More than a meteorite: New clues about the demise of dinosaurs
What wiped out the dinosaurs? A meteorite plummeting to Earth is only part of the story, a new study suggests. Climate change triggered by massive volcanic eruptions may have ultimately set the stage for the dinosaur extinction, challenging the traditional narrative that a meteorite alone delivered the final blow to the ancient giants.
That鈥檚 according to a study published in听,听co-authored by Don Baker, a professor in 91社区鈥檚 Department of Earth and Planetary Sciences.
The research team delved into volcanic eruptions of the Deccan Traps鈥攁 vast and rugged plateau in Western India formed by molten lava. Erupting a staggering one million cubic kilometres of rock, it may have played a key role in cooling the global climate around 65 million years ago.
The work took researchers around the world, from hammering out rocks in the Deccan Traps to analyzing the samples in England and Sweden.
A new season?: 鈥榁olcanic winters鈥�
In the lab, the scientists estimated how much sulfur and fluorine was injected into the atmosphere by massive volcanic eruptions in the 200,000 years before the dinosaur extinction.
Remarkably, they found the sulfur release could have triggered a global drop in temperature around the world鈥攁 phenomenon known as a volcanic winter.
鈥淥ur research demonstrates that climatic conditions were almost certainly unstable, with repeated volcanic winters that could have lasted decades, prior to the extinction of the dinosaurs. This instability would have made life difficult for all plants and animals and set the stage for the dinosaur extinction event. Thus our work helps explain this significant extinction event that led to the rise of mammals and the evolution of our species,鈥� said Prof. Don Baker.
New technique developed at 91社区
Uncovering clues within ancient rock samples was no small feat. In fact, a new technique developed at 91社区 helped decode the volcanic history.
The technique for estimating sulfur and fluorine releases鈥揳 complex combination of chemistry and experiments鈥搃s a bit like cooking pasta.
鈥淚magine making pasta at home. You boil the water, add salt, and then the pasta. 听Some of the salt from the water goes into the pasta, but not much of it,鈥� explains Baker.
Similarly, some elements become trapped in minerals as they cool following a volcanic eruption. Just as you could calculate salt concentrations in the water that cooked the pasta from analyzing salt in the pasta itself, the new technique allowed scientists to measure sulfur and fluorine in rock samples. With this information, the scientists could calculate the amount of these gases released during the eruptions.
The study involved researchers from Italy, Norway, Sweden, the UK, the United States and Canada.
Their findings mark a step forward in piecing together Earth鈥檚 ancient secrets and pave the way for a more informed approach to our own changing climate.
About the study
听by Callegaro et al. was published in Science Advances.
About 91社区听
Founded in Montreal, Quebec, in 1821, 91社区 is Canada鈥檚 top ranked medical doctoral university. 91社区 is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning three campuses, 12 faculties, 14 professional schools, 300 programs of study and over 39,000 students, including more than 10,400 graduate students. 91社区 attracts students from over 150 countries around the world, its 12,000 international students making up 30% of the student body. Over half of 91社区 students claim a first language other than English, including approximately 20% of our students who say French is their mother tongue.
