by Mars may be around 140 million miles from Earth, but the red planet is influencing our deep oceans by helping to drive “massive eddies”, according to new research.
The scientists analyzed sediment, drilled from hundreds of deep-sea sites over the past half century, to look back over thousands of years of Earth’s history, in order to gain a better understanding of the strength of deep ocean currents.
What they found surprised them.
The sediments showed that deep-sea currents weakened and strengthened over 2.4 million-year climate cycles, according to the study published Tuesday in the journal Nature Communications.
Adriana Dutkiewicz, co-author of the study and a sedimentologist at the University of Sydney, said that the scientists did not expect to discover these cycles, and that there is only one way to explain them: “They are linked to cycles in the interactions of Mars. and the Earth orbiting the sun,” she said in a statement. The authors say this is the first study to make these connections.
The two planets affect each other through a phenomenon called “resonance,” which is when two orbiting bodies exert gravitational pressure and pull on each other—sometimes described as a form of harmonizing between distant planets. This interaction changes the shape of their orbits, which affects how close they are to the circle and how far they are from the sun.
For Earth, this interaction with Mars represents periods of increased solar energy – meaning a warmer climate – and these warmer cycles correlate with more vigorous ocean currents, the report found.
Although these 2.4 million year cycles affect warming and ocean currents on Earth, they are natural climate cycles and are not linked to the rapid warming of the earth today as humans continue to burn warming fossil fuels planets, said Dietmar Müller, professor of Geophysics. at the University of Sydney and study co-author.
The authors describe these currents, or currents, as “giant eddies” that can reach the bottom of the deep ocean, eroding the sea floor and creating large accumulations of sediment, similar to snowdrifts.
The scientists were able to map these strong breccias by “fracturing” the sediment cores they analysed. Deep-sea sediment builds up in continuous layers during calm conditions but is disturbed by strong ocean currents, leaving a visible imprint of its contents.
Because satellite data that can clearly map changes in ocean circulation have only become available in the last few years, sediment cores — which help create a picture of the past going back millions of years — are very useful for identifying changes to understand circulation in a warmer climate, Müller told CNN.
If today’s human warming continues on its current trajectory, Müller said, “This effect will affect all other processes for a long time to come. But the geological record still gives us valuable insight into how the oceans work in a warmer world.”
The authors suggest that these currents may even help mitigate some of the potential impacts of the Atlantic Overturning Overturning (AMOC), a critical ocean circulation that works like a conveyor belt. huge that carries warm water from the tropics to the Dr. far in the North Atlantic.
Scientists are paying more attention to the health of this critical current system. There are fears it could be showing early signs of collapse, as global warming raises the oceans and melts ice, upsetting the delicate balance of heat and salt that determines the strength of the AMOC .
Disastrous climate consequences would ensue, including rapidly falling temperatures in some places and rising in others.
“Our work says nothing about what may or may not happen to AMOC,” Müller said. “Our point is, rather, that even if AMOC were to shut down, there are still other processes to mix the ocean, although their effects would be very different.”
There are fears that the shutdown of AMOC would mean that oxygen-rich surface waters would no longer mix with deeper waters, resulting in stagnant oceans largely devoid of life. “Our results suggest that more intense deep-ocean warming in a warmer world could prevent such ocean stagnation,” he said.
Joel Hirschi, associate head of marine systems modeling at the National Oceanography Center in the UK, who was not involved in the research, said the study’s finding that there was a 2.4 million year cycle in sea sediments was remarkable. The methodology is sound and a connection to Mars is possible, he said.
But, he told CNN, “the proposed link to ocean circulation is speculative and the evidence that deep ocean circulation linked to edges is stronger in warmer climates is thin.”
Satellite observations have shown these rifts have become more active in recent decades but the currents don’t always reach the bottom of the ocean, he said, meaning they wouldn’t be able to prevent construction. up sediment.
It’s still unclear how various processes affecting deep-ocean currents and marine life will play out in the future, the study’s authors said in a statement, but they hope this new study will help produce better models. future climate outcomes.
For more CNN news and newsletters create an account at CNN.com
