Triassic Ocean Acidification Wiped Out 95% Of All Life
Scientists report on what nearly wiped out very early dinosaurs, indeed 95% of all life on this blue planet at the time.
Dino-denialists object!
Fossil CO2 poisoned their oceans! Sound scarily familiar? It is!
The late Triassic extinction wasn’t complete and it opened the way for rapid dinosaur evolution and population explosion that led to a hundred million year domination of the planet by the lovable giant tyrannosaurus, triceratops, and brontosaurs of our childhood toys.
The early ancestors of our dino favourties along with almost every other life form on earth were nearly wiped out by the great extinction of the Triassic period a few hundred millions of years ago. And the cause is now clear it was ocean acidification resulting from CO2 entering the worlds air and oceans at about the same rate similar CO2 is filling the air and oceans today that disrupted the ancient ocean ecosystem.
Dinosaurs resumed their evolution and it wasn’t for another hundred million years and more until the final extinction event of the most recent dinosaur age finished off our favourite giants of the early earth some 65 million years ago. That final extinction is popularly thought to be caused by a giant meteor striking the Earth.
At the annual meeting of the Geological Society of America this week in Philadelphia, scientists presented and argued that it’s not just instantaneous cataclysms like giant meteor impacts with the earth that can bring on mass extinctions. Rather they show that the combined slow punches of volcanic emissions, climate change, and related impacts leave many species teetering on the brink of extinction.
The same ocean extinction scenario could be happening now.
Now researchers from a half a dozen major universities report that changes in the chemical balance of the ocean making it much less neutral and more acidic (ocean acidification) was a crucial factor in the great Triassic. This was coupled with a massive surge in carbon dioxide (CO2) levels and it created major problems with food chains at sea and on the land according to the scientists. Today we are seeing a similarly dramatic change of ocean pH and devastation brought on by high and rising CO2.
“The release of CO2 was probably at least as rapid as that caused by the burning of fossil fuels today”, Prof Whiteside said.
If there had been a Dinosaurian Internet at the time dinos from the Red States would have been reading and complaining about news stories like this one being reporting on the natural event as being overly alarming.
Reports of hundreds of thousands of dino-seabirds found washed up on beaches
or
Tens of thousands of adorable dino-sealion pups starving would have been common and similarly ignored by the dino-denialists of the day.
Geologic, Even Fossil, CO2 Ocean Crisis
While the Earth and it’s one Pangaean supercontinent was very different during the Triassic period than it is today the rate of geologic carbon dioxide release from volcanic rifts slowly tearing Pangaea apart was similar to those being experienced now through the burning of fossil fuels. The Triassic volcanism took place over some millions of years, whereas fossil fuel burning has been going on for just over 100 years. As vast floods of lava spread out across the ancient earth they burned both vegetation and shallow coal deposits releasing enormous amounts of CO2.
“Much of the volcanic activity was connected with the extensive Siberian flood basalt known as the Siberian Traps that emerged through Permian/Triassic aged coal deposits and, of course, the burning of coal created CO2,” Prof. Nestell of the Univ. of Texas notes. “
The carbon/soot from ash accumulated in the atmosphere and marine environment and was used by some marine microorganisms in the construction of their shells.
Two new reports, the first published in the upcoming edition of Geology, reveals that a condition called ‘marine photic zone euxinia (sickness)‘ took place in the Panathalassic Ocean – the larger of Earths two oceans surrounding the then supercontinent Pangaea. The second is in the March issue of International Geology Review and reveals the finding of carbon soot in the geologic record.
The planetary near-fatal illness began when Siberian volcanoes released vast amounts of CO2 that triggered ‘ocean acidification’ and ‘global warming.’ This radically changed the oceans ecology and the oxygen supply.
These ancient sickening ocean conditions were a boon for sulfur-eating microbes, which released toxic hydrogen sulfide into the atmosphere, finishing off most (95%) of the life that remained.
Common diagnosis, same deadly prognosis
A sick Earth succumbing to a final shock is apparently a common extinction formula. Researchers have analyzed geologic data from the last 488 million years and found more species died out when the environment was first stressed and then seemingly obliterated by a giant meteor impact.
The researchers have compared and combined the stress-inducing volcanic activity and catastrophic meteor impacts. When the Earth experiences both mass extinctions become more likely.
“Periods of stress are going to reduce population sizes,” one researcher said. With reduced numbers, “species are vulnerable to pulse catastrophes.”
University of Southampton’s Prof Jessica Whiteside, who co-authored the study, said: “As tectonic plates shifted to break up Pangaea, huge volcanic rifts would have spewed carbon dioxide into the atmosphere, leading to rising temperatures from the greenhouse effect. The rapid rises in CO2 would have triggered changes in ocean circulation, acidification and deoxygenation.”
“These changes have the potential to disrupt nutrient cycles and alter food chains essential for the survival of marine ecosystems. The same CO2 rise that led to the oxygen-depleted oceans also led to a mass extinction on land, and ultimately to the ecological take-over by dinosaurs.”
The international team of researchers studied fossils extracted from sedimentary rocks found in the islands of Haida Gwaii off the coast of British Columbia, Canada, which previously were on the bottom of the prehistoric ocean.
All is not lost…
We can learn a lot from volcanoes they can both take and give life. Here’s how one volcano has taught us how to save our oceans today, 40 million salmon can’t be wrong!