Yellowstone Supervolcano Changed Global Climate through Two Eruptions

Supervolcanoes are one category of natural disasters that can have a major impact on Earth. Even though the chances of coming back to life are small, Yellowstone supervolcano is a royal representative of its kind. New research determined the way its historical two eruptions changed the climate of the world.

Yellowstone Supervolcano Created Two Volcanic Winters

Geologist Jim Kennett at the University of California Santa Barbara together with his colleagues searched the global history to learn more about the caldera that lies dormant under the Yellowstone National Park. Their inquiries led to some major findings according to which the volcano erupted two times more than 6 million years ago in powerful explosions of lava.

The two events took place with a small hiatus between them. Therefore, both of them occurred during an era when Earth was warming up after an ice age. However, the two phenomena proved to be so powerful, that they created volcanic winters. Each of these climate changes lasted for 80 years at least.

The two eruptions occurred 170 years apart. Both of them propelled monstrous amounts of sulfur dioxide and ashes up into the atmosphere. The result was a toxic and dense cloud that prevented sunlight from reaching the surface of the planet. As a consequence, this lid triggered substantial global temperature drops. The water of the ocean was cooled by around 3 degrees Celsius.

Other Elements Helped the Cloud of Ashes to Block out Sunlight

Researchers presented their new study at the annual Geological Society of America in Seattle. They based their story on the existence of two different layers of ash in the seafloor sediments in Santa Barbara Basin. Both samples contained the unique chemical footprint of the Yellowstone supervolcano.

“These cool episodes also suggest that the global climate system was highly sensitive in response to such perturbations during deglacial transitions.”

On top of that, Kennett and colleagues demonstrated that the two winters began suddenly and preceded the two eruptions. On the other hand, other elements helped the cloud of ashes drop the global temperatures. These factors might have been layers of snow and sea ice that reflected sunlight.

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