Major volcanic eruptions have occurred often throughout Earth's history, some of which caused such climatic and biological disruption that they sparked some of the planet's most terrible extinction catastrophes.
Several researchers clarified the time and most probable cause of these occurrences, which happened millions of years ago.
Slowing Continental Speed Drove Some Extinction Events
An ongoing argument over the causes of five significant mass extinction events, including the one that eventually led to the extinction of the dinosaurs, may now be resolved thanks to new research sponsored by Dartmouth College.
While some scientists contend that comet or asteroid impacts caused mass extinctions, the new study lends credence to the idea that volcanic activity was the primary cause of the worst extinction events in Earth's history.
The researchers claim that four of the five global extinctions occurred concurrently with a volcanic eruption known as a flood basalt.
Scientists refer to these eruptions as "large igneous provinces" since they are known to inundate huge regions, even entire continents.
A big igneous province must contain at least 100,000 cubic kilometers of magma to fall under this heading.
As a point of comparison, less than one cubic kilometer of magma was released during the Mount St. Helens eruption in 1980.
Researchers said most of the volcanoes included in the study spewed on the order of a million times more lava than that.
"The large step-like areas of igneous rock from these big volcanic eruptions seem to line up in time with mass extinctions and other significant climatic and environmental events," said author Theodore Green per Earth.com.
For instance, the Deccan Traps, a large igneous province in west-central India, was produced about the same time as the Chicxulub impact crater 66 million years ago, when dinosaurs were exterminated.
When the Chicxulub impact crater was discovered, all other theories-including volcanism that sought to explain what killed the dinosaurs, were completely disproved, according to research co-author Professor Brenhin Keller. Despite decades of investigation, he pointed out that there isn't much proof of similar impact events that occurred with the other great extinctions.
The study's authors, Professor Paul Renne, and colleagues, aimed to quantify the alleged connection between extinctions and volcanic eruptions. They found that this connection was far stronger than it would have been through coincidence.
The findings suggest that regardless of whether there was an impact, there would have likely been a mass extinction at the Cretaceous-Tertiary boundary of some major size. This can now be demonstrated mathematically.
Researchers published the study in the Proceedings of the National Academy of Sciences.
Major Volcanic Activity Coinciding With Slowing Continental Speed
According to separate research by Trinity College Dublin, the crucial event that allowed magma to come to the Earth's surface and cause the catastrophic knock-on effects was a slowdown of continental plate movement.
Large Igneous Provinces, or significant volcanic eruptions, have occurred throughout Earth's history (LIPs). The greatest have led to dramatic changes in ecosystems, catastrophic extinction on land and in the oceans, and significant increases in atmospheric carbon emissions that changed Earth's climate.
Scientists must advance their understanding of climate-sensitive processes, and LIPs are one of those processes. This is because we are in an era where we are trying to determine the tipping points governing Earth's climate system.
"The cause of the major volcanic events is commonly thought to be linked to the 'upwelling' of magma from deep in Earth's interior, which is called a mantle plume," explains the study's lead author, Dr. Micha Ruhl, in an Interesting Engineering report.
However, the researchers found a correlation between the age of volcanic activity and models of plate reconstruction (models that depict where the continents were previously).
The Earth's historical Large Igneous Provinces, such as the Siberian Traps, which are connected to the End-Permian mass extinction, also occurred at the same time as the Karoo-Ferrar Large Igneous Province, said Dr. Micha Ruhl.
This discovery, according to Dr. Ruhl, "suggests certainly there was a direct temporal relationship between volcanism and related greenhouse gas emission," and therefore, the disastrous climate shift that followed.
Researchers published their study in Science Advances.
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