Within Earth’s inner core may lurk an ‘innermost’, fifth layer

Source: The post is based on the article “Within Earth’s inner core may lurk an ‘innermost’, fifth layer” published in Times Now on 26th February 2023

What is the News?

Seismologists at The Australian National University(ANU) have documented the evidence of a distinct fifth layer of earth at the centremost part of Earth— the “innermost inner core”.

About the research

Previously, many researchers believed that Earth had four distinct layers — the crust, the mantle, a liquid outer core and a solid inner core. 

But in the past couple of decades, scientists have proposed that the inner core actually consists of two layers, referred to as the inner core and the innermost inner core. 

Two Harvard seismologists, Miaki Ishii and Adam Dziewonski, first proposed the idea of the innermost inner core in 2002.

What did the researchers find about the innermost inner core?

The Innermost Inner core is a 400-mile-wide (644-kilometre-wide) ball of metal.

It exists in a solid state as an alloy of iron and nickel because of the extreme pressure at the centre of the Earth.

Its temperature is estimated to be about 5,500-6,000 degrees (Celsius/9,930-10,830 Fahrenheit), similar to the sun’s surface temperature.

It has a distinct anisotropy, which is a property of a substance that allows it to take on different characteristics depending on the angle from which it’s approached.

The reason this layer had not been previously observed in more detail is because its composition is so similar to what lies above it.