New research finds Earth’s oldest asteroid strike linked to ‘big thaw’

Video: Curtin University scientists have discovered Earth’s oldest asteroid strike occurred at Yarrabubba, in outback Western Australia, and coincided with the end of a global deep freeze known as a Snowball Earth

Curtin University

The research, published in the leading journal Nature Communications, used isotopic analysis of minerals to calculate the precise age of the Yarrabubba crater for the first time, putting it at 2.229 billion years old – making it 200 million years older than the next oldest impact.

Lead author Dr Timmons Erickson, from Curtin’s School of Earth and Planetary Sciences and NASA’s Johnson Space Center, together with a team including Professor Chris Kirkland, Associate Professor Nicholas Timms and Senior Research Fellow Dr Aaron Cavosie, all from Curtin’s School of Earth and Planetary Sciences, analysed the minerals zircon and monazite that were ‘shock recrystallized’ by the asteroid strike, at the base of the eroded crater to determine the exact age of Yarrabubba.

The team inferred that the impact may have occurred into an ice-covered landscape, vaporised a large volume of ice into the atmosphere, and produced a 70km diameter crater in the rocks beneath.

Professor Kirkland said the timing raised the possibility that the Earth’s oldest asteroid impact may have helped lift the planet out of a deep freeze.

“Yarrabubba, which sits between Sandstone and Meekatharra in central WA, had been recognised as an impact structure for many years, but its age wasn’t well determined,” Professor Kirkland said.

“Now we know the Yarrabubba crater was made right at the end of what’s commonly referred to as the early Snowball Earth – a time when the atmosphere and oceans were evolving and becoming more oxygenated and when rocks deposited on many continents recorded glacial conditions”.

Associate Professor Nicholas Timms noted the precise coincidence between the Yarrabubba impact and the disappearance of glacial deposits.

“The age of the Yarrabubba impact matches the demise of a series of ancient glaciations. After the impact, glacial deposits are absent in the rock record for 400 million years. This twist of fate suggests that the large meteorite impact may have influenced global climate,” Associate Professor Timms said.

“Numerical modelling further supports the connection between the effects of large impacts into ice and global climate change. Calculations indicated that an impact into an ice-covered continent could have sent half a trillion tons of water vapour – an important greenhouse gas – into the atmosphere. This finding raises the question whether this impact may have tipped the scales enough to end glacial conditions.”

Dr Aaron Cavosie said the Yarrabubba study may have potentially significant implications for future impact crater discoveries.

“Our findings highlight that acquiring precise ages of known craters is important – this one sat in plain sight for nearly two decades before its significance was realised. Yarrabubba is about half the age of the Earth and it raises the question of whether all older impact craters have been eroded or if they are still out there waiting to be discovered,” Dr Cavosie said.


The full research paper, ‘Precise radiometric age establishes Yarrabubba, Western Australia, as Earth’s oldest recognized meteorite impact structure,’ can be found online at

From EurekAlert!

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January 23, 2020 10:22 am

If the only thing it ejected into the atmosphere was water vapor they would have a point. The problem was there would be no crater to find if all it did was eject water vapor. It also had to eject other materials into the atmosphere capable of blocking the sun (nuclear winter theory).

Snowball earth may have ended in that time frame but the linkage to the crater is still a correlation.

Kevin kilty
Reply to  chemman
January 23, 2020 10:50 am

Also, if the Earth were cold at the time, water vapor would condense out onto the surface quickly. How much warming did it effect under the best of circumstances?

Charles Higley
Reply to  chemman
January 23, 2020 11:34 am

“Calculations indicated that an impact into an ice-covered continent could have sent half a trillion tons of water vapour – an important greenhouse gas – into the atmosphere. ”

First, water vapor would actually cool the planet by converting heat in the atmosphere to IR, which would be lost to space. The cloud deck created would act to cool the planet by forming a sun shield. And, as mentioned above, the rock dust thrown into the atmosphere would seriously cool the planet, causing an artificial, extended winter.

BTW, no gas at any concentration in the atmosphere can warm the climate. A “greenhouse gas” is an entity created based on flawed models of Earth’s solar energy budget. There are “radiative gases,” such as water vapor and CO2 that are saturated with incoming energy during the day and re-radiating in all directions, being a wash when it comes to heating as the surface is always hotter than the air, and downwelling IR reflected back upward. In fact, these gases probably decrease solar heating, by re-directing energy upward.

It is at night that these gases, lacking solar input, actively convert heat energy in the air to IR which is then lost to space. This is why the air chills so quickly after sunset.

Reply to  chemman
January 23, 2020 12:03 pm

From all the suspended particulate matter, how much of a thermal transfer to the atmosphere might increase at least temporarily?

What effect does newly settled dust have on reducing Earth’s albedo?
(There is direct evidence that sprinkling black cinders on snow cover causes it to melt over roadways quite well.)

Reply to  Rocketscientist
January 23, 2020 1:03 pm

All speculation and hypothesis about what projected material would aside, what it this “precise” four digit result BS?

How many “if all else remains equal” assumptions were involved in that projection?

Making a measurement of radio isotopes now and projecting backwards to work out the impact date it what is called extrapolation. In this case its running an exponential decay process backwards, that means it’s 2 billions year extrapolation of an exponential.

If anyone wants to pretend they can do that 4 sig. figs., I’ll call BS on that one right away.

Typical headline grabbing pseudo science based on the output of spurious models.

Reply to  Greg
January 23, 2020 2:49 pm

According to this article, zircon crystals can be dated to a few 100ths of a percentage point of their age in millions of years. They give an example of an error of less than 1 million years in 3 billion years.

Rud Istvan
Reply to  MarkW
January 23, 2020 3:29 pm

Yes.I just researched the science. zirconium silicate (zircon) is a complex lattice. But because Uranium has the same number of valence electrons as zirconium, there are an irregular number of U lattice substitutes. I ignore the minor thorium complication in this comment.
U has a known alpha particle radioactive decay ratio eventually to stable Pb. The resulting U/Pb ratio (which can be measured very precisely with modern instruments) gives a ‘precise’ age via radioactive decay of the zirconium crystal when formed.

Reply to  MarkW
January 23, 2020 4:34 pm

There is often some question as to whether impact heating totally or only partially resets the U-Pb clock in zircons.

nw sage
Reply to  Greg
January 23, 2020 7:12 pm

Plus or minus a couple of years!!

Mark E Shulgasser
Reply to  chemman
January 23, 2020 5:58 pm

not so much a correlation as a co-incidence.

January 23, 2020 10:29 am

Meh. Guessing about ending a glaciation w/little evidence. And I thought a major strike supposedly causes a temporary global freeze. And it doesn’t take long for uplifted water vapor to condense & fall back down — prb’ly less time than the temporary freeze.

D. J. Hawkins
Reply to  beng135
January 23, 2020 11:49 am

It could have easily injected significant quantities into the stratosphere where it would hang around a lot longer.

Reply to  D. J. Hawkins
January 24, 2020 7:55 am

DJ Hawkins, not sure, but guessing H2O high enough in the stratosphere would get disassociated by UV.

Reply to  D. J. Hawkins
January 24, 2020 11:15 am

To add to my 1st response, practically all the H2O in the stratosphere would freeze to ice crystals, and no longer a greenhouse gas and that would cool the surface by reflecting light.

Reply to  beng135
January 25, 2020 1:13 pm

Isn’t that what they were saying before? That it caused an ice age because the debris blocked the rays of the sun?

Reply to  beng135
January 25, 2020 1:17 pm

When are they going to make up their minds?
Dust from a giant asteroid crash caused an ancient ice age

September 18, 2019
Field Museum
“About 466 million years ago, long before the age of the dinosaurs, the Earth froze. The seas began to ice over at the Earth’s poles, and new species evolved with the new temperatures. The cause of this ice age was a mystery, until now: a new study argues that the ice age was caused by global cooling, triggered by extra dust in the atmosphere from a giant asteroid collision in outer space.”

January 23, 2020 10:44 am

After a quick read of paper the, it’s apparent the only real connection between the end of Snowball Earth and this impact is that they happened about the same time. The authors admit they cannot accurately model what happened…so why say anything at all? Probally cuz it’s easier to get published if they discuss “climate change”. The paper should have ended after presenting their analysis of the age of the impact crater.

Reply to  Observer
January 23, 2020 12:17 pm

The state of science 2020.

Expect at least half of all work to not be replicable, particularly in ‘soft’ sciences but across every discipline on a sliding gradient.

Reply to  Luke
January 23, 2020 1:25 pm

They have data samples which give figures all over the map, ( explained by Pb loss handwaving ) . They then take a weighted mean of bag of rocks and come up with an implausible level of uncertainty in the result.

This is like claiming to measure the “average” temperature of deep ocean to the nearest 5mK using thousand ARGO floats drifting arbitrarily around the worlds oceans.

Walter Sobchak
Reply to  Luke
January 23, 2020 7:26 pm

Half is very optimistic. Ioannidis said “most”

“The Irreproducibility Crisis of Modern Science: Causes, Consequences, and the Road to Reform”

John Ioannidis is a physician-scientist and writer who has shown that much of the published research does not meet good scientific standards of evidence. His 2005 paper “Why Most Published Research Findings Are False” was the initial report that brought this crisis to light.

Reply to  Observer
January 23, 2020 2:34 pm

Of course since it mentions climate change, it will be included as another paper that supports the belief that CO2 controls temperature.

Reply to  MarkW
January 24, 2020 5:55 am

Nah. Water vapour. CO2 is negligable.

Reply to  chaswarnertoo
January 24, 2020 4:31 pm

Yes, those who can read understand that’s the major conclusion. But since it doesn’t come right out and say, “See-Oh-Two didn’t do this!” it will be counted in the next literature survey as part of the 97% consensus! Unless it’s just rejected for some specious arbitrary reason because AGW!

Rud Istvan
Reply to  Observer
January 23, 2020 2:48 pm

Their analysis of the crater age is obviously faulty. See comment just posted below after a modicum or radioisotope dating research.

Steve Keohane
January 23, 2020 10:46 am

I wondered if this strike caused a near equatorial change in albedo. The earliest maps at Scotese,, are Precambrian, 650Mya, and Cambrian, 513Mya, at the former Australia was well above the equator, and drifted down to the equator by the latter period. Therefore at the time of this strike Australia could have been well above the equator. Anyone have some other source for land mass positions a couple of billion years ago?

John Tillman
Reply to  Steve Keohane
January 23, 2020 11:50 am

Hypothesized supercontinent Columbia apparently assembled from about 2.1 Ga.

Australia was then not united:

Part was probably below the equator, including WA, and part possibly above it and on the other side of the world.

But here’s a somewhat different reconstruction:

January 23, 2020 10:52 am

Curtin University scientists have discovered Earth’s oldest asteroid strike occurred at Yarrabubba …

My first reaction was “Earth’s oldest known asteroid strike”.

… it raises the question of whether all older impact craters have been eroded or if they are still out there waiting to be discovered …

It’s like the folks who write the headlines don’t even read the dumbed down press releases.

Reply to  commieBob
January 23, 2020 12:14 pm

Doh! And then there’s the folks who forget to close the bold tag.

… oldest known asteroid strike …

Reply to  commieBob
January 23, 2020 5:40 pm

An article in the Murdoch press today, linking dietary habits in the Chinese market where the current virus outbreak may have begun with the outbreak itself, is an example of the general lack of basic scientific understanding amongst journalists.

The article specified the eating of bats, which were referred to as “flying rodents”.
This misinformation had to come from somewhere and, sure enough, Wikipedia reads correctly, on the subject of bats – right at the start, that bats constitute the second biggest order of mammals after rodents.

In other words, it would seem likely that a journalist misread a simple sentence about bats not being rodents, but almost as taxonimically diverse a group as rodents, and wrote that they were actually rodents.

I believe this to be but a symptom of a wider malaise.

January 23, 2020 11:02 am

It might coincided, but I doubt that it was the cause:
– amount of energy released would not be sufficient enough to cause major deglaciation.
– huge amount of dust would be into atmosphere blanking the sun having opposite effect.
– Australia may have been some distance from large continental masses where most of ice would have been concentrated
– impact may have triggered volcanic eruptions along the Pacific ring of fire, again having opposite effect.

Reply to  Vuk
January 23, 2020 12:04 pm

But at last, all that dust would have settled on the ice and maybe changed Earth’s albedo dramatically.

January 23, 2020 11:05 am

If an asteroid fell on the firmament, but there was no one there to hear it, did it really fall at all?
Riddle me that, Batman.

January 23, 2020 11:08 am

It’s surprising given the dynamic nature of the surface over periods of billions of years that this one survived. How many ocean strikes remain hidden? How many have been subducted or twisted by uplift?

I’m all in favor of more investigation but we need to understand we are still in the gathering phase and conclusions even speculative are a long way off.

Reply to  Rob_Dawg
January 23, 2020 11:49 am

Speaking of ocean strikes, let’s take just this meteor as an example, can we calculate, from the impact crater, the mass and velocity of the collision? Then, taking that strike data, how much water would it take to brake the meteor down to terminal velocity in water so that it then settles to the bottom of the ocean with little more than a thump? Is there enough water anywhere on this Earth to make that happen (only the depth matters, well if it’s a non-direct impact, it could plow through the water for a ways that way). Under that scenario, there is no jarring of the Earth on its axis (think water barricades around the highway construction crew, all the energy is dissipated into the water), but there is a huge steam ejecta into the atmosphere, so then the only effects are atmospheric, really. Right? We need somebody with more physics grasp than I have to work through what might happen then (I know, another model, but some are useful).

Reply to  Red94ViperRT10
January 23, 2020 2:38 pm

At those speeds, the difference between rock and water really doesn’t matter. In both cases the asteroid completely vaporizes.

Reply to  Rob_Dawg
January 23, 2020 12:09 pm

The “gathering phase” will never end. Let’s start with that, and end with it as well.

Reply to  Rob_Dawg
January 23, 2020 4:53 pm

Can we even see any ocean strikes. The ocean floors are much, MUCH younger than the continental plates.

Reply to  MarkMcD
January 29, 2020 4:41 pm

Bigger ones we can. The Burckle Crater in the Indian Ocean is IIRC some 30 kilometres across.

The results of the impact are quite well known. As the impact was less than 6,000 years ago it is highly likely the mega-tsunamis it caused were the genesis of flood legends all around the world.

January 23, 2020 11:21 am

A very large strike might spread a lot of dark minerals and ash around on the ice surface.

Reply to  ResourceGuy
January 23, 2020 2:40 pm

Could be. It also vaporized a lot of ice that will quickly settle out of the atmosphere to create a new layer of ice/snow world wide. I suspect the dust would settle faster than the water vapor burying any layer of dust under several inches to several feet of new snow.

Reply to  MarkW
January 24, 2020 5:49 am

So water vapor is not a greenhouse gas after all. Who knew?

Ron Long
January 23, 2020 11:24 am

Maybe!” The age date, 2,229 mya, is during the end of the crustal evolution slow-down due to the cooling of the upper mantle continuing to the lower mantle, which occurred at 2,400 mya to 2,200 mya. The general Archean to Proterozoic transition, marked by emergence of crust with plate tectonic movement and significant oxygen entering the atmosphere, is around 2,500 mya to 2,300 mya, depending on markers. After this Archean to Proterozoic transition the earth behaves as it does today, albeit with some wild swings and/or cycles, and life advances to produces things more advanced than pond scum. A very large meteorite strike in Australia at 2,229 mya certainly could provide some feedback, and, if coupled with changes underway, could push us forward. All of this is scheduled to end in 10 or 12 or something years anyway, so I think I will have a drink.

John Tillman
Reply to  Ron Long
January 23, 2020 11:53 am

Also about the time of the Great Oxygen Catastrophe, a mass extinction event among the then dominant anaerobic microbes.

Somewhat later, eukaryotes developed.

Ron Long
Reply to  Ron Long
January 23, 2020 5:48 pm

I was thinking about this issue more, and looked up the location of the proto-continent of Australia during the Proterozoic/Precambrian. Surprise! During the early moving crust formation, known as Rodinia, Australia was north of the equator! There were only crustal patches, islands, during the period of the meteorite strike, aka 2,229 mya, but the impact site was almost certainly north of the equator. This time of Archean to Proterozoic transition, around 2,400 mya or so, was a dynamic time for earth crustal formation, and along with this was formation of oceans and atmosphere. This was a “beam me up, Scotty, there’s no intelligent life on this planet” kind of deal.

January 23, 2020 11:37 am

That’s an awful lot of “maybe’s”, “might-haves”, “could possibly” and speculative inferences…..

Robert Austin
January 23, 2020 11:59 am

Over 2 billion years ago but dated to four significant digits?

Reply to  Robert Austin
January 23, 2020 1:32 pm

Hey , we can measure the temperature of the global ocean to within 3mK nowadays, so ANYTHING is possible. You just have to believe.

Science is a faith based religion.

Reply to  Robert Austin
January 24, 2020 4:39 am

Why not? Fourth digit is in the order of the million year which is pretty common as precision for U-Pb age in the Archean. Uncertainty varies from a million year to ten million in average. We are talking here about analytical precision and mass spectrometers are very precise, especially if you use the ID-TIMs method. Don’t forget that when dating zircon or monazite, you are using actually 2 Geochronometers. The first one is based on the disintegration of 235U; the second one on the disintegration of 238U. Beyond this, there are of course other factor of uncertainty but they have nothing to do with analytical precision.

John Bell
January 23, 2020 12:07 pm

David Middleton are you out there? Very interesting topic to me – The Carolina Bays

The theory that the Younger Dryas was caused by an asteroid hitting Hudson Bay ice (Laurentide ice sheet), as evidenced by lots of elliptical lakes and depressions in the southern US.
Maybe you could publish a piece on the topic here?

Reply to  John Bell
January 23, 2020 12:54 pm


David Middleton devoted a series of posts to the Younger Dryas Impact Hypothesis, including this one that discusses the “Carolina Bays”.

Be sure to read the comments. The topic is still very controversial. The tremendous numbers of “bays” along the Carolina to Georgia coasts, in the many thousands across hundreds of miles is unique on the earth. David is a doubter, but I lean toward a glacial impact sending out slushy ice boulders.

Reply to  Bryan - oz4caster
January 23, 2020 1:48 pm

Carolina Bays are absolutely not impact features of any kind. While there is sketchy evidence for an impact event sometime around the Younger Dryas, there’s no evidence that it caused the Younger Dryas.

Reply to  Bryan - oz4caster
January 23, 2020 2:52 pm

Are the eccentricities and orientations of the bays ever investigated? If the impact hypothesis is right the most recent bays, which are on top of others, should be less eccentric and slightly rotated clockwise with respect to the earlier ones.

Reply to  David Middleton
January 24, 2020 1:55 am

Thanks David. Very convincing article. That settles the argument.

January 23, 2020 12:59 pm

Hi John.

David Middleton has written about the Carolina Bays before. A quick search of the site for Carolina Bays should provide you with a fairly comprehensive understanding of where he stands on the subject.



Reply to  Max
January 23, 2020 4:18 pm

This paper demolished the notion that Carolina Bays are YD impact features..

The lead author was co-author of a recent paper about YD platinum anomalies… actual evidence for some sort of impact event.

January 23, 2020 1:11 pm


An alleged asteroid.

Dated by “shock recrystallized” monazite and zircons…

All right, I understand how they theoretically use zircons to date things geologically using radioisotopes.
What I don’t get is how zircons melted by a massive impact recrystallize so that they reset their origin date? Without a fresh infusion of unaltered uranium, to my understanding the new crystal gets the old material of uranium-thorium-lead.

Impact object hit a snowball Earth, which is theorized not proven. Normally, an uncrushed un-remelted normally grown zircon crystal dates rocks to within a few million years. Plus/minus a few million years, at best, makes correlating a theorized iceball Earth to cosmic material impact.

The research team:

“The team inferred that the impact may have occurred into an ice-covered landscape, vaporised a large volume of ice into the atmosphere”

Thus ending the theorized snowball Earth…

So let’s recap.
Asteroid impact dated, sort of, by crushed reconstituted zircons and monazite impacted a theorized snowball Earth, releasing inferred huge clouds of steam and water vapor thus saving Earth…

Let me know when they prove it was an asteroid,
prove the Earth was a snowball at the time,
prove that the impact released huge amounts of unfrozen water,
prove that the combination returned Earth to hot-house Earth,
and when they prove the age of impact closer than era.

Reply to  ATheoK
January 23, 2020 2:51 pm

It’s not so much that the zircon crystals melted then reformed. It’s more that the old crystals melted and new ones formed.

Reply to  MarkW
January 26, 2020 7:47 pm

The Zircon dating process works for zircons/monazite forming normally at rates and temperatures where zircons incorporate uranium 238 atoms within the crystal lattice; whereas lead and thorium atoms are incompatible and excluded. This is what allows analyzing for uranium-thorium-lead ratios and calculating a radioactive product decay timeline estimate. Assuming a 99.284% original U238 ratio at the crystal’s formation.

Flash melted and recrystallized minerals do not get a slow chemical/crystallization process where thorium and lead are excluded. Outside of normal magmatic processes, lead, thorium and other minerals get ‘included’ as foreign objects within the crystal.
Nor is the uranium, fresh pure uranium initializing a new decay process.
What began as mostly uranium-238 has decayed into a stew of uranium decay products included as foreign objects.

Radium series
The 4n+2 chain of U-238 is commonly called the “radium series”.
comment image?dl=0
The mean lifetime of uranium-238 is 1.41 × 1017 seconds divided by 0.693 (or multiplied by 1.443), i.e. ca. 2 × 1017 seconds, so 1 mole of uranium-238 emits 3 × 106 alpha particles per second, producing the same number of thorium-234 (Th-234) atoms. In a closed system an equilibrium would be reached, with all amounts except lead-206 and uranium-238 in fixed ratios, in slowly decreasing amounts. The amount of Pb-206 will increase accordingly while U-238 decreases; all steps in the decay chain have this same rate of 3 × 106 decayed particles per second per mole uranium-238.

Thorium-234 has a mean lifetime of 3 × 106 seconds, so there is equilibrium if 1 mole of uranium-238 contains 9 × 1012 atoms of thorium-234, which is 1.5 × 10-11 mole (the ratio of the two half-lives). Similarly, in an equilibrium in a closed system the amount of each decay product, except the end product lead, is proportional to its half-life.

As already touched upon above, when starting with pure uranium-238, within a human timescale the equilibrium applies for the first three steps in the decay chain only. Thus, per mole of uranium-238, 3 × 106 times per second one alpha and two beta particles and gamma ray are produced, together 6.7 MeV, a rate of 3 µW. Extrapolated over 2 × 1017 seconds this is 600 GJ, the total energy released in the first three steps in the decay chain”

Without analyzing the crystal down to atomic level and ensuring the atoms are part of the crystal lattice and not simply foreign inclusions, I find it difficult to accept their claims as stated. Their leaps to definitive conclusive dates billions of years ago, do not help.

James R Clarke
January 23, 2020 2:00 pm

How long would it take for the post-impact amount of water vapor to drop back to the pre-impact amounts of water vapor? Seems to me that it would be a matter of days. Certainly no more than a year.

For an asteroid to permanently change the Earth’s climate, it would have to change something more permanent than a temporary spike in water vapor. A very small change in the Earth’s orbit would be the most logical. Connecting this story to greenhouse gases isn’t clutching at straws, it is fishing for funding.

January 23, 2020 2:10 pm

Y’all know me, I love data. I took a look at the paper and I went “say what”? They claim their dating is 2229Ma ± 5 Ma. Here’s the money graph:

I thought, how can that have an error of 5 Ma given those errors? So I digitized the data, and took a look. Data below.

I get 2230 ± 30 Ma from those values, much more in line with what I expected. I used the “errors” package in R, which does all the error handling.

And for the end of the “Snowball Earth”, AKA the “Makganyene Glaciation”, I find nothing precise. Everything is “circa” and “around” two billion years ago.

Not seeing the connections …


      Low     High      Mid   Error
     2160     2373     2267     106
     2208     2281     2245      36
     2223     2253     2238      15
     2223     2241     2232       9
     2207     2250     2229      21
     2218     2234     2226       8
     2200     2251     2226      25
     2213     2236     2225      11
     2215     2227     2221       6
     2196     2248     2222      26
     2211     2227     2219       8
     2143     2241     2192      49
     2236     2256     2246      10
     2220     2271     2246      25
     2216     2270     2243      27
     2212     2266     2239      27
     2172     2302     2237      65
     2224     2250     2237      13
     2212     2252     2232      20
     2205     2255     2230      25
     2207     2248     2228      20
     2199     2239     2219      20
     2205     2228     2217      11
     2183     2242     2213      29
     2199     2227     2213      14
     2166     2246     2206      40
January 23, 2020 2:13 pm

Don’t you just love the ‘scientific’ terminology – lots of coulds, mights, maybes, perhapss.

“This twist of fate suggests that the large meteorite impact may have influenced global climate”
So to join the party, therefore suggesting global warming could have begun 2.229 billion years ago.

Which of the following two choices has the best chance of success, in your opinion?
You must choose either (a) or (b)
(a) If you give me $100 every week for twelve weeks to invest, you may, could, perhaps, might get a great return in 3 months; or
(b) If you let the government take an extra $100 off you every week for twelve weeks, the temperature in 3 months time might, may, could, perhaps be 2 degrees centigrade colder everywhere on the planet every day thereafter.

Rud Istvan
January 23, 2020 2:34 pm

Shocked zircon says there was an impact. And we apparently have the remains of a large crater. which means geologically that more than just ice got vaporized.

But unless the dating zircon was formed by the impact itself (and shocked zircon suggests NOT, else would not have shock features) the trace uranium/lead radioisotope decay zircon dating method cannot say the age of the crater except younger than the zircon itself. So if the crater must be younger than the shocked zircon, that blows up (literally and figuratively) the coincidental hypothetical that this impact ended Snowball Earth via GHG water vapor release

More failed peer review warming basics in the formerly august, now merely aegean, Nature stable.

Color me VERY skeptical because of a basic logic fail inconsistency.

Reply to  Rud Istvan
January 23, 2020 4:48 pm

I’m subject to correction here – but is not shock zircon distinguished from magma zircon by noting that there is a “seed” crystal that exhibits shock features, around which zircon in the melt from the shock has recrystallized?

I’m seeing assumptions here that the crystals in question formed ab initio – which, to my mind, would be indistinguishable from crystals formed after a volcanic eruption.

Roy A Jensen
January 23, 2020 3:33 pm

The best records of impacts is on the moon. Our diameter is 4 times that of the moon so we must have had the same sort of impacts. When you hit a nail on a anvil with a hammer the nail gets hot as is adsorbs the energy from the hammer. Like our breaks on our car get hot stopping the car. It is estimated that the earth was moltin the first 600 million years as it cooled. One thing for sure, complex life can’t take that kind of heat.

Our universe had to age and get past the early days when most stars formed. Our star is a third generation star. That is determined by the type of light it produces. Each element produces it own frequency and the first stars were just hydrogen and helium. That makes us able to estimate when a star was birthed. As time passed we had more and more elements and a greater mix of frequencies in their light.

Reply to  Roy A Jensen
January 23, 2020 6:38 pm

…”Like our breaks on our car get hot stopping the car.”

Kinda like this….?

Loren Wilson
January 23, 2020 4:16 pm

Four significant figures is difficult to achieve in geology. Perhaps the reviewers did not point out that their data do not support the declared level of precision.

January 23, 2020 4:24 pm

You are all missing the point, any strike would produce a lot of heat, thus the dreaded CO2.

Its CC after all


January 23, 2020 6:35 pm

Study fits propaganda narrative.

The notion that a strike produces warming, not cooling, makes GHG warming more dangerous.

Otherwise one could argue that co2 emissions provide protection against a strike from space.

January 23, 2020 7:16 pm

A large strike on a couple of mile thick ice sheet would not launch just water vapor. Blocks of ice the size of mountains would be launched on sub-orbital trajectories. Falling back to earth these are going to leave a mark. Yet there will be no evidence these were caused by an impact from space.

Sort of like icicles falling from the eaves of a building punching a hole in someone walking underneath.

nw sage
January 23, 2020 7:23 pm

Interesting comment above above Oxygen being released and changing ALL the flora and fauna on the earth. I believe I read somewhere that anaerobic bacteria were first on earth and their waste was/is oxygen. What are the odds that the first anaerobic bacteria to touch earth came from a big rock (perhaps no atmosphere either?)?

Smart Rock
January 23, 2020 8:23 pm

There is abundant evidence of multiple ice ages in the past (i.e. before the Pleistocene glaciation), and some of them seem to have covered large areas (as did the LGM) but the current fashion is to assume that most of the “old” glaciations were global glaciations or “snowball earth” periods.

The snowball earth theory is that the oceans were frozen to the bottom all around the globe. The theory appears to have been first concocted by Paul Hoffman in 1999, as an outgrowth of the “CO2 controls climate” hypothesis. It has a few weak spots:

Because the continents move around, split apart and join together, and this has been going for about 4 billion years, it’s not immediately obvious that a historic glaciation extended into tropical regions. This depends on paleo-latitude estimates, measuring the inclination of remanent magnetism in rocks that show evidence of glaciation, and were formed at the time. Of course, this is a magnetic latitude. We know how much the poles have moved in the last 250 years, so there should be uncertainty in paleo-latitudes.

The snowball earth theory posits that frozen oceans led to a high albedo, so solar radiation could not warm the surface, which perpetuated the frozen conditions. Well, if there was no open water, there would no evaporation and no precipitation. But volcanic activity still went on, and it’s asking a lot to maintain a high albedo for hundreds of millions of years of airborne volcanic ash falling, and no fresh snow to cover it.

If the theory is correct and snowball earth could maintain its albedo for hundreds of millions of years, then how could the earth get out of its snowball condition? The theory posits that CO2 from a major volcanic event warmed the planet enough to start melting, which released CO2 from the frozen oceans, which warmed the planet more, which … and so on. Hmm …

The idea that a single injection of a large quantity of water vapour could cause enough greenhouse effect to de-snowballize a plant is even weaker. Water vapour condenses. Its presence in the atmosphere depends on a continual supply by evaporation.

January 23, 2020 9:17 pm

Non-anthropogenic global warming! Now that’s what I’m talking about!!

Robert of Texas
January 23, 2020 10:21 pm

As I read through these comments, I had not previously heard of the “Carolina Bays” and found the subject fascinating. I must admit when I first saw the images I thought “has to be impacts from debris”, but luckily I was born with something called “curiosity” and kept digging. Wow…really? Wind? In a low sandy flood plain?

OK, so if it happened in North Carolina in the past, it must be happening somewhere else today, and I thought of Alaska and when scanning along the river channels in the far north. It didn’t take long to find a startling image: “70°16’46.27″ N 158°56’06.62″ W”

Well that sort of settled it for me…Geologists 7, YDIH 0; end of first quarter.

I had no idea shallow lakes could look so entirely weird.

As for the point of this article, you hit a planet with a big enough rock it is going to release a lot of energy. Things are going to catch on fire. The air is going to have a lot of soot in it. The albedo is going to take a nose dive. You hit the Earth with a big enough rock and it will vibrate like a bell and continental plates are going to shift allowing magma to get loose and build new volcanoes (which might or might not add to warming or cooling). So I find the idea credible, but I am not taking any sides (yet) on whether it happened.

I find the idea of a “snowball Earth” far harder to believe than a big asteroid could warm up the planet. Yeah, the planet could be colder and glaciers could have grown to incredible depth and area – but I do not buy the oceans freezing over. There is a lot of heat in the ocean, and more heat being released into it all the time at especially at continental plate boundaries – more so 200 million years ago, not less. I find the term “snowball Earth” an unfortunate one…unless they convince me that the oceans really *did* freeze over.

Reply to  Robert of Texas
January 24, 2020 2:21 am

According to wiki the average geothermal heat flux is 0.1MW/km**2, which I think is 0.1W/m**2. I don’t think that would be enough to maintain liquid oceans absent the sun. Perhaps some ice volcanoes.

Reply to  Robert of Texas
January 24, 2020 2:27 am

The lunar and solar tides might have some effect at keeping the oceans liquid.

Mike McMillan
Reply to  Robert of Texas
January 24, 2020 8:51 am

There’s a series of similar lakes in Bolivia, for 500 km along the Rio Mamore by the town of Trinidad. My best bet for a meteor breakup. S15° W65°

Another bunch of lakes at S14° W67°, same orientation.

Reply to  Robert of Texas
January 24, 2020 9:57 am

Same here.
Few years ago while looking at the google Earth I stumbled across something I thought it was a fascinating impact crater, but the WUWT geologist explained what it was.
Link to image shows coordinates so anyone interested can easily find it.

Reply to  Vuk
January 24, 2020 1:01 pm

In eastern Siberia, a perfect circle of rock contrasts with the surrounding topography. The 6-kilometer- (3.7-mile-) wide ring looks like an impact crater, or the caldera of an extinct volcano, but it is neither. Kondyor Massif was formed by the intrusion of igneous, or volcanic, rock that pushed up through overlying layers of sedimentary rock, some of them laid down more than a billion years ago.

January 24, 2020 9:15 am

That they identified a crater that old is pretty impressive. What the impact event may or may not have done is something else entirely.

A 70 km crater is not particularly large as known craters go. And for it to have some sort of global climate significance is an interesting conclusion.

A more recent example for your consideration: The Chesapeake Bay impact dates around 35 Ma and left a 85 km crater. The Popigai impact crater dates around 35 Ma and left a 100 km crater. Final large structure is Tom’s Canyon off NJ which also dates around 35 Ma and left a 22 km crater. Related? Perhaps. Perhaps not, though the timing is interesting.

Only climatic event around that time is a moderate extinction event at the end of the Eocene and an overall global temp fall after then. Was the cool down due to the impact events or isolation of Antarctica from the other continents or the creation of the Himalayas disrupting global wind patterns? The closest LIP in time was one at the Afar around 30 Ma.

Kind of cool they identified a crater that old. Interesting timing with the end of a snowball glaciation. Of course we haven’t a clue about possible ocean impacts near that time. Cheers –

Steve Z
January 24, 2020 11:09 am

Half a trillion tons of water vapor from one impact sounds like a lot, but if this spread over the entire atmosphere of the earth, it would increase the water vapor content of the atmosphere by 157 ppm, or 0.0157%.

For sake of comparison, at 20 C and 100% relative humidity, the water vapor content of the atmosphere would be 2.3 vol%, or 23,000 ppm. So we are asked to believe that some prehistoric incident from over 2 billion years ago, which increased the water vapor content of the atmosphere by less than 1% could trap enough heat to melt ice covering the entire earth?

The whole “snowball earth” theory seems preposterous, that all the world’s oceans would freeze over, and all the continents would be covered in ice, particularly if the sun’s radiation output and the earth’s orbital distance from the sun were similar to what they are now.

Climate change skeptics frequently make the argument that even if CO2 in the atmosphere trapped a small amount of additional heat, it would take thousands of years to melt the Greenland or Antarctic ice caps due to the large amount of heat needed to melt ice, compared to that needed to heat air.

The same argument can be made in reverse regarding the possibility of a “snowball earth”–so much heat needs to be removed to freeze water (particularly salt water), that the heat transferred to the surroundings would inhibit further freezing, particularly in the tropics which receive strong solar radiation year-round.

In today’s location of the continents and oceans, most of the area of the tropics (between 23.5 degrees north and 23.5 degrees south latitude) are covered by water, and daytime evaporation followed by thunderstorms (as pointed out by Willis Eschenbach) tends to prevent the tropics from becoming too hot.

But if there was a period of extensive glaciation of land areas 2.2 billion years ago (outside the tropics), this would lower sea levels, meaning that a greater area of the tropics would become dry land, which absorbs sunlight better than the ocean surface, without heat loss due to evaporation. This land could only become glaciated if it was cold enough for snow to accumulate without melting (which is possible in mountainous areas), but lowland areas in the tropics would not be glaciated. In addition, an extensive area of sea ice away from the tropics would reduce the amount of water that could be evaporated, which would give land areas near the edge of the glaciers a drier climate, which would tend to cause melting.

Mark - Helsinki
January 24, 2020 11:57 am

“precise age”

oh sweet jebus, the false confidence in the accuracy of aging is still going on. Could be +/-500m/yr

Throw in the serious limitations in determining termination and starting of events, means the claims made far more certain than the actual science could ever say…

All areas of science are in real trouble, with gross misrepresentation of the science and the ignorance of the severe limitations, and the complete failure of peer review in modern times..

Unfortunately, many have to pass away before the institution of science globally, changes, the whole enterprise needs to be rethought and safeguards thought up to stop what amounts to probably 50% of all research in all science globally being utter horseshit

January 25, 2020 5:12 am

A massive comet or meteorite strike would lead to a massive release of
natural gas hydrates, not just methane. The amount of upwelling natural
gas all around the world trapped by the “snow ball” earth would have dwarfed
the amount that we see today.

Natural gas perks up all around the earth continuously, but rises where it is
not blocked by igneous or shield layers. The earth at present, is allowing most,
but not all, to rise, most be oxidized in the topsoil, the remainder, to rise into
the atmosphere, to be oxidized, and support life as we know it.

The zone of stability, a combination of temperature and pressure, limit
the amount which hits the atmosphere. The build up of natural gas
hydrates, like the massive amount off the Carolina coast, act as a stopper,
limiting the rise of more from deep in the earth, just as the cork in a
bottle of Champaign limits the release of gas. When the stopper, the ice, is
vaporized, a massive release of natural gas hits the atmosphere. A serious
green house effect takes place.

The gas would survive the initial atmospheric heat flash, then the cooling effect
of the debris, then the inevitable period of vulcanism and resultant dust occur.

The period immediately after the strike, with all of the ice gone and the ocean
temperature raised, the zone of stability would have been exceeded world wide,
and all the hydrates would flash to a gas. The cork in the bottle, the hydrates,
are the valve which limits the flow of hydrocarbons from deep in the earth,
so the flow of gas from its source, would continue, probably for hundreds
of thousands of years.

As the initial massive burst of released hydrates, exacerbated, by the mechanical
input of heat to the earth’s core, and the massive shock and vibration, the cooling
from the attenuation of the real “global warming” would have taken a long time
to return to the zone of stability which we see today.

For those who think that natural gas is a “fossil” fuel, the continuous rise of
natural gas can be seen as hydrates which accumulate under the areas of the
world which freeze every winter, and thaw every spring, releasing that short
accumulation of gas.

Another example of the rise of natural gas is the richness of topsoil wherever
the flow is not blocked by igneous rock or shield near the surface and there
is enough moisture to support the aerobic microbial life which enrich and
create the topsoil. The microbes use the hydrogen in the gasses for energy,
and the result of this process is the reason that CO2 rises from the soil.

The more natural gas rising through the soil, in the presence of adequate
moisture, the richer and blacker, (higher carbon content) the soil.

Very good examples of this are the deep, rich soils in the US Midwest, the
Ukrainian, and the Tera Preta in the Amazon, which are over plumes of
natural gas.

These areas prove that natural gas rises continuously wherever it is
not blocked by ice or rock.

A simple test for CO2 at the surface of rich topsoil is the residue of
this process. Gas also rises in areas, un oxidized where there is not
enough moisture to support the microbial culture.

Most of this upwelling gas would have accumulated under snowball
earth, save the occasional volcano, and have been the source of
of the massive release I referred to above.

This process, in a much more limited way, explains why CO2 is a
trailing indicator, after each glaciation, in more recent times.

Unlike the carbon balance, used by the USEPA, upland topsoil
is not a sink for natural gas, it is a source. Fortunately most is
oxidized by the soil culture, so the serious greenhouse effect
is mitigated or eliminated by microbes.

There would have been no life on earth without hydrocarbons
and their follow on effect, so David, the vast majority of hydrocarbons
are, in fact abiotic.

January 28, 2020 4:44 pm

A correction on the above timeline which says hundreds of thousands
of years should read tens of thousands of years.

I was pressed for time and didn’t proof read.

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