Volcanoes, asteroid impact, drove ancient climate related extinctions

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.

Advertisements

177 thoughts on “Volcanoes, asteroid impact, drove ancient climate related extinctions

    • Sal,
      Yes.
      Also, I note, 29 – say 30 – shells across 3+ million year.
      Say 3 million.
      Average 1 shell, from an entire shallow delta, per 100,000 years.
      100,000 years is about six or seven or eight times the period back to the end of the last Ice Age’s glacial period.
      [I consider we are still in an Inter-glacial, but pray I am not reminded of this in my lifetime.

      As noted below, other things were happening, too.
      And how accurate are our dates?
      To within a thousand years?
      Or ten thousand?
      One-hundred thousand?
      “These mollusks lived 65.5-to-69 million years ago in a shallow coastal delta near the northern tip of the Antarctic Peninsula.”
      (My spell-check and I spell molluscs with a ‘c’ – for what it’s worth.)

      I think, like Sal, you count me a little unconvinced.
      [Litotes, anyone?]

      Auto

      • The “29-30” bivalves is definitely a sample power problem. I am also curious about why the genus is not identified, even in the abstract.

      • My thoughts too.
        Wonder if ANY mollusc shell can be tested. Or just a selection from many. They say they were well preserved. Maybe more funding is needed to increase the data base to include backwards and forward to see if these warming events occured. Also it could have been a double impact. Of which the first has not been discovered yet.

      • I agree with earlier posts that amount of data is very sparse to draw any conclusion. Looking at the graphs in the SI. three is very little correlation ( even negative correlation ) between the data from the different mollusc species only two species cover the extinction period and they go in completely opposite directions at the time of the first extinction. The so-called ‘spike’ is one data point ( out of nine ) which shows considerably less than earlier variability that was not associated with an extinction event.

        They have picked one small feature from some very spare data and read far too much onto it. Basically like seeing faces in the clouds.

        By averaging the uncorrelated data series together in the “right” way they manage to engineer a ‘spike’. Sounds like Mann’s hockey stick yet again.

      • Auto,

        The cycles of ice ages and interglacials are a geologically recent phenomenon (last few million years). There were no ice ages 65 million years ago. Duster, the specific bivalves studied are listed in the supplemental material link above, which is not paywalled.

      • Surely these events would have left world wide sedimentary deposits with which the more difficult methods of measurement could be compared.

    • Looking at the temperature guesstimates for way back when, the equator wasn’t much warmer, Florida was a about the same temperature, and the Arctic was the temperature of Northern Florida (it supported Crocodiles).

      So the sea surface temperatures up to Florida weren’t a lot different, but they didn’t change much as you went north.

      The high humidity at the poles would cut the heat loss, and help retain the energy from the roughly 4 times higher insolation (south pole) and 3 times higher insolation (north pole). The poles weren’t ever white. Crocodiles can’t live under about 45F. So less polar loss, more polar gain and average ocean temperature at least 15C higher (since it didn’t cool at the poles).

      Without white poles or the Himalayas there was a lot more energy from a slightly weaker sun.

      So there wasn’t a massive change needed to drive temperatures higher. The only hydrogen monoxide phase change was from liquid to gas and back again.

  1. “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.”

    Apparently they left at least one pitfall in their method.

    CO2 causes 14 degree rise in ocean temperature? How much CO2 would it take to do this? “Massive amounts” is what they say, I want to see the formula.

      • That IS part of the problem. Oceans hold More CO2 when they are cold and far less when they are warmer. How much warmer would Antarctica really need to be to support a Coniferous Forest? Trees need water and the mean temperature would been to be sufficiently high enough to support Liquid Water during the Southern Summer growing season.

      • How much warmer would Antarctica really need to be to support a Coniferous Forest?

        Now best ya’ll keep in mind that Antarctica was not situated at the earth’s South Pole when it was “sporting” a Coniferous Forest.

      • Antarctica may not then have lain directly over the South Pole, but it was close. Please see map posted previously.

    • I have always wondered what affect that asteroid would have had on ocean currents in the Atlantic Ocean, north and south. It is easy enough to picture the asteroid slamming into the warm Gulf waters, which would then send a huge pulse of hot water into the Atlantic. That would change the major currents in the Atlantic for quite some time, until more normal current patterns reestablished themselves over time. Imagine a pulse of hot water being rapidly injected into the Arctic Ocean, while another pulse moved south too impact the Antarctic region. The pulses would be traveling at high speed. It would not take them very long before they impacted the ACC in the south. While the Arctic would have been greatly impacted by that massive hot flow entering into it’s mostly closed system. I wonder, has any study ever looked at the Arctic for any sign of that influential event?

      • So how woulds this “heat pulse” travel at “high speed”? Water heated by the impact would be localized and any wave pulse would not actually move water, just the energy from the wave. There would of course be heat generated by the ejecta hitting the ocean over great distances. Is this what you meant?

      • Further, after reading through the many great comments and looking at the global map depicting positions of the continents from 66 Ma/yr ago, I can see that my idea of how a pulse of water would move globally needs to be reexamined.

      • @expat…I was thinking that it would push a column of heated water, but after thinking about what you said I realize that the thought was wrong. There would only be some transfer of heated water for a short distance. It still seems that it would have the power to alter the normal current flows in the Atlantic for awhile. That was a massive strike.

      • Tsunami waves do not transfer any thermal energy ….. nor any water, …. only wave energy. Even ripples on the water surface is still wave energy.

    • The 14F ocean is dubious just from ocean heat capacity. And the authors know very little about volcanoes.
      Flood basalt eruptions are either mantle plume or seafloor spreading caused. They are always SO2 rich. But their CO2 content varies greatly depending on the traversed crust. Only andesic subduction zone volcanoes are always CO2 rich. The CO2 comes from subduction zone recycling of sedimentary carbonates. That process is what keeps Earth alive despite the relentless ocean carbonate sink of forminifera and diatoms and coccolithoflorids.
      Deccan Traps is the wrong kind of volcanism for their speculation.

      • “The 14F ocean is dubious just from ocean heat capacity. And the authors know very little about volcanoes.”

        The paper is obvious nonsense. However, it got “peer reviewed” and was published due to the claim that CO2 caused 14F warming of the ocean.

      • ristvan clearly points out weaknesses just one of the major assumption leaps this paper makes regarding the environment based on little to zero actual evidence.

        “…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…”

        Just how accurate can these clams be?

        I have always been under the impression that most clams are rather short lived, especially in comparison to centuries. Yet these clams carry such amounts of information that ocean warming can be determined so well?
        What if the clam carrying the warmth indication was a mollusk living in shallow water where the sun warms the water while other clams were living in deeper cooler water?

        Not a problem for researchers that already knew the story they wanted to discover.

      • I agree with Ristvan. There seems to be nothing but incorrect assumptions about volcanic effects. But , hey, thay managed to ‘prove’ CO2 can cause mass extinctions,right? Good enough to get published by Nature.

        Here is an alternative hypothesis: sustained eruptions from Deccan Traps releasing large amounts of SO2 caused a massive drop in stratospheric ozone. That was the cause of the warming. It is interesting that they have dropped the usual ‘nuclear winter’ assumptions about volcanoes.

        However, I agree with earlier posts that amount of data is very sparse to draw any conclusion. Looking at the graphs in the SI. three is very little correlation between the data from the different mollusc species only two species cover the extinction period and they go in completely opposite directions at the time of the first extinction. The so-called ‘spike’ is one data point ( out of nine ) which shows considerably less than earlier variability that was not associated with an extinction event.

        They have picked one small feature from some very spare data and projected their own ideas onto it. Basically like seeing faces in the clouds.

      • Wouldn’t a 14F increase in water temperature cause a shift in the types of mollusks living in that area?

    • Isn’t volcanic eruption supposed to put particulates into the air that COOL the Earth since the sunlight cannot penetrate it? Isn’t that what the “experts” tell us happened when Pinatubo and Tambora and Krakatoa erupted? Global COOLING? So why would the Deccan Traps Eruption cause WARMING???

      • I don’t think it’s been proven that any volcano in recent times has caused “global” cooling. Regional perhaps, but not global by any stretch.

      • Pinatubo cooled the Northern Hemisphere. Dunno about the Southern. Effects of Krakatoa and Tambora were global.

      • Aphan, the cooling is short term. The warming is long term (relatively). This is very basic. The experts do indeed tell us so, and those with little expertise should listen to them.

      • Aphan, you non-reader! If you had bothered to read my book “What Warming?” you would know by now that volcanic cooling is a total illusion. It is kept alive only because those wishing to be called volcanologists firmly believe that every volcanic eruption must be followed by a cool period that follows. This comes from ignorance of what they are looking at. Every global temperature curve that exists is covered from beginning to end with what looks like a set of shark teeth. This is not noise but real data. Every shark’s tooth is an El Nino peak and every valley between them is a La Nina. You may not always see them because they have been wiped out by curve-smoothing techniques like a moving average but they are there. Volcanic eruptions are not synchronized with them. An eruption may coincide with a peak, a valley, or any place in between. If the eruption coincides with a peak like Pinatubo does, the La Nina that follows immediately is co-opted to become the cooling of that eruption. In this way the 1992 La Nina became the volcanic cooling from Pinatubo. But if the eruption happens to coincide with the middle of a La Nina valley as El Chichon does it is followed by the next El Nino peak in line and there is no valley that can be called its cooling This did puzzle people studying Pinatubo but they simply lacked the analytical power to think it through. This is not an exception – the Katmai/Novarupta eruption of 1912 was said to be the most powerful in the 20th century but it lacks any cooling to call its own. And then there is Krakatoa whose emission products spread all over the skies of the world but which left a barely noticeable sign of cooling. In this case the eruption was timed to go off near the end of an intermediate time near the low end of an El Nino peak. You can go through the list of volcanoes and classify them all this way according to their nearness to an El Nino or a La Nina. There is no trace anywhere of any real cooling by any volcanic eruption known. Here I have to say that it applies to stratovolcanos and places like Yellowstone are clearly a different kind of animal. An eruption from a stratovolcano ascends to the stratosphere at first where it causes warming. Cooling follows in a few years’ time, but for reasons that are not clear it never reaches sea level where all those fake coolings are recorded.

    • no….even if there was enough CO2…..it would not do that

      These people are morons…….

    • Also at that time Antarctica was attached to Africa. It has since moved by plate tectonics. This lone would explain the temperature change.

      • Right you are, John M.

        People forget those little details …… and then try to explain conifer forest growing at the earth’s South Pole.

  2. “likely the result of massive amounts of heat trapping carbon dioxide gas” ???? Oh my!

    • If you’ve had the unfortunate and highly disappointing experience of watching the new (sort of) remake of Carl Sagan’s 1978 “Cosmos” with Neil deGrasse Tyson, the series is now liberally sprinkled with a “coal is bad, m-kay” theme.

      Tyson was probably forced into this, since I don’t know his personal views on the topic, but practically 2 full episodes were devoted to hinting (and not in a nice way) that we’re involved in our own extinction unless we mend our ways.

      Such as that the vast volcanic eruptions in ancient Siberia torched large coal reserves, spewing out CO2 that strangled the dinosaurs. Tyson barely mentions any other gas. It’s a pathetic attempt at “science education”. I dutifully recorded all 13 episodes on my Foxtel box, eventually watched, got angry and deleted them, vowing never to watch them again.

      I have and prefer the original series. Although Carl was wrong about many things, Tyson has lost an enormous amount of my respect if those are precisely his views.

  3. How have the asteroid impact and the deccan eruptions been timed? Could the deccan eruptions have been a result of the big asteroid impact?

    • Since the Indian Ocean site of the Reunion Island Hotspot is near the antipode of the Yucatan, it had been suggested that the impact caused the Deccan flood basalt eruptions. But better dating shows that the Deccan Traps started erupting before the impact, and continued after it.

      The hotspot already existed before the Indian Plate passed over it on its tectonic speed record set crossing from Antarctica to collide with Asia.

    • For some reason, no attention whatsoever is paid to the existence of a very large crater named Shiva( over 500 km X 300km) off the West coast of India, close to the Deccan Traps. There is some debate over whether or not it is an impact crater but apparently the mountains on the West coast show signs of uplift and impact fragments, with indications of heavy deposition. There is little sign of shocked grains so far. I think it’s very likely that Earth received two hits about 66 mya. If Shiva is an impact crater,it was a big one, perhaps 40kms across.

      • At the time of the Deccan Traps eruptions, India was not in its present position, but traveling across the Indian Ocean at high speed, for a tectonic plate.

  4. Confirmation bias combined with a flawed CO2 Forcing conjecture, plus a willingness to set aside the fact correlation does not mean causation. What could go wrong?

  5. “Antarctic ocean temperatures jumped about 14 degrees Fahrenheit ” !!

    I find that extremely hard to believe !!

    • Not iffen the continent of Antarctica was attached to India, ….. which it was at the time.

  6. Unsurprisingly, this fails to include the Electric Universe Theory, and the ample evidence of the proximity of major celestial objects, like Saturn, Venus and Mars, and that they were exchanging huge electrical charges with Earth. It also ignores the fact that electricity is involved with volcanoes and magma heating below the Earth’s surface. It also ignores the fact that gigawatts of electricity are even now flowing into and out of the Earth, and that those electrical flows were vastly larger back then.

    • Hey, you forgot to mention the “Unicorn Theory” !! They had some pretty potent farts don’t ya know !

      • Scoff all you want, the Electric Universe Theory has made some major predictions which turned out to be true, and unless and until you actually look at the evidence, you really don’t know anything of importance.

    • Not a single one of your facts is in fact a fact.
      They are nothing more than conjecture contradicted by known science.

  7. I think that it’s as likely that the “Deccan traps” were CAUSED BY the impactor. Hit something REALLY HARD, and the shock wave will flow to the other side of the object. A big impactor hitting the Earth might be expected to transmit a shockwave through the Earth to a place that was approximately on the other side of the Earth; i.e., Mexico to India.

    • Summary of the argument:
      Deccan traps and impact are improbably coincidental to be independent.
      But Deccan flows started before impact
      Deccan basalts started flowing 100Kyr before impact.
      Deccan basalts are chemically different after impact, dikes are more random.
      Impact would have triggered worldwide major earthquakes.
      Earthquakes can mobilize magma, especially if it is already in a plume.

      “If you try to explain why the largest impact we know of in the last billion years happened within 100,000 years of these massive lava flows at Deccan … the chances of that occurring at random are minuscule,” said team leader Mark Richards, UC Berkeley professor of earth and planetary science. “It’s not a very credible coincidence.”
      ….
      …Richards calculates that the asteroid that created the Chicxulub crater might have generated the equivalent of a magnitude 9 or larger earthquake everywhere on Earth, sufficient to ignite the Deccan flood basalts and perhaps eruptions many places around the globe, including at mid-ocean ridges.

      “It’s inconceivable that the impact could have melted a whole lot of rock away from the impact site itself, but if you had a system that already had magma and you gave it a little extra kick, it could produce a big eruption,” Manga said.

      Similarly, Deccan lava from before the impact is chemically different from that after the impact, indicating a faster rise to the surface after the impact, while the pattern of dikes from which the supercharged lava flowed – “like cracks in a soufflé,” Renne said – are more randomly oriented post-impact.

      Berkeley News April 30, 2015

      • Has anyone ever done a seismic model of the shockwave from such an impact?

      • About modeling the seismicity of an impact:
        Monday, October 24, 2011
        The Chicxulub impact–What happened on the opposite side of the earth?
        They model the impact as a single-force point source from the impact of a stony meteorite 20 km in diameter impacting at 20 km/sec. They use a Gaussian source-time function to model the duration of the event, and assume that 0.001 to 0.0001 of the meteorite’s energy ends up in the seismic waves that propagate away from the point of impact. In their model, the earth has a solid inner core, fluid outer core, ellipticity, topography and bathymetry, oceans, and rotation. The average node spacing is 10 km (this must have been done on a humongous computer!). Since the continents were in different positions 65 million years ago, they chose an impact position to mimic it’s position relative to the Eurasian and American continents at that time. The ancient antipode position was north of Australia.

        They found that it takes about 1.5 hours for the waves to reach the antipode. The maximum displacement was calculated to be 4 meters, less than half that of the older models. The structure of the displacement field is not symmetric, but has a starfish rayed shape because of heterogeneities in the crust [destructive interference], such as the thick seismically slow crust of the Andes. In vertical cross section down to the base of the mantle, there are “chimneys” of peak stress, regions where stresses are concentrated.

      • See above. There appears to be a very large crater right next to the Deccan Traps!

    • This is my thought as well. How certain are the dates for the two events? Are we within the margin of error where they might as easily be “B” then “A” as “A” then “B”?

      • Last year we discussed the KT extinction, and I brought up the idea that the asteroid impact caused or exacerbated the Deccan traps eruptions.
        I was practically laughed off the page.
        Glad people are coming around to the massive improbability of these two events occurring at about the same time but being unrelated, and the huge shock wave that would necessarily result and be focused on a point at the other side of the Earth.

  8. And here I have been told that events like a giant asteroid or massive eruptions causes global cooling.

    • for more $$$$ for your research that’s not the way to go…

      of course the deccan traps eruptions and the big impact would have caused catastrphic cooling. However these are such mega events to which even a full yellowstone blow would be a little puff of smoke compared to it.

      i suspect more a sort of weather pattern change that most likely pushed these warm waters to the poles due to shifting trade winds etc.

      they forget that events like these are easily able to turn the weather patterns haywire

    • Yes, to me, that’s the news in the paper. I always understood it as Sulfur, SO2, ash from volcanos and ejecta, soot from burned forests from the impact. The Nuclear Winter scenario. Death of vegetation, Death of herbivores, Death of carnivores, slow recovery of vegetation.

      The early part of the [Paleogene] period experienced cooler temperatures and a more arid climate than existed before the asteroid. This is most likely due to atmospheric dust reflecting sunlight for an extended time. (Wikipedia, Climate across KPg [KT] boundary

      The Wiki article makes several references to confused or rapidly warming and cooling ocean waters that existed prior to the impact, indicating large changes in ocean currents. Which is worth remembering when evaluating a paper that studies in detail one geographic location. Is it indicative of a change in local currents or global climate?

    • Minuscule. There have been dozens of impacts since, although none as large. One about 30MA ago, one 60KA ago (Meteor Crater), another in northern Canada about 14KA ago (probably caused the Younger Dryas), one perhaps 5.5KA ago in the Indian Ocean (Burckle Formation, and possibly linked to Noah and Gilgamesh and other flood legends). We’re about due, actually.

  9. Wait, chicks that you “lub” can cause planet wide extinction events? Sounds about right.

  10. My theory. The comet/astroid impact would have caused a massive mechanical input
    of energy and heat and as Ken M. says, the force would concentrate approximately
    180 degrees around the globe, causing the vulcanism.

    The heat and vibration would cause a massive release of hydrates from their zone
    of stability, causing global warming from the hydrocarbons to be added to the
    impact heat. The hydrocarbons would degrade to CO2 over time,

    • I had not yet heard of the release of methane hydrates. Worth consideration. But we have a lot of oil and gas drilling into and through Cretaceous sediments. Shouldn’t we have seen more chaotic zones in the drilling records if methane hydrate release was significant?

  11. If releasing massive amounts of CO2 caused the warming of 14 deg F in the ocean, why did the well-preserved shells of clam-like bivalves survive the acidic changes in the ocean? More CO2 yields more warming and ocean acidification, right? Or wrong?

  12. They analysed 29 shells to create a 3.5 million year temperature record. If evenly spaced over that period that would be 1 measurement every 120,000 years. How can they possibly make the claims they have based on so little data?

  13. Hopefully the carbonate clumped isotope paleothermometer will be equally useful in recovering e-mails. Here is a court ruling from today and I hope the Just -Us (sic) Dept. and Hillary take note.

    Court: Officials can’t use private email accounts to evade records laws

    http://thehill.com/blogs/blog-briefing-room/news/286490-court-officials-cant-use-private-email-accounts-to-evade

    The U.S. Court of Appeals for the D.C. Circuit overturned a lower court decision in which judges dismissed claims from the Competitive Enterprise Institute (CEI), a conservative think tank that attempted to obtain correspondence from a top White House official through the Freedom of Information Act (FOIA).

    The White House’s Office of Science and Technology Policy (OSTP) said it did not need to search for or turn over records held by the head of the OSTP on a private email account as part of the open records request.
    In addition to official White House email, John Holdren, the director of the OSTP, also sent and received emails from a domain at the Woods Hole Research Center.

    Throughout the case, the government argued that “[d]ocuments on a nongovernmental email server are outside the possession or control of federal agencies, and thus beyond the scope of FOIA.”

    Judge David Sentelle, the chief judge of the U.S. Court of Appeals for the D.C. Circuit, disagreed with that reasoning and ordered the lower court to reconsider the case.

    “If a department head can deprive the citizens of their right to know what his department is up to by the simple expedient of maintaining his departmental emails on an account in another domain, that purpose is hardly served,” Sentelle wrote.

    • But –
      Hillary is not being prosecuted – although [Thanks BBC]: –

      QUOTE

      The FBI’s key findings:
      ◾it is possible that “hostile actors” gained access to Mrs Clinton’s email account
      ◾there were more than 100 emails that contained classified information when they were sent or received, contrary to her claims
      ◾Mrs Clinton employed multiple email servers and devices
      ◾the FBI said Mrs Clinton did not delete emails in an effort to conceal them

      END QUOTE
      from – http://www.bbc.co.uk/news/world-us-canada-36711711
      And noted – FBI recommends no charges.

      But . . . .

      “there were more than 100 emails that contained classified information when they were sent or received, contrary to her claims”
      Is this sufficient to convict the Clinton distaff of terminological inexactitude?

      You might call it lying.
      I couldn’t possibly comment.

      Auto.
      Watching the resignations here with greater and greater astonishment – and even contentment.

      PS – the UK could have ANOTHER female Prime Minister next week.
      At least it would end the hiatus in government [very badly needed!!!].

      PPS Jeremy Corbyn might resign tomorrow – after questions on the Chilcott report into doing Iraq over. Or not, of course.

      • There are people sitting in prison for breaking laws they were totally unaware of, and their violations caused no harm to anyone or anything, yet hillary walks. There really is a double standard of justice in this country, and I’m afraid the mood of the country is rapidly reaching a boiling point. Something evil this way comes.

      • The Obama appointee first reads a long list of serious laws that Hillary broke, but then declared that since she didn’t mean to and was really, really, sorry, no prosecution would occur.

      • They also found 3000 work related e-mails that Hillary failed to turn over to the Dept after she resigned.
        That’s another law that she violated.

    • Did you have to mention the Hildebeat. I was just starting to wind down by reading some tech stuff. Now I’ll have to go kick the dog or something.

      • It’s unfortunate Hillary wasn’t charged but, not unexpected. I would have been pleasantly surprised if she had been indicted.

  14. “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.”
    ————————————–
    AMAZING……….. what theory, I see no theory there, no even an hypothesis, at best is just looking at some data served as evidence, and a simple link time comparison leads some how to a conclusion, scientific or intellectual one.

    Problem there is that considering the “evidence” and the time scale involved, where the evidence is not a conclusive evidence, but more like barely make it to be considered at best as circumstantial, it can not be treated more than an intellectual guess at most, due to lack of any better and more covering data “evidence” for the time period in question,,,, and further more because of no any theoretical analyzes actually applied to that particular event……..

    Please some one show me that I am wrong and I can’t actually see this wonderful theory…….where it is?

    cheers

  15. Interesting paper. Paywalled, but checked the supplemental materials. The double punch theory is pretty common, but not the way they present it. Did so research. There are three issues.

    First and foremost is radiometric dating precision using the U/Pb in zircon method. There is a .pdf available from the Princeton Geochronology lab for those interested in details. There are three methods, and two sets of U/Pb isotopes (which fact enables the Wetherall concordia plot). Section 4.10.5.1 says the best 2sigma precision possible is about +/-0.03% for this age range ~60mya. So uncertainty of about 180,000 years more or less. So all the shell temp data has massive time line uncertainty NOT treated in the SI. Temp error bars but no time uncertainty. Poor form.

    Second, the Deccan traps erupted in three phases. We know for sure because there are fossil beds between the phase layers. Phase one started about 1mya before the KT extinction and lasted maybe 100000 years, but was only about 10-20% of the total basalt. Caused by a mantle plume now known as the Reunion Island plume. Phase 2 may have started before KT, or may be coincident with the Chixilub bolide impact. See uncertainty in point 1. This phase lasted at least 30000 years and expelled about half of the total Deccan 512,000 km3 of flood basalt based on the relative layer bed thicknesses. Very massive amd violent. Phase 3 started about 300000 years later and lasted for about 200000 years. Several papers on this. Phase 2 high SO2 caused at least a 2C cooling before any warming, per other papers. It would also have acidified the oceans and done a lot of acid rain plant damage. (Note, flood basalt eruptions are always high SO2, and variable in CO2. It is the andesic subduction zone volcanos that are always high in CO2 sourced from subducted sedimentary carbonates.)
    Third, although there is local India foraminifera evidence for extinction declines pre impact, it is local and not global. Could not find the alleged pre KT clade declines in other literature for other regions given a quick search.

    UC Berkeley published the newest U/Pb redatings in 2014 and argued that the Chixlub impact is what triggered the beginning, or caused an enhancement of the massively violent Phase 2 eruption. They claim tomhave gotten the age uncertainties of both under 100,000 years combined. (30 k for the crater, maybe 50k for Phase2 Deccan (there is sample site variation). The plume was always there. The Phase 1 eruption exhaused the magma chamber and sealed it. It was rebuilding. The Chixilub impact would have produced the equivalent of a magnitude > 9 earthquake across all of Earth, ringing the crust like a bell, according tomboth Berkeley and Princeton. That ‘quake’ initiated or massively enhanced phase 2 of the flood basalt eruption from the refilled and enlarged plume magma chamber. A brutal essentially simultaneous one two punch.

      • I’m sort of primed on this topic because my daughter was the overall winner in Physics at the ISEF international science fair in Phoenix a few weeks back. The title of her project was “Constructive interference of seismic surface waves antipodal to crater impact sites on terrestrial bodies”.

        Here is her YouTube video showing the antipodal focusing effect. The video shows an impulse delivered to a submerged 300kg water balloon at full speed, 1/10 speed, and 1/33 speed.

      • That is a very cool video. If the response of the earth to a large impactor is similar to the video demonstration, it would be truly catastrophic. The ejecta falling back to earth and blocking out the sun caused by dust and aerosols would just be icing on the cake.

      • Thank you for the video, Tom. I have been talking up this hypothesis since I first learned the Deccan traps were contemporaneous with and antipodal to the Chicxulub Impact. I’m glad someone had the ingenuity and resources to cobble together a physical demonstration and record the video.

      • Very interesting, thanks. Did she look at what the effect would be of a non-normal impact (not straight in)? Most asteroid impacts come in at an angle.

      • Paul,
        My daughter got the question about non-perpendicular impact trajectories many times in her presentations. The thing to bear in mind is that the aim of this experiment was to get the best possible constructive interference at the antipode. That was not easy. The balloon must be extremely spherical. The water in the pool must be entirely still. Imperfections in the latex thickness must be held to a minimum. The impact trajectory must be perpendicular. Any in-homogeneities must be held to the absolute minimum or the constructive interference will be degraded.

        Theoretically, the motion is described by the so-called ‘spherical harmonics’. These are solutions to the Legendre wave equation and are familiar to chemists as the s,p,d,f orbitals. These harmonics come in three types: a polar angle dependency type called “zonal”, a azimuthal angle dependency type called “sectoral”, and a mixed angle dependency type called “tesseral”. Here is an illustration of the three types:

        The theoretical model used in her experiment was a traveling wave model that implemented only the zonal (polar angle) type of harmonic. Any of the inhomogenities discussed above would necessarily involve the sectoral (azimuthal angle) harmonics as well, resulting in a tesseral traveling wave which would be considerably more difficult to model. However, in a truly realistic model those effects would certainly be present.

      • Tom, this demonstration is very revealing. Has your daughter and her group been able to calculate/simulate the effect of impact on a spinning sphere? I’m curious if there would be any difference in the propagation of the energy.

  16. Some people worry that invoking 2 factors is too much of a coincidence at the same time, but there is an easy solution to this: all the isolated impacts and volcanic episodes that didnt produce a mass extinction.

  17. I maintain a database of the highest resolution temperature and CO2 estimates over time. The extinctions are mostly associated with volcanoes (2), asteroid impacts (1), severe ice age (1), unknown (1).

    People may be interested in this since it is not really shown anywhere so I am going to provide a zoom-in of each of the major geologic periods.

    First the Cretaceous – Dinosaur Extinction. Nothing special happening with Temperatures or CO2 except both were falling. A 10 km asteroid could do the trick however since there has only been one other as big as this that we know about Vredefort 2 billion years ago.

    Snowball Earth peaking at 635Mya and then the appearance of the first complex lifeforms in the Cambrian. Nice warm-up obviously helped. First complex life appears at 600 Mya just at temperatures recovered,

    Ordovician Extinction caused by an extreme ice age as Gondwana (Africa) was right over the South Pole.

    Devonian Extinctions – unknown cause although it got much warmer in this period (no CO2 increase however).

    Permian Extinction caused by the Siberian Traps volcanoes. Large enough to put 500 metres of magma on the entire continental US. It actually got much colder right at the extinction event which seems to be completely missed by all climate scientists. Hottest period was 4 million years before the extinction.

    Triassic Extinction – Central Atlantic Magmatic Province as Pangea started splitting apart, First North America pulls away and then Africa/South America split apart.

    Nothing special happened in the Jurassic to Cretaceous except there was a major ice age when Siberia moved across the North Pole (for at least the second time).

    And then, the last 45 million years at very high resolution.

    All of these going back 750 Mys.

    • Thank you, Bill. Those graphs and your color choices are very easy for my eyes to follow. I particularly like the next-to-last graph and will be studying it in more detail. (Your comment with graphs gets bookmarked!)

      Thanks again.

      • Mark,

        He shows what the temperature would have been at 3 degrees C per doubling of CO2 from today’s c. 400 ppm.

        Bill,

        Thanks!

        I’m not sure whether the ice in the Northern Hemisphere counts as an Ice Age, but the world was in an Ice House then. But globally, it was still warmer than our present Ice House conditions and associated ice ages.

        The coolness however may be one reason why feathers proliferated on coelurosaurian theropods and other dinosaurs in the Late Jurassic and Early Cretaceous.

  18. hmmm. An impact that large would put copious amounts of fine particulates and sulfate aerosols into the stratosphere. That would block solar heating by gobs and gobs. The basalt flows that cover much of the Northwest in multiple layers, was estimated to be capable of blocking essentially all solar irradiance to that of moonlight, and possibly for decades. It might be warm at first due to longwave infrared downward radiation, but not for long.

    http://volcano.oregonstate.edu/book/export/html/486

  19. 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.

    Paleothermometer … that sets off my BS filter for sure. (It sounds suspiciously like Dr. Mann’s treemometer.)

    For the last half million years, CO2 has lagged temperature. link I seriously wonder if these paleothermometer guys have adequately dealt with the timing of the CO2 and the temperature. I suspect that they are making some unsupportable assumptions.

  20. Thing, it depends upon the size of the impact. The simultaneous impact is relative,
    in geologic time. The earth could have passed through a relative storm of large
    space objects.

  21. Could someone tell me why dinosaurs didn’t just evolve into different animals over time? Just because a geological layer of rock shows that a certain type of animal lived around that time does not mean that a mass extinction wiped that animal out.

    What is the fascination with mass extinction?

    • Because it has for sure happened 6 times in the past. There are incredibly sharp fossil delineated boundaries. The most famous are the Permian and KT. Trilobites emerged about 520 MYA. Cochroaches of the seas. They went as a clade exinct at the Permian extinction event ~251mya. None since. Dinos emerged in the Triassic, thrived in the Jurassic (Park and all that), and were doing well in the Cretaceous– until the KT extinction boundary. Only dino cousins left are birds. So some dinos (the therapods) did evolve–into birds that survived the KT, probably because they could travel long distances quickly to find diminished food resources. But before the KT extinction, not after. We just newly found two amber preserved baby bird wings from about 90mya. Feathers, skin, bone, (and wing tip claws still residual of the three digit ‘toes’ clawed theropods had.). Ma Nature is grand, and complicated.

      • I agree there are fossil boundaries in the geological record. it really only shows that a type of animal was around at the time, birds are a perfect example of evolution they are adaptive and widely circulated, and that’s the key point, obviously during natural oscillations over time, animals adapt and take advantage of their changing environments, birds migrate, most other animals will migrate too including aquatic animals, is there any reason that the rise and fall of any animal such as the dinosaurs that can not be put down to that they just evolved?

      • Bet that asteroid knocked the snot out of Pangea….didn’t oceans/sea level drop a massive amount during the later Permian too? Hot asteroid, digs massive crater on impact, vaporizes ocean water….increased water vapor in air causes temperature increase by trapping heat from the asteroid?

      • Sorry…one more! Team finds MASSIVE amounts of carbon monoxide during the impact…..did air breathers actually die of carbon monoxide poisoning?? (study linked to above)

      • Ok I lied…more than one more!
        Pangea right? South America was near Antarctica at the time. Impact of asteroid=really warm water in the Antarctic ocean briefly (14F?) as asteroid’s heat absorbed by ocean. Massive storms and fallout also begin, and injected carbon monoxide kills off animal life near impact, but others, further from impact zone survive. Like the humans encased in tufa/tuff/tephra stone at Pompeii and Herculaneum, some dinosaurs/other animals etc are literally “embalmed” whole in hot ash and “preserved” as the perfect fossils we find today and a solid sediment layer is almost instantly formed in geological time scales. Ash and debris fall over time and cover up the “hard” sediment layer with dust etc (and vaporized calcite/carbonate rock blasted into tiny bits by the upheaval) releasing CO2 into the air in massive amounts (but not causing any real temperature increase). Also possible…did this impact drive the initial tectonics that broke apart Pangea? Broken up crust….moves easily apart-and far more rapidly than ocean ridge spreading…..

        Such delightfully fun and imaginative scenarios are now dancing in my head….:)

      • Aphan,
        There is evidence of comet and asteroid impacts on the planet in the past, I’m not disputing that, none of which have been large enough to cause a mass planetary extinction, and an impact too large would have been total annihilation, so are you suggesting a type of “goldilocks zone” of asteroid impacts?

      • Sparks,

        The non-avian dinosaurs were all wiped out. Now and then somebody comes up with an alleged Paleocene dinosaur, but so far none have held up.

        Had many other theropod, sauropod and ornithischian dinosaurs besides birds survived the K/T extinction, they would show up in the fossil record, or their descendants would still be among us.

        Lots of other large animals went extinct then, too, such as the big pterosaurs (flying reptiles) marine reptiles, which left no descendants. Some crocodilians, other smaller reptiles and mammals did however survive.

    • All descendants of the dinosaurs would still have traits common in their ancestors. No such animals have been found.
      Secondly the demise was too rapid.

    • They did. Mammals and birds are both descended from the dinosaurs. What died out were all of the large, highly specialized dino’s that couldn’t live through the post-impact conditions. This, then, opened up niches for the smaller, less specialized species to expand.

      • Paul,

        Mammals are not descended from dinosaurs. The last common ancestor of mammals and dinosaurs was an early amniote living in the Carboniferous Period, more than 312 million years ago. Amniotes include synapsids (mammals along with their extinct kin) and sauropsids (“reptiles” and birds), as well as their ancestors. Synapsids were the dominant land animals before the Permian-Triassic extinction at the end of the Paleocene. Their descendents, the mammals, again rose to prominence after the dino-destroying Cretaceous-Paleogene extinction. In between, during the Mesozoic Period, dinos arose during the Triassic, then ruled after the Triassic-Jurassic extinction.

      • Hmm. You’re right. Sorry about that.

        I wonder how closely the after effects of the impact have been studied to figure out what died out when and where? One would think that the antipodes would be relatively save from the direct blast effects, but with the volcanism going on there, things must have gotten …. Interesting.

  22. Impact events have been postulated to cause global cooling by throwing large amounts of particulate matter into the air, which impedes solar input. This paper proposes that a large impact event and volcanic eruptions caused large warming spikes: ”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 statement alone raises a whole bunch of questions, such as:
    1. How much increase in atmospheric CO2 would be required to raise global temperature 14 degrees F? The effect of CO2 on temperature is minuscule—it makes up only 0.040% today and accounts for only about 3-4% of greenhouse gas warming. The answer would have to be a humungous amount. How much CO2 did the Deccan eruptions put into the atmosphere? Hard to say. We know from ice cores that CO2 does not cause warming—it follows warming in all cases. There have been other large scale eruptions of basalt that did not result in global warming—that says a lot about the viability of this proposal.
    2. Impact events cause global cooling, not warming. How could a major impact event cause 14 degrees of global warming?
    3. The extinctions of many sea creatures at the end of the Permian and end of the Cretaceous was quite profound—if it was due to water temperature, why didn’t it kill all species (many species did survive). This could be easily tested by looking at the oxygen isotope ratios in their shells. I know of no studies that show this kind of elevated temperature.
    4. An impact event is instantaneous, yet many of the extinctions occurred over a fairly long period of time. How could an impact or volcanic event account for that? If such a massive “dying out” of species was caused over a very short period of time, why do we not see massive fossil layers at the event boundaries?

    There are many more questions that arise from this postulated cause of extinctions, too many to discuss here, but you get the general idea.

    • My own view on the evidence is that the Deccan traps volcanic activity occurred around the time of the impact. The large impact would have disrupted weather patterns. The changing weather patterns could impact ocean currents and I think it is certainly possible that some areas of the earth experienced much warmer weather for a brief time. But the impact would cause cooling due to the material injected into the upper atmosphere blocking sunlight. This would be sufficient to kill most large animals both in the oceans and on land. The exception being animals like crocodiles which can live a long time without food and can eat and thrive on carrion.

      The extinction event ends. Due to the extinction event, many ecological niches would open up. There would be rapid evolution to fill those niches. As this happened, some of the old animals that had survived would not be as well suited to the new conditions which would also include rapid climate change due to the aftermath of the impact and Deccan traps. This would cause continued extinctions for some period of time until a new stable status quo was reached.

    • The 14C rise in temperature causing a mass extinction is laughable, especially in context when it is actually types of reptile they have concluded to have become extinct, they are cold blooded animals, they would thrive in a 14C temperature rise…

      • 14F not 14C.
        Just because something is cold blooded is not proof that any amount of warming will be good for it.
        Beyond that, anything that disrupts an animals food supply compromises it’s ability to survive.

    • Never having heard the term “Deccan traps” before , I googled it . Wikipedia says ” The release of volcanic gases, particularly sulfur dioxide, during the formation of the traps contributed to contemporary climate change. Data points to an average drop in temperature of 2 °C in this period.[4] ” .

      Sort of a contradiction .

      Certainly I can believe a spike in SO2 having much more of an effect on out spectrum than any addition to our already highly saturated CO2 spectrum . But I’m too skeptical to put much faith in either .

    • Don “”Antarctic ocean temperatures jumped about 14 degrees Fahrenheit …”This statement alone raises a whole bunch of questions, such as:
      1. How much increase in atmospheric CO2 would be required to raise global temperature 14 degrees F?”

      The quoted passage says Antarctic Ocean, not global.

  23. 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.

  24. 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

    • 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.

      • … the Neanderthal people went extinct.

        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. :-)

      • 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

  25. 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

      • 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:

      • 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.

  26. 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.

      • 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.

  27. 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.

  28. 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…

    It is important to note that the temperature of carbonate formation is not always the mean an-nual temperature at a given location, particularly when the material being analyzed is biogenic in origin. The temperature obtained from clumped isotopes reflects the body temperature of the or-ganisms at the time of carbonate formation. Body temperature obviously differs from air tempera-ture in teeth of homeotherms such as mammals and some dinosaurs (Eagle et al. 2010; Eagle et al. 2011) but also may occur in poikilothermic inver-tebrates (as shown in land snails; Zaarur et al. 2011b), resulting from biological/behavioral adap-tations. Even in simpler cases, the temperature derived reflects the growing season and habitat depth of the organism, which may differ signifi-cantly from mean annual temperature at the sea or ground surface, the variable usually of interest in paleoclimate studies. For example, clumped iso-tope values from brachiopod shells were assumed to reflect the mean annual temperature, but clumped isotope values from mollusks were as-sumed to reflect a growing-season bias toward warm months (Figure 3.2; Came et al., 2007). Two notable exceptions to the conformity to the thermometer calibration above have been identi-fied and likely reflect growth from a solution that is not at isotopic equilibrium—speleothems and shallow-water corals. Disequilibrium processes as well as other processes that require caution will be discussed below.

    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.”

  29. These mollusks lived 65.5-to-69 million years ago in a shallow coastal delta near the northern tip of the Antarctic Peninsula

    (my bolding)

    and then

    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

    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.

  30. 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.

  31. 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!

  32. So, a couple hundred ppmv CO2 causes super volcanoes and asteroids at the same time?

  33. 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.

  34. 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.

  35. 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?

    • 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.

  36. 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.

  37. 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 …

  38. “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

  39. 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?

Comments are closed.