A Massive Impact Crater Has Been Detected Beneath Greenland's Ice Sheet (gizmodo.com) 172
An anonymous reader quotes a report from Gizmodo: An unusually large asteroid crater measuring 19 miles wide has been discovered under a continental ice sheet in Greenland. Roughly the size of Paris, it's now among the 25 biggest asteroid craters on Earth. An iron-rich asteroid measuring nearly a kilometer wide (0.6 miles) struck Greenland's ice-covered surface at some point between 3 million and 12,000 years ago, according to a new study published today in Science Advances. The impact would've flung horrific amounts of water vapor and debris into the atmosphere, while sending torrents of meltwater into the North Atlantic -- events that likely triggered global cooling (a phenomenon sometimes referred to as a nuclear or volcanic winter). Over time, however, the gaping hole was obscured by a 1,000-meter-tall (3,200-foot) layer of ice, where it remained hidden for thousands of years. Remarkably, the crater was discovered quite by chance -- and it's now the first large crater to be discovered beneath a continental ice sheet.
Whoda thunk (Score:2)
Something not known to be there amazingly found by chance.
range (Score:4, Insightful)
Isn't 12,000 --3,000,000 years a pretty big window?? Or is that par for the course?
Re: (Score:1)
Re: (Score:2)
It might have been a supernova. There was evidence of neutron bombardment of chert in the North American continent.
Re: (Score:2)
Citation?
My hits start off with "PALEOINDIAN OCCUPATION of North America ..."
WTF.
North America is not India.
Re: (Score:2)
Re: (Score:2)
I do swim in these waters and the "Americas" part of it is just as wrong.
Re: (Score:2, Funny)
Isn't 12,000 --3,000,000 years a pretty big window?? Or is that par for the course?
Their other job is Ocean Climate Scientist [slashdot.org].
Re: (Score:3)
If it hit slushy water, it would be hard to tell when the actual collision occurred as there isn't any Carbon to do Carbon-dating. They could take ice cores, but that would only tell when the crater was filled in, but not when it was formed.
Re: (Score:3)
I'm not sure what carbon dating could have to do with this anyway, since carbon dating generally involves the uptake of carbon by biologic systems.
Not to mention that 14C has a half-life of only ~ 5700 years.
Some ice cores from central Greenland have shown undisturbed annual layering (looking at the stable isotope 18O) going back to 125K years... so I would think either this impact occurred before that, or else the region affected by the impact did not reach to the center of the island.
Re: (Score:2)
Re: (Score:2)
Carbon dating is not the only tool in the dating toolbox. For this, I'd hope for micropalaeo, but since they don't mention that they either couldn't budget for getting seabed samples (icebreakers with a hefty over-side crane, significant tonn
Re:range (Score:5, Informative)
<quote>
Some pre-glacial channels were seen below the ice sheet at the site of the crater, which suggests the Greenland Ice Sheet was already in place when the asteroid struck. The exact timing of the asteroid strike, however, is fairly vague, with the researchers saying it happened between 3 million and 12,000 years ago. But preliminary evidence suggests it happened relatively recently. The crater appears to be well-preserved—a surprising observation given that ice is a powerful erosive force. The crater is likely fairly young from a geological perspective.
“It is correct that the crater is not well dated but there’s good evidence that it is geologically young, that is, it formed within the last 2 to 3 million years, and most likely it is as young as the last Ice Age [which ended around 12,000 years ago],” Larsen explained to Gizmodo. “We are currently trying to come up with ideas on how to date the impact. One idea is to drill through the ice and get bedrock samples that can be used for numerical dating.”
<unquote>
Re: (Score:2)
It's under a half mile of glacier. Tell you what, we'll get you a long pole and you go up to poke around. Be sure to come back and tell us your estimate.
Re: (Score:2)
pfff... half a mile? That's nothing!
The deepest hole my buddies and I dug was 3.5 miles and we did it with a long pole made of a string of pipes. Also, a geologist was analyzing the layers as we were doing it.
Some other dudes even went as deep as almost 8 miles...
https://www.oilandgasiq.com/dr... [oilandgasiq.com]
Re: (Score:2)
Re: (Score:2)
Nope Rock Doctor! But I have posted about oil rigs about 2-3 times on /. since maybe 2005 and you have always replied to my posts. You are the only one that did so we must be the only persons on /. with oil rig experience :)
I believe the last time we were arguing about spinning chains and I was telling you it was pretty safe if you knew what you were doing and you had a hard time to believe that but you finally admitted that you never did spin a chain. Spinning chains is very low risk compared to other haz
Re: (Score:2)
Oh! I forgot, your argument was in favor of iron roughnecks while I was bitching about them making the whole process much slower and that they were for dummies similarly to where technology sometimes seems to be going these days.
In truth, iron roughnecks prevent a lot of injuries but very few if any that would have been caused by spinning a chain. Hints: tongs, rotary table...
The danger of chain spinning is a myth that is used to make things look scary in documentaries.
As well, iron roughnecks might be fas
It's under an ice sheet (Score:2)
Isn't 12,000 --3,000,000 years a pretty big window?? Or is that par for the course?
The main reason for the wide window is just that they only recently discovered it and most of the geologic record needed to pin it down more accurately is buried under hundreds to thousands of feet of ice. It's going to take them a little time to gather the evidence and narrow the error bars.
Re: (Score:2)
Re: (Score:2)
Paris (Score:2)
Is Paris a unit of area now?
Are we talking the 105 km^2 inside the old city walls (plus east and west parks?),
or the 17,174 km^2 of present-day Paris?
Re: (Score:2)
Indeed. Library of Congress is a well-established unit and should be enough for anyone.
Re: Paris (Score:2)
One Paris is one megacoffee. Well known unit.
Re: (Score:2)
Is Paris a unit of area now? Are we talking the 105 km^2 inside the old city walls (plus east and west parks?), or the 17,174 km^2 of present-day Paris?
We ran out of football fields.
Paris (Score:2)
Re: (Score:2)
Think of all the sidewalk cafes unceremoniously destroyed by this meteor...
Asteroid estimator (Score:4, Informative)
https://impact.ese.ic.ac.uk/Im... [ic.ac.uk]
So, you get a crater roughly the right size in that sort of rock if it is 2.5 km in diameter. You get 0.85 megatonnes equivalent energy, which is next to nothing. No significant global effect.
Re: (Score:1)
Um, you get 850,000 MegaTons.
Re: (Score:2)
Re: (Score:2)
Your math is... way, way off - 8.47*10^5 megatons is 847,000 megatons, not .85 megatons.
Is this the impact? (Score:2)
So is this the impact that caused the Caroline Bays [youtu.be]?
Re: (Score:2)
Incorrect units used. (Score:2)
Area is always measured in Rhode Islands, volume in Olympic Sized Swimming Pools, Length in Football fields, ( = 10 school buses). Information in LoC (Library of Congress). BTW, length != distance. Distances are measured in Trips Around the Equator.
Re: (Score:2)
Area is always measured in Rhode Islands,
Much of the US is familiar to foreigners, but aside from Family Guy being set on the island, we know nothing of it.
Can't you use something more famous like Grand Canyons?
Re: (Score:2)
For area we have "Size of football field (= 1 micro Rhode Island)" and "Size of Manhattan (= 1 milli Rhode Island)".
SI = Systems Idiotica
Re: (Score:2)
Rhode Island: more road than island. Discuss.
Re: (Score:2)
Come on people, the International Standards of Units and Measurements is head quartered in Paris.. But Paris is NOT a standard unit of measurement for area.
In the UK the area units of that order are the "Isle of Wight" and, next up, "Wales". Paris is obviously an EU unit, to be deprecated. However I thought that in the USA the nearest equivalent to the Isle of Wight or Paris is "The area a man can ride round on a horse in a day". Isn't that the way that Oklahoma was carved up in 1889?
Mine it (Score:2)
Large metallic meteor impact? Mine it. True fact: pretty much all the gold we mine got here by way of metallic meteor impact. [bbc.com] Our own gold supplies having sunk deep into the core before the crust was formed. South Africa got its gold this way. Of course, the crater that did it for them is a bit bigger, just the lava dome in the middle is twice the diameter of this Greenland crater.
Re: (Score:2)
You're not wrong about there being inhomogeneity in the minor element and isotopic composition of the upper mantle - as sampled by diamond inclusions, and includin
Re: (Score:2)
A large meteor isn't that big compared to a mine.
Not the meteor, the crater. Look at the map. [wikipedia.org]
Interesting To Look At the Article Map (Score:2)
Too bad Slashdot doesn't do images (or maybe not, goatse and all). Looking at the map in the article the glacier perimeter actually follows the crater rim for about 40% of its circumference. The rim must be stabilizing the glacier right now.
Re: Date Range (Score:2, Funny)
It also caused climate change. We should outlaw asteroids, perhaps a bunch of world leaders could fly to Paris and sign an agreement saying that no more asteroids are allowed to hit the earth, or the US should pay for damages if one does.
Re: Date Range (Score:4, Funny)
"Hey, you know this thing we can do something about? Lets not do anything because it's possible for things we can't do something about to also do it! Lol!"
Re: (Score:2, Interesting)
You need to define the something in "do something about". Most of the "somethings" that people have proposed are more expensive than they're worth and result in vast amounts of dead people in third world nations. At least, that is so according to a recent Nobel Prize winner.
Re: (Score:2)
Honestly it's not a bad idea if only for the reason that we could gain a consensus on whether or not to just let one hit us.
Re: (Score:2)
Honestly it's not a bad idea if only for the reason that we could gain a consensus on whether or not to just let one hit us.
How's about instead we drum up interest for asteroid mining?
Re: Date Range (Score:3)
On the bright side, we now have a solution to global warming. Let's get NASA on this stat!
Re: (Score:2)
What's your estimate?
Re: (Score:2)
I think if it was only 12,000 years ago, we'd have known about it. Physical evidence, written evidence (it would be in the precursor texts to the old testament or something).
Re: (Score:2)
Which we have, it is called "The Flood". And we have written texts about it ...
However written texts are not such old ... perhaps you want to google "oldest written language" or something similar.
Re: (Score:2)
However written texts are not such old ... perhaps you want to google "oldest written language" or something similar.
About half that, yes, but folklore is older and it gets incorporated.
You think this was the cause of the flood?
Re: (Score:2, Interesting)
Many "scientists" examinating old sites like stone henge or sites like https://en.wikipedia.org/wiki/... [wikipedia.org] believe that "the flood" happened about 12000 years ago, just before the end of the ice age. The reason is that magalitic stone sites like this have astronomic properties that point to a particular point in sky. (All over the planet big monuments point to the same point).
That is the suns rising point during the spring equinox 12000 years ago, researchers believe that this is a "time reference". Many site
Re: (Score:2)
"And it is plausible that we once had a civilization on the level of industrialized England 1890 or so, 12000 years ago."
And your evidence of plausibility is what, precisely? It is not plausible there are pink unicorns. Why? Fossil evidence doesn't lead to horses with horns coming out of their foreheads. But you can believe in pink ones if you like. There is also no evidence that there was anything beyond some rudimentary tools 12,000.
You don't work for the "Aliens!!" guy with the electric hair do you? He g
Re: (Score:2)
And your evidence of plausibility is what, precisely?
Perhaps you want to open a dictionary and check again what the words "plausible" and "evidence" mean.
If there was an civilization like my example: England around 1870/1900, somewhere e.g. in Indonesia, it is now 70m under the sea, hundreds of km off the coast, burried below sediments created over a time of 12000 years.
That is completely plausible. Is it true? No, I just made it up, obviously. It is called: "Gedankenexperiment"!
Re: (Score:2)
Well, there's a story of great flood associated with Sumeria's Gilgamesh, of whom the Hebrew priests might have modeled their Noah's flood story after. What seems likely is that, as glaciers receded and ice melted at the end of the last ice age, severe and extreme flooding occurred across many parts of Eurasia, giving birth to various world flood myths.
Re: (Score:2)
Yes,
but the myths are all about rain, and the retreating glaciers did not cause that.
There are assumed three floods. Two caused by volcanoes around the great lakes (which would cause a quick sea level rise and tsunamis) and the third one by an asteroid/comet impact. However that was also supposed to have happened on the north american ice shield. But Greenland is close.
Re: (Score:2)
Most people's ideas of the "world" at the time probably involved a 50 mile radius.
Re: (Score:3)
There's a number of ideas as to why a "global" flood myth shows up IN CULTURES NEAR LARGE BODIES OF WATER, one of which being the collapse of the containment of Lake Agassiz. Others point to the eruption of Thera, or even a particularly bad annual flood of the Mesopotamian flood plane. The common point of all of
Re: (Score:2)
Flood myths are planet wide, and they are all cornered about rain.
Re: (Score:2)
Flood myths are not planet wide, they're typically localized to cultures that are near bodies of water
You need to read more; @angel'o'shere has it right, there are a lot of "flood stories" from cultures all around the world, even from cultures that live in the mountains.
There's also a lot of evidence for a global flood. I live at over 700 feet above sea level and over 300 miles from a large body of water. Yet, there are all kinds of fossils of sea-dwelling animals around where I live. A perfectly reasonable explanation is the land masses used to be flatter, until something (like maybe a big asteroid hitti
Re: (Score:2, Insightful)
This post getting modded up to +4 interesting is a perfect example of how slashdot has jumped the shark. Or at the very least proof of mod bots.
Re: (Score:2)
You are right. It should have been modded +5 Interesting and not +2 Informative.
So: what is your mental problem?
Re: (Score:1)
Re: (Score:2)
...12,000 years ago we were coming out of an ice age - and have been doing so since.
"Have been doing so since? Only if you ignore the last 6000 years. [climate.gov]
Re: (Score:2)
Re: (Score:3)
Interesting. I have a new contender for favorite name of event, the Bølling oscillation. Not quite as good as the Defenestration of Prague, but it's up there.
Re: (Score:2)
CSB: That extinction strongly contributed to holding back civilization advances in the Americas as there were no usefully domesticatable beasts of burden and those turn out to be a big deal for food production, which is a requirement for being able to support trade specialists.
Re: (Score:3)
I think if it was only 12,000 years ago, we'd have known about it. Physical evidence, written evidence (it would be in the precursor texts to the old testament or something).
Extract from the diary of Olaf Gunnerson form Greenland....."February 27th. Sitting on the glacier looking up to the sky. There's something unusual there, and it's getting bigger. In fact, I think it's coming towards me. I think it m "
Thousands of years before written records (Score:2)
I think if it was only 12,000 years ago, we'd have known about it.
It would be shocking if we knew anything about it. It's in a remote and barely inhabited part of the world, far from any sizeable human settlement at the time, thousands of years before there were any written records we know of outside of a few cave drawings.
Physical evidence, written evidence (it would be in the precursor texts to the old testament or something).
Physical evidence outside of the geologic record would be extremely sketchy. The oldest written records we have are from about 4-5000 years ago [wikipedia.org] so there would be nothing reliable in even our oldest texts about an event that happened at least 7 thousan
Re: (Score:2)
The leading hypothesis for the Biblical flood is the inundation of the Black Sea basin as interglacial rising sea levels caused the Mediterranean to spill over through the Bosphorus. The timing would have been about right for the Old Testament.
We could trawl Viking sagas for traces of the Greenland impact.
Re: (Score:2)
Re: (Score:2)
My point is that if there is no legend of a fall of great fire, wecan exclude Viking historical times from that rather broad date range.
Re: (Score:2)
Applehu Akbar claimed:
The leading hypothesis for the Biblical flood is the inundation of the Black Sea basin as interglacial rising sea levels caused the Mediterranean to spill over through the Bosphorus. The timing would have been about right for the Old Testament.
Mmm - no. On both counts.
There's considerable controversy [wikipedia.org] about whether the Black Sea Deluge was a sudden, catastropic event, or one that took place more slowly, forcing inhabitants of the basin to evacuate, but not instantly drowning them. There are experts of equal qualification on both sides of the debate, and it has not been resolved in any definitive way.
Meanwhile, the Flood Myth [wikipedia.org] is a feature of many ancient civilizations' mythologies. The Sumerian version includes a man who overh
Re: (Score:2)
Yeah, there's no physical evidence that there was ever global flooding.
And I find the idea that an oral tradition would survive several thousand years of retelling to be...questionable.
Australian Aborigines have an accurate oral history that goes back over 10,000 years. Do a google search and there is much to read about. A quote:
The researchers now believe that these stories could constitute some of the oldest accurate oral histories in the world, passing through some 300 generations.
Oral histories (Score:2)
Australian Aborigines have an accurate oral history that goes back over 10,000 years.
They might have an oral history with some verifiable facts but you'd have to be pretty generous with your definition of "accurate" to use the word meaningfully. There might be some evidence in the information but it's deeply unlikely that any such stories passed down through that many generations survived without substantial alterations and errors. Not to mention that there is no means to go back and actually check what the stories originally said for most types of facts.
Oral histories and eyewitness test
Re: (Score:2)
Yeah, there's no physical evidence that there was ever global flooding.
That's not exactly true, there IS evidence that is consistent with this theory of a global flood and evidence that is inconsistent with the idea. However, what's missing is overwhelming evidence to prove it or consensus among researchers that it happened.
Consensus is that it didn't happen.
However, given that nobody was there to witnesses what did or didn't happen, we are left with little actual proof either way, just the evidence and all the possible ways to explain how it fits into the theory of choice
Just discovered and still under ice (Score:2)
That's quite the range of ages: two orders of magnitude. Not an impressive estimate.
They just discovered the thing and it's buried under a huge amount ice. It's going to take a minute to find the evidence to more precisely pinpoint the impact date. Furthermore, when you are talking about geologic time, a million years is barely a blink of an eye.
From TFA:
“It is correct that the crater is not well dated but there’s good evidence that it is geologically young, that is, it formed within the last 2 to 3 million years, and most likely it is as young as the last Ice Age [which ende
Re: (Score:2)
Re: (Score:2)
You're moms ...
We're dads.
Re: Date Range (Score:2)
Re: (Score:2)
... stable genius ...
Know what you don't see much anymore?
Horseshit in a garage.
Re:Dinosaurs had feathers (Score:5, Informative)
Which to believe
Which to believe? The most obvious thing to believe is that your concept of science is drastically wrong.
What you should believe is that scientists will update their hypotheses and conclusions as new data becomes available. Try that out. Then you won't be so perplexed by the list you posted.
Re: Dinosaurs had feathers (Score:2)
Another point that what happened a million years ago cannot be used by himanity in any practical way. All that matters is what we have now: technoloy, experiments, verifiable and falsifiable hypotheses.
Re: (Score:2)
What you should believe is that scientists will update their hypotheses and conclusions as new data becomes available.
The problem with that is that so will the OJ Simpson defense team ("update their hypotheses and conclusions as new data becomes available").
"Oh . .. so you found his DNA at the scene? Well, er, ah, he "bleeds all the time", yeah, that's it! We updated our model!"
Re: (Score:2)
Re: (Score:2)
That's a description of religion, not science.
Is it really?
Where I understand the argument you are making, logically if you start with assumptions and doggedly try to construct ways the evidence supports that assumption as a scientists, are you not doing the same thing as religious proponents? I think they are eerily similar in appearance from the outside observer.
This whole discussion rapidly become a question philosophy does it not? Which precludes your statement actually being provably true, but just an assumption, does it not?
Re: (Score:2)
I think they are eerily similar in appearance from the outside observer.
Appear similar to someone ignorant about the subject - got it.
LEDs and stars are eerily similar in appearance too, from a distance. Must be the same thing.
Re: (Score:2)
Woosh!
But hey, that's what you where after wasn't it, missing my point.. Oh? You where making fun eh?
If that's what you tried to do, you just proved my primary point is true, in claiming to be the holder of "absolute truth" you've done the same logical thing as those you make fun of have done. Which again, WOOSH only bigger this time.
Re: (Score:2)
I think they are eerily similar in appearance from the outside observer if the outside observer is a fucking idiot.
Fixed that for you. Science doesn't twist evidence to fit the hypothesis. If you find evidence that disagrees with the hypothesis, science says the hypothesis has to change... not the evidence. That's exactly opposite for religion. ANYONE with a remote understanding of the scientific process understands that.
Re: (Score:2)
Thanks for helping to make my point.
How so?
Well you display all the hallmarks of religious zealots who severely judge those with whom they disagree with rude impatience. Which is why I say they are similar. You do see the irony of all this right? Yea, I didn't think so...
Re: (Score:2)
Note that most of those sentences come from Journalism, not Science. The scientific papers will have probabilities and distributions and often alternative explanations, but the general public can't cope with that, so the journalist breaks it down to "Science proves ..."
Re: (Score:2)
https://en.m.wikipedia.org/wiki/Younger_Dryas_impact_hypothesis
Exactly. There is more and more evidence mounting that the 'fringe' story we're being told about human history is the mainstream view of it. Sooner or later the archeological "theories" and gradualism will collapse under the weight of geological evidence.
Re: Younger dryas culprit? (Score:2)
Too small, according to the impact calculator.
Re: Fuck this garbage website (Score:2)
It has always been a news aggregator, yes.
Re: (Score:2)
Was it always like this and I never noticed?
Not always, no. For the last 20+ years, yes.
Re: (Score:2)
Well, it is where she sat down at any rate. I think further test will indicate a bifurcated depression.
Re: (Score:2)
The impact was massive, exactly as the head line states.
Since this is a nickel-iron asteroid there will be a mass concentration below the crater, so yes there should be anomalous mass there.
Re: (Score:2)
we finally have it: anti-gravity has been discovered
If the crater material had negative mass it would have flown out of its own accord. No asteroid needed.
Re: (Score:2)
After several years of work by seismic survey boats, seabed samplers, more seismic on a different spacing, and a team of a dozen geologists working for about 5 years on "developing the prospect ... and several lawyers and bean counters working on the drilling permits and financials ... I've seen 300+million year errors assigned to a structure. And proved wrong as soon as we put a drill bit into the structure.