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Earth is Missing a Huge Part of Its Crust. Now We May Know Why. (nationalgeographic.com)
A fifth of Earth's geologic history might have vanished because planet-wide glaciers buried the evidence. From a report: The Grand Canyon is a gigantic geological library, with rocky layers that tell much of the story of Earth's history. Curiously though, a sizeable layer representing anywhere from 250 million years to 1.2 billion years is missing. Known as the Great Unconformity, this massive temporal gap can be found not just in this famous crevasse, but in places all over the world. In one layer, you have the Cambrian period, which started roughly 540 million years ago and left behind sedimentary rocks packed with the fossils of complex, multicellular life. Directly below, you have fossil-free crystalline basement rock, which formed about a billion or more years ago.
So where did all the rock that belongs in between these time periods go? Using multiple lines of evidence, an international team of geoscientists reckons that the thief was Snowball Earth, a hypothesized time when much, if not all, of the planet was covered in ice. According to the team, at intervals within those billion or so years, up to a third of Earth's crust was sawn off by Snowball Earth's roaming glaciers and their erosive capabilities. The resulting sediment was dumped into the slush-covered oceans, where it was then sucked into the mantle by subducting tectonic plates.
Effectively, in many locations, Earth buried the evidence of about a fifth of its geological history, the team argued this week in the Proceedings of the National Academy of Sciences. The notion is elegant but provocative, and the authors themselves predict that some geoscientists will express skepticism. "I think, though, we have extraordinary evidence to support that extraordinary claim," says study leader C. Brenhin Keller, a postdoctoral fellow at the Berkeley Geochronology Center.
So where did all the rock that belongs in between these time periods go? Using multiple lines of evidence, an international team of geoscientists reckons that the thief was Snowball Earth, a hypothesized time when much, if not all, of the planet was covered in ice. According to the team, at intervals within those billion or so years, up to a third of Earth's crust was sawn off by Snowball Earth's roaming glaciers and their erosive capabilities. The resulting sediment was dumped into the slush-covered oceans, where it was then sucked into the mantle by subducting tectonic plates.
Effectively, in many locations, Earth buried the evidence of about a fifth of its geological history, the team argued this week in the Proceedings of the National Academy of Sciences. The notion is elegant but provocative, and the authors themselves predict that some geoscientists will express skepticism. "I think, though, we have extraordinary evidence to support that extraordinary claim," says study leader C. Brenhin Keller, a postdoctoral fellow at the Berkeley Geochronology Center.
It's called the moon.
Except the glaciers didn't "saw" off the crust (because glaciers don't "move") but pulverized it under their weight as the ice and snow built up and with annual run-off draining the sediment away.
Certainly that's what I was taught in my midwest high school surrounded by lots of plains and "flatland", made so by the glaciers that came before us.
up to a third of Earth's crust was sawn off by Snowball Earth's roaming glaciers and their erosive capabilities.
Let's see, we could worry about the Earth maybe getting a few degrees warmer and having to back away from the ocean a bit.
Or we could worry about ENTIRE CONTINENTS being "sawed off the earth" by glaciers as the rest of us starved because there was nowhere on earth you could grown more than a handful of crops in the icy cold.
Way better in my mind to engineer how to deal with warming - and keep it permanent - rather than let the Earth slide back into yet another long ice age, as it is otherwise bound to do.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
Someone, I don't know who, saw "crust" but heard "pie crust" and started eating the Grand Canyon!
you exactly where the crust went, and when, and why.
Why would they? Snowball Earth has been in the public consciousness for a while.
I knew it. Something good will come out of climate change. The ice melt will now expose Earth's hidden past.
Their entire society, technology, space ships, etc. were all wiped clean by the glaciers! Their satellites eventually decayed and burned up or got tossed into the sun.
What sort of monolith can we erect to withstand time to commemorate our existence to the future species who probably won't care?
Firstly, the age or the earth was estimated around the 6 billion year mark at least as far back as 40 years ago when I was in primary school so your timeframe is definitely off.
Secondly, are you saying science has to get things exactly correct the first time or it's bullshit? You live in a world where our ability to measure and estimate things does not improve over time and on the basis of other discoveries? Does that mean you live on a flat earth as well?
What are you talking about? The age of the Earth has been what rely known to be in the billions years for a lot longer than thirty years. They have narrowed in more on the exact age, and more precisely agreed on the dates for the various eras, of course.
Basically, in 1904, Earnest Rutherford demonstrates radioactive dating and the Earth was quickly determined to be not less than 1.6 billion years old (and recognized to be probably older). Before that, it was widely recognized as at least 100 million years old.
Nonsense.
The problem they might encounter with the skeptics is explaining why the missing rock seems to be so uniform all over the globe. Surely the glaciers would be thinner at the equator? The missing rock should not go as far back at the equator as the topical zones, I would think.
Look back up at my post, now look back down, you're on the Internet. Now look back up. I'm a signature.
Were you home schooled?
Has the made it difficult to find other people who think like you?
I would suggest that you become besties with superkendall, he is from the same background
Strip mined by aliens?
it's responsible for the disappearance of Pangea as well.
The poor sods who wrote this paper will be crushed by the Global Warming maniacs.
Not at all. This aligns perfectly with our existing understanding of Earth. Climate changes slowly over periods hundreds of thousands and millions of years.
The problem with global warming is that the climate is changing in a periods of decades. This is a problem because this does not provide the time required for fauna/flora to evolve. As a result of this decreased period, many species are facing extinction.
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All the cool, popular kids have their PB&J sandwiches made with the crust cut off. So Mother Gaia just tried to copy!
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
Expected to see comments about how it was an alien civilization that resided here and then wiped their evidence by snowballing the planet (purposefully or through total warpocolypse); but it looks like I'm the first to postulate that theory...here...at least.
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What if, instead, the layers where the rock is were caused by some massive impact?
Or are the densities of the rock layers that are present too much for that to be feasible?
I guess it would depend on the ratios of present rock : not present rock layers.
Or potentially volcanic in nature. But that would be a harder sell since it would also require finding a volcano big enough to spew out potentially so much dust and new land. Also needs to be the proper material since volcanoes spit out very identifiable materials. Less likely as it was probably already checked, although again, depends on the ratios.
Glaciers do seem the most likely though. We've known Earth has went through many ice-age periods that has eroded the absolute shit out of landscapes.
God only knows what secrets have been wiped clean off the surface by erosion.
We'll never know the full evolutionary history of life because most of it gets wiped away by erosion.
The fossils we find were in ideal conditions for fossilization. Most of Earths biochemistry is not ideal for fossilization.
There are some lifeforms that are ideally suited to self-fossilize, like shell-based lifeforms. But even that's iffy at times.
The only way we will know is literal time machines
.
The poor sods who wrote this paper will be crushed by the Global Warming maniacs.
Not at all. This aligns perfectly with our existing understanding of Earth. Climate changes slowly over periods hundreds of thousands and millions of years.
The problem with global warming is that the climate is changing in a periods of decades. This is a problem because this does not provide the time required for fauna/flora to evolve. As a result of this decreased period, many species are facing extinction.
How do you know climate change is limited in rate like that?
Because that's the resolution of the rocks that recorded the changes?
In other words, there was no instrument in place to record any faster changes if they happened.
We all get embarrassed about our teenage years. But most of us don't go to the trouble of destroying a sizable portion of ourselves in order to hide the evidence of what we've done during that time.
Y'know, I'm no geologist (clearly), but every time I hear things like the earth was previously entirely covered in ice, it makes me wonder: What's "normal"?
It seems like we're worried about climate change, and willing to spend trillions of dollars (or some politicians are trying to get us to spend that much, that is) in order to prevent it from happening, but this sounds pretty ignorant of us considering the earth's history. It seems like we're defining "normal" as whatever we've been used to during our lifetimes (which, in geological terms, amounts to a fart in the wind). It seems incredibly arrogant of us to try to "reverse" what (it's been claimed) we've done.
And even if we don't have proof, we all know it is happening.
Sometimes the crust is the best part. Though not pizza crust; no sauce, no cheese, no meat, no shrooms.
But apple crumble crust? Oh baby...
Maybe there is nothing missing and the Biblical story is correct after all. If so, then we are all just searching for phantoms.
https://www.livescience.com/62...
Artifacts of human or other industrial civilizations are unlikely to be found on a planet's surface after about 4 million years, said Frank and study co-author Gavin Schmidt, director of NASA's Goddard Institute for Space Studies in New York. For instance, they noted that urban areas currently take up less than 1 percent of Earth's surface, and that complex items, even from early human technology, are very rarely found. A machine as complex as the Antikythera mechanism â" which is considered to be the world's first computer from ancient Greece â" remained unknown until the development of elaborate clocks in RenaissanceEurope.
One may also find it difficult to unearth fossils of any beings who might have lived in industrial civilizations, the scientists added. The fraction of life that gets fossilized is always extremely small: Of all the many dinosaurs that ever lived, for example, only a few thousand nearly complete fossil specimens of the "terrible lizards" have been discovered. Given that the oldest known fossils of Homo sapiens are only about 300,000 years old, there is no certainty that our species might even appear in the fossil record in the long run, they added. [In Images: The Oldest Fossils on Earth]
https://www.nbcnews.com/mach/s...
âoeOur cities cover less than one percent of the surface,â he says. Any comparable cities from an earlier civilization would be easy for modern-day paleontologists to miss. And no one should count on finding a Jurassic iPhone; it wouldn't last millions of years, Gorilla Glass or no.
There is tons of theories that there has been previous intelligent civilizations prior to our own current one. Hell, NASA is even researching it. You are a moron to just activity dismiss this possibility. Both articles I reference note that artifacts would not survive millions of years.
Do I believe this? Not at the moment. But I am not a moron like some posters here that would refuse to acknowledge the possibility, even if a fucking previous intelligent artifact hit them in the head and was dated to 1,000,000 years of age. Fucking idiots
Anonymous comments are as pathetic as the anonymous "sources" that contaminate gutless journalism from the New York Time
We should have a reward here for the most misleading topic.
The very linked article itself, and further research about "Great Unconformity" clearly state that this particular unconformity is limited to the Great Canyon GRAND CANYON - THE GREAT UNCONFORMITY and from wikipedia Great Unconformity one can further learn about this "annomaly" together with it's explanation:
Unconformities in general tend to reflect long-term changes in the pattern of the accumulation of sedimentary or igneous strata in low-lying areas (often ocean basins, such as the Gulf of Mexico or the North Sea, but also Bangladesh and much of Brazil), then being uplifted and eroded (such as the ongoing Himalayan orogeny, the older Laramide orogeny of the Rocky Mountains, or much older Appalachian (Alleghanian) and Ouachita orogenies), then subsequently subsiding, eventually to be buried under younger sediments.
We could've avoid all the wide speculations if only the topic was reflecting the content, as "Hi, look what interesting about geology I found - it's old but a great read".
Don't tell me ... Trotsky-slut lib'rals die-bad from AGW ... po po poooz gag and choke, bend and weeeez, bleed from noz each time they peez.
99.9% of all the species ever to exist are extinct. I am pretty sure that every species is "facing extinction."
Current change is within the range of natural variation.
Assuming your assertion is true, it's not going to stay in that range much longer. On our current path parts of the planet will become so hot that they will uninhabitable to humans. That's totally out of wack.
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99.9% of all the species ever to exist are extinct. I am pretty sure that every species is "facing extinction."
Sure... but this is the difference between dying of natural causes and being brutally murdered. But hey, keep up the semantics, asshole. ;)
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I watched this video on YouTube just a little while ago. I've not really looked into the science of it nor modeled the impacts he's talking about but it might be possible that our earth is a remnant from a not-that-long-ago clash with an itinerant planet's moon. We live on the half of a then larger planet that was smashed by that moon, the rest became an asteroid belt and probably our moon. I think this is a more likely explanation for why a huge part of the crust might be missing than it having been scraped by icebergs. I'm just guessing the icebergs wouldn't have scratched that deeply and it seems like the fossil record would still be there at the bottom of the ocean if it had happened that way. Although I like the tectonic plate subduction argument, clashing rocks in space is much more violent and attractive.
https://youtu.be/ogw6BJRL_rQ?t...
This has to do with Sumerian civilization and the possibility of extra-planetary beings having given us technology way back then. If you're completely closed to that idea, this may not be for you. OTOH, you may be able to compartmentalize and accept the interplanetary collision separate from the extra-terrestrial civilization interference argument.
Only I can judge you.
but it checks out.
Jokes aside, approx 38 % of Americans believe in "Young Earth" creationism and 24% believe everything in the bible is the literal word of God ("literal" here means that nothing is a parable).
Hi! I make Firefox Plug-ins. Check 'em out @ https://addons.mozilla.org/en-US/firefox/addon/youtube-mp3-podcaster/
You must have head of the Roman Optimum and the Medieval Warm Period - and the many other examples of this. Even the Little Ice Age.
1. The Medieval Warm Period was localized to the north Atlantic region, with the pacific region getting colder. Current warming is increasing average temperatures across the globe.
2. The cause of the Medieval Warm Period (as per the link) is believed to have been solved.
3. Atmospheric CO2 has increased from ~300 to ~400 PPM since the 60s, in line with increased fossil fuel emissions.
4. The cause of the current warming is believed (by 90+% of the scientists investigating it) to have been solved. Spoiler alert it's the increasing atmospheric CO2.
Generally not all at the same time though, we tend to call those mass extinctions.
Aliens had a quarry here for a billion years or so before moving operations elsewhere...
Anyway what would really blow some people's minds and start some speculation would be if in exploring other planets such as mars, we find the same discrepancy during the same time period... Some destructive stellar event perhaps?
Also one of the big detractors of a past advanced civilization is the lack of any evidence surviving at all. However if about a billion years of geological data is missing, that's a pretty big gap to fall into!
Anyway before just now I didn't even know about the "Great Unconformity" which is pretty cool and interesting in of itself!
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Well, no. It never has over geological history, has it.
Yeah, I'm not talking about geological timescales, I'm talking about human timescales. By 2100 it's going to be 7*F hotter globally and that's a conservative estimate. That's a HUGE shift which is unprecedented. After that it's only going to get hotter until we do something about. You would have to be stupid or insane to think this is normal.
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Plus if the earth starts to cool like that we will have centuries to come up with a solution, perhaps burning that fossil fuel we kept in reserve..?
You are not thinking about all this in terms of momentum - way easier to keep the Earth from sinking into a decline, than it is to stop a decline in progress (especially given how long it would take us all to agree the danger is real).
We have lucked out into warming the climate by about the right amount before we switch to mostly alternative energy sources.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
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Good grief. Do you really believe that? It's complete and utter nonsense.
Perhaps you should tell that to the Trump administration because that's what they reported.
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They've all been captured by this nonsense.
What's more likely, that climate scientists who have studies the Earth for decades are correct or some fool on Slashdot knows better despite never actually studying the climate? Occam's razor does not favor you.
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Wow, you look at scientists and scientific evidence and decide it's all politics. You have brilliantly deluded yourself, sir.
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Right. You know, all a researcher has to do is be a "climate skeptic" and they get funded by any number of oil companies, they don't even have to be a climatologist. Have you considered that fact?
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Let's put it this way: the evidence for warming from CO2 is good. The sensitivity is nothing like the scenarios you suggest. The evidence for all the feedbacks needed to generate "runaway warming" is flimsy to non-existent.
Nobody claimed it was a runaway effect. The estimate is based on past, present and projected pollution. The report has 500 pages explaining this or you could have simply read the article.
There's been a 14% greening of the planet over the last 33 years as a result of the extra CO2 in the atmosphere (from satellite studies). This remarkable fact has been almost invisible to the mainstream media, NGOs and other activist scientists involved in perpetuating the paradigm.
I'm aware that the planet is getting greener as a result of CO2 and climate change. It's understood that flora will flourish in some regions while dying in others. The issue with climate change has always been about the death of fauna and the migration of arable regions of land. It's when the weather becomes erratic that crops are threatened but some flora will thrive. This doesn't mitigate the damage of climate change.
I would suggest you turn down your hysterics knob a few clicks.
You dismiss science as being hysterical instead of pointing to research that counters the evidence put forth? You response is as sound as that of an anti-vaxxer who is certain autism is a just a shot away.
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Haha, don't be daft. The 7C mentioned earlier is absurd based on the physics. Almost all of that increase is "runaway effect" (positive feedback).
7C? Who's the daft one now? Both I and the article clearly state it's 7F. The only runaway is effect being calculated is our use of polluting fuels in addition to the damage already done (which yet to come to full fruition).
The models using this clearly diverge from actual reality, which is why they have to be "tuned" to past data periodically. It's an exercise in curve fitting. People like you seem to think they're making some kind of super-robust prediction. Nothing could be further from the truth.
You're right that it's perfectly accurate but the "tuning" is not arbitrary, it's identifying previously unknown factors and correcting data from previously unidentified ill-calibrated sensors. For every time it's been "tuned" it's always turned out our previous estimate was too optimistic.
How is an argument to doubt the science because the reality is worse than predicted supposed to convey that in the future reality will be better than predicted?
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Wrong. It includes things like water vapour increase with temperature increase.
Those are feedback effects but they are far from being runaway effects. Perhaps you define it differently but to me if it's a runaway effect that means it's self-sustaining.
There's no evidence this is net increase or decrease as increased water vapour implies increased cloud cover, which itself reflects sunlight.
Wow, you are arrogant to think you are the only person that has even consider this. Understanding hydrology is the cornerstone of weather prediction.
The tuning is against past data so the model looks like it's accurate. You show the graph without any divergence today because you fitted it to past data, so it looks "accurate". The prediction of future warming is way too hot because the feedback assumptions in the model are wrong
The problem with this idea is that the models have been overly optimistic and it's hotter now than it we previously predicted. Assuming they are just data fitting then it's going to be even worse than predicted.
My argument is that it's not politically correct to research positive changes from warming and CO2 fertilisation. If you want tenure, you won't do it. If you want research grants, you won't do it. If you want other academics to say hello to you on campus you won't do it. And if you don't want to be piled on by mobs of NGO supported tards on social media, you won't do it.
You have presumed people are researching positive or negative impacts but research doesn't assume what the value of the impact beforehand but rather explains what has happened and concludes possible futures. If there are tangible benefits of any kind then Oil companies will fund that research and spend millions advertising it.
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