An ultra-weak Earth’s magnetic field between 591 million and 565 million years ago (the Ediacaran period) coincided with a significant increase in oxygen levels in the atmosphere and oceans, according to a research team led by geoscientists at the University of Rochester. It is said that he did.
When the macroscopic animals of the Ediacaran fauna diversified and flourished, the Earth’s magnetic field was in a highly abnormal state. Image credit: NASA.
Between 600 million and 540 million years ago, life on Earth Ediacaran faunathe earliest known complex multicellular animal.
The fossil record shows that these organisms greatly diversified in complexity and variety between 575 and 565 million years ago.
Previous research suggests that this diversification is related to a large increase in oxygen levels in the atmosphere and oceans that occurred during the same period.
However, it is still not clear why this increase in oxygen occurred.
In a new study, the University of Rochester Professor John Tarduno The research team analyzed the magnetic properties of 21 plagioclase crystals, a mineral commonly found in the Earth’s crust, extracted from a 591-million-year-old rock formation in Brazil.
Plagioclase crystals contain small magnetic minerals that maintain the strength of the Earth’s magnetic field at the time of their formation.
Analysis of the crystals showed that Earth’s magnetic field at the time of its formation was the weakest ever recorded. This was about 30 times weaker than both the current magnetic field strength and the field strength measured from similar crystals formed about 2 billion years ago.
Scientists combined their results with previous measurements to establish that Earth’s magnetic field was at this weak level for at least 26 million years, from 591 million years ago to 565 million years ago. .
This coincides with an increase in oxygen that occurred between 575 and 565 million years ago.
“The weakening of the magnetic field may have allowed more hydrogen to escape into space, thereby increasing the proportion of oxygen in Earth’s atmosphere and oceans, thereby increasing the variety and complexity of life. “This may have promoted diversification,” the authors conclude.
of findings It was published in the magazine Communication Earth and Environment.
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W fan other. 2024. The near collapse of the Earth’s magnetic field may have contributed to the oxygenation of the atmosphere and the generation of radiation in animals during the Ediacaran era. symbiotic global environmentn 5, 207; doi: 10.1038/s43247-024-01360-4
Source: www.sci.news
