In the geological past, the Earth was extremely hot. Scientists estimate that it arose about 4.6 billion years ago, after a huge explosion. Over time, there was a slow and gradual cooling, but the iron-nickel-rich interior still held a lot of heat.
Radioactivity – the spontaneous emission of radioactive particles by dissociating isotopes in minerals and rocks in the Earth’s interior – also explains the heat in the planet’s interior.
The crust of the Earth, the layer that surrounds the planet – and where all beings inhabit – is the thinnest on the planet.
This layer is divided into an oceanic layer, with heights of 5-10 km, and a continental layer, from 30 to 80 km thick (most of this volume is below sea level).
The magma that volcanoes spew into the mantle is emitted below the Earth’s crust.
Photo: Getty Images
It is found under the Earth’s crust, and its depths range from 30 kilometers below the surface to 2,900 kilometers toward the core. Internal temperatures can reach 2,000 degrees Celsius, which is the point at which rocks melt and produce the magma that volcanoes expel.
Finally, there is the nucleus, the exact composition of which is unknown. It is divided into two layers: outer, which is in a liquid state, and inner, which is solid due to the pressure of the planet on it.
Experts estimate the Earth’s core to be around 5,000 degrees Celsius, although researchers at the European Synchrotron Radiation Laboratory (ESRF) argue that a more accurate estimate is 6,000 degrees. So far, no probe has reached the core of the planet, so we are now within the range of estimates.
Over time, the Earth’s core will cool completely, a few billion years from now. When this overall cooling occurs, the magnetic field What protects the Earth will be greatly diminished or even extinct. Without this protection, solar radiation would destroy our atmosphere.
Sources: Alexander Hello, Professor and Researcher at the Department of Geology at the Federal University of Minas Gerais (UFMG); Norberto my kids Professor and researcher in the Department of Geology at UFMG.
* With text by Tatiana Pronin
