Researchers at the University of Alberta have helped make a scientific breakthrough regarding the early origins of Earth’s atmosphere.

Together with earth scientists from the University of Waterloo, Arizona State University, University of California Riverside, and Georgia Institute of Technology, U of A scientists have found evidence that Earth’s transition to a permanently oxygenated atmosphere was riddled with bumps along the way.

Using sedimentary rocks in Western Australia, scientists were able to show a burst of oxygen production temporarily increased oxygen levels in Earth’s atmosphere and shallow oceans approximately 2.5 billion years ago.

“We are tracking atmospheric changes through time to understand how oxygen increased to the level needed to support complex life,” said Rob Creaser, U of A professor of earth and atmospheric sciences. “When the Earth first formed, there was no oxygen in the atmosphere. Our analytical facilities here at the U of A allowed us to conduct precise analyses of this rock sample to understand the tempo at which that oxygen built up through photosynthesis.”

This new study is a follow-up to work published in 2007 by the same group indicating a small amount of oxygen was present on Earth’s surface 2.5 billion years ago.

But according to their most recent findings, which were published this month edition of “Science Advances”, oxygen levels in the atmosphere fluctuated until they finally reached the right level to create a permanently oxygenated atmosphere around 2.4 billion years ago, a transition known as the “Great Oxidation Event.”

Creaser’s lab at the U of A in the Canadian Centre for Isotopic Microanalysis is one of only a few in the world capable of taking the precise measurements needed to conduct this type of analysis.

Up next, Creaser aims to use these findings as away of answering questions surrounding preservation.

“You can only do this kind of analysis on beautifully preserved samples,” said Creaser. “And there’s very few of these that are 2.5 billion years old.”

trevor.robb@sunmedia.ca