28-02-2025
Study finds early life on Earth got a boost from ... Glaciers and uranium?
Study finds early life on Earth got a boost from ... Glaciers and uranium?
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'Doomsday Glacier' could be disastrous if it collapses into sea
Warmed by ocean currents, Antarctica's Thwaites Glacier could collapse in a few years causing a sea levels to rise by several feet, researchers say.
Scott L. Hall, USA TODAY
About 700 million years ago, enormous glaciers flowed across the Earth's surface in powerful frozen rivers like "giant ice bulldozers" that pulverized our planet's crust and may have contributed to the evolution of complex life along their way, new research shows.
A study published in Geology, a journal published by the Geological Society of America, on Tuesday found glaciers in rivers sometimes more than a mile deep scraped parts of the Earth's crust, releasing key minerals and setting off "chemical chain reactions that reshaped the planet," study author Chris Kirkland, who teaches and leads the Timescales of Mineral Systems Group at Curtin University in Australia, said in a statement.
'When these giant ice sheets melted, they triggered enormous floods that flushed minerals and their chemicals, including uranium, into the oceans,' Kirkland said. 'This influx of elements changed ocean chemistry, at a time when more complex life was starting to evolve.'
Kirkland and researchers the University of Portsmouth in England and St. Francis Xavier University in Canada chemically analyzed crystals in rocks from Earth's Cryogenian period. Earth was so cold at the time that the oceans were frozen all the way to the equator, and life only existed in the oceans and on continental shelves, study co-author Donnelly Archibald, of St. Francis Xavier University, said in a statement.
'Our research shows that ancient glaciers did far more than shape the landscape - they triggered chemical transformations that helped set the stage for complex life," said study co-author, Rob Strachan , emeritus professor at the university. "These findings highlight the deep connections between Earth's geology, climate, and the evolution of life itself.'
The planet experienced at least two "extreme global glaciations" during the Cryogenian period, traces of which can be observed in sedimentary rocks, Kirkland wrote in The Conversation.
The Doomsday Glacier is melting − fast: How sea level rise could drench the world map.
It's not clear what triggered those events, but high levels of carbon dioxide in the atmosphere produced by volcanic activity may have later caused the planet to warm and the ice to melt, according to Kirkland. He wrote that while many scientists believe that this caused changes in the ocean's chemistry that set the stage for the development of complex life, his new research found that the paths carved by the retreating glaciers may also have been a factor.
The glaciers ground surface rock into fine sediment, which flowed rapidly into the oceans, Archibald said in a statement. 'Some of this sediment carried essential nutrients to the oceans and fundamentally changed ocean chemistry and oxygen levels in the atmosphere, which may have stimulated the evolution of multicellular life," he said.
The uranium that was released into the ocean by the movement of melting glaciers, for example, boosted oxygen levels in the water, helped cycle nutrients and fueled underwater heat sources, all of which may have contributed to the early development of life, the University of Portsmouth said in a release.
Kirkland said the research can not only help understand ancient climate shifts, but also modern, human-influenced climate change.
"These ancient climate shifts demonstrate that environmental changes, whether natural or human-driven, have profound and lasting impacts," Kirkland said. "Understanding these past events can help us better predict how today's climate changes might reshape our world."
