Our knowledge of the outer part of the Earth’s core and its role in the planet’s magnetic field is based on theory since scientists have not yet been able to observe anything directly.
For this conclusion, the seismic waves of two earthquakes that occurred in close proximity but 20 years apart were studied.
The waves from the two earthquakes traveled through the same region of the outer core. The difference is that the waves from the second earthquake traveled faster than the waves from the second, which means that the material that was there 20 years ago is no longer the same. It is estimated that there is now lighter material there for this to happen. If this is true, it means that this lighter material will move upwards changing the density of the region as well as the magnetic field.
But as we said before, there are no proofs yet, only these observations.
[Source: http://www.skai.gr]
