This circulation generates bands of electrons that envelop the planet. The molten metal cools as it approaches Earth’s rocky mantle and sinks. The liquid outer core, which extends to 1,795 miles above the solid core, Koper says, produces a protective field of magnetic energy.
The liquid outer core envelops the solid inner core. It’s made up of mostly iron and some nickel, along with a few other elements. While the idea of an inner core was first discovered in 1936 using seismic wave information, we’ve now measured the core about 4,300 miles across. We’ve known about some of the interplay between solid iron and liquid iron. Not all of the iron became solid, so some liquid iron could be trapped inside.” “It reached an equilibrium, and then it started to grow much more slowly. “A long time ago the inner core grew really fast,” Utah seismologist Keith Koper, who oversaw the study, says in a statement. These changes come thanks to the growth of the inner core.
