By: Ethan Shen

Often, in your standard geology textbook, you will see a cutaway diagram of the Earth with four layers. There will be the crust, mantle, outer core, and inner core. However, recent studies have shown there might be another layer inside the inner core: the innermost core.

Scientists used powerful earthquakes to see how the seismic wave travels through the Earth’s innards. Analyzing information from multiple earthquakes, two Australian scientists were able to prove the existence of an innermost core.

Seismic waves travel at different speeds depending on the direction of the wave and the material it travels through. When the seismic waves traveled differently through an area in the middle of the inner core, the scientists were able to prove that something different was there.

Instead of trying to place seismometers on the other side of the world, the scientists got smart with this and took advantage of the fact that seismic waves bounce back. Thus, they quickly put seismometers near the epicenter of the earthquake, as soon as the earthquake happened. This way, they could capture seismic waves that traveled through the innermost core two times or even four times.

People study the inner core structure to find some events that happened with the Earth’s magnetic field when the inner core crystallized 600 million to 1 billion years ago. They think that the inner core structure is related to Earth’s magnetic field. Either way, the mysteries are just waiting to be found. We can only begin to learn the structure of the deep innards of the Earth.