Australian and French geoscientists have used the geological record of Earth's deep ocean to discover a link between our home planet and the orbit of Mars. They discovered a surprising 2.4 million-year cycle of increase and decrease in deep ocean currents, which they found was related to periods of increased solar energy and climate warming.
This image from Mars Express' high-resolution stereo camera shows the Martian Earth set against a dark background. The planet's disk is speckled with yellow, orange, blue, and green, giving it an overall muted shade of gray, representing the varying composition of its surface. Image credit: ESA / DLR / FU Berlin / G. Michael / CC BY-SA 3.0 IGO.
“In 1976, scientists first demonstrated and confirmed the presence of 10,000- to 100,000-year astronomical cycles in deep-sea Pleistocene sediments. Milutin Milanković's theory “Earth's climate is regulated by the periodicity of perturbations in the Earth's orbit around the Sun and Earth's axis of rotation,” said Adriana Dutkiewicz, a researcher at the University of Sydney, and colleagues.
“Apart from the well-known astronomical cycles of 19,000, 23,000, 41,000, 100,000, and 400,000 years, which vary according to the Earth's climate, the geological record includes Large-period signals with longer periods are also included.”
“These large cycles contain orbitally forced periodicities of millions or even tens of millions of years, which are similarly related to incoming solar energy and paleoclimate changes. I am.”
In a new study, the authors used deep-sea sediment records to confirm the link between sediment movement and changes in Earth's orbit.
They discovered that the strength of deep ocean currents changes over a 2.4 million year cycle.
“We were surprised to find these 2.4 million-year cycles in deep-sea sediment data,” Dr. Dutkiewicz said.
“There's only one way to explain them. They're related to the cycle of Mars-Earth interactions around the sun.”
“The gravitational fields of the planets in our solar system interfere with each other, and this interaction, called resonance, changes the planet's eccentricity, a measure of how circular a planet's orbit is.”
“For Earth, that means a 2.4-million-year period of increased solar radiation and a warming climate.”
The researchers found that warming cycles are associated with an increase in deep ocean circulation, which correlates with increased breaks in the deep ocean record.
They identified deep eddies as a key component of early ocean warming.
Although these may partially alleviate ocean stagnation, some predict that subsequent stagnation may follow. AMOC (Atlantic meridional overturning circulation) drives the Gulf Stream and maintains Europe's warm climate.
“We now know that there are at least two distinct mechanisms that contribute to the active mixing of deep water in the ocean,” Professor Müller said.
“Deep-ocean eddies, of which AMOC is one, appear to play an important role in keeping the ocean ventilated in warmer climates.”
“Of course, it doesn't have the same effect as the AMOC in terms of transporting water masses from lower to higher latitudes and vice versa.”
“These eddies are like giant whirlpools that often reach the ocean floor in deep oceans, resulting in seafloor erosion and the accumulation of large sediments called contours that resemble snowdrifts.”
“Our deep-sea data over 65 million years suggests that there is a more active deep circulation in warmer oceans,” Dr. Dutkiewicz said.
“This could prevent ocean stagnation even if the AMOC slows down or stops altogether.”
of study It was published in the magazine nature communications.
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A. Dutkiewicz other. 2024. Deep-sea hibernation records reveal orbital pacing with an orbital eccentricity of 2.4 million grand cycles. Nat Commune 15th, 1998. doi: 10.1038/s41467-024-46171-5
Source: www.sci.news
