The Earth's magnetic field is more than half a year old

New research shows that the Earth's solid iron core forms a magnetic field that formed about 1.5 billion years ago and the Earth's magnetic field will last about a billion years.

The Earth's magnetic field exists for 1 billion years

The Earth's magnetic field is caused by a molten iron layer around the solid inner core. This magnetic field will exist for a very long time, about a billion years, according to the ancient house from Andy Biggin, University of Liverpool, co-author of this discovery. Antiquity is the study of the Earth's magnetic field history, based on rock samples, sediments or archaeological documents.

"The theoretical models best suited to the data we collected show that this molten core loses heat much slower than it was 4.5 billion years ago, and it will help maintain the Earth's magnetic field. For at least a billion years, " Biggin said.

The existence of the Earth's magnetic field is surprisingly long, if compared to Mars. Mars also had a strong magnetic field that blocked solar wind radiation, but the magnetic field disappeared completely about 500 million years ago. Without a protective magnetic field may be the cause of life that can only grow on Earth that may not be in Mars.

Structure of the Earth.(Photo: Mopic).

The Earth formed 4.54 billion years ago, about 100 million years after the solar system was formed. At first, this was just a ball of molten rock. Over time, the surface rocks cool down, harden to form continents, "float" above the molten core, then the atmosphere and life form.

The strength of the Earth's magnetic field is directly proportional to the motion of ferromagnetic molecules in the molten core. This is the movement that occurs due to heat convection, when the heat from the molten core passes to the solid geology layer between it and the Earth's crust. This convection heat loss is significantly increased when the core solidifies, increasing the magnitude of the magnetic field, the researchers conclude.

It can be seen that this solidification process is very important. Thus, Earth's life is protected from harmful radiation from the solar wind. However, scientists still have not agreed on the time of this phenomenon. Some argue that the solid core formed 500 million years ago, while others believe that two billion years ago. The solid core is the size of Pluto.

To answer this question, Biggin and colleagues studied a database that tracks the direction and strength of magnetic fields in ancient stone particles. They found a sharp increase in magnetic field strength in the range of 1-1.5 billion years ago. They also calculated the rate of solidification of the core. Diameter of solid core increases about 1mm per year. This conclusion was published in the October 7 issue of Nature.

"This discovery could change our understanding of the inner structure of the Earth and its history," Biggin said.