
Crater under Greenland points to climate-altering impact in the time of humans - henridf
https://www.sciencemag.org/news/2018/11/massive-crater-under-greenland-s-ice-points-climate-altering-impact-time-humans
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noetic_techy
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/R31SXuFeX0A)

[https://youtu.be/G0Cp7DrvNLQ](https://youtu.be/G0Cp7DrvNLQ)

[https://youtu.be/0H5LCLljJho](https://youtu.be/0H5LCLljJho)

[https://youtu.be/tFlAFo78xoQ](https://youtu.be/tFlAFo78xoQ)

The Younger Dryas Impact Hypothesis:

[https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesi...](https://en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesis)

The controversy:

[https://www.sciencenews.org/article/younger-dryas-comet-
impa...](https://www.sciencenews.org/article/younger-dryas-comet-impact-cold-
snap)

~~~
kijin
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.

~~~
todd8
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.

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

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mrleiter
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](https://twitter.com/pablorodas/status/1062795179139194880)

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njarboe
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](http://advances.sciencemag.org/content/4/11/eaar8173)

[2][http://advances.sciencemag.org/content/advances/4/11/eaar817...](http://advances.sciencemag.org/content/advances/4/11/eaar8173.full.pdf)

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Etheryte
> 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"?

~~~
jon_richards
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.

~~~
arethuza
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](https://en.wikipedia.org/wiki/Nuclear_weapons_testing)

~~~
mabbo
As a species, we really enjoy blowing things up.

~~~
thanosnose
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](https://en.wikipedia.org/wiki/List_of_nuclear_weapons_tests)

~~~
marssaxman
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.

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chiefalchemist
> "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.

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

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

[https://www.theatlantic.com/magazine/archive/2018/09/dinosau...](https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-
extinction-debate/565769/)

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?

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MadcapJake
> 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.

~~~
craftyguy
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.

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kiproping
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.

~~~
ghthor
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.

~~~
craftyguy
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.

~~~
ahje
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.

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

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thrower123
Weird, I posted this yesterday, same article, same url, but it doesn't show up
under the past link.

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

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ulrikrasmussen
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"

~~~
henridf
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.

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

