The 1995 Kevin Costner movie Waterworld might be set in the distant future – but if recent research is to be believed the film’s setting may have been a reality in the past.
New research shows that more than 3 billion years ago, early Earth may have been a real-life “waterworld”, without a continent in sight.
Tell-tale chemical signatures were spotted in an ancient chunk of ocean floor which points to a planet once devoid of continents, the largest landmasses on Earth.
Geobiologist Boswell Wing, of the University of Colorado, Boulder, and his former postdoctoral student Benjamin Johnson, now at Iowa State University, launched the project to break fresh ground in the debate over what ancient Earth might have looked like and how hot or cold it may have been.
The team’s research work centred on a geological site called the Panorama district in north-western Australia’s outback, where a 3.2bn-year-old slab of the ocean floor has been turned on its side.
Locked inside the ancient crust are chemical clues about the seawater that covered Earth at the time.
Their findings, published in Nature Geoscience earlier this week, claims that the oxygen ratios found in their rock samples could be attributed to a lack of continents.
That doesn’t mean the planet was necessarily entirely covered in water, claims Science Alert, but it could’ve had far less dry land than Earth has right now.
“There’s nothing in what we’ve done that says you can’t have teeny, micro-continents sticking out of the oceans,” Wing explains. “We just don’t think that there was the global-scale formation of continental soils like we have today.”
The next step of the research is to establish why and when exactly the continents emerged. The team plans to investigate younger rock formations to try to piece together that timeline.
If the team’s findings are confirmed by future work, it’ll help researchers to refine their theories on where and how the first single-celled life emerged on Earth, and what other planets may be habitable.