Most living things need oxygen to thrive, and science shows that they began to appear in large quantities in the Earth’s atmosphere 2.2 billion years ago.
However, a small amount of oxygen was injected about 100 million years ago.
A new study reveals that volcanoes may be responsible for this short oxygen event leading up to the main event. By analyzing the rock records, the researchers found a corresponding increase in mercury levels indicating volcanic activity.
The researchers said the process would have produced nutrient-rich volcanoes and volcanic ash, which were later released by the weather into rivers and coastal areas. This will help the cyanobacteria and other single-celled organisms to thrive and begin to expel more oxygen.
Roger Buick, a geologist at the University of Washington, says: “This study suggests that the direct drive is an increase in oxygen production, rather than a decrease in oxygen consumption by rocks or other inanimate processes, because of the unstable oxygen odor.
Buick and colleagues looked at the Greater Cores from the Mount Macrae Shale system in Western Australia, which has geographical time scales 2.5 billion years before the onset of the Great Oxygen phenomenon.
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Symptoms of both mercury enrichment and antioxidant climate led researchers to believe that volcanic eruptions and the introduction of phosphorus – the key nutrient for altering biological function over the long term – played a key role in the early uptake of oxygen.
Although it is not clear where this volcanic activity occurred on Earth, geological records from places in modern India and Canada, among others, support the hypothesis of volcanoes and volcanic eruptions at this time.
“During weathering under the Archaean atmosphere, new basalt rocks slowly dissolve and release essential phosphorus into rivers,” says Jana Miksnerova, an astronomer at the University of Washington. This, in turn, may have created an increase in oxygen.
There may have been other oxygen surges before the Earth’s atmosphere began to change drastically, but although this study explains only one of them, it remains a useful source for observing the first moments of life on our planet.
As with any study like this, it’s for research on climate change (showing how life changes with less oxygen) and the search for life in space (showing us what kind of weather microorganisms can be).
There are questions about how life on Earth began in its simplest form, a billion years before the planetary antioxidant event, and the geography of the planet must be well understood over time to answer these questions.
And publish the study PNAS.
Source: Scientific warning
