Research indicates that fresh water emerged on Earth approximately 4 billion years ago.

Geologists have analysed 4-billion-year-old zircon crystals from Jack Hills in Western Australia’s mid-west region to date the emergence of fresh water back just a few hundred million years after the Earth formed.

On the early Earth, extensive interactions between flowing (fresh) water and the emerging continental crust may have been key to the emergence of life, but when the water cycle first began is unclear.

In the new study, Curtin University scientist Hamed Gamaleldien and his colleagues used the oxygen isotope composition of zircon crystals from Jack Hills in Western Australia to determine when the water cycle began.

Their findings suggest that meteoric water appeared on Earth about 4 billion years ago, 500 million years earlier than previously thought.

“We were able to date the origins of the hydrological cycle, the ongoing process by which water moves around Earth and is essential for maintaining ecosystems and supporting life on Earth,” Dr Gamalerdien said.

“By examining the age and oxygen isotopes of microscopic crystals of the mineral zircon, we discovered an anomalously light isotopic signature that dates back 4 billion years.”

“These light oxygen isotopes typically result from hot freshwater altering rocks several kilometers below the Earth’s surface.”

“The evidence for the presence of fresh water this deep in the Earth casts doubt on existing theories that the Earth was completely covered by oceans 4 billion years ago.”

“This discovery was crucial for our understanding of how Earth formed and how life began,” said Curtin University scientist Hugo Orioluk.

“This discovery not only sheds light on the early history of Earth, but also suggests that land and freshwater systems provided the foundation for life to thrive within a relatively short time frame – less than 600 million years after Earth’s formation.”

“This discovery represents a major advance in our understanding of Earth’s early history and opens the door to further exploration of the origin of life.”

of Investigation result Published in this week’s journal Nature Chemistry.

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H. Gamaleldine othersThe Earth’s water cycle began 4 billion years ago or sooner. National GeographyPublished online June 3, 2024; doi: 10.1038/s41561-024-01450-0