Old igneous rocks reveal inner core of Earth formed 1-1.5 billion years ago

London, October 8: Researchers from the University of Liverpool, analyzed magnetic records from old igneous rocks and discovered that there was a sharp search in the Earth’s magnetic field strength within 1 and 1.5 billion years ago. The boosted magnetic field is a probable sign of solid iron’s first occurrence at the Earth’s center. It’s also the time in Earth’s history at which solid inner core started to separate out from the cooling down the molten outer core.

The research leader, Dr. Andy Biggin, opined that the discovery would fundamentally change the comprehension of the Earth’s core and its history.

The results indicate that the planet’s core is cooling down much less fast than earlier thought. It also indicates an average growth around 1 millimeter a year of the solid inner core.

The Earth’s magnetic field is produced by the moment of the liquid iron alloy in the outer core that is 3,000 km below the Earth’s crust.

These movements happen as the core is losing heat to the covering solid mantle that goes up to the crust on which we live. This is also called the convection phenomenon.

Once the inner core began to take shape, this convection got a powerful surge in power as light, non-metallic elements continued to be in the molten state in the outer core and were afloat relative to the covering liquid. The process still exists presently and is believed to be the major originator of fuel for producing the planet’s magnetic field.

The theoretical model determines that the core is dissipating heat much slower than ever in the previous 4.5 billion years. This particular flow of energy would sustain the earth’s magnetic field for another 1 billion years or more.

As per the study, the planet’s inner core was constituted 1 to 1.5 billion years ago as it froze from the molten iron out core surrounding it. The inner core is Earth’s innermost layers and a relatively newer addition to the planet.

Agreeing on when it was constituted, is the subject of immense scientific debate with estimates being given from 0.5 billion up to 2 billion years ago.