Volcanic eruptions caused first 'whiffs' of Oxygen in Earth's atmosphere: Study

Volcanic eruptions might have stimulated surge in population of marine microorganisms creating first puffs of oxygen into atmosphere, analysis of 2.5 billion-year-old rocks from Australia has revealed. latest revelations regarding volcanic eruptions would change existing stories around early atmosphere of Earth that mainly assumed that most of changes in early days of green planet were controlled by geological or chemical processes.

findings of analysis were published in journal ‘Proceedings of National Acemy of Sciences.’ Although research is focused on Earth’s early history, results also have implications for extraterrestrial life and even climate change. study was led by University of Washington, University of Michigan and or institutions.

"What has started to become obvious in past few deces is re actually are quite a number of connections between solid, nonliving Earth and evolution of life," said first author Jana Meixnerova, a UW doctoral student in Earth and space sciences.

"But what are specific connections that facilitated evolution of life on Earth as we know it," questioned Meixnerova.

Earth’s became oxygen-rich about 2.4 bn years ago

Earth’s atmosphere became permanently rich in oxygen about 2.4 billion years ago, according to researchers, it is likely after an explosion of lifeforms that photosynsise, transforming carbon dioxide and water into oxygen. Back in 2007, co-author Ariel Anbar at Arizona State University analysed rocks from Mount McRae Shale in Western Australia. Anbar reported a short-term whiff of oxygen around 50 to 100 million years before it ultimately became a permanent fixture in atmosphere. 

more recent research has confirmed that re were short-term oxygen spikes but failed to explain rise and fall in its levels.  In latest study published on Thursday by researchers at University of Michigan and led by co-corresponding author Joel Blum, y analysed same ancient rocks for concentrations and number of neutrons in element mercury, emitted by volcanic eruptions.

Massive volcanic eruptions blast mercury gas into upper atmosphere where it remains for a couple of years before raining onto Earth’s atmosphere. new research showed spike in mercury a few million years before temporary rise in oxygen. "Sure enough, in rock below transient spike in oxygen, we found evidence of mercury, both in its abundance and isotopes, that would most reasonably be explained by volcanic eruptions into atmosphere," said co-author Roger Buick, a UW professor of Earth and Space Sciences.

authors of study have also reasoned that in places where re were volcanic emissions, re must be lava and volcanic ash fields. Those rocks, rich in nutrients, would have weared in wind and rain, introducing phosphorus into rivers that could fertilise nearby coastal areas. This would have furr allowed oxygen-producing cyanobacteria and or single-celled lifeforms to flourish.

"re are or nutrients that modulate biological activity on short timescales, but phosphorus is one that is most important on long timescales," Meixnerova said. "During wearing under Archaean atmosphere, fresh basaltic rock would have slowly dissolved, releasing essential macro-nutrient phosphorus into rivers.”

"That would have fed microbes that were living in shallow coastal zones and triggered increased biological productivity that would have created, as a byproduct, an oxygen spike," Meixnerova explained.

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