The results of seismic wave analysis are allowing us to understand more and more about the interior of the earth. For example, there is an inner core in the innermost core-a dense iron ball located in the very center of the earth.
The internal structure of the Earth consists of a series of concentric layers from the crust to the core.
The densest structure is the inner core with a radius of about 1,227 kilometers, mainly composed of iron and nickel, accounting for less than 1% of the Earth’s volume, like a time capsule of Earth’s history.
The solidification process of the inner core will release heat and light to drive the convection of the outer liquid core-like a generator to provide power.
Converting kinetic energy into magnetic energy maintains a global magnetic field, allowing life to thrive.
Therefore, any changes in the inner core may trigger a dynamo chain effect, which in turn may affect the habitability of the earth over time.
More than 20 years ago, scientists discovered the existence of another core under the inner core, called the innermost inner core, and many studies support this discovery.
But it was difficult to find more information, in part because the inner core was obscured by other layers,
Another reason is that it is difficult to place seismic stations in the correct position to detect the rebound of seismic waves.
New research by a team at the Australian National University supports the innermost core theory, showing that there are actually five major layers of Earth as seismic waves travel back and forth up to five times from one side of the planet.
The reason this layer has not been observed in detail before, the researchers say, is because the innermost core is very similar to the inner core shell.
The latest discovery points out that the innermost core is a metal ball with a width of 644 kilometers-the outer shell is made of iron-nickel alloy and contains traces of other elements.
And the transition from the innermost core to the outer core shell is gradual, so it was difficult to observe through the direct reflection of seismic waves in the past.
The detection of a new layer 1,600 kilometers below our feet is significant. This unique innermost core can give scientists a better understanding of how Earth’s magnetic field has evolved.
The new paper was published in the journal Nature Communications.
