What massive volcanic eruptions say about climate change

A new study details the tremendous effects a massive volcanic eruption can have on Earth's climate.

Scientists say their findings are proof that a series of dramatic eruptions snuffed out nearly all of life on Earth roughly 200 million years ago. The research also suggests that prehistoric eruptions can serve as ideal models for measuring the effects of rising CO2 concentrations on the ecosystem.

Using the levels of a unique mercury isotope in prehistoric rock samples, researchers at the University of Southern California were able to plot the escalation of volcanic activity 200 million years ago.

Their plot correlates neatly with the rise in extinctions revealed by the fossil record. As mercury levels in the ancient rocks rise, so do the number of disappearing species.

Researchers believe the disruptive volcanism was triggered by the pulling apart of the supercontinent Pangea, and that the offending magmic system was the Central Atlantic Magmatic Province, or CAMP. CAMP was located in the middle of Pangea, in the spot where the Atlantic Ocean would settle as the supercontinent broke apart.

Though CAMP spewed massive amounts of lava, researchers believe it was the release of CO2 that ultimately spelled doom for some 80 percent of life on Earth.

"By some estimates, it rose nearly as rapidly as we're putting CO2 into the atmosphere today," Frank Corsetti, a geobiologist at USC, said in a news release.

"We wanted to see how the Earth system responded from a rapid rise of CO2," Corsetti continued. "The spoiler alert is there was a mass extinction. What we've been able to do is use this mercury as a fingerprint to tie the event to the volcanoes, and therefore the emissions."

Corsetti and his colleagues say the Triassic-Jurassic extinction is especially relevant today, as the animals most affected then are most similar to modern species.

The new research was published this week in the journal Nature Communications.
   [upi.com]
15/4/16