Earth’s Inner Core Formed Earlier than Expected

There have been several estimates about when earth’s inner core was formed, but researchers of a new study claimed that the earth’s inner core was formed 1-1.5 billion years ago as it froze from the surrounding molten iron outer core.

The cooling of planet’s core triggered the formation of Earth’s magnetic field, which shields the planet from solar radiation.

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 signs will help them know the approximate time when the planet started to cool down.

Andy Biggin of the University of Liverpool said, “The timing of the first appearance of solid iron or “nucleation” of the inner core is highly controversial, but is crucial for determining the properties and history of the Earth’s interior”. Through reassessment of ancient rocks, researchers said that the inner core developed around 4 billion years ago.

Earth’s inner core is a solid ball of iron. It’s surrounded by an outer core of liquid iron and nickle.

Scientists from the School of Environmental Sciences at the University of Liverpool in England led a group of scientists from around the world to analyze magnetic records from prehistoric igneous rocks.

In order to study the Earth’s iron core, scientists devised a method that can determine with a fairy amount of accuracy how old is in fact that blob of molten steaming hot iron and how long it took to freeze.

Biggin has explained that it is very important to find out the date when the inner core was formed because this particular piece of information could shed further light on Earth’s evolution. “This contrasts sharply with Mars which had a strong magnetic field early in its history which then appears to have died after half a billion years”.

These movements happen as the core is losing heat to the covering solid mantle that goes up to the crust on which we live. However, while looking for concrete evidence on when solidification started at the core, it constituted one of the best ways too.

The beginning of this freeze at the time of the new findings would make sense as this convection received a strong boost in power because light, non-metallic elements remained molten in the outer core and were buoyant relative to the overlying liquid. In turn, much of the outer core’s turbulence is caused by excess heat escaping upwards from the inner core by convection.

Scientific community suggests that life has thrived on earth due to the magnetic field allowing the protective atmosphere to carry on for several million years.

Findings of the latest study suggests that contrary to prior beliefs, Earth’s core is cooling at a lot slower rate and this has implications for the whole of Earth Sciences.