Nav: Home

Primordial oceans had oxygen 250 million years before the atmosphere

January 24, 2018

Research by a University of Minnesota Duluth (UMD) graduate student Mojtaba Fakhraee and Associate Professor Sergei Katsev has pushed a major milestone in the evolution of the Earth's environment back by about 250 million years. While oxygen is believed to have first accumulated in the Earth atmosphere around 2.45 billion years ago, new research shows that oceans contained plentiful oxygen long before that time, providing energy-rich habitat for early life. The results of the two UMD scientists and their co-author Sean Crowe from the University of British Columbia have been published in the peer-reviewed journal Science Advances.

"When tiny bacteria in the ocean began producing oxygen, it was a major turning point and changed the chemistry of the earth," explained Katsev. "Our work pinpoints the time when the ocean began accumulating oxygen at levels that would substantially change the ocean's chemistry and it's about 250 million years earlier than what we knew for the atmosphere. That is about the length of time from the first appearance of dinosaurs till today."

The results are important, according to the authors, because they deepen our understanding of conditions on Earth when all life consisted of single-cell microbes and their metabolisms that we know today were only just emerging.

"This helps us theorize not only about early life on Earth but also about the signatures of life that we might find on other planets," said Fakhraee.

The study conclusions are the result of creating a detailed computer model of chemical reactions that took place in the ocean's sediments. Researchers focused on the cycle of sulfur and simulated the patterns in which three different isotopes of sulfur could combine in ancient sedimentary rocks. By comparing the model results to a large amount of data from ancient rocks and seawater, they were able to determine how sulfur and oxygen levels were linked and constrained the concentrations of oxygen and sulfate in ancient seawater.

"We're trying to reconstruct the functioning of early life and early environments," said Katsev. "No one was really looking at how the isotopic signals that were being generated in the atmosphere and the ocean were being transformed in the sediment. But all that we can observe now is what has been preserved as rocks, and the isotopic patterns could have been modified in the process."

Much of this research builds on the past work of the team members, and the modeling results help put together some of the observations that seemed contradictory. "We've resolved some puzzles in the historical timeline and contradictions that existed in the sulfur isotope records," said Fakhraee.
-end-
Fakhraee is finishing a doctorate in Water Resources Science at UMD in July and will then move into a post-doctoral position at Yale University for two years.

Katsev is an Associate Professor in UMD's Department of Physics & Astronomy and a faculty member at the Large Lakes Observatory. His modeling work and data gathering from Lake Superior and Lake Matano in Indonesia have helped lead to these new discoveries. Both bodies of water have unique characteristics that helped make these conclusions about ancient oceans.

The Large Lakes Observatory and the Department of Physics & Astronomy are part of UMD's Swenson College of Science and Engineering. The college has 3,440 undergraduates and 327 graduate students and is home to ten academic departments, as well as the Large Lakes Observatory, the UMD Air Force ROTC program, and the Iron Range Engineering program. SCSE connects students with hands-on research opportunities through its collaboration with multiple research institutions and area businesses. To learn more, visit: http://www.d.umn.edu/scse/.

University of Minnesota

Related Atmosphere Articles:

Primitive atmosphere discovered around 'Warm Neptune'
A pioneering new study uncovering the 'primitive atmosphere' surrounding a distant world could provide a pivotal breakthrough in the search to how planets form and develop in far-flung galaxies.
NASA's MAVEN reveals Mars has metal in its atmosphere
Mars has electrically charged metal atoms (ions) high in its atmosphere, according to new results from NASA's MAVEN spacecraft.
Northern oceans pumped CO2 into the atmosphere
The Norwegian Sea acted as CO2 source in the past.
Study opens new questions on how the atmosphere and oceans formed
A new study led by The Australian National University has found seawater cycles throughout the Earth's interior down to 2,900km, much deeper than previously thought, reopening questions about how the atmosphere and oceans formed.
How a moon slows the decay of Pluto's atmosphere
A new study from the Georgia Institute of Technology provides additional insight into relationship between Pluto and its moon, Charon, and how it affects the continuous stripping of Pluto's atmosphere by solar wind.
Fossil fuel formation: Key to atmosphere's oxygen?
For the development of animals, nothing -- with the exception of DNA -- may be more important than oxygen in the atmosphere.
Researchers dial in to 'thermostat' in Earth's upper atmosphere
A team led by the University of Colorado Boulder has found the mechanism behind the sudden onset of a 'natural thermostat' in Earth's upper atmosphere that dramatically cools the air after it has been heated by violent solar activity.
New biochar model scrubs CO2 from the atmosphere
New Cornell University research suggests an economically viable model to scrub carbon dioxide from the atmosphere to thwart global warming.
Venus-like exoplanet might have oxygen atmosphere, but not life
The distant planet GJ 1132b intrigued astronomers when it was discovered last year.
Middle atmosphere in sync with the ocean
In the late 20th century scientists observed a cooling at the transition between the troposphere and stratosphere at an altitude of about 15 kilometers.

Related Atmosphere Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".