Turns out, Earth's inner core isn't just a solid ball of nickel and iron but consists of two layers.

 

 

Turns out, Earth's inner core isn't just a solid ball of nickel and iron but consists of two layers.

Researchers have confirmed the existence of this innermost inner core using a unique type of seismic wave that travels through and bounces back and forth within the Earth's interior, providing valuable data about the core's structure. 

 

By analyzing seismic waves from earthquakes of magnitude 6 or larger that occurred over the past decade, the scientists identified 16 events with waves bouncing through the inner core multiple times.

 

Seismic data revealed that this inner heart is approximately 600 kilometers across, about half the diameter of the full inner core. 

 

Understanding the core is essential because it generates Earth's magnetic field, which protects us from solar particles and radiation. Earth’s core, which is about 6,600 kilometers across, consists of a liquid outer core and a solid inner core.

 

As iron-rich fluid cools and crystallizes in the outer core, it forms a solid center, generating a magnetic field.

 

The exact origins and timing of the core's formation remain uncertain, but it plays a crucial role in Earth's history. The core's magnetic field has likely undergone numerous pole reversals over the planet's lifespan. Seismic data suggests the presence of a hidden heart in the innermost core, potentially a long-preserved remnant of the core's early formation.

 

Image: Drew Whitehouse, Son Phạm and Hrvoje Tkalčić