Guest “whatever” by David Middleton
Texas cave sediment upends meteorite explanation for global cooling
7 hours ago
Baylor UniversityTexas researchers from the University of Houston, Baylor University and Texas A&M University have discovered evidence for why the earth cooled dramatically 13,000 years ago, dropping temperatures by about 3 degrees Centigrade.
The evidence is buried in a Central Texas cave, where horizons of sediment have preserved unique geochemical signatures from ancient volcanic eruptions—signatures previously mistaken for extraterrestrial impacts, researchers say.
The resolution to this case of mistaken identity recently was reported in the journal Science Advances.
“This work shows that the geochemical signature associated with the cooling event is not unique but occurred four times between 9,000 and 15,000 years ago,” said Alan Brandon, Ph.D., professor of geosciences at University of Houston. “Thus, the trigger for this cooling event didn’t come from space. Prior geochemical evidence for a large meteor exploding in the atmosphere instead reflects a period of major volcanic eruptions.
[…]
One unnecessary hypothesis upends another… So what? In terms of Late Pleistocene Greenland stadials, the Younger Dryas isn’t even particularly anomalous. The real anomaly, to the extent there is one, is the preceding Bølling–Allerød interstadial.
Phys Dot Org
The Bølling–Allerød interstadial featured a sharp rise in atmospheric carbon dioxide (possibly >400 ppm according to at least one plant stomata study) and Central Greenland temperatures as warm as the Little Ice Age.
While impact events and/or volcanic eruptions certainly could have played a role in Late Pleistocene to Early Holocene extinctions and may have even had transient effects on Younger Dryas climate change, the Dansgaard–Oeschger Events occurred with clock-like regularity during the final Pleistocene glacial stage. These episodes of rapid warming to nearly interglacial conditions occurred approximately every 3,000 years from 90 ka to 12 ka, indicating a periodic drive mechanism.
No one really knows what drove the Dansgaard–Oeschger and Heinrich cycles… But neither impact events nor volcanic eruptions can explain such a clearly quasi-periodic climate change signal.
That is a clear as mud.
Mud that is deposited in a cave as secondary, tertiary, quaternary, quinary, senary… levels of erosion.
Expecting heavy and rare Earth metals to be found as distant isolated deposits in a cave is absurd.
Nor are the volcanic episodes identified and verified by the volcanic craters and fallout.
Competing theories are still competing theories without a clear conclusion.
Please read the paper:
Volcanic origin for Younger Dryas geochemical anomalies ca. 12,900 cal B.P.
https://advances.sciencemag.org/content/6/31/eaax8587
Timing of volcano eruptions with Hall’s Cave sediment deposition
Distant volcanic eruptions may provide both the compositional control and physical mechanism to produce the HSE-enriched cryptotephra horizons in Hall’s Cave. The multidecadal to century scale time resolution for sedimentation in Hall’s Cave obviate correlation with specific volcanic eruptions. However, this section documents significant eruptions within the time frame of the cryptotephra horizons fingerprinted by 187Os/188Os ratios and HSE systematics. These times indicate active volcanism in regions in the Northern Hemisphere that could have contributed cryptotephra to Hall’s Cave sediments. The cryptotephra horizon at 151 cm at the YD basal boundary layer at 13.11 to 12.90 ka was likely sourced from the 13.10 ± 0.10 ka eruption of Laacher See. The Laacher See eruption ejected 6.3 km3 (DRE) of sulfur-rich magma far into the stratosphere and likely dispersed volcanic aerosols throughout the Northern Hemisphere (8, 9). Laacher See released from 2 to 150 Mt of sulfur. Although under debate, this may have triggered the temperature decline associated with YD climate change in the Northern Hemisphere (10).
To identify possible volcanic sources for the other horizons in Hall’s Cave that have 187Os/188Os ratios and HSE signatures consistent with cryptotephra, the 14C ages of large-magnitude volcanic eruptions during the late Pleistocene to Holocene are compared to the 14C ages of the five HSE-enriched unradiogenic horizons (UR1 to UR5) in Hall’s Cave (Fig. 1 and table S5). The five interpreted cryptotephra horizons can be grouped into three volcanic mixing events that correlate well with known eruptions. The couplet of UR1 and UR2 horizons at 176 and 171 cm BDT [below datum by Toomey in 1986; (23)], with a depositional age of 13.33 ± 0.19 ka, is similar to the Glacier Peak volcano in Washington, USA erupted at 13.71 to 13.41 ka and/or the J Swift tephra from Mount Saint Helens erupted at 13.75 to 13.45 ka (table S5). These eruptions demonstrate that the Cascade volcanic arc was highly active at these times and would likely have dispersed volcanic aerosols and cryptotephra widely across the Northern Hemisphere.
There are possibly two eruptive candidates for Horizon UR5 at 140 cm BDT, which dates to 10.98 ka. Both the Fisher Tuff eruption from the Aleutian Arc and the Lvinaya Past eruption from the Kuril Arc occurred during the appropriate time interval (table S5). Each of these large-volume arc volcano eruptions produced a Plinian eruption column that reached the stratosphere and distributed volcanic aerosols across North America (46).
I like it when these things go back and forth. Engages the mind.
“But neither impact events nor volcanic eruptions can explain such a clearly quasi-periodic climate change signal.”
I wouldn’t hang my hat on that. A periodic stream of meteor debris orbiting may have a large amount hit on one pass then not much or more on the next etc.
Another possibility I’ve read about is that the sun has quasi-periodic Super-Carrington events.
More interesting brain food to let digest. Love it.
None of the putative impact detritis is of ET origin, so there’s no evidence for a meteor or comet collision, hence no basis for imagining that such a thing caused the YD.
Dear John T,
Please don’t give up on WUWT. I thoroughly enjoy and have learned a lot from your contributions. Yes, the moderation may be slow at times, but there is not an army of paid staff here. Patience is a virtue…
Thanks!
I know that everyone suffers delays.
Do you also get 409 messages and lose comments entirely. I don’t always remember to save them, if worth saving.
Who was it who said
“They’ll kill us if it turns out to be natural variability”?
Anyway, they are right…
Wow!
That was a big comment thread!
I think what I got out of all that is that mankind better prepare for the consequences of a sudden glaciation event. I’d vote for a consistent development of nuclear power plants.
It wouldn’t “cost” much, as we need the power anyways, and it would be resilient to cold climate change.
The precautionary principle would break the bank, probably for naught. We simply have to wait for objective evidence of an impending event and deal with it as best we can. And as of now there is no evidence that CO2 controls anything but the income of certain “scientists.”
True.
But it wouldn’t break the bank to set up an asteroid detection and defense system, on the model of integrated air and missile defenses.
Humanity might be able to interrupt the next glaciation, still probably thousands of years away. Fusion power would help.
Perhaps I am too late for this party, but I would not have been invited anyway. I feel like a voice in the wilderness. I take exception with most of what is being said here. The first thing is, Charles Lyell was not at all accepting of catastrophic events on the large scale. Just read or see Richard Huggett’s book on the subject. Huggett clearly indicates an overwhelming opposition to catastrophes in Pleistocene and Holocene times. Lyell and James Hutton and others believed that most all the Earth’s geological processes were gradual. Secondly, I really take exception to some of the comments being made that comets and and / or asteroids have not been involved in initiating the Younger Dryas and some of the lesser but still cold and dry Holocene events. Well respected astronomers like William Napier, Duncan Steel, Asher, Victor Clube and John Lewis and more, have developed the theory of impacts as extremely important factors going back into at least the late Pleistocene. I as a climatologist for all my working life am following that theory and attempting to prove from a climate standpoint that many factors confirm their theory. One of the items I have found, is that meltwater could not have caused the Younger Dryas. There are so many reasons for this and oceanographer Carl Wunsch highlights this thought by saying, ocean water such as the North Atlantic are not driven by temperature and salinity change (thermohaline circulation). Instead, the mechanism involves winds and to some extent tidal forces. There is in addition,no proof that the North Atlantic circulation was slowed or stopped during the Younger Dryas as the few marine cores that supposedly supported the hypotheses have been proven as flawed. Also a marine core off the coast of Portugal indicates that the ocean waters were very saline during the Younger Dryas. Finally, the fact that events such as the Younger Dryas and other events like that near 8200 BP were so sudden, in perhaps in as little time as few years, or so excludes such ideas as the very slow, orbital, axis changes etc. of the Earth, as they are far too slow to cause climate shifts that are being addressed here.
You just don’t know what Uniformitarianism means…
https://www.usna.edu/Users/oceano/pguth/md_help/geology_course/lyell.htm
Meteor and comet impacts are covered. Noah’s flood isn’t.
Please read Lyell’s “Principles of Geology”. All editions are available on line. Lyell continually writes about the role of catastrophes–floods, volcanoes, earthquakes, etc.–in shaping Earth. A single sample from the first edition:
“In speculating on catastrophes by water, we may certainly anticipate great floods in future, and we may therefore presume that they have happened again and again in past times. The existence of enormous seas of fresh-water, such as the North American lakes, the largest of which is elevated more than six hundred feet above the level of the ocean, and is in parts twelve hundred feet deep, is alone sufficient to assure us, that the time will come, however distant, when a deluge will lay waste a considerable part of the American continent. No hypothetical agency is required to cause the sudden escape of the confined waters. Such changes of level, and opening of fissures, as have accompanied earthquakes since the commencement of the present century, or such excavation of ravines as the receding cataract of Niagara is now effecting, might breach the barriers. Notwithstanding, therefore, that we have not witnessed within the last three thousand years the devastation by deluge of a large continent, yet, as we may predict the future occurrence of such catastrophes, we are authorized to regard them as part of the present order of Nature, and they may be introduced into geological speculations respecting the past, provided we do not imagine them to have been more frequent or general than we expect them to be in time to come.”
Lyell defined uniformitarianism as the view that the geological processes observable now operated in the past. Today catastrophes occur, so they must have done so during the whole history of our planet. He contrasts uniformitarianism with catastrophism not because he believed that cataclysms don’t happen, but because he could see that Earth was not shaped by a single global flood.
That the onset of the YD happened quickly is no surprise. Same goes for the beginning and end of the previous B/A warm spike. As the sources I’ve provided show, cold snaps like the YD during glaciations, deglaciations, and to a lesser extent during interglacials, as now, are associated with infusions of fresh cold water into oceans, affecting sea level, submarine and surface currents and atmospheric circulation.
You confuse Wunsch’s view of surface currents with deep circulation:
https://journals.ametsoc.org/mono/article/doi/10.1175/AMSMONOGRAPHS-D-18-0002.1/28254/100-Years-of-the-Ocean-General-Circulation
Please cite the salinity studies you mention. Without knowing to which you refer, I can’t comment. But the Gulf Stream still functions during deglaciations, if farther south, so Portugal might well have been washed by salty water during the YD. I know that IRD from Heinrich Events indiates that icebergs from across the Atlantic off Labrador made it to off the Portuguese coast.
Dave: Although I appreciate where you are coming from, not all agree with your conclusions in regard to catastrophic events as being a part of the Uniformitarianism doctrine as espoused by Charles Lyle and others . I have relied heavily for my information upon Richard Huggett and his book, “Catastrophism: Asteroids, Comets, and other Dynamic Events in Earth History, 1997, and also Michael Benton’s Book where he spells out Lyell’s thesis in detail, and his book is “When Live Nearly Died, The Greatest Mass Extinction of all Time” 2003. Thank you for your response Dave, regards, Rod Chilton
How about actually reading what Lyell wrote, rather than someone else’s opinion about his work?
https://www.gutenberg.org/files/33224/33224-h/33224-h.htm
Other online versions as well.
Lyell, Hutton etc. have been dead for a long time. Uniformitarianism doesn’t preclude anything not known at the time they were alive. Every real geologist in the world knows that catastrophic events have occurred and will occur again. Without the principle of Uniformitarianism, we couldn’t identify past impact craters, less obvious than this one:
Upheaval Dome in Canyonlands National Park is a perfect example. The world’s foremost expert on impact craters, the late Eugene Schumaker, concluded that it was an impact crater. The world’s foremost expert on salt tectonics, the late Martin Jackson, concluded that it was salt structure. Both employed the principle of Uniformitarianism and conducted extensive field geology work. They were both likely wrong and right. Upheaval Dome is very likely the result of both an impact and a collapsed salt dome.
https://wattsupwiththat.com/2018/05/31/the-mystery-of-upheaval-dome-uniformitarian-impact-craters-part-quatre/
The alternative to Uniformitarianism is circling round things up on satellite photos and declaring them to be impact features.
https://wattsupwiththat.com/2018/04/25/uniformitarian-impact-craters-same-as-it-ever-was/
John: Point taken re: Lyle, yes you are correct at least to some extent, but I am still not convinced he really appreciated the full range of where the catastrophes originate. Richard Huggett and Michael Benton do not nor did French scientist in Lyell’s time, Georges Cuvier. So I see a dilemma here, and I think it best we just disagree on this point. The other issue concerns me much more as and that is freshwater presence as acting to slow or shut down ocean circulation, in this case the North Atlantic. if you care to read what if you can hold of my earlier book “Sudden Cold: An Examination of the Younger Dryas Cold Reversal,2009, you will see some of the reasons that this did not happen. I am building on this with my new manuscript that I have been working on over the last nine or ten years as well. I also believe there is a synthesis of the views expressed as in the book on the Internet, if you type my name, it should come up. Finally, climate modelling failed to satisfy one of the main criteria, that of meltwater being able to initiate the North Atlantic shutdown rapidly. Regards, Rod Chilton.
You’re right that Lyell didn’t anticipate ET impacts, but they too fit in with uniformitarianism, since small meteors fall all the time.
Meltwater from the Cordilleran and Laurentide Ice Sheets did reach the North Atlantic, via Fram Strait. Also inundated Bering Strait for the second time during Termination I, into the Bering Sea and North Pacific.
Please see the links I’ve posted.
Not just the continental ice sheet runoff, but formerly landfast sea ice on the Barents Shelf:
The Younger Dryas and the Sea of Ancient Ice
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.211.2718&rep=rep1&type=pdf
Maybe a better version of “Principles of Geology”, 1st edition:
http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=A505.1&pageseq=1
Sorry! Meant Beaufort Sea Shelf.
Thank-you John, I am aware of the influxes going into the Northern Oceans, but as you should know by now, I do not believe they disrupt ocean circulation, the nature we are talking about here. I certainly do respect your diligence in reading and writing John about this topic. It is just that again, we simply are not convinced by each others ideas. So be it, but like you I do find this time very fascinating and it is good to have intelligent debate, so missing from many other important topics. Kind regards, Rod.
And to you.
I just go with the evidence, all of which that I’ve found points to weakening by cold, fresh water infusion of the AMOC during the Younger Dryas, to include predicted knock-on effects thereof. Some of the latter are even counter-intuitive, like Greenland Ice Sheet mass loss.
In less than 48 hours Dr. Sweatman popped this bubble. Wait until the YDI authors respond, it will become even more clear Sun et al. fudged it. Conclusions start at 15:00 mins: https://www.youtube.com/watch?time_continue=1&v=1gVvblVcKu0&feature=emb_logo
The folks on this blog should understand the overwhelming compulsion for the mainstream to hide, fudge and “re-explain” the truth. Earth and paleo-climate are not a closed system. Mysterious “tipping points” are best explained by impacts and have zero relevance to our current situation, unless CO2 somehow attracts comet fragments. Comets are not nearly as fun politically.
Right.
George,
You missed the whole point of this post.
It doesn’t argue that volcanoes caused the YD. It uses volcanic geochemical deposits to show the YD impact “hypothesis” false.
Explaining the YD by the Laacher See eruption (LSE) is just as preposterous as the YDIH, but volcanic eruptions do account for the supposed “evidence” of an impact.
As you also must know Sweatman is only a little better educated for commenting on paleoclimatology than are you, a sociology undergrad. althoug your university does have good geologists, some of whom have even studied the Eifel Hot Spot, source of the 12.9 Ka LSE. They’ve, no surprise, discovered that the Greenland Pt signature doesn’t match any meteoritic source, nor for that matter LSE tephra.
Thus all that geology can say about the putative Pt fingerprint near the start of the YD is that it definitely didn’t come from outer space.
But I for one am glad to welcome the Crackpot in Chief to commenting here.
Sorry for typos: “undergrad, although”.
Mea maxima culpa.
But now, on reflection, I find it ironic that your university is home to the three academics, ie two profs and a doctoral student, promoting the ludicrous LSE hypothesis for the YD, ie that attacked in the YouTube video you cite.
But at least PhD candidate Charlotte Green shows that the Greenland Pt signature can’t be of ET origin.
http://etheses.dur.ac.uk/13490/
Investigating the origin of a Greenland ice core geochemical anomaly near the Bølling-Allerød/Younger Dryas boundary
George Howard: Thank-you for your contribution. I have been attempting to defend the Comet hypothesis here, but I have not made much headway. I even cited well respected astronomers including William Napier, Victor Clube, D. J. Asher, Duncan Steel, John Lewis and must not forget scientists in other disciplines such as Firestone and of course yourself, who hold that the Younger Dryas was the result of impacts. Many including Firestone remained convinced that an impact event likely derived from the Taurid Meteor Complex is the origin. Also, it is absolutely ridiculous that volcanic eruptions, the nature of those cited in the paper referred to are able to cause more than a few years, to perhaps slightly more years of climate change, only the extremely ancient Deccan and Siberian traps would be able to accomplish this. And on the topic of freshwater being able to cause slowing of the THC, this has been proven to many, that it just not plausible. This I am attempting to spell out in my new book, that expands on what I wrote in the 2009 book ” Sudden Cold”.
Napier, et al, argue for a large, disintegrating comet, for which there is zero evidence.
Clube argues for a meteor, for which there is zero evidence. But also, with fellow fantasists, for an escapee from the Taurid stream, ie Clube, Napier, Asher & Steel, from the last century. for which there is zero evidence.
Lewis is a ChiCom shill. Please be careful as to whom you chose as friends.
They’re all really old guys who have been shown wildly wrong repeatedly.
You’re right about volcanoes not being able to cause the YD, but the same applies to impacts, even if they did occur, which all evidence shows they didn’t.
However the 700 year-long flow of meltwater into the Arctic Ocean not only could but did weaken the AMOC.
The odds against an extinction event causing bolide impact within the past 13,000 years are 2000 to one, so, no surprise, there is no evidence whatsoever of such and event. Science requires evidence, unlike the fantasy of an impact on or above the Laurentide Ice Sheet, for which there is none, with all the evidence in the world against it.
No matter how many fantasists you cite, argument from fantasists is a logical fallacy.
If the odds are 1/2000 against , then the odds for would be1999/2000. I’ll take the latter.
The odds that an impact capable of mass extinctions occurred 12,900 years ago are one in 2000.
We know that an impact did not cause extinctions during the YD because megafauna on Caribbean islands survived thousands of years after the YD until humans arrived there, but related animals were wiped out in distant Patagonia earlier.
Also, many extinctions happened before and after the YD.
The YDIH is complete, total and utter nonsense.
John: Sorry but you are wrong on all counts, except that volcanoes, perhaps except the supervolcanos are not capable of long-term climate shifts the nature of the ones being considered here, and none of these has erupted big time within the past twenty thousand years plus.
And John, I believe you have overstepped the bounds of good taste when you call scientists that I respect highly as fanatics. I have corresponded with William Napier many times over the past number of years and he is anything but, what you have said. I must take leave of this exchange with you, as you are never going to see the light and I will never except your line of thinking. Take care, Rod.
I don’t think that volcanoes can control the climate, just weather for a few years at most.
It appears that you’ve misunderstood the point of this post as well.
The volcanic signatures show the YDIH false, yet again. They don’t suggest that repeated eruptions caused the YD, as in the LES hypothesis.
Dr. Napier’s supposedly scientific papers are as fictional as his novels. His cometary hypothesis is just as whacky and evidence-free as Firestone’s meteor impact delusion. People can make contributions outside their area of specialization, but Napier would have benefitted from studying oceanography, atmospheric sceince, paleoclimatology and geology before presuming to publish on these disciplines.
Napier’s cometary speculation fails even by his own discipline, astronomy. To qualify as a scientific hypothesis his WAG must make testable predictions capable of being confirmed or shown false.
Where in the inner solar system is the parent body from which he claims cometary debris showered Earth, igniting fires? After just 12,900 years, it should still be there.
Sharing this with colleagues.