Warming pulses in ancient climate record link volcanoes, asteroid impact and dinosaur-killing mass
ANN ARBOR — A new reconstruction of Antarctic ocean temperatures around the time the dinosaurs disappeared 66 million years ago supports the idea that one of the planet’s biggest mass extinctions was due to the combined effects of volcanic eruptions and an asteroid impact.
Two University of Michigan researchers and a Florida colleague found two abrupt warming spikes in ocean temperatures that coincide with two previously documented extinction pulses near the end of the Cretaceous Period. The first extinction pulse has been tied to massive volcanic eruptions in India, the second to the impact of an asteroid or comet on Mexico’s Yucatan Peninsula.
Both events were accompanied by warming episodes the U-M-led team found by analyzing the chemical composition of fossil shells using a recently developed technique called the carbonate clumped isotope paleothermometer.
The new technique, which avoids some of the pitfalls of previous methods, showed that Antarctic ocean temperatures jumped about 14 degrees Fahrenheit during the first of the two warming events, likely the result of massive amounts of heat-trapping carbon dioxide gas released from India’s Deccan Traps volcanic region. The second warming spike was smaller and occurred about 150,000 years later, around the time of the Chicxulub impact in the Yucatan.
“This new temperature record provides a direct link between the volcanism and impact events and the extinction pulses–that link being climate change,” said Sierra Petersen, a postdoctoral researcher in the U-M Department of Earth and Environmental Sciences.
“We find that the end-Cretaceous mass extinction was caused by a combination of the volcanism and meteorite impact, delivering a theoretical ‘one-two punch,'” said Petersen, first author of a paper scheduled for online publication July 5 in the journal Nature Communications.
The cause of the Cretaceous-Paleogene (KPg) mass extinction, which wiped out the non-avian dinosaurs and roughly three-quarters of the planet’s plant and animal species about 66 million years ago, has been debated for decades. Many scientists believe the extinction was caused by an asteroid impact; some think regional volcanism was to blame, and others suspect it was due to a combination of the two.
Recently, there’s been growing support for the so-called press-pulse mechanism. The “press” of gradual climatic change due to Deccan Traps volcanism was followed by the instantaneous, catastrophic “pulse” of the impact. Together, these events were responsible for the KPg extinction, according to the theory.
The new record of ancient Antarctic ocean temperatures provides strong support for the press-pulse extinction mechanism, Petersen said. Pre-impact climate warming due to volcanism “may have increased ecosystem stress, making the ecosystem more vulnerable to collapse when the meteorite hit,” concluded Petersen and co-authors Kyger Lohmann of U-M and Andrea Dutton of the University of Florida.
To create their new temperature record, which spans 3.5 million years at the end of the Cretaceous and the start of the Paleogene Period, the researchers analyzed the isotopic composition of 29 remarkably well-preserved shells of clam-like bivalves collected on Antarctica’s Seymour Island.
These mollusks lived 65.5-to-69 million years ago in a shallow coastal delta near the northern tip of the Antarctic Peninsula. At the time, the continent was likely covered by coniferous forest, unlike the giant ice sheet that is there today.
As the 2-to-5-inch-long bivalves grew, their shells incorporated atoms of the elements oxygen and carbon of slightly different masses, or isotopes, in ratios that reveal the temperature of the surrounding seawater.
The isotopic analysis showed that seawater temperatures in the Antarctic in the Late Cretaceous averaged about 46 degrees Fahrenheit, punctuated by two abrupt warming spikes.
“A previous study found that the end-Cretaceous extinction at this location occurred in two closely timed pulses,” Petersen said. “These two extinction pulses coincide with the two warming spikes we identified in our new temperature record, which each line up with one of the two ‘causal events.'”
Unlike previous methods, the clumped isotope paleothermometer technique does not rely on assumptions about the isotopic composition of seawater. Those assumptions thwarted previous attempts to link temperature change and ancient extinctions on Seymour Island.
###
The Nature Communications paper is titled
“End-Cretaceous extinction in Antarctica linked to both Deccan volcanism and meteorite impact via climate change.”
Abstract
The cause of the end-Cretaceous (KPg) mass extinction is still debated due to difficulty separating the influences of two closely timed potential causal events: eruption of the Deccan Traps volcanic province and impact of the Chicxulub meteorite. Here we combine published extinction patterns with a new clumped isotope temperature record from a hiatus-free, expanded KPg boundary section from Seymour Island, Antarctica. We document a 7.8±3.3 °C warming synchronous with the onset of Deccan Traps volcanism and a second, smaller warming at the time of meteorite impact. Local warming may have been amplified due to simultaneous disappearance of continental or sea ice. Intra-shell variability indicates a possible reduction in seasonality after Deccan eruptions began, continuing through the meteorite event. Species extinction at Seymour Island occurred in two pulses that coincide with the two observed warming events, directly linking the end-Cretaceous extinction at this site to both volcanic and meteorite events via climate change.
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Don E, It wasn’t CO2 which caused the warming but a massive release of gas
hydrates which occured after the impact. The CO2 rose as the hydrocarbons were
oxodized.
The source for much of my information is “Close encounters with crystalline gas”,
Chemistry In Britian, May 2002.
Unfortunately, I have beenunabl to find an E copy.
There are also many claims that the Deccan eruptions released CO2 that caused warming.
As I read the comments above, I am reminded that we are on a planet that is some 4 to 5 billion years old. Of that approximately 4.5 billion years we have some rough idea of the 800,000,000 years and a only a poor scientific guess as to a few million. That is it. And the little we have is not real pretty. But we do know that the climate has changed over time. Sometimes dramatically and sometimes just a gradual swing from warmer to cooler.
So what causes the climate on this planet to shift over time? Many, many factors and most of us fixate on only one factor as the “driver” of climate change. The present accepted (by the group-think experts) is the CO2 delusion, but there are other items that people fixate on. Some say it is all the sun. Just the sun and nothing but the sun. Some claim it is ocean currents and anything that effects ocean currents. And on and on and on ….
I would just like to point out for the record that climate change is a natural phenomenon and there are many, many factors involved in the recipe that Mother Nature uses control the climate.
Disclaimer: Many factors, some known and some unknown. The only thing that I can say for sure after decades of watching this debate is that CO2 does not do a darn thing that we can measure. The effect is so tiny that if it were a man’s [rest of that thought need not be expressed in this comments section for obvious reasons]. That is to say, CO2 is way down the list of suspects.
~ Mark
Well, I typed 800,000,000 but meant to type 800,000. Oh well.
OK, it is now 66.000.000 AC and we should answer the question what caused the fall of the Berlin wall. Some events should be taken quite seriously, for example, that in about the same time the Neanderthal people went extinct. There was also a rapid warming after an Ice Age, while sea levels rose by hundreds of meters. Mammoths as a food source disappeared which may have caused in Eastern Europe starvation on an unprecedented scale. The fall of the Roman Empire directly preceded the event and should be considered therefore one of the most plausible causes.
No we didn’t. My great great … (a whole bunch of greats) … great grandmother was Neanderthal. link
“… most Europeans and Asians have between 1 to 4 percent Neanderthal DNA.” That’s actually a huge amount. We are told that we share 99% of our DNA with chimpanzees. It sounds like some Europeans are more distinct from the rest of humanity than the rest of humanity is from chimpanzees. Maybe someone who actually understands DNA can enlighten me.
Now that I think about it, I do know a few people who are quite distinct from the rest of humanity. 🙂
In 66M AD, all the scientists will have is bones and not many of them.
Many years ago I had a landlady who remarkably resembled the low-browed illustrations of hypothetical Neanderthals in the textbooks of the time. That their genes survive in us does not surprise me. /Mr Lynn
Silly questions time… What was Antarctica’s estimated position relative to both the Chicxulub impact and the Deccan Traps eruption? Could local heating have occurred due to proximity to one or the other?
Antarctic ocean temperatures around the time the dinosaurs disappeared 66 million years ago …
There was no Antarctic ocean 66 million years ago…..the Antarctic was still attached to south American and Australia
…these people are morons
Yep, stupid is forever right up to today.
There were however oceans on the coasts of the combined Antarctic-Australian continent. South America was already separated by a shallow channel, near the study area:
http://www.scotese.com/images/066.jpg
Also note that Chixulub and the Deccan Traps are NOT antipodal to each other 66 million years ago.
Gabro: Not precisely, but looking at Tom Yoke’s video above and the other posts on the impact, if the region was weak already the impact would have triggered additional eruptions.
Bill,
Correct, as always.
The Indian Plate was passing over the Reunion Hot Spot at that time.
Well, at least we have proven that Darwin’s theory of gradual change from generation to generation is just wrong. So, that proves God.
I assume you’re kidding.
Both gradual and rapid change occur in the evolution of new species, genera, families, orders, classes, phyla and kingdoms.
A few hundred thousand years contains quite a few generations.
True.
An interval of even just 150,000 years would cover a lot of dinosaur generations, let alone organisms with shorter generation times. For instance, anatomically modern humans probably didn’t exist yet 200,000 years ago, but by 50 Ka they had not only evolved in Africa but were displacing older forms of humanity outside of Africa. Polar bears either didn’t exist 150,000 years ago, or had only just started differentiating from grizzlies.
Some paleontologists argue that dino diversity was in decline before the impact.
It is amazing how they focus on two warming spikes to indicate times of extinctions. However, volcanic eruptions and asteroid strikes bespeak huge events that cause cooling and death. What they mindlessly assume is that warming kills when it is very clear that cooling is much more lethal. Volcanic events in our time cause cooling. Asteroid strikes also indicate “nuclear” winter. How come in these people’s hands these same events mean lethal warming? Makes no sense. Snore.
The most interesting part of this story to me is the “Clumped isotope paleothermometry”
Here is a paper describing the technique
https://www.researchgate.net/publication/235891063_Clumped_isotope_paleothermometry_Principles_applications_and_challenges
And whilst it does indeed look better than other paleo mechanisms that use isotopes (which are appalling), it still has considerable uncertainty attached. For example the paper points out…
So the proxy is completely useless for warm blooded creatures and mostly useless for sea creatures where there is any doubt about their depth during the growing season. Or whether they lived near volcanic vents that make have warmed the local water. Or any number of ways their habitat’s temperature may not correlate with a “global” temperature. Which as far as I can see, still makes the proxy very uncertain indeed.
Yes, I immediately though about localized, underwater thermal vents. The clams came from exactly the same area. The researchers would be on much firmer ground if they had data from multiple areas of the earth. All they can really claim is temperature spikings of the water in this area. They seem to have nothing to justify extrapolating it to a global event.
I was taught never to claim anything outside the bounds of what the data showed. Any speculation beyond that was used to form a hypothesis for future research. This paper should have done that, and ended with, “More research is necessary to determine if this was a localized or widespread anomaly, and any possible contributions to mass extinctions.”
(my bolding)
and then
Who uses Fahrenheit anyway, except to make the numbers look bigger?
Shallow coastal waters can be much warmer than the open sea, and can vary a lot as factors like wind, sunlight and time of year change. I think I would be very, very cautious about extrapolating local temperature variations into global climate changes, especially when there is so much weight of opinion that the Deccan Traps and the Yucatan meteorite both caused cooling events.
Who uses Fahrenheit anyway… except to make numbers look bigger.?
?w=720
Too funny… a skeptic who can read minds…
you know what? I think you are right everyone who uses fahrenheit is out to fool us
https://wattsupwiththat.com/2013/06/30/it-seems-noaa-has-de-modernized-the-official-death-valley-station-to-use-older-equipment-to-make-a-record-more-likely/
https://wattsupwiththat.com/2013/02/14/the-monthly-report-noaa-never-produces-from-the-climate-reference-network/
https://wattsupwiththat.com/2013/01/07/announcing-the-first-ever-conus-yearly-average-from-the-climkate-reference-network/
or when you want to make adjustments look big
funny thing that conspiracy thinking
If looked at without preconceived notions this rather sparse record only corroborates what was known before – climate was growing colder during the late Maastrichtian.
There was apparently global cooling during the (still much warmer than today) Campanian and Maastrichtian Ages, but of course studies confuse cause and effect, blaming the fall in CO2 for the lower temperatures, rather than the other way around. The preceding mid-Cretaceous interval had been one of the hottest such phases in the geological record.
However, a warming trend set in about 450 Ka before the K/T extinction, ending some 22 Ka before the catastrophe. This has been attributed to CO2 from the onset of the Deccan Traps flood basalt eruptions.
The continuing development of new and more accurate and reliable isotope dating techniques is highly valuable in improving our understanding of these past cataclysmic events. So in regard to the Deccan traps and the Chixilub meteorite, it is no longer an “either-or” argument.
Google “Shiva crater” to see that a lot of this conversation may well be irrelevant!
Looking at their actual data here: http://www.nature.com/ncomms/2016/160705/ncomms12079/fig_tab/ncomms12079_F1.html
I would say they would be more likely to divine temperatures around the “extinction pulses” from the entrails of current goats rather than the shells of ancient bi valves.
So, a couple hundred ppmv CO2 causes super volcanoes and asteroids at the same time?
I just want to point to the fact that there is no proof that climate change had anything to do with the mass extinction. They do not provide a mechanism to link a change of 7K in temperature with a mass extinction, but they are still convinced that it must be that. It is very obvious that if something can cause a mass extinction, it can certainly cause a small change in temperature. But the alarmist will believe that a small change in temperature can automatically cause a mass extinction.
The truth is that animals are very resistant. They can die from poisoning or lack of food, or their specie disappears because of competition. So when a science article links climate change to mass extinction without looking at these possibilities, you know it is junk.
An entertaining, if not accurate, alternative explanation from RadioLab.
Basically the rentry of the ejecta caused the entire Earth’s atmosphere to reheat to 1200 F for a few hours.
Everything was fried.
Another alternative theory…
Has anyone calculated the amount of heat energy released from the asteroid at Chixulub? That is, translate the kinetic energy into btu and then see what the global temperature response would be?
That was explained in the video link I posted above.
Jim,
Estimated energy of the impact was 100 teratonnes of TNT-equivalent (4.2×10^23 J). That’s over a billion times the power of the Hiroshima or Nagasaki A-bombs.
Hiroshima bomb yielded 12 to 15 kilotons; Nagasaki around 20 KT.
Since a teratonne is 1000 gigatonnes, which is a million megatons or a billion kilotons, the impact was equivalent to around five billion Nagasaki bombs.
The increase in temperature, both marine and terrestrial, at the end of the Cretaceous was due to the disassociation of methane from the hydrates at the bottom of the seas. Methane is more potent than carbon dioxide, which it transforms into. What caused this to happen:
1. Warm ocean waters.
2. A massive marine regression.
3. Lower surface, not universal, gravity near Pangea.
In other words, the hydrates experienced very low pressure and higher temperatures. This is explained by the Gravity Theory of Masss Extinction.
running through a few papers on this topic from a different field, trying to link extinctions to astrophysical events, skepticism required
in 2005 a letter in Nature formally graphed a longstanding claim about fossil diversity [read: extinctions] that the record has a 62 (+/- 3) million-year cycle (Rohde & Muller)
in 2006, two astrophysicists linked this to the solar system’s ~60M ride up and down the galactic rim
http://arxiv.org/abs/astro-ph/0602092
Immediately, it was pointed out the dinosaurs went extinct when the solar system was nearer the middle than than an edge (unless the dating is badly off due to CR flux?)
2010 – some astrophysicists now go with extinction cycle twice as often, 27 Myr (sometimes said to be 30 My, namely, more associated with the middle of the galactic rim. where ‘nemesis’ lurked, or something
http://arxiv.org/abs/1007.0437
2015 . a paper considered that Planet 10 (“the perihelion precession of its inclined orbit”) did the deed.
http://mnrasl.oxfordjournals.org/content/455/1/L114.short
surprise, surprise 🙂
I probably got something wrong …
“The new technique, which avoids some of the pitfalls of previous methods, showed that Antarctic ocean temperatures jumped about 14 degrees Fahrenheit during the first of the two warming events, likely the result of massive amounts of heat-trapping carbon dioxide gas released from India’s Deccan Traps volcanic region. The second warming spike was smaller and occurred about 150,000 years later, around the time of the Chicxulub impact in the Yucatan”
Others claim the Chicxulub impact was earlier than, and triggered, the Deccan Traps volcanism.
http://science.sciencemag.org/content/350/6256/76
And others [different others] claim that the Chicxulub impact occurred during Deccan Trap volcanism
http://news.berkeley.edu/2015/04/30/did-dinosaur-killing-asteroid-trigger-largest-lava-flows-on-earth/
Then there’s that pesky temperature rise claimed by Sierra Petersen and friends..
Well, if it happened these chaps don’t think the Deccan Traps did it http://www.ncbi.nlm.nih.gov/pubmed/11538480
And this lot think an asteroid and a lot of CO2 did it…
http://www.pnas.org/content/99/12/7836.full.pdf?sid=7cfda3e8-aa85-41d0-9f65-170846abbf5d
And this lot believe there was cooling immediately following the Chicxulub impact
http://www.pnas.org/content/111/21/7537.short
And this lot think that even if the Deccan Traps did it, it may have been due to cooling caused by sulphur aerosols
https://www.researchgate.net/profile/Thorvaldur_Thordarson/publication/222512178_Volatile_fluxes_during_flood_basalt_eruptions_and_potential_effects_on_the_global_environment_A_Deccan_perspective/links/0fcfd5114425828c40000000.pdf
Seems the science isn’t quite settled
Someone help me out here. Less than a year ago I recall seeing an article here about the discovery of at least two more impact sites discovered in Australia that rivaled in size and energy the Chixulub impact.
Are these impacts all related? If I recall, there were questions regarding the dates of the Australia impacts and I have not seen nor heard anything since.
What would have been the result if they all impacted at the same time?