Asteroid That Killed Dinosaurs Acidified the Oceans
Experts agree that a collision with an asteroid caused a mass extinction on our planet, but there were hypotheses that ecosystems were already under pressure from increasing volcanism.
The picture shows the Cretaceous-Palaeogene boundary at Geulhemmerberg in the Netherlands, where the boundary clay samples were taken. The event bed is clearly visible as a grey clay-rich layer, between the otherwise yellowish carbonate sediments. It was thought to have been laid down during calm periods between strong storm events.
Credit: Michael Henehan
Henehan and his team at Yale University reconstructed the environmental conditions in the oceans using fossils from deep-sea drill cores and from rocks formed at that time. According to this, after the impact, the oceans became so acidic that organisms that made their shells from calcium carbonate could not survive. B
ecause of this, as life forms in the upper layers of the oceans became extinct, carbon uptake by photosynthesis in the oceans was reduced by half. This state lasted several tens of thousands of years before calcareous algae spread again. However, it took several million years until the fauna and flora had recovered and the carbon cycle had reached a new equilibrium.
The researchers found decisive data for this during an excursion to the Netherlands, where a particularly thick layer of rock from the Cretaceous-Palaeogene boundary is preserved in a cave.
“In this cave, an especially thick layer of clay from the immediate aftermath of the impact accumulated, which is really quite rare” says Henehan.
In most settings, sediment accumulates so slowly that such a rapid event such as an asteroid impact is hard to resolve in the rock record.
“Because so much sediment was laid down there at once, it meant we could extract enough fossils to analyse, and we were able to capture the transition,” says Henehan.
Most of the work was done at his former place of work, Yale University. Now, at the GFZ, he is using the infrastructure here and hopes that this will provide a major impetus for his work. “With the femtosecond laser in the HELGES laboratory, we are working to be able to measure these kind of signals from much smaller amounts of sample,” says Henehan.
“This will in the future enable us to obtain all sorts of information at really high resolution in time, even from locations with very low sedimentation rates.”
Funding: The main part of the study was done at Yale University, with financial support from the Yale Peabody museum.
Contacts and sources: Josef Zens
Source: http://www.ineffableisland.com/2019/10/asteroid-that-killed-dinosaurs.html
PRINCIPIA SCIENTIFIC INTERNATIONAL, legally registered in the UK as a company 
incorporated for charitable purposes. Head Office: 27 Old Gloucester Street, London WC1N 3AX.
Please DONATE TODAY To Help Our Non-Profit Mission To Defend The Scientific Method.
Trackback from your site.
Andy Rowlands
| #
Interesting. I had thought the K-T Iridium layer got gradually thicker as you approached the Yucatan, which is how the area of the impact was initially suspected by Louis & Walter Alvarez, then subsequently confirmed with the discovery of the Chicxulub crater? Have I remembered that wrong?
Reply
Robert Beatty
| #
The Cretaceous-Palaeogene boundary certainly represents a period when the globe experienced one or more major meteorite impacts. Possibly similar to the ‘chain of pearls’ impacts we observed hitting Jupiter a few years ago. It is difficult to imagine an association with reducing sea pH as a result of such impacts, but certainly an increase in sea surface temperature (SST) could be anticipated.
We are only aware of the Chicxulub crater, but there may have been other impacts which hit the Pacific or Atlantic oceans. If these impacts resulted in SST lifting to nearer 50oC this would have resulted in huge volumes of CO2 dissolved in the oceans, as the bicarbonate radical, returning to the atmosphere. The result would be suffocation for land animals residing at low altitudes as well as distress for sea creatures living near the surface. The distress would be in two forms including high temperature and low availability of shell building carbon.
These factors could lead to the conditions discussed in this paper without having to invoke an acid sea scenario.
Reply
Michael Clarke
| #
Does any one have any numbers for CO2 and distilled water ratios to alter the PH from mildly alkaline to mildly acidic?
There is one hell of a lot of water out there!
I think it would need a very large pure carbon asteroid (string of pearls event) to burn up and create all the CO2 needed to cause acidification of the oceans.
Reply
Charles Higley
| #
Do not forget that carbonic acid is a weak acid and that seawater is a complex buffer such that carbonic acid would have a hard time lowering seawater pH, compared to CO2 in distilled water. With huge out gassing from heated seas, CO2 would become less and any effect or attempted effect on seawater pH would decrease. It is also important to point out that the partition coefficient for CO2 in water 50 to 1 seawater/atmosphere.
It would be easier to imagine an extended “nuclear” winter, massive injections of sulfur oxides into the atmosphere, and starvation of sunlight and cold temperatures. resulting sulfuric acid fallout would indeed acidify the oceans and force CO2 out of the seas, causing even more stress to marine organisms. And animals would still be heavily damaged for sure.
Reply
jerry krause
| #
Hi Michael,
When you ask–“Does any one have any numbers for CO2 and distilled water?”–the answer is: Too many to ever count.
Have a good day, Jerry
Reply
Michael Clarke
| #
May I suggest a simple experiment. Take 100cc of distilled water. evacuate a space above it in a sealed container. Introduce 1cc of pure CO2. shake vigorously and add some heat while shaking.
Allow to cool back to starting temperature.
Measure the resultant PH.
From such an experiment one could arrive at number of molecules of water/to molecules of CO2 to change the PH levels by a specific amount.
Reply
Herb Rose
| #
Hi Michael,
Distilled water is neutral with a pH of 7. CO2 dissolves in water creating carbonic act which is a weak acid where only about .1% of the CO2 molecules are converted to H+ & HCO3- ions. The pH depends on the concentration of CO2 in the water and the presence of any other ions can affect it.
The amount of other ions in the oceans has increased as the Earth has gotten older as salts have been dissolved from the land and when sharks first evolved the oceans were more like fresh water than the salt water they now contain. These dissolved act as a buffering system stabilizing the pH of the ocean so back when the meteor hit it would have been easier to tip the scale into the acid range, releasing CO2 gas, than currently. A meteor striking the crust, besides raising the temperature of the water, could also trigger seismic activity releasing sulfur producing sulfuric acid (strong acid) which would add to the release of CO2 from the oceans.
Herb
Reply
Michael Clarke
| #
That to me seems a circular argument.
To make the oceans significantly acidic from what was alkaline requires addition of CO2 and or other salts like lots of Sulphur dioxide.
Water strike? Land Strike? Some of both with string of pearls event?
How does this cause MORE CO2 to be released into the atmosphere?
Reply
Herb Rose
| #
Hi Michael,
To make the ocean more acid (lower pH) you must add acids. Acids combine with metals (alkali) to form salts. These salts exist both as insoluble salts and as positive and negative ions. When a weak acid (carbonic) reacts with with a metal, such as calcium, it forms calcium carbonate (sea shells, corals) that maintain the pH. When a stronger acid is added to the system it displaces the weak carbonic acid and produces a more insoluble salt (calcium sulfate) The released CO2 comes out as a gas (add vinegar to baking powder) The addition of the stronger acid doesn’t produce much change in the pH until the buffering system is destroyed by the stronger acid but it will result in CO2 being released into the atmosphere. When CO2 is added to the system it will nor displace the CO2 already contained in the buffering salts but can combine with other alkalis to form more salts.
Herb
Reply
jerry krause
| #
Hi Herb,
You wrote: “When a weak acid (carbonic) reacts with with a metal, such as calcium, it forms calcium carbonate (sea shells, corals) that maintain the pH.”
‘Carbonic acid molecules in water solution (where they are only stable) do not react with calcium metal. These molecules react (one way or another) with divalent calcium ions in the solution of say calcium chloride (a soluble, in liquid water, ionic compound) to form the insoluble ionic compound calcium carbonate..
Have a good day, Jerry
Reply
Herb rose
| #
Hi Jerry,
Since water molecules disassociate into OH- and H3O+ ions the water will convert reactive metals into ions. Distilled water is very corrosive to metals converting some of the metal to ions. These metal ions will combine with carbonic or other acids to form salts Nature abhors a vacuum and isn’t to fond of pure water.
Have a good day,
Herb.
jerry krause
| #
Hi Michael,
If you “Take 100cc of distilled water. evacuate a space above it in a sealed container.” you will pump the sealed container ‘dry’ with the necessary vacuum pump.
Have a good day, Jerry
Reply
Michael Clarke
| #
DOH, did not know vacuum pumps could do that, how long would it take to sublime 100cc of distilled water?
Ok change things a bit take a container 100cc pump all the air out.
let in 90cc of distilled water.
Add 10cc of dry ice.
Mix well.
Test the resultant PH.
Reply
jerry krause
| #
Hi Michael,
You propose others do your proposed experiment for you. And you ask questions. All this without you telling us why you need this information. If the answer to your question is 3 minutes, what does it mean to you? If the experimentally determined pH is say 6.5, what does it mean? There is some’s considerable effort and equipment required to do your proposed experiment, if it can be preformed. Which would be the first important experimental result. Can or cannot it even be done.
Have a good day, Jerry
Reply
Michael Clarke
| #
From Ice core results we see CO2 lags temperature as the ice field melted.
No one seems to have noticed that it also lags as the ice field formed.
There is speculation that the ice age transitions were quite rapid yet the CO2 concentrations lag by around 800 years so not a rapid change.
Those Ice sheets. I dislike the term Glaciation as Glaciers form on mountain tops and flow down hill.
Where were the mountains that formed Glaciers that became ice sheets 2000+ meters thick? Glaciation and inter Glacial are misnomers when applied to those Ice Sheets!
I know more questions, but that’s what I do!
Reply
Michael Clarke
| #
I am not a Scientist or even a scientist. I am a Logician. I ask questions about things, lots of them!
Let me be Devils Advocate here. and make some statements that will indicate my ignorance and let you guys show off your knowledge.
I think the Water is a very complicated combination of Hydrogen and Oxygen.
It can exist as a solid, Ice.
It can exist as a liquid, Water.
It can exist as a gas, Not sure about that as there seems to be some confusion about Water Vapor being small drops of Water in free air, (Not sure that’s the right word either!)
I was an apprentrise steam locomotive driver for a very short time and was taught about ‘Wet’ and ‘Dry’ steam. You had to apply heat to wet steam to make it dry steam, you could not go from hot water to dry steam in the boiler it had to go through a separate unit (a Super Heater).
Is ‘Dry’ steam that elusive H2O as a Gas?
‘Dry’ steam is not stable. it will revert to ‘Wet’ steam given half a chance. Which is why those Super Heaters were positioned as close to the steam chest as possible!
Not sure if insolation or mass of metal prevented the rapid revertion dry to wet. I do know that it did happen in just a few seconds.
If the LOCOMOTIVE driver did not open the cylinder drain cocks BEFORE he applied the ‘DRY’ steam to start form stationary then the water (vapor) in the cylinder could destroy the machine if it did not have an escape route. This is why you see those clouds of steam ejected as the locomotive move off, the driver can close the cylinder cocks after a few revolutions of the driving wheels. There will have been a small increase in the external temperature of the system but what is now going up the blast pipe is dry steam turning back into wet steam as it goes. We can see steam escaping from various glands, the more steam the more in need of maintenance!
Under certain circumstances the blast pipe ejecta is colorless until it gets well above the funnel where it become visible as ‘Steam’.
If you watch preserved steam locomotives being re-fueled you may see yellow blocks being put into the tender. Soft water makes for better steam and reduces the time between tube cleaning.
A steam locomotive with ‘Birmingham’ water (Soft) used less coal traveling non stop to London, than that same locomotive filled with ‘London’ water (Hard).
Water and heat conversion into motion, those were the days and all worked out with-out knowing very much at all about Water!
Reply
Matt
| #
Hi Compadres
This from wikipedia.
The steam dryness fraction is used to quantify the amount of water within steam.
1 Dry steam – all water molecules are in the gaseous state.
2 Wet steam – a portion of the water molecules have lost their energy – latent heat – and condensed to tiny water droplets.
Regards
Matt
Reply
Herb Rose
| #
Hi Michael,
It takes 100 calories/gram to raise the temperature of water from 0 C to 100 C. It takes 540 calories/gram to convert that 100 C water to 100 C steam. This energy breaks the hydrogen bonds that hold the water molecules together as a liquid. With any loss of heat the hydrogen bond reform converting steam (clear) to water vapor (droplets). The wet steam is where water droplets have formed and any energy added will be used in breaking these bonds rather than adding pressure to the gas. When all the water is converted to a gas the 540 calories/gram can be converted to work as the hydrogen bonds reform.
At temperatures under its boiling point water is a liquid where the water molecules are in contact with other water molecules (non-compressible). This means the molecule will distribute any heat to other molecules and makes it impossible for one molecule to have 5.4 times the energy of neighboring molecules and become a gas.
Water is indeed very complicated. According to its molecular weight (18 grams/mole) it should be a gas. The bonds in water change with temperature resulting in the size of a calorie (the energy needed to raise 1 gram of water 1 C) changing with the starting temperature of the water. It takes 80 calories/gram to convert 0 C ice to 0 C water. It takes 100 calories/gram to raise the temperature to the boiling point (100 C) then an additional 540 calories to convert 100 C water to 100 C steam so a thermometer only registers about 14% of the energy needed to convert 0 C ice (solid) to 100 C gas (steam)
You should read James McGinn’s articles on water. He can explain it better than I.
Herb
Reply
Michael Clarke
| #
Hi Herb.
Did all those experiments at school and I understand them well, however, they ate what I call ‘End Effects’, or’ State Transition Boundaries’. They are also well documented, well in controlled conditions. The real world is chaotic, and it is what that happens between freezing and Boiling that interests me.
Have you ever seen ‘Smoking Sea’?
It happens wen the ocean temperature is below about 15 celcius and the wind speed is above 40 knots. The ‘Smoke’ is very wet but not noticeably very cold. put your hand in the smoke and it will get wet. Take your hand out and then it will get cold as it rapidly dries.
I will ask another question or two.
If the sun, our variable start gets very cold then the ice at the poles expand.
what mechanism can create Ice fields 2000+ meters thick and how long would it take?
Subsidiary question, how cool would the sun need to have been, to freeze at the poles but not the entire Earth?
If the sun, our variable star gets very hot then ice at the poles tend to shrink.
Ho long would it take to melt Ice 2000+ meters thick?
Subsidiary question, How hot would the sun need to have been and for life as we know it survive the heatwave?
Maunder Minimums exist, they have a frequency and periods that wax and wane, would minimum and maximum last long enough to make all that ice and then melt it 110ky later? What would have happened during that 110ky?
Reply
Herb Rose
| #
Hi Michael,
I have never seen “Smoking Sea” and all I can do is speculate as to its cause. What is the air temperature above the 15 C water? Is it warmer or colder? The fact that it only occurs when the wind is over 40 knots would indicate to me that the wind is playing a critical role in creating the aerosol smoke. Water holds more heat than gases. A pot of boiling water will cook food faster than a 100 C oven even though they have the same temperature. Because their temperatures are the same it means the same amount of kinetic energy is being transferred to the two thermometers but since there are more water molecules (mass) transferring kinetic energy to the thermometer in the boiling water it means that the kinetic energy of the gas molecules is greater than the kinetic energy of the water molecules. Since objects transfer kinetic energy, not temperature, even though the water molecules may have the same (or lower) temperature than the gas molecules they can still absorb energy from the gas molecules. When you pull your hand out of the smoke does the combination of warmer water and lower humidity (I assume the humidity in the smoke is 100%) cause the rapid evaporation and cooling?
As to your other questions I haven’t a clue. Climatology is not my main interest and I only got involved because the GHGT violates basic laws of physics. All we really know is what the evidence shows us and since life seemed to survive I guess we can say it all worked out somehow.
Herb
Reply
Herb Rose
| #
Hi Michael,
I’ve been thinking about how glaciers formed.
The Earths in equilibrium with the energy from the sun at present. It also generates heat from its interior,.with the equilibrium point where the temperature received from the sun and the heat from the interior of the Earth being in the Earth’s crust. If the sun were to cool enough the geothermal heat would become dominant in the northern and southern latitudes and determine the temperature of the Earth’s surface in these areas.. This would result in the water on the Earth’s equator being evaporated and transported into a cooler atmosphere leading to continuous snow at the northern and southern latitudes and glacier formation..
Another possibility is, what if the tilt of the Earth increased reducing the amount of energy reaching the polar areas. A return to a more perpendicular position would result in more energy in these areas and glacier melting. Do we know if the tilt of the Earth is stable or do e just assume it is? Could the weight of glaciers change the tilt of the Earth?
Herb
Reply
jerry krause
| #
Hi Herb,
What is your definition of ‘stable’? We have observed that the number of ‘sun spots’ on the ‘surface’ of the sun vary significantly. Yet, it is difficult to observe (now that we observed from outside the obvious influence of the earth’s atmosphere) that its energy flux as we measure it, has significantly changed during the little more than a half century that we have been able to measure a significant change of this energy flux from outside the influence of the atmosphere.
And if you want to ignore the obvious influence of atmospheric cloud upon that energy flux of the sun which reaches the earth’s surface; you clearly have not seen the obvious.
And if you have not seen the obvious, how can you study the influence of the obvious upon the temperature changes that are being measured daily at many, many locations on the earth’s surface.
Instead of attempting to study these daily variations, you consider the hypothetical: “Another possibility is, what if the tilt of the Earth increased reducing the amount of energy reaching the polar areas.”
It seems you are not content to live in the real world.
Have a good day, Jerry
Yes,
Herb Rose
| #
Hi Jerry,
What I mean by stable is has the tilt of the Earth,\’s axis always tilted at a 23.5 degree angle or has it or will it change. If glaciers form on land and 95% of the Earth’s land mass is in the northern hemisphere would removal of water from the oceans (less weight in the southern hemisphere) and additional mass in the northern hemisphere cause a change in the tilt of the Earth’s axis.
You talk about variation in daily temperature but when referencing the change in climate over millions of years your time frame is like referencing the change of temperature each minute. There are always variations but those variations reduce to trends over time. The formation of glaciers is a result of colder summers not winters and since it is the tilt of the Earth’s axis that produce these seasons would a more perpendicular Earth result in glaciers forming or glaciers retreating?
Have a good day,
Herb
Matt
| #
Hi Herb.
Mr wikipedia again.
“The angle of the Earth’s axial tilt with respect to the orbital plane (the obliquity of the ecliptic) varies between 22.1° and 24.5°, over a cycle of about 41,000 years. The current tilt is 23.44°, roughly halfway between its extreme values. The tilt last reached its maximum in 8,700 BCE. It is now in the decreasing phase of its cycle, and will reach its minimum around the year 11,800 CE.”
One of the three Milankovich Cycle manifestations.
Regards
Matt
Herb Rose
| #
Hi Matt,
Thanks for the information. Is there a theory on what caused the tilt, why the wobble, or why Uranus axis is perpendicular to its orbit?
Herb
Matt
| #
Hi Herb.
First step could be to ask a physicist why a toy “spinning top’ wobbles.
Second contributor would be the continents and tides being “off balance” which would lead a “logician” or even a conceptualist to consider whether if we had two moons constantly equal and opposite would that reduce the earths axial tilt.
Which leads one to consider a third possible contributor being confllcting gravitation forces from the planets and sun that cause the Milankovich Cycles and finally the other day I was checking out global maps of gravitational anomalies and one can clearly see were the Chicxulub crater has formed a circular gravitational anomaly as does the pacific rim ring of fire so some of the anomalies could contribute to our mum “the earth” throwing a wobbly.
I have a mantra. Cumulative effect. Many contributing factors.
Kind Regards
Matt
Matt
| #
Self correction.
“gravitation forces from the planets and sun that cause the Milankovich Cycles”
should read “gravitation forces from the planets and sun that cause the Eccentricity manifestation of the Milankovitch Cycles.
jerry krause
| #
Hi Herb,
I do not waste my time considering what may have been occurring relative to “the change in climate over millions of years” when I read that the last glaciers to which we are referring only melted about 10,000 years ago.
Have a good day, Jerry
Reply