Scientists are now analyzing magnetic records obtained from prehistoric igneous rocks where an international team revealed a significant difference in Earth's magnetic field ranging from 1 billion to 1.5 billion years ago.
A team from the School of Environmental Sciences at the University of Liverpool, conducted this new study where they theorized how a higher magnetic field determines the initial presence of solid iron inside Earth's core. Scientists believe that the inner core began to solidify and freeze during this time.
Some 4.5 billion years back, before Earth's inner core possessed a solid one, the planet most likely appeared to be a huge mass of liquefied rock where this molten, rocky mess developed a crust in time, as its surface started to cool down. At 1 billion years old, the planet's inner core is considered to be relatively new.
According to the lead author of the study, Andy Biggin from the University of Liverpool, this new finding can change how scientists perceive and understand the evolution of Earth and its layers. Biggin says that these results are suggesting that the planet's core is cooling down slower than the rate that is previously thought, that can cause many implications in the field of Earth Sciences today.
Apart from this, the findings now suggest that the planet's core is growing at 0.04 inches or one millimeter in diameter every year which means that the inner core of Earth is roughly the size of dwarf planet, Pluto.
Researchers also add that the magnetic field of Earth is protecting the planet from dangerous solar radiation, that keeps ecosystems alive and thriving. This new understanding about the Earth's magnetic field and its core will help scientists predict the future of this electromagnetic shield that is currently protecting life on Earth from radiation.
The key findings also reveal how the Earth's magnetic field is being generated by the inner core's power, lasting for another 1 billion years. Compared to Mars, Martian magnetic field began strongly in its early history but disappeared around 4 billion years ago.
This new study is published on the journal, Nature.