According to the new researches, it can be answered how Earth’s magnetic field has survived for billions of years. There are several reports which indicate that researchers have worked to prove that the magnetic field of Earth is generated by its mantles liquid component, not the core. This new study may lead to a deeper understanding of the early history of the Earth.
Scientists from the University of California, San Diego, have proved that the Earth’s outer core(liquid) has always been the significant source of the dynamo which generates the magnetic field.
Scientifically speaking, Earth’s magnetic field protects us from solar radiation and has also been the basis of navigation. This magnetic field is the result of convection currents in the Earth’s outer core, and due to temperature differences, convection current causes the movement of energy (electricity) in the fluid.
But, the scientists have provided us in the study that it wasn’t always the core that generated the magnetic field. According to some previous theories, it was suggested by scientists Dave Stegman and Leah Ziegler that the mantle was not always completely solid. Besides this, they also theorized the presence of ‘the basal magma ocean’ which at the bottom of the mantle was rich in silicates in the early days of the Earth.
In addition to this, scientists also suggested that Earth’s magnetic field was created by the silicate-rich mantle at that point in the history of the Earth, but this theory was not so persuasive because silicates are an inferior conductor of electricity and it is an element which is very important for convection currents as it produces the magnetic field of the Earth.
Apart from this, there is a study which was published in the journal ‘Earth, and Planetary Science Letters’. It suggested that a new theory provides an opportunity to resolve inconsistencies in the narrative of the planet’s early days.
Co-author Dave Stegman from the University of California (UC) San Diego in the US claimed in a study that “Currently we have no grand unifying theory for how Earth has evolved thermally” and Stegman further added that they do not have this conceptual framework for understanding the evolution of the Earth.
In the current research, Stegman and his team demonstrated how this once-liquid portion of the lower mantle might have reached the thresholds required to establish the magnetic field of the Earth at that time, rather than the core.