Scientists have discovered a previously unknown structure in the Earth’s outer core. It is oriented in the equatorial plane, and its shape resembles a giant doughnut. Researchers are confident that its study will help solve some of the mysteries of our planet’s magnetic field.
Giant doughnut inside the Earth
Scientists from the Australian National University have discovered inside the Earth a giant structure that looks like a torus, or simply put, a doughnut. They believe that it may hide the clue to some phenomena related to the magnetic field of our planet.
As we know, at the very center of the Earth is a rather small inner core, mostly composed of iron and nickel. It is in a solid state. It is surrounded by an outer nucleus with a very similar chemical composition, but liquid.
It is the interaction of the inner and outer core and the outer core with the surrounding mantle that gives rise to our planet’s magnetic field. All this was what scientists decided to study by tracking the way seismic waves travel through the central regions of the Earth.
Areas of seismic wave deceleration
In fact, all we know about the Earth’s internal structure are models that are designed to explain the phenomena we can observe on the surface and what happens when seismic waves pass through its thickness.
The fact that the oscillations generated by earthquakes are not limited to the area around the epicenter of the phenomenon, but spread through the core and mantle of the planet, scientists have known for a long time. And in different media, the speed of oscillations is different. Due to this, simply by measuring the time it took the waves to reach different points, we can learn a lot about the environments they encountered on their way.
In this way, people learned that there were zones within the mantle where the oscillations moved quite slowly. However, all these were separate small centers. Now scientists have found that a similar but global structure is also found in the outer core.
This giant doughnut of material, which has different properties than the rest of the outer core, is located at low latitudes and is parallel to Earth’s equator. It is difficult to say what it consists of, but the authors of the study believe that it contains many lighter elements and that this is what causes a decrease in the speed of seismic waves.
As to why such a giant structure has not been seen before, everyone already has an opinion. The matter is that they collected data on the passage of oscillations from dozens of earthquakes propagating in different directions. This gave them a holistic statistical picture.
Now scientists hope they will be able to study the giant doughnut in more detail. After all, it hides the answers to the question of whether the magnetic field of our planet may change or weaken in the future.
According to phys.org
