Take a Deep Breath, and Thank a Volcano

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Lava from Kilauea volcano in Hawaii Volcanoes National Park enters the Pacific Ocean at dawn on Wednesday, Feb. 2, 2005, in Volcano, Hawaii. (Image credit: AP Photo/David Jordan.)

Volcanoes are partly to thank for the air you’re breathing right now, a new study shows.

Billions of years ago, Earth had very little oxygen in its atmosphere, in part because most of the volcanoes on our planet were undersea. The mixture of gases and lavas that erupted from these volcanoes scrubbed out any oxygen floating around from the atmosphere and bound it into minerals.

Terrestrial volcanoes could form because land masses were more stable under the new tectonic regime ushered in by the continental shift. These volcanoes erupt at higher temperatures than undersea volcanoes and so are less efficient at converting oxygen.

So the shift from undersea to terrestrial volcanoes allowed oxygen (produced by photosynthetic bacteria) to accumulate in the atmosphere, with profound implications for life on Earth.

"The rise of oxygen allowed for evolution of complex oxygen-breathing life forms," said study leader Lee Kump of Pennsylvania State University.

The study is detailed in the Aug. 30 issue of the journal Nature.

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Andrea Thompson
Andrea Thompson
Live Science Contributor

Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.