According to the results of a new research, Earth’s inner core started to transform into solid elements much earlier than it was initially believed, more than 1.3 billion years ago.
Thanks to the analysis conducted by American experts, new data reveals that the planet’s innermost core began to solidify from the nearby melted metal external core. Based on seismological tests and documents, Earth’s internal core is a dense ball composed mainly of iron and nickel elements which reach temperatures similar to those of Sun – approximately 5700 K. The dimension of the core is over 750 miles in width – about 70 percent the size of the moon.
The US scientists assume that the “freezing” of our planet’s core activated a more powerful magnetic field. Researchers believe that this magnetic area served as a safety net, which protected our green environment against harmful solar rays. The ongoing activity of the liquid metals in the external core, which is around 1,800 miles under the Earth’s surface, is the main reason for our planet’s magnetic forces. These activities are caused by the core that is losing heat to an overlying solid layer reaching the planet’s crust.
As the metal core located in the Earth’s center is cooling down, it pushes heat and gas toxins into the fluid external core. The elements then rise and increase the convection in the external core, strengthening the magnetic forces of Earth during this process.
The initial process of hot metal appearing inside the internal core, called “nucleation”, is very complex, but is essential for identifying the physical characteristics and structure of the planet’s core. This activity has powerful effects on the Earth’s magnetic forces, which work as an invisible protection against dangerous rays from space, as well as a handy navigational tool. This study could change scientists’ theories about the formation of Earth and its evolution.
The crucial problem of when hot metals in the middle of the core started cooling and forming a solid sphere has been the subject of many serious geological debates. Current reports and models of the planet’s inner core development completely depend on knowing the properties of its metals. This is very hard to study since the conditions in the center of the Earth are extreme, to say the least: immense pressures of over 2 million atmospheres and metal temperatures going above 6,000 C.
A theoretical concept that suits best scientific data show that the main core is cooling slower than at any time in the last 4 billion years. This decreased traffic of planetary forces should maintain the planet’s magnetic field for another billion of years. One of the factors responsible for the experts’ different views in determining the internal core’s age is the research procedure, which is very challenging and tedious.
Researching the magnetism of prehistoric stones is a large scientific task, because ancient rocks might lose some magnetic qualities. Other problem is that the magnetic patterns that they possess can become over-written and damaged, just like a data file on your personal computer.
Nevertheless, this is one of the top methods to search for tangible proof of when Earth’s core began to solidify. Although information is limited, this research used strict rules to choose which methods were the most efficient and used this data to show that an increase in the planet’s magnetic field happened 1.3 billion years ago. If that is the explanation for the development of Earth’s inner core, then scientists might have to revise their theories about the planet’s formation once again.
Image source: Thewatchers