Crater under Greenland points to climate-altering impact in the time of humans | Hacker News Reader

Crater under Greenland points to climate-altering impact in the time of humans

sciencemag.org

89 pointshenridf43 comments

Looks like the maverick geologist Randall Carlson was right. The evidence was pretty damn good, but many in the mainstream geology had a hard time accepting it for some dumb reason. Just goes to show that real scientists should never bow to consensus opinions. The outliers always advance the fields.

Go listen to Randall's Joe Rogan appearances, they will blow your mind:

https://youtu.be/R31SXuFeX0A

https://youtu.be/G0Cp7DrvNLQ

https://youtu.be/0H5LCLljJho

https://youtu.be/tFlAFo78xoQ

The Younger Dryas Impact Hypothesis:

https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesi...

The controversy:

https://www.sciencenews.org/article/younger-dryas-comet-impa...

Maybe.

> The crater was left when an iron asteroid 1.5 kilometers across slammed into Earth, possibly within the past 100,000 years.

So there's a chance that there was an impact in the last 100,000 years. Carlson is saying that there was an impact 12,000 years ago. That's an even smaller chance.

I'm not saying Carlson's wrong, but I am saying you're taking a bit of a logical leap here. Further study could put this impact 1M years ago, or even 40,000 years ago, and either option would mean that this is not the impact Carlson is looking for.

This quote from the article makes no sense to me:

> Statistically, impacts the size of Hiawatha occur only every few million years, he says, and so the chance of one just 13,000 years ago is small.

If an event happens every one million years on average, for example, it's just as likely that the last one happened 13,000 years ago and the next one will happen 987,000 years in the future as that the last one happened 999,999 years ago and the next one will happen tomorrow. Even the interval can be highly variable.

But the total probability of the event happening "recently" (even if this is a fuzzy description) is far lower than the probability of it happening further away. If there's an event known to occur once in a trillion years and we observed it in our lifetimes, wouldn't you think that was remarkable?

Assuming that a meteor impact is totally random (which might not be true because objects that impact the earth could conceivably influence each other through gravity, etc), it is probably best to model these impacts as a poisson process.

A poisson process with an average arrival time of one million years means that we would find that if these size impacts happen on average once per million years that on any given day, like the day before this Greenland discovery, we should expect the next impact to happen a million years in the future and the previous impact to have occurred one million years in the past.

If buses arrive randomly and independently on average every 10 minute, then we can expect a ten minute wait at the bus stop if we get there at a random time.

Think of random points on the number line averaging a point every million years. Now throw a stochastic dart at the line. It’s much more likely to land in a large interval not the small ones—-they take up more space on the line. For this reason, the distance between the dart and the next random point is on average one million, not 500,000. So it is very unlikely that the meteor impact was only a few thousand years ago.

Yes... but averages are not overly meaningful when considering a single event.

Pablo Rodas-Martini on the significance of those findings:

"Wow! This scientific finding is huge. It rewrites the Younger Dryas: it explains the melting of ice sheets, the pouring of meltwater into the Atlantic, the disruption of the ocean conveyor belt, and the colder temperatures in the Northern Hemisphere."

[1] https://twitter.com/pablorodas/status/1062795179139194880

If you are interested in facts, it is always better to read the scientific article ("A large impact crater beneath Hiawatha Glacier in northwest Greenland"), if you can[1][2].

I stopped reading this summary at "and the released steam, a greenhouse gas, could have locally warmed Greenland, melting even more ice." Yes, steam is a greenhouse gas. No, that is not why Greenland may have been warmed by the steam. The steam itself is hot and would melt more ice. I can't find the word "steam" mentioned in the science paper. Gell-Mann amnesia effect I suppose.

[1]http://advances.sciencemag.org/content/4/11/eaar8173

[2]http://advances.sciencemag.org/content/advances/4/11/eaar817...

> The resulting explosion packed the energy of 700 1-megaton nuclear bombs

While not strictly on-topic, this wording is just weird, what's wrong with simply "700-megaton"?

Readers are likely much more familiar with the destructive power of a 1MT detonation (e.g. they can go watch one set off on YouTube). Nobody alive has seen a 700MT explosion.

Most people don't realize how variable a nuclear bomb is, so they want a soundbite that makes people think "a lot of nuclear bombs".

For context, nukes range from about .000001 to 50 megatons. If you combine all the nukes ever detonated, I don't think it would top 700 megatons.

Total appears to be 635 megatons - 545 Mt atmospheric and 90 underground Mt. Quite a bit more than I would have expected!

https://en.wikipedia.org/wiki/Nuclear_weapons_testing

As a species, we really enjoy blowing things up.

It's a bit unfair to blame the entire species when 2 countries are responsible for most of the nuclear tests.

https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests

How weird that countries that develop a new technology would test it far more than others who simply copied their work...

I have never been responsible for a nuclear test, but as a member of the human species, I can confirm that I really enjoy blowing things up.

The use of "nuclear" unnecessarily makes this a two-step relationship, too: an equivalence to the energy of a nuclear explosion that is itself being equated to a TNT explosion.

"The resulting explosion packed the energy of a 700-megaton bomb"

Because it was not 1 nuclears, but 700 nuclears! 700 nuclears AT ONCE!

> "Though not as cataclysmic as the dinosaur-killing Chicxulub impact, which carved out a 200-kilometer-wide crater in Mexico about 66 million years ago"

To clarify, this theory is has been called into question. I believe there have been previous HN discussions.

Which theory? That KT extinction was based on an asteroid strike, or that the 200km wide crater in the Yucitan was the specific impact?

That it was the strike that single-handedly caused the extinction rather than just being the straw that broke the camel's back. It's still being debated but usually for something as established as the Yucatan impact to be called into question I can assume there must be some solid evidence to weaken the earlier assumptions.

Time (and further investigation) will tell.

I've read others. This is the one that I knew were easy to find.

https://www.theatlantic.com/magazine/archive/2018/09/dinosau...

p.s. The arc of my point being the OP original article makes a statement as an absolute when it should know that that just isn't the case. Which also perpetuates the myth, and thus delays people being able to unlearn what is a non-fact.

Kinda makes ya wonder how science ScienceMag really is, yes?

> I can't imagine how something like this impact in this location could have caused massive fires in North America

I'm no scientist but my initial thought would be that the asteroid prior to impact could have broken up during entry and scattered debris across North America.

An object with a diameter of roughly 1.5km (which is very close to 1 mile) doesn't break up in the atmosphere. Considering that the vast majority of the atmosphere's mass is within the first 16 km, this object has a width just over 9% of the thickness of the most dense part of the atmosphere), and it's likely moving at tens of thousands of km per second. It would have punched right on through the atmosphere in no time, impacted the Earth, and ejected molten crust all over the place.

I know this is going into conspiracy realm but do you think this could have caused mass wipe out of both humans and wildlife and that it could have possibly killed earlier advanced (agricultural and can build rather than hunter gatherer) civilisations.

Yes. Part of the hypothesis about the lost civilization of Atlantis is related to this younger dryas extinction event. The massive shift in weight from the 2 mile deep ice sheet back into the oceans, along with the water rise itself could have pushed the plate deeper into the mantle where the civilization is said to have existed, the mid Atlantic.

Isn’t the prevailing theory is that Atlantis was in east Africa specifically in modern day Mauritania?

King Atlas who was the king of the Mauri people shares a name with the King of Atlantis the Atlas Mountains are also in Africa and the Eye of the Sahara seems to match the ring structure of Atlantis as described by Plato.

Massive flooding would make sense (many cultures have flood myths), but I don't believe a whole civilization could have sunk into the ocean in the given time frame. There is no plate in the mid-Atlantic that could have been pushed deep into the mantle. The mid-Atlantic is an area where new oceanic plate is created, not where existing plates go down.

Really? 12000 years ago would have pre-dated any known invention of written language by something like 8000 years. Even if Atlantis existed 12000 years ago when this event happened, how can we trust any description of it that was passed along orally for 8000 years before anyone had any chance of writing it down (and then maintain accuracy for another 4000 years of religions, states, entertainers and others who would readily change such a story for their own benefit)?

Atlantis is likely a made-up story, for entertainment purposes, just as Hollywood has made a billion dollar business out of making up stories for entertainment. I wonder if historians in 1000 years will wonder where Frodo Baggins is buried, or how to get to the planet featured in Avatar.

Atlantis may very well be a true story. Problem is we have no idea what the original myth was; such stories have a tendency to develop over time, getting more and more fantastical for every iteration.

How would a Paleolithic hunter/gatherer describe a neighboring tribe who developed certain tools and techniques far ahead of anyone else? A small town of wooden buildings and 400-500 people would seem a great marvel from that perspective.

Imagine there was such a tribe 12000 years ago. Now imagine a tsunami hitting that village and that hunter/gatherer describing the event to future generations. Imagine how that oral tradition would develop over the years until someone writes it down 4000 years later.

There's some anectotal evidence for pre-Younger Dryas civilizations, such as various peoples' myths regarding previous golden ages ended by terrible floods and so on, as well as some early civilizations using techniques and doing stuff that seems impossible to us.

If there was a relatively advanced civilization somewhere in the area, a meteor strike and subsequent climate instability could definitely have brought it down. Ice sheets could easily have crushed any cities in the northern hemisphere without leaving much trace except from the oral traditions of more primitive peoples who managed to survive.

Problem is, that without solid evidence it's just guesswork.

"And wildlife": Seems to me this matches the timeframe of the extinction of several North American megafauna species. Those extinctions have been blamed on the arrival of humans; maybe there's another explanation here.

"Massive crater under Greenlands ice points to climate-altering impact of humans" is the current title which is blatantly misleading.

Weird, I posted this yesterday, same article, same url, but it doesn't show up under the past link.

The past link searches the exact title, if you just search "Crater under Greenland" your thread shows up as well.

Why was this renamed from the original title, erasing "in the time of"? This is highly misleading.

This is the actual title of the article: "Massive crater under Greenland’s ice points to climate-altering impact in the time of humans"

Yeah, sounds like the humans have made the crater. Not bad of us doing that under the ice.

HN has a max title length and that's over it. Would've been better to chop off the ending.

It’s not misleading, it’s wrong, the article is about supporting evidence for the Younger Dryas (13,000 years ago) being caused by a meteor strike instead of some internal ice-age cycle.

Also, the impact in the title refers to a meteor impact. Probably OP just misunderstood the article and summarized the title incorrectly. “Meteor crater under Greenland points to climate altering effect of recent meteor strike” would be better.

It's because of the title length limitation I think. I tried uploading the article and I removed some parts of the title, although OP totally changed the meaning.

OP here, my bad indeed. I was fiddling around trying to figure out the right way to shorten and carelessly ended with this. No intention to mislead, but I agree this changes the meaning in a bad way.

Most importantly I don't see a way to revert; hopefully the moderators will see this and do it instead.

I've sent an e-mail to the moderators asking them to fix the title. (The moderators can be reached at hn@ycombinator.com.)

We've just updated the title from “Massive crater under Greenland’s ice points to climate-altering impact of humans”.

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