By listening to the echoes of earthquakes reflecting inside our planet, we can make a good guess about what is inside the Earth without cutting it apart. Unfortunately, seismic waves often have inconsistencies that scientists have yet to fully understand.
Photos from open sources
One source of variability lies in pockets of low-density material about 3,000 kilometers below the surface, between the liquid iron alloy outer core and the mantle.
A new study suggests that the silicon-rich “snow” that rises from the outer core may help explain some of the anomalies in the observations. Because the silicon makes the particles lighter than the surrounding liquid iron, the material can flow into the mantle and settle in drifts that cause sound waves to distort in unpredictable ways. The study is published in Nature.
“If silicon and hydrogen are the two main light elements in the outer core with appropriate abundances, such a growing silicon-rich snow can occur,” says geologist Suyu Fu from the University of Tokyo in Japan.
Many will think that all this does not matter much to us living on the surface of the Earth, but it is worthwhile to understand that the movement of the outer core sets in motion the magnetic field of our planet, which, in turn, protects us from the harsh effects of outer space and solar weather. .
Understanding what’s in the outer core, how it moves, and how that might affect its interaction with the mantle is critical to predicting how Earth’s magnetic field might continue to operate in the future.