ESA: jet stream of liquid iron in the heart of the Earth's core
When we think about jet stream, we imagine rather the fast air currents of high altitude, but the mission Swarm on the terrestrial magnetism of the ESA reveals that there is also a jet stream of liquid iron in the heart of the Earth's core.
The three satellites of the European mission Swarm of terrestrial magnetism study were launched in 2013, and carry out measurements of the different magnetic fields emitted from the core of the Earth that constitute the protective barrier against the ionizing radiation of the solar winds.
Their origin comes from the heart of liquid iron of the planet surrounding the solid core and whose movements create electric currents and generate magnetism. And how the Earth's magnetic field evolves, the movements of liquid iron within the Earth can be determined.
The three Swarm satellites made it possible to discover that there is a real jet stream of liquid iron whose movements are now better understood and predicted. It appears that this jet stream moves more than 40 kilometers per year, three times faster than the fluid layers around the solid core and hundreds of thousands of times faster than the displacement of tectonic plates of the Earth's crust. Moving this liquid material which has a high density at such speed requires phenomenal energy.
This jet stream is located under the pole of the northern hemisphere and emerges under the Alaska and Siberian regions. It explains the more intense pockets for the earth's magnetic field in these geographical areas.
One of the reasons for the Swarm mission is also to try to understand why the Earth's magnetic field seems to steadily decrease in intensity, a rate of 5% per century. One possible reason is that the Earth is about (in geological time) to switch its magnetic field by inverting the poles.