The new understanding about the Earth’s inner core (from The University of Texas at Austin), formed of tiny particles of iron that fall from the molten outer core and which settle onto top of the core, provides a new understanding of not only how the core functions, the insight may also reveal more about the physical forces that affect our entire planet. The Earth’s inner core is a solid ball with a radius of about 1,220 kilometres (760 miles), equivalent to 20 percent of the Earth’s radius.
The ‘snow’-like covering of particles leads to the formation of huge piles, some of which are 200 miles thick, with the entire core covered with the tiny fragments of iron. The new insight has not come from direct observation (no technology exists that can do this). Instead data was derived from analysis of recordings and then applying big data analytics to study the signals produced from seismic waves.
Suspicion that the inner core has an iron-coating came from the observation that waves tend to move more slowly than expected as they move through the base of the outer core; coupled with the finding that waves proceed to move faster than expected when moving through the eastern hemisphere of the top inner core. This happens because the accumulated snow-particles act as the cause of seismic aberrations.
According to principal scientist Professor Jung-Fu Lin the process is very much like the way rocks form inside volcanoes, explaining: “The Earth’s metallic core works like a magma chamber that we know better of in the crust.”
The significance of the research arises because the Earth’s core affects the entire planet, including influencing the magnetic field and with radiating heat which drives the movement of tectonic plates. The new finding will help geologists to understand more about these wider forces.
The research has been published in the Journal of Geophysical Research: Solid Earth, with the research paper titled “Fe Alloy Slurry and a Compacting Cumulate Pile Across Earth’s Inner‐Core Boundary.”
