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Earth Science

Asteroid Dust Caused 15-Year Winter That Killed Dinosaurs, Scientists Say 135

Posted by BeauHD from the land-before-time dept.
Around 66 million years ago, the Chicxulub asteroid caused a mass extinction event, killing three-quarters of life on Earth, including the dinosaurs. A new study suggests that fine silicate dust from the asteroid, which remained in the atmosphere for up to 15 years, played a more significant role in causing the impact winter and extinction than previously thought. Phys.Org reports: Fine silicate dust from pulverized rock would have stayed in the atmosphere for 15 years, dropping global temperatures by up to 15 degrees Celsius, researchers said in a study in the journal Nature Geoscience. [...] For the study, the international team of researchers was able to measure dust particles thought to be from right after the asteroid struck. The particles were found at the Tanis fossil site in the US state of North Dakota.

Though 3,000 kilometers (1,865 miles) away from the crater, the site has preserved a number of remarkable finds believed to be dated from directly after the asteroid impact in sediment layers of an ancient lake. The dust particles were around 0.8 to 8.0 -- micrometers -- just the right size to stick around in the atmosphere for up to 15 years, the researchers said.

Entering this data into climate models similar to those used for current-day Earth, the researchers determined that dust likely played a far greater role in the mass extinction than had previously been thought. Out of all the material that was shot into the atmosphere by the asteroid, they estimated that it was 75 percent dust, 24 percent sulfur and one percent soot. The dust particles "totally shut down photosynthesis" in plants for at least a year, causing a "catastrophic collapse" of life, [said Ozgur Karatekin, a researcher at the Royal Observatory of Belgium].
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Asteroid Dust Caused 15-Year Winter That Killed Dinosaurs, Scientists Say More

Asteroid Dust Caused 15-Year Winter That Killed Dinosaurs, Scientists Say

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  • How the hell did anything survive? Caves?

    • Re:That's crazy (Score:5, Informative)

      by linzeal ( 197905 ) on Tuesday October 31, 2023 @02:20AM (#63967966) Journal

      Plants kept growing at most latitudes and almost everywhere at lower altitudes. Just not as fast for 15-20 years. Mammal species ate a lot of tubers and nuts from the trees, which spread seeds that exploded in diversity in the years after the dinosaurs.

      https://www.science.org/conten... [science.org]

      • The Southern Hemisphere was affected less than the Northern Hemisphere.

        Most bird species in the Southern Hemisphere were wiped out.

        As far as we know, ALL bird species in the Northern Hemisphere were wiped out.

        • The Southern Hemisphere was affected less than the Northern Hemisphere.

          That's probably true, but taking Pinatubo as a calibration point again, there was likely some cross over between hemispheres (because there is today), though a lot of the coarse material had probably fallen out before then.

          Complicating the question in the other direction, it is a "racing certainty" that there were many "secondary impacts" from ejecta from the primary crater, and they're likely to be pretty randomly distributed globally.

    • Re:That's crazy (Score:5, Interesting)

      by The Evil Atheist ( 2484676 ) on Tuesday October 31, 2023 @02:22AM (#63967968)
      Caves wouldn't protect you from a lack of food caused by the shutdown of photosynthesis.

      The things that survived did so because they were small. Under 1kg, if I remember correctly. They could live off scavenging because their food requirements were minor.

      The Permian extinction was worse, so life can survive the dinosaur extinction much easier.

      • Re:That's crazy (Score:5, Funny)

        by Rosco P. Coltrane ( 209368 ) on Tuesday October 31, 2023 @02:50AM (#63967982)

        The things that survived did so because they were small. Under 1kg

        That's impossible. The metric system hadn't been invented yet.

      • Re:That's crazy (Score:4, Interesting)

        by AmiMoJo ( 196126 ) on Tuesday October 31, 2023 @05:46AM (#63968250) Homepage Journal

        It's interesting that after the event, evolution didn't go down the same path of extremely large animals like the dinosaurs.

        I'm not expert by it seems like if you removed the stimulus that lead to smaller, more efficient animals, whatever drove dinosaurs to be huge would cause the same evolutionary paths again. So either something changed permanently after the extinction event, or there is some other explanation as to why animals didn't get so huge again.

        • Whales are pretty huge mammals with some bigger than the biggest dinos.

        • Re: (Score:3)

          by olau ( 314197 )

          This is not something I know anything about, but while not quite dinosaur size, there was in fact a trend towards megafauna [wikipedia.org] after the extinction of the dinosaurs. It doesn't seem to get much publicity.

          • Funny thing, I came across something the other day that suggests it looks like animals tend to get big mainly because big animals fossilize much better, and also are easier to find. If we run our large dataset processing now, we actually see plenty of animal species going down the small/nimble route.

          • I wouldn't call it so much a trend - that implies a general movement, and there was no shortage of animals that stayed small.

            However, so long as the environment has the carrying capacity for very large animals, those will evolve too - life spreads to fill all available niches, and size comes with some major advantages - namely a large herbivore is practically immune to small predators. And cold. And once you have large herbivores, large predators tend to evolve to make use of the competition-free food sup

          • The reason that megafauna died out is because they wouldn't fit on the Ark.

            • Re: (Score:2)

              by shmlco ( 594907 )

              So God either unilaterally decided to kill 'em all off... or he sucks at measuring things.

              Ummm... I suppose Noah could have gotten the whole "cubit" thing wrong.

              Or maybe God-sized cubits are different from man-sized cubits, and...

              Ah.

              Nevermind.

              • So God either unilaterally decided to kill 'em all off... or he sucks at measuring things.

                Ummm... I suppose Noah could have gotten the whole "cubit" thing wrong.

                Or maybe God-sized cubits are different from man-sized cubits, and...

                Ah.

                Nevermind.

                Noah misunderstood, due to a verbal ambiguity common to the voice-dictation systems of that era.
                What Jehovah actually said was "qubits". There were supposed to be multiple Quantum-Arks, or QuArks for short, in superposition to accommodate and distribute creatures of any size. Which is also why Jehovah told him to build it using the Gopher tree - they needed a way to search for and retrieve millions of species distributed across a network of superposed QuArks, but they didn't yet have HTTP, so Gopher was the

        • or there is some other explanation as to why animals didn't get so huge again.

          Temperatures were cooler, the atmosphere was less rich in oxygen, the lack of food sources stunted growth.

        • Re:That's crazy (Score:4, Interesting)

          by The Evil Atheist ( 2484676 ) on Tuesday October 31, 2023 @07:00AM (#63968374)
          My understanding is that, whenever there is some extreme tendency, it's because there was an arms race to get there. So extreme sizes probably came about due to heavy predation/prey pressure? The dinosaurs that were large not only evolved to become large, but evolved to become fast at growing to that size.

          Certainly, there are large mammals, and giant flightless birds (post-KT dinosaurs) in the past, so predation/prey pressure was still there.

          Of course, with the onset of hyper-intelligent hunters aka hominins, size is no longer an advantage against predation, or burning grasslands and forests, but rather made them desirable hunting targets. So we see with the arrival of hominins that megafauna go extinct.

          • Re: (Score:2)

            by hawk ( 1151 )

            Huge predators couldn't evolve without big enough herbivores to get fed.

            The huge herbivores likely needed limited competition.

            I suspect that the pathway to huge was the exception, rather than the norm. You would need the absence of lethal but more agile smaller competitors.

            (and those little weirdos with sharp sticks would eventually make it tough to be a big, slow, herbivore . . .)

            hawk

        • They did get pretty huge again - mammoths, cave bears, etc. It took a long time for the small shrewlike mammals that survived to evolve into mammoths, but it happened.

          Then we came along and hunted pretty much all the megafauna to extinction.

        • It did, they just died again https://en.wikipedia.org/wiki/... [wikipedia.org]

        • Insects size depends on oxygen levels.

          Mammals have some size limits on land that are practical and physics based, but like others said there were megafauna. In south america not that long ago too. Giant sloth was 1000 kilos or something.

        • It takes time. Large predators need large prey, and large prey needs a reason to be large as in large predators. In the end much megafauna disappeared around the same time humans started spreading.

      • Alligaters, Crocodiles, and turtles can get big, they live in a swamp mostly so i can see how they survived, all the dying left them with a smorgasboard to choose from for a while, then when the dead were consumed it was back to the law of the jungle

      • Caves wouldn't protect you from a lack of food caused by the shutdown of photosynthesis. The things that survived did so because they were small. Under 1kg, if I remember correctly. They could live off scavenging because their food requirements were minor. The Permian extinction was worse, so life can survive the dinosaur extinction much easier.

        I've made a habit over the last forty years or so of studying Earth's major extinctions. I can confirm, the Permian-Triassic extinction was the best/worst. The dino extinction event was like a little rave. The Permian-Triassic was full-blown riots in the streets, parents killing the neighbors, cops under tanks, tanks under bombs brutality. By far, the most metal of Earth's extinction events.

      • Re: (Score:2)

        by dbialac ( 320955 )
        Alligators? Crocodiles? They're not under 1kg and they survived. I'll admit, I've never fully gotten how some things survived and others didn't. I would think that Pangaea would have normalized a lot of the outcome as opposed to today when the continents are more spread out.
        • They are over 1kg now. While there are examples of large alligator/crocodile relatives in the past, scientists cannot be sure those are direct descendants of current species. They can only be sure that ancient alligators are related based on features in fossils.
        • My memory of the number was unreliable. According to Wikipedia: https://en.wikipedia.org/wiki/... [wikipedia.org] , it was actually 25kg, for tetrapods. I don't know why I remembered it as 1kg.

          But other than that, no one said there is a hard and fast limit. It was merely to illustrate the point that large animals tended to suffer all round, more than the smaller ones.

      • Over time, the big dinosaurs were on their way out anyway, they depending upon high oxygen levels. This event just sped that up.

      • "Troglobites" - obligatory cave-dwelling life forms, as opposed to troglophiles (which can live on the surface, even if they prefer caves) - are pre-selected to live on intermittent and unreliable food sources. Which is a set of skills you'd really prefer to have inherited from your grandparents rather than try developing when the sky gets very bright.

        so life can survive the dinosaur extinction much easier.

        I almost forgot my signature line, which I don't think I've edited this side of the millennium. When d

    • That, and expired MREs.
    • Normally the specialist die out while generalists survive in events like this. A weed that grows anywhere has a much higher chance of surviving than a subtropical plant. An omnivore not opposed to scavenging will survive better than a carnivore that feasts only on live prey. We see that these days in some species. Cheetahs and pandas are doomed should something happen.

    • Re: (Score:2)

      by hawk ( 1151 )

      >How the hell did anything survive? Caves?

      they held their breath until the air cleared!

      silicon dust in the air is Bad Stuff(tm).

      hawk

    • Re: (Score:2)

      by Askmum ( 1038780 )
      Yes, humans retreated into their caves and started making rock paintings.
    • A whole trophic class - the chemoautotrophs - would be unconcerned. The last I saw, they were considered "life".

      Considering that at least three, and probably many more than that, such impacts have happened since the origin of life on Earth, it's no big deal. A bigger deal for multicellular life, but that too is unlikely to have been terribly concerned. The whole class of soil invertebrates (with representatives from several phyla) are not likely to be terribly concerned, for an example.

      Amongst the plants,

  • would have stayed in the atmosphere for 15 years, dropping global temperatures by up to 15 degrees Celsius

    So basically in 50 to 100 years, we'll have pumped enough carbon into the atmosphere to ride out the next Chicxulub event, and we can stop worrying about asteroid impacts and trying to figure out how to deflect them.

    Who said there wasn't a silver lining to global warming eh?

  • Fake News (Score:5, Funny)

    by 93 Escort Wagon ( 326346 ) on Tuesday October 31, 2023 @02:56AM (#63967986)

    Gary Larson tells me that smoking killed the dinosaurs - and he's never steered me wrong.

    http://www.damnedct.com/wordpr... [damnedct.com]

    • They *thought* it was smoking, but it was actually the particulate in the air causing cancer, silicosis-type ailments, and so forth.

  • Such an epic struggle. (Score:4, Interesting)

    by Eunomion ( 8640039 ) on Tuesday October 31, 2023 @04:54AM (#63968172)
    Countless species climbing across oceans of time, only to be swept away by a fragment of events long before they started.

    This story is one of the great rewards of science. It shows us the vastness and richness of time.

    • Countless species climbing across oceans of time, only to be swept away by a fragment of events long before they started. This story is one of the great rewards of science. It shows us the vastness and richness of time.

      It's also a lovely warning of what's to come that most of us are far too content ignoring.

  • Some of them are probably sitting in a tree outside your window right now.

    Odd how of all the dinosaur genera only the birds made it through. Other than flying I wonder if there's anything else that gave them an advantage in those conditions?

    • Crocodiles, coelacanths, horseshoe crabs, komodo dragons, tuatara, axolotls, natlilusses, turtles and tortoises - lots.

    • Size. They are small, they feed on fruits and small insects that can also probably survive on the reduced plant biomass. They can manage body heat better. Also, other reptiles survived as well, (snakes, crocodiles, turtles, lizards etc), I assume because conditions were survivable near the equator. But no large fauna survived.

      • Not "other reptiles" - dinosaurs were not reptiles, they split from the common common ancestor almost as far back as the proto-mammals did (Those sail-backed "lizards"? Those are our very early proto-mammal ancestors). Some of the big early differences were that dinosaurs were probably warm-blooded before they got large, and definitely evolved more efficient lungs and hearts pretty early on - heck, that's probably one of the reasons the early proto-mammals mostly died out, we couldn't compete against thos

    • The flying probably made the difference. They could range further in search of food, and escape predators in three dimensions. Maybe the ground dwelling dinosaurs that were the same size as birds couldn't compete against birds who could just swoop in and eat all the food and then find and migrate to a new area much faster.
      • Also the feathers, for warmth.

        It's probable that some non-avian theropods also had feathers, and of course, the pterosaurs could fly (and many small species). So the only reason I can think why birds survived while none of the other dinosaurs or pterosaurs did was the combination of small size, flying, and warmth.

        • I've never heard any suggestion that pterosaurs had feathers - their wings were great big flaps of skin, like a bat. They were also reptiles, not dinosaurs, so there was zero chance they had any of the adaptations that evolved among dinosaurs.

          I'm trying to remember if I've heard of any evidence that *any* dinosaurs other than the hollow-boned theropods had feathers - I think it's believed to have been a relatively late adaptation, even if you include the more fur-like proto-feathers I think the oldest evide

        • Pterosaurs had 'pycnofibers' analogous to hair and were warm blooded, so I'd either guess that they were just unlucky or perhaps birds and mammals were more adaptable in important ways post impact https://en.wikipedia.org/wiki/... [wikipedia.org]
          • But feathers probably provided more warmth than hair, while also being very aerodynamically useful.
            • That probably depends on the species (I imagine the insulative capabilities of penguins and sparrows differs) but you could be right that the pterosaurs had different tolerances. I do wonder if maybe the intelligence differences mattered since mammals and birds are famously clever compared to other clades.

    • Some of them are probably sitting in a tree outside your window right now.

      Odd how of all the dinosaur genera only the birds made it through. Other than flying I wonder if there's anything else that gave them an advantage in those conditions?

      Perhaps there were more feathered smaller species at the time? Survival of those first few months/years would have been tough for larger creatures looking for food. Tiny beaked creatures? Tough, but not nearly as tough.

      • Were they beaked yet? I thought that was a later adaptation.

        But yeah, small size and insulation seems to be a really common theme among the few land species that survived.

        I couldn't swear to it, but I suspect the reptiles that survived were either aquatic (e.g. the crocodillians), or burrow-dwellers that could hide from the cold and maybe even hibernate.

        • Were they beaked yet? I thought that was a later adaptation.

          I'm going for the probability that, even if they didn't have beaks, they were heading toward the "pecking things from the ground" mouth protrusion for their mouths. I should probably research that at some point, but the research list grows longer than the hours I have to get looking.

    • Small size, insulation, ability to migrate more easily than land based creatures to where food was. Pterosaurs were also very diverse and shared many of these traits, so there were certainly other things or perhaps stability of nesting sites that would've played into it.

    • Re: (Score:2)

      by Saffaya ( 702234 )

      The answer is Thermal Isolation.
      Any hot-blooded species that didn't have it went extinct.
      Some dinosaurs had feathers -> survived as birds.
      Mammals had fur -> survived
      etc...

  • oblig... (Score:5, Funny)

    by LordHighExecutioner ( 4245243 ) on Tuesday October 31, 2023 @05:31AM (#63968222)
    ...xkcd [xkcd.com] post

    • Re: (Score:2)

      by PPH ( 736903 )

      That's just big dust.

    • The tooltip on this one is particularly good. "The Late Heavy Bombardment was followed a few billion years later by the Comparatively Light but Oddly Specific Bombardment".

  • We used to have that. Now it's 23 C and tomorrow is the first day of November.

    • So, you are in the southern hemisphere?
      • I am in the Northern hemisphere, above the 38th parallel, and yesterday the high in my region was about 23 degrees C.
        • I'm only above the 37th parallel, but we had snow here on Sunday. There's still some on the ground in shady spots, so I can call this a White Halloween.

    • -11 C this morning where I live... (Norway)

    • We used to have that. Now it's 23 C and tomorrow is the first day of November.

      I live in Texas, near the Gulf Coast. Yesterday the temperature went from about 29 C down to about 8 C.

    • Still have winter here.

      47 N and 34 F at 09:40.

    • A drop of 15 deg C: what is that in kelvins?

  • I just scanned the previous artice "Google Promises a Rescue Patch For Android 14's 'Ransomware' Bug" and got to this one "Asteroid Dust Caused 15-Year Winter That Killed Dinosaurs, Scientists Say". So Google's patch doesn't emit deadly dust, right?

    • > So Google's patch doesn't emit deadly dust, right?

      They call it 'shedding' these days.

      "How could they have possibly missed this?"

  • Make Up Shit So You Can Keep Your Overpaid Job (Score:5, Funny)

    by zenlessyank ( 748553 ) on Tuesday October 31, 2023 @06:10AM (#63968298)

    Next week it will be some other stupid made up shit. They died in the fucking flood, you stupid motherfuckers.

  • Around 66 million years ago, an asteroid bigger than Mount Everest smashed into Earth

    Mount Everest? What kind of unit is "Mount Everest"? [theatlantic.com] What is that in hippos or adult koalas?

  • The "Amy Schumer method of research": steal research, like how she steals jokes, from decades years ago thinking nobody will remember.

    The effect of dust & ash, particulate matter, from the impacts of global-extinction-sized asteroids has been established for decades.

    The line 'But the idea that it was sulfur, rather than dust, that caused the impact winter has become "very popular" in recent years' is misleading because articles & papers from 20+ years ago contain statements like "shrouding the glob

    • Did you read the paper or even the article? No one is "stealing" research. It had been previously proposed that dust from the impact causing prolonged winter could have contributed to the mass extinction. Logically that made sense but an objection was the dust may not have stayed in the atmosphere long enough to cause prolonged winter for a large area. The paper details how analysis of particles from one site provides evidence in that the very small dust particle sizes could have blanketed the hemisphere in

    • Just because something became popular recently doesn't mean it's never been popular before. Think bell-bottom jeans.

      It's less common in science because there does tend to be a fairly steady march towards greater knowledge. But the study of ancient history, be it archaeology or paleontology, is particularly low on available facts to work from - mostly spinning elaborate stories to fit extremely limited data, without the benefit of being able to conduct experiments to get more. And as such particular stori

  • Couldnt hit harder to finish the fucking job?
  • A 15 degree temperature drop seems to be the only thing that can rescue us from our own self-created temperature rise doom.

    • No, that would just make things worse. Once we have stabilized CO2 levels, and started to lower it, we could consider dropping temperatures by a degree or so using geoengineering, and even that is probably inadvisable.

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