:Cue climate change deniers (Score:2)
With respect to nuclear power, you are on the same page with many of the climate scientists. (e.g.: https://www.scientificamerican... [scientificamerican.com] ) However, there are real barriers at the moment. If you want nuclear power, I would strongly suggest that you should start political advocacy to restart nuclear fuel reprocessing, since without reprocessing, nuclear won't solve any problems. Once you've got reprocessing restarted, then you've got a shot.
And I will remind you of the elephant in the room. There is an i
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And I will remind you of the elephant in the room. There is an industry, the fossil fuel industry, that would literally lose trillions of dollars if we move away from fossil fuels
I won't argue that energy companies will emphatically defend whatever energy they provide and however they provide it. But:
I disagree, by the way, with your statement that all solutions would require fundamental restructuring of the global economy.
But it will. If you live in the suburbs, you require a car to go places. It's all well and good to say "well, move to where you don't need a car," but now you're down a rabbit hole of property tax bases, public education, social mobility, and employment in infrastructure industries. These are not trivial.
It also doesn't address container ships. These have a pretty impressive carbon foot
Technology pessimists [Re:a few more comments ] (Score:2)
And I will remind you of the elephant in the room. There is an industry, the fossil fuel industry, that would literally lose trillions of dollars if we move away from fossil fuels
I won't argue that energy companies will emphatically defend whatever energy they provide and however they provide it.
And, more to the point, they spend a trivial fraction of that money on funding think-tanks to spread FUD about climate change. Not all the deniers are funded by oil companies-- in fact, by this time, probably none of them are. But there is a large and well-greased machine that amplifies the denialists, and that machine doesn't care about whether what they are amplifying is true or not, just that it spreads that FUD.
But:
I disagree, by the way, with your statement that all solutions would require fundamental restructuring of the global economy.
But it will. If you live in the suburbs, you require a car to go places. It's all well and good to say "well, move to where you don't need a car," but now you're down a rabbit hole of property tax bases, public education, social mobility, and employment in infrastructure industries.
Yes, and if electric cars hadn't been invented, you would have had a point. But they have a
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Yet you're still sitting on the fence despite 99% of man made climate scientists who are experts and can decide citing it as real.
Nearly all scientists agree that the Earth is the center of the universe. It's only the crackpot fringe who claim the sun is the center.of the universe
Nearly all scientists agree that the Earth's geology is fixed and unchanging. It's only the fringe who believe in "continental billiards" or whatever that crackpot theory is called.
Disease spread by tiny "germs"? Conveniently too small to see. What kind of crackpot theory is that?
Nearly all scientists agree that the universe is eternal and unchanging at
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If you have to go back hundreds of years to make your "point" then you don't have one. As for string theory, which part of the word "theory" is confusing you?
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More than half of those are within a century. String theory is a sadly ongoing failure of an entire field of physics.
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Those "my science is more real than your science" snobs crack me up!
If they were alive around 100 years ago they would be making snide remarks towards Wegener for his false theory of continental drift because other scientists tell you the earth geology is static an immutable, calling Einstein's theories of relativity fake news because other scientists told us that Newton's laws can explain all motion, and call Hubble's discovery of proof that galaxies lie outside of our own Milky Way as alternative facts be
Wait, why is this news? (Score:5, Insightful)
I thought it was established for quite a while now that a meteor impact in the Yucatan Peninsula was the cause for the chain of events that led to the mass extinction. I won't read the paper, maybe it has some nice insights for scientists into this stuff, but it is definitely not news.
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I thought it was established for quite a while now that a meteor impact in the Yucatan Peninsula was the cause for the chain of events that led to the mass extinction. I won't read the paper, maybe it has some nice insights for scientists into this stuff, but it is definitely not news.
You thought wrong. There are a number of competing theories to explain the Cretaceous–Tertiary extinction event and the asteroid impact is just one of them. The Cretaceous–Tertiary extinction could just as easily have been caused by a combination of events as it could have been caused by an asteroid impact (or any other single event) all by itself. Anybody who wants to argue for some single event being an explanation for the Cretaceous–Tertiary extinction has to provide a preponderance of
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...the hell? What does the term "nerd" mean to you, if it doesn't include paleontologists!?
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Its not "news for nerds" It MIGHT be news for geologist and those dinosaur study guys. But odds are they already knew this. Especially Since i already knew this. It's Merely another study pushing a point of view. At this point it's just as likely that they were made extinct by flying sharks with lasers on their heads. in other words we really do not know. It's possible we never will know for sure, barring the invention of some sort of time travel device.
Tons of nerds like geology and palaeontology (a.k.a. those dinosaur study guys) and whatever you though you knew wasn't established science. Science has never been afraid to admit it does not know something but that is what scientific method is about, finding things out and through observation, experimentation, data gathering and reason. That is not as simple as sitting on a couch, with a beer in one hand pizza in the other and deciding with a belch that the dinosaurs were wiped out by sharks with lasers on
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Hahaha
Can't even take a differing viewpoint. In case you missed it i said FLYING sharks with lasers!
seriously though, another position paper about how something happened. It's most certainly NOT tech news.
But ad hominem attacks do seem to be your style. Good job! It doesn't make my reductio ad absurdium any less valid.
Additionally, it's still not tech news. I honestly don't care about people who have watched too much Jurassic Park.
Something more valid would be, we have determined that an
One positive note about the impact... (Score:2)
If the earth can survive being hit by a 6 mile wide lump of rock going at 5 miles per second it can survive (long term) any kind of mess we make of the biosphere. Of course whether we'll survive is another matter.
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The problem is that with the way we're headed, we'll survive but nothing else will.
But who will care? (Score:3)
At one time, Lake Michigan was a commercial fishery. Today, even with the conservation efforts, even with the knowledge of how to manage fisheries, even with a single, unified government controlling it, it still cannot produce the same yield of fish it did just a century ago.
If we could not prevent that ecological catastrophe, even though we had the science and political will to do so, what makes you think a politically divided world can do any better with global climate change?
Let's just face it: Glo
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Errrr... what is this even supposed to mean? Life on Earth has thrived just fine with and without "a substantial portion of Earth's carbon sequestered in its crust" as the second part of your statement implies.
The only question is if any such changes happen gradually enough so that we and the lifeforms we depend on having with us, can adapt and thrive.
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Asteroid impact (Score:1)
Is that the same research team that recently found (Score:1)
Huh? New? (Score:2)
And every 12-year-old kid in the entire world didn't know this?
Asteroids Killed the Dinosaurs? Well Damn. (Score:2)
CRASH. THUMP. "HAAA! Got another one! Only Thirty Million or so to go now. Damn, those flying ones are hard to hit, they keep moving around."
"Hmmmm? You called? But I like birds."
a gravitational event wiped out the dinosaurs (Score:1)
A gravitational event wiped out the large Dinosaurs, the is no way that animals as large as dinosaurs could support there own weight with our current gravity, so gravity must have been lower in the time of large Dinosaurs, and the reason that all the large animals disappeared at the same time and other animals didn't, is a result of impact, whatever hit our planet, hit it so hard that our orbit around the sun changed (moved closer would be my guess) and our gravity changed and the large Dinosaurs could not
This is why we need high co2 (Score:2)