In a new study, scientists say they have found evidence along the New Jersey coast that an extraterrestrial object hit the earth at the same time a mysterious release of carbon dioxide suddenly warmed the planet, some 55.6 million years ago. The warm period, known as the Paleocene-Eocene Thermal Maximum (PETM), is often cited as the closest analog to today's rapid human-induced climate change. The study does not explicitly say that an impact triggered the PETM, but the implication is consistent with the authors' previous work suggesting such an abrupt trigger. By contrast, mainstream theory says that the carbon came from volcanism or some other earthly cause, over thousands of years.
"This could very well be the ground zero" of the PETM, said coauthor Dennis Kent, a researcher at Columbia University's Lamont-Doherty Earth Observatory and Rutgers University. "It got warm in a hurry. This suggests where it came from." It was Kent who first suggested in a 2003 study that a comet triggered the PETM. He based his argument on magnetized clay particles found in New Jersey that he said could have been altered by a comet. Many colleagues quickly rejected the hypothesis.
The new study, published today in the leading journal Science, offers additional evidence: tiny spherical droplets of glass called microtektites. These are thought to form when an extraterrestrial object hits the Earth and sprays out vaporized material that solidifies while flying through the air. The study's lead author, geochemist Morgan Schaller of Rensselaer Polytechnic Institute, and his student Megan Fung spotted the sand-grain-size spherules at the base of a layer of fine clay believed to mark the start of the PETM. The samples came from drill cores taken in suburban Millville and Wilson Lake, N.J., and from a streambank in nearby Medford, N.J. The 30-foot-thick section of fine material, known as the Marlboro clay, is found in several areas along the U.S. East Coast, and appears to have been laid down rapidly. All the microtektites came from a seven- or eight-inch layer at its base. A fourth sample, correlated to the same time, came from a deep-seabed core taken off Bermuda.
"It's got to be more than coincidental that there's an impact right at the same time," said Schaller. "If the impact was related, it suggests the carbon release was fast."
Most scientists say that the carbon release at the start of the PETM took anywhere from 5,000 to 20,000 years. Many suspect it came from a surge of massive volcanism. The resultant warming may have been abetted by a sudden release of frozen methane from the seafloor, due to warming from the carbon, changes in the earth's orbit or shifts in ocean circulation. Temperatures ascended 5 to 9 degrees Centigrade (about 9 to 16 Fahrenheit), during a nearly simultaneous warm period that lasted some 200,000 years. The planet was essentially ice free, and sea levels drastically higher than now. Many small, single-celled ocean-bottom creatures went extinct, but on the surface, many species seem to have adapted by moving poleward. Mammals, including primates, rapidly evolved. "It was almost a happy time for some, but of course there were winners and losers," observed Kent.
Many scientists suggest that human carbon emissions are now far outpacing anything that took place during the PETM. The consequences might be more drastic, because many life forms will not have time to evolve or move, they say. Earlier this year, a study led by Richard Zeebe of the University of Hawaii asserted that humans are now pumping carbon into the atmosphere 10 times faster than whatever natural forces drove the PETM.
In 2013 Schaller and James Wright of Rutgers University (also a coauthor of the new paper) published a study asserting that the PETM carbon release was virtually instantaneous. Their evidence: extremely high levels of carbon isotopes that appear in a narrow band of the Marlboro clay representing just about a dozen years. This band, it turns out, is near the newly found impact ejecta layer.
Kent said there are various scenarios about how an extraterrestrial impact might have operated. A comet would bring its own load of carbon into the atmosphere; the impact may also have vaporized carbon-rich sediments stored below the earth's surface. But those events alone might not account for the magnitude of the carbon increase and warming. In line with existing theory, Kent says the impact also could have shaken loose frozen methane from the seabed, or helped waken massive volcanism. "It's an event with a lot of consequences that would have unfolded in various aspects over seconds, minutes, hours, months and years," he said.
The authors admit that they have not located a crater. "It could have been next door, or it could have been on the other side of the planet," said Schaller. The spherules are thinly spread, he said, which suggests the impact was large but far away, or close, but relatively small.
Charles Langmuir, a prominent paleoclimate researcher at Harvard University who was not involved in the study, said the evidence of an impact at or near the PETM boundary was "very strong." However, he said, the study does not address what caused the carbon release, nor how long it took.
Christian Koeberl, an impact specialist at the University of Vienna, said the paper could indicate such an impact, but that the spherules could have come from another time and been reworked into the PETM sediments. He pointed out that the researchers did not directly establish the spherules' age using radiometric dating—an omission that other critics also noted. An impact thought to have contributed to the extinction of dinosaurs took place off what is now Mexico's Yucatan Peninsula about 11 million years before the PETM. And, 20 million years after the PETM, a much closer impact dug out much of what is now Chesapeake Bay.
Gerald Dickens, a marine geologist at Rice University who studies the PETM, says the new paper does not "really explain anything." There are "multiple arguments for why the carbon input took thousands of years," he said. "Finding a few spherules does not change this."
Langmuir said the study is unlikely to change anyone's view of what the PETM might teach us about our own time. "From the point of view of the Earth system, a week vs. a century does not make that much difference," he wrote in an email. "Both are almost geologically instantaneous. Whether it is an impact, or huge volcanic eruptions, or human emissions, rapid changes to the atmosphere have a major impact on planetary systems, and particularly on life."
Explore further:
New evidence of a long-term planetary thermostat to remove excess CO2
More information:
"Impact ejecta at the Paleocene-Eocene boundary," Science, science.sciencemag.org/cgi/doi … 1126/science.aaf5466
HannesAlfven
I have to imagine that the climate scientists will implicitly realize the slippery-slope nature of this problem, and they will probably fight to avoid the destruction of their closed-system narrative that, in practice, climate is only sensitive to things happening internal to the climate system.
We've been through this before with the Firestone group, and that basically played out to a draw.
jonesdave
As usual, all prose, no science.
Mark Thomas
This is how we begin to terraform Mars in decades, not millennia.
Comets must have brought some volatiles to the inner solar system. We would only be replicating a natural process to thicken the atmosphere of Mars and warm the planet by using comets again. This idea was featured in a 2005 episode of Star Trek: Enterprise, titled, Terra Prime. One of my favorite.
TrollBane
jonesdave
TBH, this whole terraforming thing is centuries away, if it happens at all. I read some interesting proposals, some years ago, but can't remember where. It involved initially putting 2 mirrors in orbit over the poles. Technologically speaking, most of the proposals were either doable now, or within a reasonably short time period. The cost, however, would be horrendous. Until there is some pressing need to do such a thing, or some new piece of technology makes it far cheaper (nanotech?, genetically engineered bugs?), then I don't see it happening any time soon.
Nik_2213
Not *impossible*, despite the so-scary math but, IMHO, easily a century (*) beyond current tech...
FWIW, check out the 'Rosetta' and 'Deep Impact' missions for a first-look at the scale of the task...
Oh, and research the effects that recent comet pass had on the fragile Martian atmosphere.
:-(
(*) IMHO, you'd need game-changer breakthroughs in nuclear fusion, space-craft launch and deep-space propulsion, plus 'unobtanium' for radiation shielding. AI may help...
howhot3
jonesdave
What you really want to say is that there is absolutely zero evidence for any of the rubbish spouted by Velikovsky, Talbott et al, and you want to throw doubt upon the records so that you can somehow turn this rubbish into respectable science. Guess what? Never going to happen. It was not then, nor is now, nor will ever be, science. Best off in a mythology forum. Like Thunderdolts.
daqddyo
Mark Thomas
- Agreed, although it might take surprisingly few to thicken the atmosphere beyond the point where pressure suits are required because of positive feedback from existing ices on Mars.
Not *impossible*, despite the so-scary math but, IMHO, easily a century (*) beyond current tech...
- Fine, but not millennia and that was my point.
Oh, and research the effects that recent comet pass had on the fragile Martian atmosphere.
- Had we been ready early enough, we probably could have diverted that comet right into one of the Martial poles with current technology.
(*) IMHO, you'd need game-changer breakthroughs in nuclear fusion, space-craft launch and deep-space propulsion, plus 'unobtanium' for radiation shielding. AI may help...
- I would not be the first to suggest an NTR, but yes, nuclear fusion could be a real game changer, IF we could make it work. Frankly, you seem to be working through this on your own.
Mark Thomas
If I remember correctly, I read somewhere that a fully terraformed Martian atmosphere would only last a few million years before we would have to supplement the atmosphere. I think I could live with a million year lease on Mars with a breathable atmosphere.
antigoracle
Oh, look what his man crush, False "Profit' Al, pooped out. No wonder he's seeing ass-steroids and predicting ex-stink-tion.
jonesdave
And it would be stripped away by the solar wind. No magnetic field. We would need some way of continually replenishing the losses.
antigoracle
Is that you Retard of the Decade.
This is more evidence that the award was well bestowed.
tblakely1357
howhot3
I was really hoping we could have a good conversation about this, but obviously not. So, the reason I make this analogy is the obvious one. CO2 is a gas that varies only when carbon is injected into the atmosphere. It doesn't happen often but events like a large comet strike, large super volcano eruption can drag enough sequestered carbon into the atmosphere to impact the greenhouse parameter. Mankind, from fossil fuel use has had a similar impact on the greenhouse parameter and so we have caused an extinction event that will be proportional to a direct comet strike.
antigoracle
His man crush, False "Profit" Al, pooped him out, so now he's here making anal.ogies. Instead of a "good", how about you educate your dumb self so that you can have an intelligent conversation.
Do you even know what humans contribute to the GHE?http://www.geocra...ata.html
BradJensen
I postulate that there are extremely large amounts of natural gas, methane, beneath the crust of the Earth. When a very large body strikes the Earth, it can temporarily crack the crust and release billions of tons of methane in a short time.
This would rapidly raise the temperature of the atmosphere because methane is a potent green house gas, unlike Co2. This methane would then be consumed by bacteria and converted to CO2 and water in a process that might take thousands of years.
Gradually the Co2 would be drawn out of the atmosphere by the formation of carbonates and the accumulation of dead algae in the ocean bottoms.
In the time of the dinosaur extinction 66 million years ago, so much oxygen was taken up in the oxidation of methane that it significantly reduced the percentage of oxygen in the air.
BradJensen
By the way, the dinosaurs died because their unique advantage, their method of respiration that took advantage of the higher percentage of oxygen in the air, became a disadvantage when the oxygen level dropped precipitously and they could no longer breathe. Mammals evolved at higher altitudes and were therefor okay with the oxygen drop.
antigoracle
Considering how many Chicken Littles give you 5s for your retarded trolling, then by your retarded argument you must be a dozen retards. Retard of the Decade.
howhot3
howhot3
My close friend AlGoreacle wishes me all the best. Thanks AlGoreacle. And thank you for the link. What is interesting is when they get to what is natural and what is man-made. It was 278ppm CO2 up until the industrial revolution and now its over 400ppm. So mankind has increased to CO2 levels in the atmosphere; (400 - 278) / 278 * 100% = 44%. That doesn't jive with your link, so I'm inclined to believe your sources are wrong my friend.
antigoracle
Were you born this stupid or have you been practicing?
You actually think that all the CO2 increase since the start of the Industrial Revolution was man made?
Captain Stumpy
sorry aunti-g, that is all you
no scientist or person who follows the evidence thinks that one: that is your strawman!
antigoracle
Reason like an engineer or scientist is beyond a retard like you who cannot even read. Have a gander at HowShats comment in which he is claiming all the CO2 increase since the Industrial Revolution, is man made. Idiot...jackass.
blurking
curious.
howhot3
Actually, this graph explains it far better than me just waving my hands.
http://img.huffin...bc0.jpeg