The video explains that molten iron crystallizes in the Earth's outer core, forming a layer of iron particles above the solid inner core. Researchers from Sichuan University analyzed seismic waves to understand the core's composition. They found that seismic waves travel at different speeds due to the varying thickness of the iron slurry layer. This understanding helps explain the core's role in driving tectonic plate movement and generating Earth's magnetic field.

What role does the Earth's core play in tectonic plate movement?

Why is understanding the composition of the Earth's core important according to researchers?