Support: comet impact may have triggered the Younger Dryas period

From the University of South Carolina – PNAS: Topper site in middle of comet controversy

By Peggy Binette, USC

Did a massive comet explode over Canada 12,900 years ago, wiping out both beast and man in North America and propelling the earth back into an ice age?

That’s a question that has been hotly debated by scientists since 2007, with the University of South Carolina’s Topper archaeological site right in the middle of the comet impact controversy. However, a new study published today (Sept.17) in the Proceedings of the National Academy of Sciences (PNAS) provides further evidence that it may not be such a far-fetched notion.

Albert Goodyear, an archaeologist in USC’s College of Arts and Sciences, is a co-author on the study that upholds a 2007 PNAS study by Richard Firestone, a staff scientist at the Department of Energy’s Lawrence Berkeley National Laboratory.

Firestone found concentrations of spherules (micro-sized balls) of metals and nano-sized diamonds in a layer of sediment dating 12,900 years ago at 10 of 12 archaeological sites that his team examined. The mix of particles is thought to be the result of an extraterrestrial object, such as a comet or meteorite, exploding in the earth’s atmosphere. Among the sites examined was USC’s Topper, one of the most pristine U.S. sites for research on Clovis, one of the earliest ancient peoples.

“This independent study is yet another example of how the Topper site with its various interdisciplinary studies has connected ancient human archaeology with significant studies of the Pleistocene,” said Goodyear, who began excavating Clovis artifacts in 1984 at the Topper site in Allendale, S.C. “It’s both exciting and gratifying.”

Younger-Dryas is what scientists refer to as the period of extreme cooling that began around 12,900 years ago and lasted 1,300 years. While that brief ice age has been well-documented – occurring during a period of progressive solar warming after the last ice age – the reasons for it have long remained unclear. The extreme rapid cooling that took place can be likened to the 2004 sci-fi blockbuster movie “The Day After Tomorrow.”

Firestone’s team presented a provocative theory: that a major impact event – perhaps a comet – was the catalyst. His copious sampling and detailed analysis of sediments at a layer in the earth dated to 12,900 years ago, also called the Younger-Dryas Boundary (YDB), provided evidence of micro-particles, such as iron, silica, iridium and nano-diamonds. The particles are believed to be consistent with a massive impact that could have killed off the Clovis people and the large North American animals of the day. Thirty-six species, including the mastodon, mammoth and saber-toothed tiger, went extinct.

The scientific community is rarely quick to accept new theories. Firestone’s theory and support for it dominated the annual meeting of the American Geophysical Union and other gatherings of Paleoindian archaeologists in 2007 and 2008.

However, a 2009 study led by University of Wyoming researcher Todd Surovell failed to replicate Firestone’s findings at seven Clovis sites, slowing interest and research progress to a glacial pace. This new PNAS study refutes Surovell’s findings with its lack of reported evidence.

“Surovell’s work was in vain because he didn’t replicate the protocol. We missed it too at first. It seems easy, but unless you follow the protocol rigorously, you will fail to detect these spherules. There are so many factors that can disrupt the process. Where Surovell found no spherules, we found hundreds to thousands,” said Malcolm LeCompte, a research associate professor at Elizabeth City State University and lead author of the newly released PNAS article.

LeCompte began his independent study in 2008 using and further refining Firestone’s sampling and sorting methods at two sites common to the three studies: Blackwater Draw in New Mexico and Topper. He also took samples at Paw Paw Cove in Maryland, a site common to Surovell’s study.

At each site he found the same microscopic spherules, which are the diameter of a human hair and distinct in appearance. He describes their look as tiny black ball bearings with a marred surface pattern that resulted from being crystalized in a molten state and then rapidly cooled. His investigation also confirmed that the spherules were not of cosmic origin but were formed from earth materials due to an extreme impact.

LeCompte said it was Topper and Goodyear’s collaboration, however, that yielded the most exciting results.

“What we had at Topper and nowhere else were pieces of manufacturing debris from stone tool making by the Clovis people. Topper was an active and ancient quarry at the time,” LeCompte said. “Al Goodyear was instrumental in our approach to getting samples at Topper.”

Goodyear showed LeCompte where the Clovis level was in order to accurately guide his sampling of sediments for the Younger Dryas Boundary layer. He advised him to sample around Clovis artifacts and then to carefully lift them to test the sediment directly underneath.

“If debris was raining down from the atmosphere, the artifacts should have acted as a shield preventing spherules from accumulating in the layer underneath. It turns out it really worked!” Goodyear said. “There were up to 30 times more spherules at and just above the Clovis surface than beneath the artifacts.”

LeCompte said the finding is “critical and what makes the paper and study so exciting. The other sites didn’t have artifacts because they weren’t tool-making quarries like Topper.”

While the comet hypothesis and its possible impact on Clovis people isn’t resolved, Goodyear said this independent study clarifies why the Surovell team couldn’t replicate the Firestone findings and lends greater credibility to the claim that a major impact event happened at the Younger Dryas Boundary 12,900 years ago.

“The so-called extra-terrestrial impact hypothesis adds to the mystery of what happened at the YDB with its sudden and unexplained reversion to an ice age climate, the rapid and seemingly simultaneous loss of many Pleistocene animals, such as mammoths and mastodons, as well as the demise of what archaeologists call the Clovis culture,” Goodyear said. “There’s always more to learn about the past, and Topper continues to function as a portal to these fascinating mysteries.”

Goodyear joined USC’s College of Arts and Sciences and its South Carolina Institute for Archaeology and Anthropology in 1974 to pursue prehistoric archaeology.

The Topper story

Albert Goodyear, who conducts research through the University of South Carolina’s S.C. Institute of Anthropology and Archaeology, began excavating Clovis artifacts along the Savannah River in Allendale County in 1984. It quickly became one of the most documented and well-known Clovis sites in the United States. In 1998, with the hope of finding evidence of a pre-Clovis culture earlier than the accepted 13,100 years, Goodyear began focused excavations on a site called Topper, located on the property of the Clariant Corp.

His efforts paid off. Goodyear unearthed small tools such as scrapers and blades made of the local chert that he believed to be tools of an ice age culture back some 16,000 years or more. His findings, as well as similar ones yielded at other pre-Clovis sites in North America, sparked great change and debate in the scientific community.

Goodyear reasoned that if Clovis and later peoples used the chert quarry along the Savannah River, the quarry could have been used by even earlier cultures.

Acting on a hunch in 2004, Goodyear dug even deeper into the Pleistocene terrace and found more artifacts of a pre-Clovis type buried in a layer of sediment stained with charcoal deposits. Radiocarbon dates of the burnt plant remains yielded ages of 50,000 years, which suggested man was in South Carolina long before the last ice age.

Goodyear’s findings not only captured international media attention, but it has put the archaeology field in flux, opening scientific minds to the possibility of an even earlier pre-Clovis occupation of the Americas.

Since 2004, Goodyear has continued his Clovis and pre-Clovis excavations at Topper. With support of Clariant Corp. and SCANA, plus numerous individual donors, an expansive shelter and viewing deck now sit above the dig site to allow Goodyear and his team of graduate students and public volunteers to dig free from the heat and rain and to protect what may be the most significant early-man dig in America.

The Topper timeline

1998 Goodyear and his team dig to a meter below the Clovis level and encounter unusual stone tools up to 2 meters below the surface.

1999 Team of outside geologists visit Topper site and propose a thorough geological study of the location.

2000 Geological study done is by consultants; ice age sediment is confirmed for pre-Clovis artifacts.

2001 Geologists revisit Topper and obtain ancient plant remains deep in the Pleistocene terrace. Optically stimulated luminescence (OSL) dates sediment above ice-age strata show pre-Clovis is at least older than 14,000 years.

2002 Geologists find new profile showing ancient sediment lying between Clovis and pre-Clovis, confirming the age of ice age sediment layer between 16,000 – 20,000 years.

2003 Archaeologists continue to excavate pre-Clovis artifacts above the Pleistocene terrace. New and significant Clovis artifacts are found.

2004 Goodyear discovers major Clovis occupation on the hillside. Additionally, radiocarbon dates for sediment associated with pre-Clovis artifacts come back at 50,000 years.

2005 “Clovis in the Southeast” conference held in Columbia, S.C., with tours of Topper and Big Pine Tree sites.

2006 The 3,500-square-foot roofed structure is built over pre-Clovis excavations.

2007 Firestone study about a possible Clovis comet is published in the Proceedings of the National Academy of Sciences, including evidence from Clovis age sediments from Topper.

2008 PBS “Time Team America” spends a week at Topper filming for an hour-long television special devoted to Topper.

2008 SCETV broadcast of “Finding Clovis,” a public television presentation of Topper Clovis. 2009 PBS “Time Team America” program airs.

2011 Topper and Big Pine Tree included in a study of post-Clovis Paleoindian decline/reorganization that is published in the journal “Quaternary International.”

2011 The first permanent exhibit of Topper artifacts installed at the University of South Carolina Salkehatchie.

2012 Independent study of micro-spherules related to an extra-terrestrial impact hypothesis is published in the Proceedings of the National Academy of Sciences using Clovis-age sediments from Topper that confirm the original 2007 Firestone study.

2013 The pre-Clovis occupation of Topper will be presented in October at the international conference on the peopling of the Americas, titled “Paleoamerican Odyssey,” in Santa Fe, N.M.


h/t to Dennis Wingo

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Phil Wilson
September 20, 2012 10:30 am

Great article. The whole pre-Clovis ‘heresy’ debate fractured American science deeply through the end of the 21st century. Glad to see a paper that addressed why the initial findings weren’t easily replicated. Good science articles like this make WUWT a greg must read site.

September 20, 2012 10:36 am

Interesting. Everybody should read The First American by Hardaker. It caused a big controversy back in the old days due to dating (250,000 years!). I wonder if they’re going to start looking into that now. Even 50,000 years old was very tough for people to accept back then too. It took 30,40 years to get to 50,000 years old. Talk about slow progress!

September 20, 2012 10:40 am

Maybe OT, but “The scientific community is rarely quick to accept new theories”.
Didn’t take the warmists long, though.

September 20, 2012 10:42 am
Jeff D.
September 20, 2012 10:47 am

oldseadog says:
Didn’t take the warmists long, though.
Acceptance is way easier when your check depends on it.

Crispin in Waterloo
September 20, 2012 10:49 am

The presence of the black spherules of terrestrial origin means a major ground impact. OK. I presume that based on a search for Iridium concentrations in various N American sites of the right age, it may be possible to locate the impact site. I understand that is how the Yucatan impact site 65m years ago was located.
Perhaps it was in Hudson Bay which is quite shallow. Being so recent it would otherwise have left a very rather obvious mark.
Is there any evidence for a simultaneous change in the sea level around the 40-50 degrees latitude mark? That would indicate that the Earth wobbled and settled on a slightly altered axis. If this is the case then it would change the ‘expectable’ future of climate, in effect putting us forward or back on the Milankovich Cycle. High latitude, high speed impacts are quite capable of altering the length of the day and the tilt of the earth and the precession rate. It sounds as if this may have been one. Perhaps we have broken out of our 500k year pattern. Interesting.

September 20, 2012 10:50 am

Goodyear & Firestone , hmm .

September 20, 2012 11:05 am

Yet another reason to provide the most detailed account possible of one’s experiment.

Crispin in Waterloo
September 20, 2012 11:13 am

Excellent link.
“‘…the dates were so old that to take them seriously would impugn their own scientific credibility.”
So it is not for the first time that people discovering scientific truths turn silent in order to protect their positions from those contollling the dominant paradigm.
The difference with ‘climate science’ is that the evidence for a CO2 hypothesis never dominated anything – it was just a hypothesis. At least the Clivis First supporters had plenty of evidence, they just rejected other evidence.
Surely is it interesting to note that the Reis Map of Antarctica (the original was painted on animal skin) shows what the shoreline was about 250,000 years ago, a similar age? Here we go again…

No Name Guy
September 20, 2012 11:14 am

Hmmmm…I notice a complete lack of references to “peer review” and lots of work trying to independently replicate the earlier study / studies.
Who would have thought of that…..real science in this field, unlike certain others (cough…AGW / warmists…..cough). Could it be that these folks actually understand the scientific method while our warmist friends don’t?

P. Solar
September 20, 2012 11:18 am

vukcevic says:
September 20, 2012 at 10:50 am
>> Goodyear & Firestone , hmm .
Yes, you have to wonder is someone is having a laugh sometimes. Why is no one mentioning Dr Dunlop’s noteworthy research on this period 😉
“The so-called extra-terrestrial impact hypothesis adds to the mystery of what happened at the YDB with its sudden and unexplained reversion to an ice age climate,… ” Goodyear said/
So is it now common practice to misuse the term “ice age” instead of glacial period ? Or are these guys archeologists who do not understand the terms they are using?

NZ Willy
September 20, 2012 11:24 am

I presume these “black spherules” have also been found at non-quarry sites, else they would only some kind of soot related to tool manufacture.

September 20, 2012 11:28 am

Crispin in Waterloo says:
September 20, 2012 at 10:49 am
Perhaps it was in Hudson Bay
Nastapoka ( was most likely hit by a huge lamp of iron which is slowly sinking into the upper mantle, as both the Geoid depression and the strong magnetic field intensity indicate.

September 20, 2012 11:53 am

Would a comet have much iridium?

September 20, 2012 11:54 am

NZ Willy:
Just how much soot does chipping chert produce?

September 20, 2012 11:55 am

Is there any evidence for a simultaneous change in the sea level around the 40-50 degrees latitude mark? That would indicate that the Earth wobbled and settled on a slightly altered axis. If this is the case then it would change the ‘expectable’ future of climate, in effect putting us forward or back on the Milankovich Cycle. High latitude, high speed impacts are quite capable of altering the length of the day and the tilt of the earth and the precession rate. It sounds as if this may have been one. Perhaps we have broken out of our 500k year pattern. Interesting.
Crispin, “altering” is difficult to argue with, but “measurably” or “significantly” altering requires some defense, does it not? The mass of the Earth is ballpark 6 \times 10^{24} kg. The mass of a kilometer radius comet is ballpark 5 \times 10{^13} kg. The ratio of the masses is thus ballpark of 10^{-11} (comet to planet). Even comet with a diameter of 4 kilometers would still have only one ten billionth the mass of the Earth, and would have a one part in a billion impact on any macroscopic aspect of the Earth’s orbit or rotation rate or inclination. I’m not seeing that having much impact on length of day or precession rate or any Milankovitch cycle behavior — I doubt that one could detect its influence compared to other natural sources of “noise” (nutation, tidal coupling, orbital resonance with the gas giants, movement of the continents, continental-scale uplift and downfall, melting of icepacks (which alters the moment of inertia tensor, not just its magnitude. A largish comet would have roughly the same sort of effect on tensor moments than the eruption/explosion of Tambora, which caused 16 cubic miles of mountain to basically blow away into the atmosphere, and there are literally dozens of Tambora-scale events likely to have occurred over the last 12,000 years.
Even if the comet was considerably larger — say, 5 km in radius (and hence 125 times more massive) it would barely perturb the Earth’s orbital properties. The Earth is small compared to stars and gas giants, but it is enormous compared to most observed comets or probable candidate asteroid sizes.
I may be making some sort of arithmetic or conceptual error here, so please feel free to correct me — this is back of the envelope stuff — but I’m having a hard time agreeing with you that alteration of axial tilt or length of day or eccentricity of orbit due to any likely comet impact at any latitude would have any serious effect on the climate beyond the obvious, and extreme, short-and-medium term effects of releasing a few gigaton-of-TNT-equivalents of energy, cubic miles of vaporized or pulverized matter, and a supersonic shock wave of pyroclastic flow sufficient to blow down and/or ignite or bury or flood any structure within a million square kilometers or so of land surface area. Which might well be enough, but which isn’t orbital.
Having meditated upon Tambora (and Krakatoa) and its (their) apparent LACK of clearly visible long term impact on the climate, I’m increasingly inclined towards the belief that the Earth’s negative feedback is more than sufficient to cope with even gigaton-scale explosions involving cubic miles of ejecta. There is a “suspected” impact site for a crater large enough to dwarf Krakatoa or Tambora in Hudson Bay, although AFAIK there is no hard evidence that proves it to be such a site or (obviously) a site that has the right age to have been associated with the YD.
I’ve read a number of articles suggesting a meteoric cause for the YD, and there is “some” evidence that supports it. So far, though, I don’t think there is smoking-gun-specific evidence that e.g. includes the probable impact site or any sort of hint about how large it was. It might not have had to be very large, of course, if the Earth was still in the critical regime in between warm and cold phase where small fluctuations would have been nonlinearly amplified by the critical instability, or if it (for example) broke an ice dam and caused the OTHER major suggested YD cause, sudden freshwater dilution of the North Atlantic that interrupted the thermohaline circulation for a thousand years or so.

September 20, 2012 11:55 am

vukcevic says:
September 20, 2012 at 11:28 am
“was most likely hit by a huge lamp of iron ”
Was there a genie in the lamp?

September 20, 2012 11:58 am

rgbatduke says:
September 20, 2012 at 11:55 am
Is it possible that since the Younger Dryas impact occured at a time of climate transition, that the climate could have been more sensitive to pertubations?
The other events that you mention all occurred when the climate was solidly within the inter-glacial.

September 20, 2012 12:28 pm

Strange coincidence: BBC4 (UK) is at this moment transmitting ‘Horizon’ about the asteroids, there are apparently 900 of 1 km or larger diameter.

September 20, 2012 12:44 pm

So how does this timeline work?
16,000 years ago there was an ice age culture in NA. It started to warm up. Until that ignorant ball of rock about 13,000 years ago, cooled things off a bunch. When the dust from that settled, it started to warm up. Something happened about 600 years ago, cooled things off a bunch, we call is the LIA. When the dust from that settled, it started to warm up. Again.
I conclude from the available evidence that the internal combustion engine was invented 16,000 years ago. There’s no way that the earth could have been warming for 16,000 years punctuated only by the YD and the LIA from just natural causes could it?
Oh wait. This was a North America thing, not a global thing. Probably only “regional”. Never Mind.

Crispin in Waterloo
September 20, 2012 12:45 pm

@rgbatduke first
There is an important assumption you make in your reasonable back of the envelope analysis that must be dropped: that when it comes to changing the pole or rotation, the Earth is basically lke a solid ball, cricket ball if you will. It is not.
There are three poles for the Earth, the lithosphere, the core, and everything in between. They rotate slightly differently and the lithosphere can be perturbed independently of the other two. They are not, at present, aligned. They were disturbed 3200 years ago and probably again in about 1650 BC. The flooding of the Dogger Bank was probably a single-day event. Ditto the civilisation that farmed what is now the floor of the Irish Sea. There are stove walls around fields in Wales that go into the sea and continue across the seafloor. This is describe in detail in a book: Atlantis of the west: the case for Britain’s drowned megalithic civilization”, by Paul Dunbavin, 2003. The first three chapters are relevant to the axes and their relative motion. He postulates there was a 7 year long cylical wobble that was significant enough to be visible to humans. It has now damped down considerably but is still detectable (to about 10 inches I think).
Basically a high latitude impact or as described in ( h/t Tallbloke) can make the lithosphere wobble without immediately affecting the major % of the mass of the Earth. It is one reason why the theory that enough ice piling up on the poles, asymetrically, can make the ‘earth flip’ (in fact, move the lithosphere relative to the mantle). My reference to the Milankovich Cycle was really made while thinking about the precession of the tilt. To be clearer, I was thinking of the change in insolation between summer and winter which goes through a cycle. I was not thinking about moving the Earth from its orbital path, just that the effect is the same.
That iron is consistent with most of the theory in the link above, but only if it is really recent.
Iridium is very rare on Earth and much more plentiful in asteroids and rocky comets. It is used as one of the proofs that some lump is extra-terrestrial. When blasted all over the show, a layer of iridium indicates an inmpact, the thicker the layer, the closer it is assumed to be. That is how the Yucatan impact site was located, first generally then confirmed from the air.
A definite impact site is the crater around Sudbury Ontario, but it is old. They are mining the nickel from the bolide and it used to provide 95% of the nickel in the world. Most of the world’s nickel is in the core out of reach. 🙂

September 20, 2012 12:47 pm

So, a comet’s impact set off an ice age that lasted a 1300 years; and all of this took place over 12K years ago.
So, what caused this ice age to end and warming to begin?
Let’s see, oh, it must have been elevated levels of CO2, because THE DEBATE IS OVER – CO2 CAUSES GLOBAL WARMING. THERE IS A SCIENTIFIC CONSENSUS ON THIS FACT.
What you say, CO2 levels were not elevated at the time the YD ice age ended and the climate warmed up.?
Well then , if you believe that you are fascist/commi pig s**t on the payroll of big oil.

george e smith
September 20, 2012 12:48 pm

So why a comet ? Is the core of a comet not simply a meteorite ? Presumably the ice coating would leave not a trace; the old tired worn out who dunit ice dagger murder mystery.

September 20, 2012 12:51 pm

Re Mark W: “Is it possible that since the Younger Dryas impact occured at a time of climate transition, that the climate could have been more sensitive to perturbations?”
Good question. Problem is that nobody knows (to my knowledge) what the sensitivity is and what drives the move to and from glaciation. The thing that makes the YD so interesting is that it marked a strong move back to glaciation for a millennium after the climate was coming out of the last ice age. After the YD, the warming trend resumed, so you have 4 different moves in the direction of climate within the period of a couple thousand of years – a strong move toward warming starting around 15k years ago, a sudden and sharp cooling trend around 12,900 years ago, steady state during the cold, followed by a resumption of the warming trend 10,500 years ago. How do you explain any or all of these? The suggestion of an impact event answers the middle two.
And the YD event is thought by some to be a series of multiple impacts / airbursts centered about two sites in North America – Michigan and central Mexico. Think of thousands of Tunguska sized airbursts over the course of an hour as the earth rotates underneath a thick part of a incoming debris stream. Think continental extinction event. And there may be another center of impact. It is all very new and the discussion is very loud. The significance of this paper is that one set of critics have been shown to be wrong. Cheers –

September 20, 2012 1:32 pm

One thing you need to know about such studies in areas like paleontology and such ancient studies of man, critters, and such is that the evidence is often fragmentary in the extreme, small fragments of bone and the like, similar to here. The evidence is so fragmentary that it is subject to a huge range of interpretations. Once someone digs up some such, they often spend decades arguing about what it actually means. This often runs into entrenched (to an extreme degree) interests which fight to keep their previously “established” theories intact to preserve their own prestige and standings in the academic community. An example was where some guy suggested that dinosaurs were warm blooded. He was attacked and basically saw his career take a big hit, and now, 20 years later, pretty much everyone agrees that dinosaurs were warm blooded. .
I would not be surprised to see this new study, as well as any evidence for mankind in the Americas before about 13,000 years ago treated pretty much like a Watt on PBS interview.

Paul Marko
September 20, 2012 1:42 pm

The YD ice comet theory may explain the origin of the Siberian and Alaskan “Muck” beds that cover approximately 14% of the earth’s land surface surrounding the Arctic Circle. The beds contain a jumbled assortment of whole and pieces of extinct fauna, most notably the mammoths, all frozen so rapidly that their food source remains undigested in their stomachs, and flower petals and grasses preserved in their mouths. Russian research revealed suffocation as the initial cause of death prior to burial and freezing.
The “Muck’ also contains abundant lenses and house-size deposits/inclusions of a saline, bubble included, granular ice that oxidizes orange upon exposure, thought to be extraterrestrial.
The petroleum industry in Alaska has also noted flora anomalies associated with the “Muck” deposits:
“Though the ground is frozen for 1,900 feet down
from the surface at Prudhoe Bay, everywhere the oil
companies drilled around this area they discovered
an ancient tropical forest. It was in frozen state, not
in petrified state. It is between 1,100 and 1,700 feet
down. There are palm trees, pine trees, and tropical
foliage in great profusion. In fact, they found them
lapped all over each other, just as though they had
fallen in that position.”
Lindsey Williams, The Energy Non-Crisis, 2nd edition
(Kasilof, Alaska: Worth Publishing Co., 1980), p. 54.
The fauna and flora deposits have all the earmarks of an explosion, sudden death and burial.
The quick freeze is another problem.

September 20, 2012 1:49 pm

My question with the Younger Dryas is: yes, I can see how a cometary impact might have caused a sudden plummeting of temperature, but what caused the equally rapid warming at the end of it?

September 20, 2012 2:49 pm

Crispin in Waterloo says:
September 20, 2012 at 10:49 am
The presence of the black spherules of terrestrial origin means …

There are no proposed “black spehules of terrestrial origin.” The argument by Firestone is that the “impact” was actually an aerial blast. The spherules are presumed to be part of the object that blew up, if such a thing happened. Part of the argument us that there is no astrobleme because the detonation took place above an ice sheet, which would absorb the brunt of the energy released. This could possibly account for the purported Atlantic “freshening” suggested at the onset of the YD. Depending upon just where the epicenter of the blast might have been, neither the Clovis site, nor Topper would necessarily have experienced much more than dirty rain. Clovis is roughly 2,000 miles from the center of Hudson Bay and Topper is about 1,900 miles away from the same point.
Of far more interest when considering the period of the Younger Dryas is the huge C-14 anomaly which indicates a large increase in cosmic rays or some other form of event that exposed the earth to a serious increase in highly energetic radiation. At the Southeast Paleoindian Conference at the University of South Carolina Firestone initially suggested that the purported cometary impact could account for this, but when we questioned him about that, could not offer any convincing mechanism.

September 20, 2012 3:14 pm

Crispin in Waterloo says:
September 20, 2012 at 12:45 pm
Some 25,000 years ago the Laurentide ice sheet had a thickness of several kilometers, the vast majority of the ice eventually melted at the end of the Ice Age. Impact did not leave any debris, so if it did happen it would be at the end of the last (or possibly an earlier) Ice Age, perhaps with the ice thickness up to several tens of meters.

September 20, 2012 3:42 pm

Disputin says:
September 20, 2012 at 1:49 pm
My question with the Younger Dryas is: yes, I can see how a cometary impact might have caused a sudden plummeting of temperature, but what caused the equally rapid warming at the end of it?
Plasma event? – – I thought that was interesting.
It reminded me of that moving Knowing…

Brian Adams
September 20, 2012 3:49 pm

Golly, real science based on physical evidence, not computer models, and a publicized protocol which can be replicated, not “proprietary” raw, and “corrected”, datasets which are off limits to skeptical scientists.

Chuck Forward
September 20, 2012 3:59 pm

You have not taken into account the energy component of velocity and explosive content of the comet storm, especially with an oblique hit. From the evidence so far, a fair portion of the North American glacial cap was shattered and flung south. That a lot a mass to be on the move and when the non-vaporized chunks came back down, their MV=MV would have far greater influence than the comet itself. Evidence also points to vast fresh water lakes below the glacial cap draining south, not northward which also changed the mass distribution on the earth’s surface. While the mass of the earth is great, it is rotating in a vacuum and only the gravitational influences of the Sun and planets keep it rotating around the sun. The polar point currently walks and wobbles just by tidal changes caused by such distance gravitational influences so just think what a quarter of the northern icecap being hurtled south could do.
Evidence for affecting the pole position can be seen by taking a look at the glacial distribution of the last ice age (Wikipedia map of ice age) and draw a circle around the glacial extent. The center is located in northern Greenland. The Bering Strait, eastern Siberia and Alaska would have been 800 miles further south thus able to support the mega-fauna at the height of the last glacial age where they couldn’t exist today at the height of the interglacial period. Now draw a map of the today’s snow extent and its center is at the current pole. One can also make the argument that the Bering Strait had not been punched through until that hit and the Arctic Ocean had no flow thru component of cold water from the pacific until the last 12,900 years. Had the giant tsunami that accompanied the impact not punch a path through, the Bering Strait might not exist today and the Arctic Ocean would be a closed body of water with a circulation pattern using only the warmer Atlantic waters. Those warmer waters would be causing greater snow accumulation and glacial buildup surrounding the arctic ocean. Glaciers build at altitude and flow downhill until they become self-supporting in height like Greenland. Could the last Glacial age actually be warmer than today? This brings up the question whether the polar weather patterns are now changed enough to prevent a glacial buildup like before with less oceanic moisture present at the pole.
What caused the long recovery time after the hit is open to speculation but my take is a portion of the atmosphere got ripped away by the impact as majority of the comet fragments would be airbursts. At the edges of the conflagration would have experience flash freezing and hurricane winds. The loss of atmospheric pressure produced adiabatic cooling across the globe. This coupled with a polar wobble would have extended the polar zones. This also reduced the insulating blanket of the atmosphere so it took another thousand years for the ocean to outgas enough to build it back up as the polar wobble settled down. What affect the lower pressure and cooler temperatures had on plants and animals can be questioned. The worldwide biosphere would have been stressed and the larger fauna taking the bigger hit. The animals which lived at higher elevations prior would have greater chance of surviving afterward.
The Clovis were totally destroyed and only a small band of Siberia mammoth hunters were on this side of the Bering strait before it got punched through. It is they that eventually repopulated the Americas (all American Indians DNA can be traced back to seven women IIRC).
Chuck Forward

Crispin in Waterloo
September 20, 2012 4:00 pm

“There are no proposed “black spehules of terrestrial origin.” The argument by Firestone is that the “impact” was actually an aerial blast. The spherules are presumed to be part of the object that blew up, if such a thing happened”
No, the spherules are said to terrestrial in origin. The melting of the surface and the blast of hot gases that made the ground flow which produced them is explained in detail at the reference I gave above, suggested by TallBloke. It is quite long. The object(s) that struck the earth are presumed to have evaporated, there being no classical impact site evident. There was plenty of melting on surface materials as the temperature of the heat blast was about 100,000 degrees C. The landing of a train of objects is thought to be needed to create a continent-wide catastrophe as a second object plunges into the fire trail of the first. He also suggests that the Laurentian Ice Sheet may have been catastrophically melted. There is in the central-northern US evidence of a series of glacial lake discharges of huge proportion that were from that sheet’s melting which does not exactly line up with the idea; also the explosive destruction of the Laurentian Ice Sheet followed by melting does not exactly fit with the idea of an impact followed by a huge cooling event. The impact, yes, the LIS melt, maybe not. I think the LIS breakup was long before.
There is a lot of mammoth evidence that their deaths were very rapid, chilling and species-complete. I also heard once that they are all facing in the same direction (i.e. away from something). Other of course blame mankind for killing them all, in spite of the evidence. The 3m tall deer in Ireland also disappeared at this time.

September 20, 2012 4:42 pm

Would a tsunami have resulted? The sea-level being 120 or so meters lower would cover the effects, I suppose, but shelf coring projects could have covered the interval …
Hmmm. Somewhere in the 12,500 YBP area there were massive landslides and subsequent glacial dam collapses and a mega-flood from central Alberta down through Montana, Idaho and out through Washington State, leaving an erratic train of Cambrian blocks from the Tonquin Valley into Montana, dry waterfalls in Idaho and the scablands of Washington.
Okay, lots of things happen all the time. But a couple of catastrophic events seem to be lining up … somewhat.

September 20, 2012 5:18 pm

Does reading research from Goodyear and Firestone make you Tired?
Is it a good thing or a bad thing if the Goodyear and Firestone data is Inflated?
Hopefully with this new research direction, Goodyear and Firestone will Tread carefully.

Steve Tabor
September 20, 2012 5:24 pm

There was global warming at the time, fed by released methane. It’s well-known that methane gas forms spherules by induction.
Induction of what? Don’t ask.

Chris Schoneveld
September 20, 2012 5:44 pm

” Radiocarbon dates of the burnt plant remains yielded ages of 50,000 years, which suggested man was in South Carolina long before the last ice age.”
Very strange! We are living at present in an iceage which started some 500,000 years ago. Even if the ice age term is confused with the term glacial period, this sentence makes no sense since the last glacial period lasted from 110,000 years ago to some 12,000 years ago. This glacial is called in Europe the Wurm, in North America the Wisconsin. So 50,000 years ago was right in the middle of a glacial period.

September 20, 2012 7:07 pm

By what mechanism would an air burst rip off a huge chunk of the atmosphere. And no, the shock wave would not be big enough to do it.
Secondly, if such a big chunk of the atmosphere did get ripped off, how did the Earth manage to get that atmosphere back over the last 20K years?

September 20, 2012 8:03 pm

Astounding the resolution and chronology attainable by careful sedimentology methods. The ‘umbrella’ effect described here is everywhere in the sedimentary record, and it would appear to apply no matter the source of the sedimentary particles!

September 20, 2012 8:06 pm

Considering that the YD impact hypothesis as stated in the PNAS paper “Evidence from central Mexico supporting the Younger Dryas extraterrestrial impact hypothesis” by Isabel Israde-Alcántara et al, (the most recent iteration of the YDIH) now uses the astronomical model provided by W.M Napier in Palaeolithic extinctions and the Taurid Complex, and which describes comets from the Taurid complex impacting as large clusters of small fragments, then maybe it’s time to consider the very real probability that we are not talking about a single bolide impact at all. But rather, a concentrated impact storm consisting of something like 10,000 Tunguska class airbursts in a matter of seconds.
Professor Napier points out that the breakup of comets is now recognized as a common route to their destruction. And when we look at images of fragmented comets like Comet Linear, or SW-3, we can see that he is probably correct.
The thing is, all of the available impact simulations we see are based on the assumption of one-at-a-time single bolide impacts. In spite of the fact that such common objects exist in elliptical orbits that cross all of the orbits of the inner solar system, no one to date has done any real science to consider what the impact of such a cluster would do.
But if a dense cluster like Linear that’s a few hundred miles wide of small air bursting comet fragments arrives within a few seconds of each other, then we get to find out what happens in an impact storm when only the first fragments on the leading edge are falling into cold atmosphere, and the rest fall into the already superheated atmosphere created by the impact plumes of those that lead the way. And they just crank up the heat, and pressure.
In other words we are talking about an extinction level catastrophic impact mechanism that’s different from anything that’s ever been studied before, and which leaves no crater.

September 20, 2012 9:11 pm

I wish I had something to add to this stimulating and educational discussion, other than to comment how it’s frankly quite freaky how often scientists’ last names or initials relate to their field of expertise. E.g. in my own area of study, Charles Fish, the fisheries scientist, or C.O’D. Iselin, the second director of the Woods Hole Oceanographic Institution. Let’s see: Goodyear, Firestone, vulcanized rubber — Vulcan, god of fire, exploding bolides…I get the impression of much heat production being involved in this aerial explosion. It’s a stretch.

Yoshi Sheva
September 20, 2012 11:25 pm

” comet impact may have triggered the Younger Dryas period” Nope. Definitely not. It was the humans what done it.

September 20, 2012 11:44 pm

vukcevic says:
September 20, 2012 at 11:28 am
Did you read that Wikipedia report on Nakapooska? Good geologists examined the area in detail and found no evidence of it having an impact origin. Therefore, there is no “lump of iron” sinking into the mantle. It is an odd geomorphic feature, but why don’t we stick with the facts?

September 20, 2012 11:50 pm

In my previous, make “Nakapooska” read “Nastapoka”.

September 21, 2012 12:26 am

MarkW says: September 20, 2012 at 11:55 am
Hi Mark
Sorry missed your comment, however the answer has to be: most definitely not, although overheated large meteorite or even asteroid, coming trough the atmosphere could be classified as a source of illumination. Possibly yes, in a case of primitive extraterrestrial technology, but iron would be less suitable than titanium and ceramics, as I believe are currently employed by contemporary space vehicles. Using spellchecker in such cases is no good, need also to check alternative meaning too, so one has to have sense of humor or desist from posting.

September 21, 2012 1:42 am

JimF says:
September 20, 2012 at 11:44 pm
vukcevic…Did you read that Wikipedia report on Nakapooska? Good geologists examined the area in detail and found no evidence of it having an impact origin. Therefore, there is no “lump of iron” sinking into the mantle. It is an odd geomorphic feature, but why don’t we stick with the facts?
Yes I have, but you obviously did not read what I wrote:
vukcevic says:
September 20, 2012 at 3:14 pm
Some 25,000 years ago the Laurentide ice sheet had a thickness of several kilometers, the vast majority of the ice eventually melted at the end of the Ice Age. Impact did not leave any debris, so if it did happen it would be at the end of the last (or possibly an earlier) Ice Age, perhaps with the ice thickness up to several tens of meters.
As our friend Steven Mosher often says: ‘go figure’.

September 21, 2012 1:49 am

Ben says:
September 20, 2012 at 5:18 pm
This research is clearly funded by Big Rubber!

September 21, 2012 1:54 am

JimF says:
September 20, 2012 at 11:44 pm
Good geologists examined the area in detail and found no evidence of it having an impact origin.
…… in the Hudson Bay basin, iron formation, 100 feet thick or more, is the topmost member of a sedimentary series of unknown age.
The formation is thin-bedded. Some of the layers contain much magnetite and specularite, some are jaspery, and some consist of clastic material with considerable carbonate.

Adam Gallon
September 21, 2012 3:23 am

MarkW says:
September 20, 2012 at 11:53 am
Would a comet have much iridium?
george e smith says:
September 20, 2012 at 12:48 pm
So why a comet ? Is the core of a comet not simply a meteorite ? Presumably the ice coating would leave not a trace; the old tired worn out who dunit ice dagger murder mystery.
Comets are essentially “Dirty Snowballs”. Their Iridium content would be miniscule, so no signature like the K-T Boundary layer.
Comets & meteorites are different creatures, the former being largely made of ices, that latter of rocks and/or metals. Cometary bodies are less likely to retain their form when they enter the Earth’s atmosphere, so the “Airburst” ensues, as happened with the Tunguska Event. Little cratering is one outcome of this.
Comets aren’t just a meteorite covered in a layer of ice, a cosmic M&M!

September 21, 2012 5:02 am

There are alot of scientist who still assign blame for the demise of mastodon, mammoth and saber-toothed tiger on human predation. I think they believe that humans are born sinners and are is some way responsible for everything bad, all they need to do is find the evidence to support that belief. Comet or meteor impact does not support it.

September 21, 2012 6:01 am

Albert Goodyear, an archaeologist in USC’s College of Arts and Sciences, is a co-author on the study that upholds a 2007 PNAS study by Richard Firestone, a staff scientist at the Department of Energy’s Lawrence Berkeley National Laboratory.
This issue’s finally getting some rubber on the road…..

Alan the Brit
September 21, 2012 9:50 am

Dr Pirelli from Milan, Italy, fully concurs with the conclusions of Drs Goodyear & Firestone, as does Dr Avon from the UK! Sorry couldn’t resist it, it is Friday after all!
A most fascinating exchange of ideas & thoughts on the impact of a comet/meteor issue, it is something about which I have wondered often. I think I also made a comment some months back on another post here as to whether several miles/kilometres height of compacted ice, could have altered the Earths sping characteristics over a 100,000 year period. I appreciate that we orbit the really big shiney thing that doesn’t affect the Earth’s Climate in any way whatsoever, in what is to all intents is a vacuum, but the thoughts were of the similarities of a Cricket ball being roughed up by a spin bowler to allow it to spin unpredictably by altering the balls “wobble” through the air. Is it possible for this to happen on a large scale, could it help explain some of the periodocity issues with the Milankovitch Cycles? Perhaps not, but it would be interesting if anyone has any (polite) comments, I am only a humble engineer, not a Climate Scientists!

September 21, 2012 10:25 am

MarkW says:
September 20, 2012 at 7:07 pm
By what mechanism would an air burst rip off a huge chunk of the atmosphere. And no, the shock wave would not be big enough to do it.
Secondly, if such a big chunk of the atmosphere did get ripped off, how did the Earth manage to get that atmosphere back over the last 20K years?”
What gives you the idea that the atmosphere before such an event would have the same density or composition as after?

Jim G
September 21, 2012 12:35 pm

vukcevic says:
September 20, 2012 at 10:50 am
>> Goodyear & Firestone , hmm .
“Yes, you have to wonder is someone is having a laugh sometimes. Why is no one mentioning Dr Dunlop’s noteworthy research on this period ;)”
Or Cooper or Michelin?

September 21, 2012 1:48 pm

Thanks for the post, Anthony, this subject can’t receive enough attention — and to date it has received very little. Addtional background on the recent publication from LeCompte can be found at my blog:

September 21, 2012 1:52 pm

Dr. Goodyear & Dr. Firestone are tired, the joke is over inflated.

Interstellar Bill
September 21, 2012 4:55 pm

To Duster and many others, please note:
Earthquakes have an epicenter, directly above them.
Aerial explosions such as meteorites or nukes have a hypocenter, directly below them.

matt v.
September 22, 2012 5:23 am

Threats from comets and asteroids are very real .NASA just released a news clip asking people to name a massive asteroid[1999RQ36] that could hit us by 2182. This is half a kilometer in size. The passover mentioned in the bible during Exodus could have been a comet “passing over” and the plagues were the after effects of the comets tail on the landscspe and the atmosphere. [See the Kolbrin Bible also]We have been lucky recently as comet NEAT which was twice the size of Jupiter spun around the sun in 2003 and Earth just happened to be in safe position. There are many craters in Canada of past direct hits by asteroids and comets , one large crater in Quebec that can be seen on most maps . So this story may be real although the impact could have been in the Atlantic as well. The real problem is with the asteroids and comets that we do not know about yet or which we are not being told about.

Steve Garcia
September 22, 2012 7:02 pm

@Nerd September 20, 2012 at 10:36 am:

Interesting. Everybody should read The First American by Hardaker. It caused a big controversy back in the old days due to dating (250,000 years!). I wonder if they’re going to start looking into that now. Even 50,000 years old was very tough for people to accept back then too. It took 30,40 years to get to 50,000 years old. Talk about slow progress!

I read that book on Kindle, and I can recommend it highly. But the ‘firestorm’ never really happened, because the participants conspired to keep it under wraps. It was only seriously controversial to those who knew about it, and they made certain that circle of people was small..
The book is a revelation for two reasons. One, that the author is an insider. Two, that the real science of geology proved out to be correct over the more-or-less historical story/timeline that the archeologists had constructed. The two sides wer so far apart that there was no common ground possible. Over time the archeologists’ position had every leg knocked out from under it – by real science.
This same story seems to be happening with the YDB impact story. There are entrenched forces that don’t want it to be true (careers on the line and all that being a part of it), and those have done distorted studies with bad sampling and gotten tons of main stream media science editors to hype the supposed rebuttals. has this on every page:

Kerr Watch
Number of days writer Richard Kerr has failed to inform his Science readers of the confirmation of nanodiamonds at the YDB: 1 year and 9 months

There is irony in Anthony having articles on the YDB impact, because this issue is potentially a really real – and huge – threat (if real), as opposed to AGW, which is a manufactured and tiny threat and over which so many millions of words have been written. Very few words have been written about the potential of an impact in our future. At is a report that Jupiter has again been hit by an object, this one big enough to cause a flare the size of a continent on Earth. This is the third incident since Shoemaker-Levy 9 in 1994 – which itself wasn’t supposed to happen in any of our lifetimes.
The plain truth is that objects keep hitting planets much more often than was thought at the time of SL-9, and much more often than our astronomers are willing to tell us even now.
This sounds like alarmism. I apologize for that. But if humanity has a real threat it is not global warming. It is this: We have the potential for the first time in human history to intercept an incoming object that might send us back to the stone age, and we need to decide if we are going to do anything to protect the planet or just play Russian roulette. The cost will be much, much less than the trillions that Kyoto would cost. The first step is to determine for sure if such a risk is real. If it is not, then fine. If it is, then what do we do?
Firestone et al’s work brought this all to our attention as a possibility of having happened in the past. Certainly few would think it could happen in the future if it hadn’t happened in the past. So this YDB vetting work is important. Even if it is eventually found to be wrong, we will have taken the proper steps to prove it or falsify it.
Steve Garcia

September 22, 2012 8:04 pm

Does the Younger Dryas really exist? There is this idea (or non-idea, product of not thinking clearly) that the default global climate and temperature is total stasis. Stupid, yes, but true. So every wiggle up or down must come from some external gate-crashing forcing event or catastrophe, disturbing the “dignity and repose” of the climate tea-party.
This leads to the comical game of musical catastrophes being endlessly played. Did he temperature rise in the past? Oh noes! – either some civilization must have developed suvs, only then to disappear without trace, or maybe a bunch of cows or mammoths all farted in unison. Did the climate cool? Then it must be a comet or volcano or lightning evolution of a culture making soot-polluting factories – only again to disappear without race.
However the climate system characterised by multiple feedbacks is in reality a nonlinear oscillator system. For instance the flips between glacial and interglacial are the tell-tale flips between two stable attractors. Thus the “Younger Dryas” might be nothing more than an interval between an abortive jump to interglacial and a subsequent successful jump. Glacial periods are in fact punctuated by repeated such abortive jumps, kind of mini-interglacials which last only a matter of decades.
Of course the comet impact evidence might well represent a real event. But if we fall into the way of thinking of needing a discreet forcing event foe every climate wiggle, ignoring the fact of climate nonlinear oscillation, the we are fighting on the AGW camp’s chosen territory and by their rules. Not smart.
The null hypothesis is oscillation.

September 23, 2012 12:42 am

Steve Garcia
Interesting on the bolide cover up. Doesn’t Jupiter (+ Saturn) act as a solar-system vaccuum cleaner, or maybe flypaper / goalkeeper, gravitationally sucking in bolides that might otherwise hit us?
Of course some do hit us, which is clear enough.

Grey Lensman
September 23, 2012 2:19 am

Adam Gallon, clearly you have been absent the last ten years and not seen the closeup pictures and the particle collection results. Comets and asteroids/meteors same thing just different charge.

Steve Garcia
September 23, 2012 7:33 am

phlogiston –
Yes, the understanding is that Jupiter acts as a vacuum cleaner for the Solar System.(and, Saturn, too, though it is not often mentioned because it is far out from the asteroid belt and I assume that minimizes its effect).
I put two caveats on that.
One is that Jupiter’s gravity evidently doesn’t just suck things in. On a close enough pass it alters the object’s orbit, which then brings it into a closer pass the next orbit. That is what happened to SL-9 and why it made a bee-line for Jupiter then next time around. In altering the orbit, Jupiter actually has the possibility of throwing an object toward us, for at least its last orbit before diving into Jupiter.
Also,, Jupiter can only be on one side of ts orbit at a time, so incoming objects that are not on the same side of the orbit cannot be affected by any vacuum effect. Science fiction books and movies that talk about slingshot effects of Jupiter and Saturn are at least misleading, because such slingshot effects as NASA uses have to be very precisely timed to take advantage of when those two are in good position for fly-bys. That isn’t often, in human years. Movies that show starships passing Saturn’s rings – well, that is Hollywood.
Steve Garcia

September 23, 2012 8:28 am

Steve Garcia
Yes the “slingshot” effect could be a double edged sword (mixing metaphors horribly), throwing objects toward us as well as away from us, a.k.a. the alien bugs in Starship Troopers. Anyone modelled this? (gravity – unlike climate – is something that you can accurately simulate mathematically).

Steve Garcia
September 23, 2012 10:15 am

phlogiston –
Yes, they know well how to model orbital stuff, if they know precisely enough their givens. My own take on it is that the slingshot is affected by how the object comes in – high or low – and it can put the object into a high or low new orbit. either of those actually I see as good, because if its orbital plane is skewed, its chances of hitting us are diminished probably by a magnitude or three. But I don’t know if they can get precise enough data on objects to be able to determine any of that well. A matter of 200 meters in or out, up or down, might mean we re threatened or that we are completely safe. And I’d think 99.9999% of the time we are safe. But we should still have some funding (microscopic vs what AGW gets) to have some office handle such things, just to make sure that number is correct and keeps on being correct. And I think it should be under an international sanction, not solely USA. China is probably going to be the ones who will, going forward, have the best space program. And the ESA should have some participation. But it doesn’t have to be big, except when they get a solid plan to intercept – just in case. (I don’t think any of the plans so far are worth a hill of beans.)
I myself am not capable of doing any of the modeling, and I am not interested in getting into it. Modeling is for younger people than me, IMO. Unless they have point-and -click programs!
Steve Garcia

Steve Garcia
September 23, 2012 10:18 am

dammit. I am in the process of changing my ID here, and the ID defaulted to my old one before I caught it.

September 23, 2012 1:13 pm

@Crispin in Waterloo:
not all grazing animals face towards a problem.
old montana wild west tails are that bison will face into a storm and slowly walk into it. whereas cattle will face away and slowly walk away from it.
an item of proof is that there are many stories about the folks that have bison on their ranches finding herds of buffalo at the upwind fence of a pasture alive after a heavy winter storm and herds of cattle on the other side of the wire (on their downwind side) and frozen solid.
so the herds of mastodons may have been facing the danger of storm or facing away from said danger. also they may have been facing towards danger (aliigators or tigers) or away from it.
its a coin toss.

Matt G
September 23, 2012 1:22 pm

There were massive changes found in the North Atlantic Ocean during this period with a gyre of Arctic polar water moving as far south as Spain. This indicated that the Gulf Stream and NAD were moving towards Spain instead of Norway and the Arctic. This massive energy loss towards to the Arctic Ocean easily caused this event, but what caused this has been suggested to be melting ice sheets from North America into the Atlantic Ocean. This likely rules out a comet because how could one change ocean circulation especially over 1000 years with just one impact. Dust would be just around for a few years, so the atmosphere would warm back up again soon after.

Steve Garcia
September 23, 2012 3:03 pm

Matt –
You make several assumptions that may or may not be true. Some have been demonstrated to be incorrect.
The gyre you talk of is suggested by one or more proxies, about which the linearity is assumed. That is the nature of proxies – that such and such indirect evidence tells us something about some changes we cannot directly measure.
Climatologist Rodney Chilton in “Sudden Cold’ has collected the evidence against the meltwater/Lake Agassiz outflow being a cause for the cooling of the N Atlantic. Mostly, the St Lawrence has been ruled out, and the timing has been rebutted, meaning that the reasonable assumption about this event turns out to not be true. It was a good try, but no cigar.
You also make statements about comets without taking into account that different sizes may have vastly different effects. The SL-9 impactors on Jupiter in 1994 ranged from slightly larger than Tunguska (about 25 meters) to about 1.29 km across. The larger two or three made blasts as large as our entire planet. How large would those blasts have been here on Earth? Twice as big is pretty close. A blast which extended out 4,000 miles on either side of Earth would do a lot more than your assumption about putting some dust into the stratosphere. One or two magnitudes more than a volcanic eruption would be my own assumption.
You assume “a few years” of dust in the atmosphere. It would only take a few years to screw up all wind currents. But what is “a few years,” anyway? 3? 10? 25? It is clear that the YD changed in less than 100 years, some have suggested that the evidence indicates less than 10 years. What mechanism would make them go back to normal, once they were screwed up? (And that IS an important question – because the recovery after 1300 years was pretty much every bit as sudden as the beginning of the YD). Right now our weather/climate all starts with the Intertropical Convergence Zone. That is driven by convection, due to the Sun heating the ocean along the Equator. Nothing is ‘normal’ if that isn’t happening. After a body about 60-120 times wider than Tunguska hits, we can make no assumptions. We are off the high end of the charts; we will have pegged the Richter Scale and/or any tsunami scale. An ocean impact would make a tsunami close to or exceeding 100 times as high as Sumatra or Japan.
It is my own assumption that we can make no assumptions and expect them to really be right. Your limiting of a comet impact to what you can envision – that is one guess. You are welcome to it. But it will certainly be much worse that some dust for a few years.
Also, right now we only have SL-9 fragments and Tunguska to gauge off. We have little idea what size of objects are in the Taurid stream, which appears to be the remnants of the progenitor of Comet Encke. Little is known about the many, many thousands of Taurid objects, but it is a good bet that Tunguska was one of them. And we run through them twice a year, being a duck in a shooting gallery.
Steve Garcia

September 23, 2012 3:18 pm

A comet from the Ort Cloud arrives at just under solar escape velocity, so that a near encounter with Jupiter would throw a fresh arrival back out to the Ort Cloud and beyond. In discounting the importance of gravity we are left with the next most important effect: the target’s surface area. Jupiter’s is two orders of magnitude greater than earth’s, and the sun’s is two orders of magnitude greater than Jupiter’s.
But the fact remains, some comets or comet fragments (meteors) do hit the earth after a few thousand alterations of orbit. But have the indicated spheroids ever been found near an impact crater? Have they been found in any layer other than the YD/Clovis? Do we have any evidence whatever that ET impacts have or can cause them? Or is it only the imagined comet X which wiped all the megafauna (no microfauna) and their hunters which leaves this unique trace? Not a continental extinction even, mind you, but two continents, North and South America, which are further apart than North America and Asia or Europe, but which just happen to be connected.
Thanks, Prof. Brown. Crispin’s claim, “They were disturbed 3200 years ago and probably again in about 1650 BC,” is as reliable as his chronology. There is not a shred of evidence for this B.S., and Brown’s back-of-an-envelope calculating is hardly rebutted by Crispin’s argument that less than 100% of the earth’s mass is located in the mantle. Most of it is, and more of its angular inertia is.
And no, there is neither evidence for mass simultaneous mammoth deaths or for any quick freezing–this is all silly myth that makes the worst GW alarmism look sophisticated by comparison. Some people are afraid of illegal immigrants, some of genetic engineering, some of radical Islam, some of climate change, some of comet collisions, some of epidemics, some of nuclear war, and so on. So build your bomb shelter, buy a gas mask, load up with weapons and food, or move north, but most of us will die of old age. We’re making Wikipedia look reliable.

September 23, 2012 4:09 pm

Big rock hit the ice shield over Canada. There are various scour and scorch artifacts on the rocks there. As it wasn’t an air burst, lots of the stuff made it to the ground. There’s a large chunk of “platinum group metals”, in particularly platinum, nicely deposited at the impact site:

Most of the platinum group metals produced in Canada are by-products of nickel mining. The Sudbury Basin in central Ontario has the largest number of pgm-producing mines. Pgm are also extracted from the Raglan nickel mine in northern Quebec and from a nickel complex in Manitoba. In all of these orebodies, palladium is the predominant platinum group metal.
The Sudbury Basin was discovered in 1883 during the building of the Canadian Pacific Railway and by 1886 copper mining had begun. Nickel production followed several years later. Commercial production of pgm began around 1908 when International Nickel Company (later Inco and now Vale), the largest mining company in the Basin, opened a refinery in the United Kingdom to refine the Sudbury ores. Falconbridge, the other major producer in Ontario, produces pgm at its refinery in Norway. Both companies were the subject of acquisitions in 2006, with Vale now owned by the Brazilian base metals producer Companhia Vale do Rio Doce (CVRD) and Falconbridge by the Swiss company Xstrata.

Nickel and PGM kind of shout meteor impact…
More stuff here:
There’s also good evidence for secondary impact ejecta landing in the US and making the Carolina Bays. If you take the long axis of their ellipse, it points back at the proposed impact site in Canada.
Clovis folks AND the megafauna of N. America were wiped out by a rock fall from space. We didn’t hunt the critters to extinction.
Oh, and the reason we have mammoths with mouths full of food flash frozen is that the impact sent a tsunami of tundra / ice / sludge over the top into Siberia and engulfed them in it. That’s also why the stratigraphy is screwed up and why some mammoth are found under dozens of meters of ‘fill’.
“Big Bada Boom!”
And it will happen again…

September 23, 2012 5:07 pm

Look at the surface of the moon. Look at the video of impacts on Jupiter. Look at Arizona and Meteor Crater (not that old). Look at the count of OTHER craters found all over the planet (one, in Germany, so large that whole cities are inside the rim). Then look at the known NEOs and Earth Crossers:
The amount of “stuff” in the neighborhood is very large.
It is not irrational fear to recognize what the math says. A small “nuke like” event about every year (mostly high altitude and over water / empty. Noticed by ‘nuke detecting’ satellites so they had to go to a ‘double flash’ filter to screen out the false positives).
Right now we’re nearer the edge of the Taurid path than the center, but that changes on a long duration cycle. We’ll get back to the massive rock falls of earlier times soon enough. (It is probable that heavy Taurid infall has shifted history several times and possibly climate as well).
BTW, I have no ‘fear’ of it. Frankly, I like watching meteors and wish we had more big shows. In some ways I feel ‘cheated’ that we’re out of the thick of it for a few hundred years. I do have a gas mask, weapons, and food; but mostly due to it being a fun hobby and a little bit due to having come through a 7.1 quake (the gas mask came after looking at the map of phosgene and arsine tanks in the area and the damaged ones after the quake… silicon valley and all…)
Basically, prudent preparation after reasonable and rational evaluation of the risks has no emotional content. There have been and will be again large crop failures. (We almost had one from corn rust some years back as it ripped through the monoculture, we DID have one from GMO rice polluting the ‘founders stock’ seeds resulting in global rice riots a couple of years ago). We will have various floods, tsunamis, tornadoes, hurricanes, wars and riots. (Check any news source for the ones happening now…) What is lacking in reason, is to believe, naively, that no bad thing of that sort will ever happen in your neighborhood…
I have 150 gallons or so of water in barrels in the back yard. Why? Because after the quake, which we have had, and will have again, it is the thing that you are most likely to need here. Not from fear. From understanding.
For anyone else interested in living through the (mathematically) inevitable Bad Things in life, I’ve made some lists of helpful stuff:
though in reality, everything is a resource and what you really need is the mind set to know how to use it. But while I can make a fire from sticks and make dinner from a squirrel, I’d rather just turn on the Coleman Stove, and have Turkish Coffee while cooking some nice Ravioli and pouring a Chianti to go with them…
In short: I fully expect to die of old age. I also know I’m going to be more comfortable on my way to reaching it “during the bad thing”. (Having lived through a couple already I have no doubt that they happen…)

Chuck Forward
September 23, 2012 6:16 pm

I would like to expand on my comments about the last glacial age being warmer than today. The more I think of it, the more it makes sense that the polar shift is key to the why we don’t see glacial fields like before. When the comet storm hit, it immediately increased the sea level and its tsunami punched a path through of the Bering land bridge. Before the comet storm, the land bridge between Siberia and Alaska remained a barrier to the cold Pacific waters. The warm Atlantic waters penetrated much further north past the pole in northern Greenland before chilling. The polar winds would have taken that warm moist air and fed the mountainous glaciers surrounding then polar region. Excuse me for a side bar, but one of my minors was ocean engineering in which half the curriculum was on weather and ocean currents. At that time, we were taught the glaciers actually formed in warm moist periods which seemed counter intuitive. The glaciers flow downhill and grow. When they grow enough in height, they become self sustaining as Greenland is. The world may have been considerably warmer than today but the glacial extent was in lands much farther north before the hit so it fools us into thinking it was actually colder than it was with those same lands now laying further south today. Our reference frame is skewed. With Alaska further south before the hit, it is conceivable that palms would have co-existed with pines until they were all jumbled together by the giant tsunami and the land turns frozen by the polar shift. As the world cools, the warm moist air that feeds the glaciers cease to be and the glaciers shrink and the sea level continues to rise thus enlarging whatever breach the giant tsunami had made in the land bridge. The cold pacific waters disrupts the warm Atlantic flow northward. We are in that temperature range now where we are cold enough to starve the high altitude glaciers but warm enough to melt the lower ends. If we turn colder, we would feed the lower glacial fields while the top ends remain stagnant. If we turn warmer, then the lower ends melt faster but glaciers also grow faster at the higher altitudes (i.e. middle of Greenland versus the edges}.
Chuck Forward

Paul Marko
September 23, 2012 6:30 pm

agfosterjr says:
September 23, 2012 at 3:18 pm
“And no, there is neither evidence for mass simultaneous mammoth deaths or for any quick freezing–this is all silly myth that makes the worst GW alarmism look sophisticated by comparison.”
You could do yourself a favor by an inquiry into the scientific research related to the death and preservation of the mammoths, rhinoceros, and assorted fauna found frozen in the “Muck “ beds that cover approximately 3000 square miles of the Russian Arctic. The only thing silly concerning your statement of quick freezing is a lack of knowledge.

September 23, 2012 7:37 pm

E M Smith: As a former boy scout I still believe in being prepared, and I congratulate you. As for the moon, one side is older than the other: the one with more craters. It’s been getting progressively safer as the solar system has cleaned up the inner debris. What history tells us more than math is that plagues, quakes, volcanoes and tsunamis are more dangerous than meteors–so far. Nobody has ever been killed by a meteor or comet, as far as we know–in recorded history, for the last 5,000 years. You are more likely to run over your offspring in the driveway than get wiped out by a comet–I think. Pompei had Vesuvius, Lisbon had the sea. Every decade hundreds of thousands die by some castastrophe, but so far no city has been wiped out by a bolide–as far as we know. (And Sodom and Gomorah sure don’t count.)
You say, “Clovis folks AND the megafauna of N. America were wiped out by a rock fall from space. We didn’t hunt the critters to extinction.” And you talk about math. What are the chances that only big beasts are affected and little critters aren’t? Do you have a mechanism for this? These fragments just pick on big game and nary a bird. Doesn’t sound at all scientific to me.
Chuck Forward: what do you mean by “polar shift”? –AGF

Chuck Forward
September 23, 2012 10:36 pm

By polar shift, I’m speculating that the north pole was in north eastern Greenland prior to 12900 years ago and the comet storm shifted enough mass to move the pole to its current location.
Nature abhors a vacuum. We live within a quarter mile of the Station Fire burn so I get to appreciate nature’s recovery. Shortly after, we had birds that don’t normally live at our area but now they are all gone as vegetation revives up in the mountains. Even if the center of the continent was scorched clean in an hour, there would be growth and repopulation by the grasses and burrowing animals within a few years. We lose perception of time and how fast nature recovers. There would be refuges in the mountains whether the Rockies or the Appalachians where the bigger animals would have survived the blast just like forest fires will skip some canyons where animals take refuge. Not all of the mammoths and giant ground sloths would have perished but they do have slow reproductive cycles compared to the smaller animals. Yes, you can blame man for finishing them off as large game feeds the tribe with less effort. There was no mass migration from the Siberia down to the America but a few surviving tribes of mammoth hunter fleeing south from the now frozen lands they once had hunted on. What did they hunt there? Mammoths, so you would expect them to go after the bigger game once they got south. How many generations would it take before they finished off the few mammoths that survived? Not many. Once they are gone, the next biggest would do. Others would go extinct for lack of mates. The last giant ground sloth didn’t perish until 800 years ago IIRC.
Chuck Forward

September 24, 2012 7:15 am

Paul Marko says:
September 23, 2012 at 6:30 pm
One of the more serious problems with this mass extinction scenario is that more animals are supposed to have been killed than the land could possibly support at any given time. It’s like saying all our fossil fuels were created by a K/T like event. A less silly interpretation is that over tens of thousands of years mammoths that grazed on ice growing moss often slipped and fell into crevasses where they were preserved till the ice melted. Others, along with the rhinos, are killed when rivers flood, and occasionally get buried in the permafrost.
You are the one who needs to educate himself–you have been fed on creationist nonsense where C14 dates are ignored or discounted. Moving ice collects mammoths just like it collects meteorites, and many of the carcasses are much older than the YD. Furthermore, mammoths survived on Wrangel island till 3700BP precisely because it took that long for humans to arrive.

Paul Marko
September 24, 2012 11:54 pm

agfosterjr says:
September 24, 2012 at 7:15 am
The “Muck” deposits of Siberia and Alaska that contain the frozen fauna and vegetation consists primarily of unstratified loess. The large ice inclusions and lenses are not contiguous. The ice is saline and not of glacial origin. There are no fissures or crevices associated or noted. The areal extent of the deposit across two continents precludes a landslide origin. Nothing in its texture or stratification suggests lateral or horizontal movement. The areal extent, content, and lack of stratification of the deposit indicates a common mode of deposition unassociated with fluvial or marine processes. This leaves few options when one takes into account the preservation of both fauna and flora incased where quick freezing has been documented.
The concern with C14 dating is the result of divergent dates from the same mammoth:.
Russia Dima – 8 month old male, 26,000 RCY and 40,000 RCY; Alaska – two males, same deposit, 16,150 RCY and 22,850 RCY; Alaska – 6 month old, 15,380 RCY and 21,300 RCY. It would appear this needs additional work.

September 25, 2012 3:06 am

If there is good evidence, not from a model, then more research would be a good idea.

September 25, 2012 9:30 am

If there is good evidence, not from a model, then more research would be a good idea.
As in, replicate this particular 20 to 50 micrometer spherical melt quench fraction of the magnetic microspherule fraction for further soil samples from in and around any definitively dated Younger Dryas Boundary sediments, from anywhere in the world, or even just in North America. Preferably without any of the previous collaborators on the team – a completely fresh look at these things.
I’d like to see more ultra precise nanoprobe isotope analysis of a larger variety of these objects if they are demonstrated to be genuine markers from the dated sediments of that era and not anomalous in some manner. They seem to be the easiest to both extract and work with.
It’s quite possible they may have just reached the detection threshold for moderately size impacts such that Corossol crater in the Gulf of St. Lawrence or Charity Sholes or any number of smaller and newly discovered craters could be viable candidates. Certainly these are not climate reversing impacts. To do that the only hypothesized location would be south of Nipigon, and even then the climate reversal would be hydraulic and not atmospheric, although any ozone collapse could have exacerbated the multiple stresses that the megafauna were already experiencing.

September 25, 2012 10:44 am

Paul Marko says:
September 24, 2012 at 11:54 pm
You continue to lump everything together as if due to a single catastrophe, and to make very questionable assertions. Sue Bishop writes: “Their ages fall into two main groups, one ranging in age from 45,000 years to 30,000 years and a smaller number of remains from 14-11,000 years old.” (
Nor is there any evidence for quick freezing, nor could there be–this fairy tale is getting pretty old now. And what’s this “saline ice” you mentioned. I never heard of such a thing.
Finding carcasses of different C14 ages in the same cache is precisely what refutes your catastrophe hypothesis, and your approach is to kill the messenger (C14). Like I described, animals from different ages are collected by the ice, and of course the killer crevasses are long gone. It’s time you recognized that Velikovsky was a crackpot.
Thomas Lee Elifritz says:
September 25, 2012 at 9:30 am
“…although any ozone collapse could have exacerbated the multiple stresses that the megafauna were already experiencing.”
No end of disasters! Meaning climate stresses presumably, which stresses never affect the little critters, not worth hunting. At least these climate stresses involve peer reviewed nonsense, somewhat more acceptable than creationist nonsense. But really size discriminating climate stresses are just as silly as size discriminating comets and ozone holes. It was good to be small then. –AGF

Paul Marko
September 25, 2012 7:31 pm

agfosterjr says:
September 25, 2012 at 10:44 am
The listed carbon dating documents the occurrence of widely different C14 dates acquired from the same Mammoths. This is a problem that clouds the water regarding dating.
Russian research determined that the only definitive cause of death for the Mammoths and Rhinos was asphyxiation. Their mouths and air passages contained sand, small gravel and clay particles derived from an airborne source. Their small blood vessels and capillaries were gorged with coagulated blood, an occurrence used to distinguish asphyxia from drowning. Some of their mouths also contained freshly cropped, perfectly preserved grasses, bean pods and flowers that they had no time to swallow. It is not reasonable that these animals had their last meal foraging on the barren surface of a glacier.
Frozen Mammoths have been noted in the literature since the early 1700’s, but most notably Tolmachoff (1929) in Russia and Hibben (1946) in Alaska. In addition, the Mammoths have been found associated with other animal assemblages, trees and vegetation strewn together and frozen. The “Muck” deposits and their frozen fauna assemblages have always provided a problem for uniformitarian proponents, but they have not been discounted by field research.
The ice associated with the “Muck” deposits is very granular, similar to compacted hail and air undersaturated compared to tiny granularity and air saturated glacial ice. The ice is described having large linear bubbles, unlike glacial ice, and dirt and plant material is prevalent and visual. The salinity is noted in the following:
“Cryohydrochemical Peculiarities of Ice Wedge Polygon Complexes in the North of Western Siberia,” Permafrost: Fourth International Conference Proceedings (Washington, D.C.: National Academy Press, July 17–22, 1983).
The “Muck” beds and their fauna and flora assemblages are an enigma deposited by no known or accepted geological process. Until further research provides an answer, nothing noted should be discounted.

September 26, 2012 7:23 am

Paul Marko says:
September 25, 2012 at 7:31 pm
The listed carbon dating documents the occurrence of widely different C14 dates acquired from the same Mammoths. This is a problem that clouds the water regarding dating.
This is an outright falsehood perpetrated by a professional liar. If you take the trouble to check it out you’ll see.
“The “Muck” beds and their fauna and flora assemblages are an enigma deposited by no known or accepted geological process.”
More nonsense. Your sources are an assemblage of know-nothings–don’t believe them. Arctic rivers routinely freeze up and ice dams form on a tremendous scale. This was especially true for Siberia during the last ice age which had no permanent ice cover, hence plenty of seasonal flooding. I don’t know how salt walter gets into the permafrost but I think a good geologist could come up with an explanation. And if mammoths died of starvation they stood little chance of being preserved–on the surface; those which died accidentally had food in their stomachs, and if they died in a flood the food would not be ice moss.
You use the label “uniformitarian” the way a Creationist does. Therefore I assume you attribute the mammoth deaths to Noah’s flood. Noah’s flood is a myth, as any good Bible scholar will tell you. The Genesis version is a conflation of two sources, J and P, J derived mainly from the Sumerian version and P from the Babylonian. That’s why it is so full of contradictions. The Sumerian retains traces of a regional flood while the P version is full blown universal. (Note that while Noah is still stuck on Mt. Ararat a dove is able to return with on olive twig–makes no sense.) The Hebrew word for ‘ark’ is ‘teva,’ which is only used otherwise of the basket that baby Moses was saved in. And in the Sumerian version Siusudra turns his reed hut upside down to make a boat out of it. Therefore ‘ark’ in the old J version means a contraption made of reeds–yet the J tradition assimilated the universal zoological salvation of the Babylonian version while still theologically independent of P: J has Noah distinguish between clean and unclean animals, which P considers impossible since the Torah had not yet been revealed.
Of course the most serious problem with the flood myth is the present distribution of species, which is proof in itself of Darwinian evolution. Or do you believe that Noah unloaded all the marsupials in Australia? So what I’m trying to tell you is there is nothing scientific about your approach to the problem, but in this the Creationists and Velikovskians have plenty of peer reviewed company. “Overkill” is the only reasonable explanation for the Pleistocene extinctions. –AGF

Chuck Forward
September 26, 2012 3:53 pm

Even though this post has gone past the first page, I’m trying to figure out your beef? Are you stating that you do not buy any comet(s) impact theory at all or just tweaked that some use it as an excuse as to why man isn’t to blame for killing off the mega fauna? I agree with you that man is most like source of the extinctions but those extinctions were helped along by having a much smaller population of animals than otherwise should been present. If not, then how come all of the mega fauna of Africa and Asia have not met the same fate? Granted, the dim witted quadruped herbivores might have been easier prey but those that survive learn. It is surprising how many more deer habitat the safe zones of parks when hunting season opens.
Something big happened 12900 years ago that triggered a major cooling event. The evidence is building that something caused the black mat that extends across this continent, parts of Europe and down to Venezuela. My contention is a polar shift happened during that event that made lands which supported a large bio mass unsustainable today. It caused a geographical change (the Bering strait) that disrupted an ocean’s circulation pattern which contributes to making those lands uninhabitable.
Now comes to question, is hot really cold and cold really hot? Were the glacial epochs a period of great warmth and the interglacial times that we currently live in a period of cold? Is the warming we are experiencing the natural process of heading back into a glacial age (post the next 30 year minimum)? As I was taught back in the 70s, glaciers grow at altitude from warm moist conditions. Tropical plants could have existed next to the walls of melting ice on arctic shores if that was the case.

Paul Marko
September 26, 2012 9:16 pm

agfosterjr says:
September 26, 2012 at 7:23 am
The dialog has moved off topic with certain assumptions related to a Biblical Flood and Creationism.
It’s possible that certain authors may have derived the wrong conclusions interpreting their observations. It’s also possible an author is fabricating the observation, data or conclusions – this website has had considerable experience in that regard. It’s the recorded observations, not the interpretations that are anomalous.
The critical anomalies are the quick frozen fauna and flora, saline rock ice, dismembered fauna, and shredded vegetation deposited in unstratified loess.
What’s missing is a unified geologic theory to explain the extinction, deposition and association of those assemblages.

September 27, 2012 7:01 am

Chuck, Africa experienced the fewest Pleistocene extinctions because humans and animals evolved together. As humans evolved hunting skills, animals, through a combination of evolved instinct and learning passed from one generation to the next, adapted to the new predator. Man evolved in and was adapted to a warm climate, and in Africa seems to have played a minor role compared to climate in animal population fluctuation and movement. To a lesser extent these factors held in temperate Eurasia. The first great extinctions occurred in Australia, about 40ky, when humans arrived. The next, when a combination of cold surviving technology and easy passage allowed for the colonization of the New World. The sudden meeting of predator and naive prey allowed for very rapid population growth and prey depletion that exceeded replenishment. Only the most northern animals survived: island mammoths, polar bears, and the small musk ox. The new arrivals only took centuries to wipe out the big game in South America as well.
So, it’s the suddenness of the encounter that matters. No meteor was involved in Australia in 40k BP, or in South America 12ky; why should we invoke such in North America? Who knows where these strange carbon nodules came from? Maybe impact, maybe not. How do we know a volcano didn’t do it? They never did before? Neither did a meteor.
As R G Brown indicated earlier, the notion that a meteor could cause a change in earth rotation is pretty far fetched. The core and Greenland ice can move the North Pole a few meters relative to the crust. Chandler wobble moves the crust itself a few meters in periods of about one and five years. But it’s been a long time since the planet had an impact big enough to affect its rotation. The K/T event probably did not. The impact that supposedly made the moon certainly would have. So no, I don’t believe you’ve done the math to support any polar shift, nor has anyone done good science to show a meteor can change the climate for a thousand years.
Paul, I repeat, there is no good evidence for quick freeziing mammoths–this is a creationist fairy tale. Check it out. These carcasses get pretty beat up after being dragged through the ice for thousands of years. That’s no evidence for a catastrophe. See if you can find me a reliable source for salt water getting into the permafrost. –AGF

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