A Yale-led team of scientists may have found a new factor to help explain the ebb and flow of Earth’s magnetic field — and it’s something familiar to anyone who has made a vinaigrette for their salad.
Earth’s magnetic field, produced near the center of the planet, has long acted as a buffer from the harmful radiation of solar winds emanating from the Sun. Without that protection, life on Earth would not have had the opportunity to flourish. Yet our knowledge of Earth’s magnetic field and its evolution is incomplete.
In a new study published May 6 in the Proceedings of the National Academy of Sciences, Yale associate professor Kanani K.M. Lee and her team found that molten iron alloys containing silicon and oxygen form two distinct liquids under conditions similar to those in the Earth’s core. It is a process called immiscibility.
“We observe liquid immiscibility often in everyday life, like when oil and vinegar separate in salad dressing. It is surprising that liquid phase separation can occur when atoms are being forced very close together under the immense pressures of Earth’s core,” said Yale graduate student Sarah Arveson, the study’s lead author.
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Image: A laser-heated diamond anvil cell is used to simulate the pressure and temperature conditions of Earth's core. Inset shows a scanning electron miscroscope image of a quenched melt spot with immiscible liquids. (Credit: Sarah M. Arveson/Yale University)