The Earth’s magnetic field plays an important role in protecting us from dangerous radiation, geomagnetic activity and solar emissions, which affect satellite communications and the operation of electrical grids. However, this protective magnetic field is always in motion and even to a point. Analyzing the small changes it undergoes can help us predict more sudden changes in the future.
A scientist from the University of Massachusetts Lowell, in the United States, analyzed an article published in The Conversation on the possible reversal of the Earth’s magnetic poles. It shows that although we know that the Earth’s magnetic field protects life on our planet and our infrastructure from harmful solar radiation, and that at the same time it can act and causing the magnetic poles to reverse we have yet to determine exactly when this profound change will take place.
For the physicist Ofer Cohen, the fact that the magnetic north pole moves a little is not something very serious, but the reversal of the magnetic field and the change of the poles can have a big impact on the climate of Earth and our modern technology. However, these changes do not happen immediately, but progressive for thousands of years. Do we now have the information needed to know where we are in that process?
Electricity in motion
Basically, magnetic fields are created from electric charges in motion. We know that Earth is not the only planet with a magnetic field: gas giant planets like Jupiter have a hydrogen-conducting metallic layer, which creates its own magnetic field.
On Earth, the planetary magnetic field is activated due to the so-called “dynamo effect”. This concept shows that the Earth’s magnetic field is mainly generated by electric currents caused by the movement of ions of molten metals within the planet, especially in the region known as the Outer Core, located at a depth between 2,900 and 5,100 kilometers.
The movement of these conductive layers within the planets results in various consequences. Larger motions, such as large planetary rotations, lead to symmetrical magnetic fields, with a north pole and a south pole. However, these conductive layers may have some local irregular motion, due to regional turbulence or smaller currents which does not follow the pattern on a large scale.
These irregularities will show themselves in some small anomalies in the magnetic field of the planet or in places where the field deviates from the perfect dipole symmetry. the anomaly They are the most noticeable and cause concern, because some can be interpreted as the beginning of a deeper and more sudden change, which produces a change in the poles.
Can we predict the next investment?
The Earth’s magnetic field reverses on different time scales between 100,000 and 1,000,000 years. Scientists can tell how often it repeats by looking at volcanic rocks in the ocean: They get the orientation and strength of the Earth’s magnetic field when it was created, so dating these rocks gives and a good picture of how the magnetic field develops over time.
But even if the changes in the field happen quickly from a geological point of view, they are very slow from the human point of view. The change usually takes several thousand years, but during this time the orientation of the magnetosphere can change and expose more of the Earth to the cosmic radiation. These events change the concentration of ozone in the atmosphere.
Scientists cannot say for sure when the next reversal of the magnetic field will occur, but it is possible to continue mapping and tracking the movement of Earth’s magnetic north. The precise measurement of these small changes may give us in the future some pattern to determine the origin of a more radical changes in the magnetic field.