The process is still continuing and generates the Earth’s magnetic field, which according to the study, will continue to remain strong.
Advertisement
A new study conducted by scientists from the University of Liverpool suggests that the solid iron inner core of the Earth – the deepest layer of our planet – was formed about 1 to 1.5 billion years ago as it started freezing out from the surrounding molten iron outer core. According to their research, after Earth’s core froze down like a popsicle, it expelled impure particles of lower atomic mass into the outer flow core, where the magnetic field is amplified.
Earth’s inner core is a solid ball of iron. It’s surrounded by an outer core of liquid iron and nickle.
The emergence of the inner core had profound effects on Earth’s development.
Trying to determine the actual age of Earth’s inner core – the hot, molten iron core at the centre of our planet – has somewhat perplexed researchers until now with the best estimates putting its age somewhere between 500m years old and 2bn years old.
The current research has further enabled scientists to discover that the inner core gets cooled down at a much faster rate than initially estimated.
It aligns compass needles north-south, but in addition protects Earth from the photo voltaic storms that the Solar throws out relentlessly.
The turbulent movement of iron within the liquid outer core is partly generated by extra warmth within the centre of the Earth being transferred upwards and outwards by convection, and partly by the sluggish solidification of the strong internal core on the very coronary heart of the planet.
On the poles, these storms produce Aurora – northern or southern lights. But they can also work destructively to strip away ozone in the upper atmosphere, an important shield against the Sun’s harmful ultraviolet radiation.
“This finding could change our understanding of the Earth’s interior and its history.” said Dr Andy Biggin, the lead author of the study and a palaeomagnetism expert at the University of Liverpool.
Scientists have long disagreed on when the planet’s solid inner core first formed, with estimates ranging from 0.5 to 2 billion years ago.
The query of when molten iron within the coronary heart of the planet began to freeze and type the internal core has, lately, been the subject of vigorous scientific dialogue.
Advertisement
Dr Biggin added: “The theoretical mannequin which most closely fits our information signifies that the core is dropping warmth extra slowly than at any level within the final four”. However, while looking for concrete evidence on when solidification started at the core, it constituted one of the best ways too. “If this turns out to be the elusive signature of inner core growth, then we may have to revise our ideas about the core yet again!” said Dr. Harrison.
