A team of geologists from China and the United States has found new evidence that “snow” may be landing in the hot core. This, of course, is different from the snow that can be seen in winter – the researchers say the “snowflakes” will be made of ferroalloys and gently fallen onto the mainland’s nuclear core through more fluid foreign cores.
The best models of how the Earth works inside show that our planet is a “clutch cake” made up of different materials. The Earth has a silicon-rich crust, a sticky mantle, a liquid outer core, and a solid core.
There is a “transition allot”, and it’s hard for scientists to find out what’s going on there. To study it, the scientists recorded and analyzed how seismic waves travel through different materials. If they accelerate or decelerate at some point, they can reveal the viscosity of the different layers and suggest what they might make up. But this work reveals some surprises that don’t match our current model. For example, seismic waves appear to move more slowly than expected through the outer core, while moving faster than expected through the top of the core, especially in the eastern hemisphere.
The researchers in the new study have come up with a theory that explains these anomalies: iron “snow.” According to experiments using materials similar to the core, the iron in the lower part of the outer core may crystallize and then slowly sink and settle into a stronger core.
Nick Dyger, co-author of the study, said: “This is a strange thing. Crystals in the outer core drift into the core at a distance of hundreds of kilometers. “This iron “snow” will have a slurry texture that slows down seismic waves. And because it’s not an even layer, it’s probably thinner in the eastern hemisphere and thicker in the west, which suggests that these regions are different in speed. The team says this process could also explain why the kernel is growing. If the “iron snow” falls on the core, this may have an impact on many Earth processes, including how heat and rock move in different regions and how magnetic fields are produced.
“The core boundary is not a simple, smooth surface, it can affect the thermal conduction and convection of the Earth’s core,” said Zhang Youjun, lead author of the study. “
The new study was published in the journal JGR Solid Earth.