A new study has confirmed existing assumptions about the age of the deepest structure in the bowels of the planet.
American scientists analyzed ancient rock crystals and using the obtained data on their magnetism, that is, the change in magnetic force, they were able to determine the most accurate age of the Earth's inner core, reports ScienceAlert.
Our planet formed 4.5 billion years ago. It is made up of the crust, the outermost layer on which we all live, followed by the 2,900 km thick mantle, and at the very center of the Earth is the core. But it consists of a liquid outer core of molten iron, about 2.2 thousand km thick, and an inner solid core, consisting of iron and nickel, with a diameter of about 1.3 thousand km.
The inner core is extremely hot sphere, the temperature of which reaches 5.5 – 6 thousand degrees Celsius. It is technically impossible to get to the Earth's core, and therefore scientists get all the data about this object by studying ancient rocks.
In a new study to determine the exact age of the Earth's inner core, scientists at the University of Rochester, New York, have studied feldspar crystals that make up a rock called anorthosite. These crystals serve as a kind of registrar of changes that have occurred in the Earth's magnetic field over millions of years.
Scientists compared rocks aged 565 million years and 532 million years and noticed that the crystals reflect a change in magnetic strength, that is, a change in the magnetic field 550 million years ago. It was during this period that a sharp recovery of the magnetic field began, which lost most of its strength 565 million years ago. Therefore, scientists believe that the previously liquid interior of the Earth's core solidified just 550 million years ago, which finally confirms previous theories.
“As for the magnetic field, the formation and growth of the inner core is inextricably linked with an increase in the strength of the Earth's magnetic field. If it were not for the core, then the magnetic field would almost completely disappear and there would be no rapid development of life, as happened 540 million years ago as a result of The growth of the inner core, and itself, maintains the planet's magnetic field in a stable state, which protects all life on Earth from harmful cosmic and solar radiation, “says John Tarduno from the University of Rochester.
Back in 2020, scientists found that the inner core most likely consists of two parts. Inside the larger sphere is a smaller one with a diameter of about 600 km. According to Tarduno, as a result of the new study, it became known that the structure of the inner core changed about 450 million years ago, when the boundary between the two parts of the Earth's inner core appeared.
Scientists believe that important new data on the core will make it possible to model its further evolution, as well as the history of its creation will help in the study of other planets. For example, if we are talking about Mars, then this planet lost its magnetic field billions of years ago, and then its normal atmosphere, and the same could happen on Earth, if not for the intervention of the inner core in the evolution of the planet.
” If the magnetic field had not recovered 550 million years ago, then now the Earth would have looked very different, perhaps it would have looked like Mars,” says Tarduno.
Focus already wrote about a previous study by the same scientists, which proved that the growth of the inner core directly influenced the rapid development of life on Earth 540 million years ago.