According to the calculations, which held the French geophysics, core of the planet are not nearly as stable as previously thought, says Pop-top.net melting and crystallization are still going on and they are responsible for the fact that the nuclear shape is not symmetrical.
How do they see?
Determination of the shape the earth’s core – is far from trivial. No wells not deeper than the earth’s crust, not to mention the mantle, and therefore directly look at the kernel can not. That is at depths of over ten kilometers, geologists in the early XX century learned the dissemination of seismic waves (vibrations created by earthquakes).
Wave arising in the earthquake shocks, different moves in different rocks, and when it encounters the boundary between two media, it is partially reflected from it. By registering with the help of seismic wave arrival times at different points, scientists can reconstruct the internal structure of the Earth, roughly the same way as fishermen use echo sounder to monitor hidden in the water column shoals of fish.
In a paper published in the journal Science, researchers from the University of Toulouse, analyzed data collected from 1976 to 2009, including about 90 large earthquakes. Putting together the results of observations of seismic waves, scientists have restored the form of the Earth’s core, once again making sure its asymmetry.
Sound in iron
However, only some data on the form of the earth’s core would be insufficient to conclude that melting of the core in one place and it solidifies in the other. For similar conclusions needed to use information about how to apply vibration in various forms of iron.
Because iron has most of the Earth’s core. And the inner part of the core is solid, and the outer, surrounding him from all sides, the liquid. Find a managed again to reflect seismic waves.
Iron, depending on the pressure and temperature, can take different forms: the atoms can be positioned differently relative to each other. And this is a different location leads to different mechanical properties, including velocity of propagation of oscillations. Where iron is melted or only solidifies, the fluctuations are distributed not as a continuum and not subject to change monolith.
What practical significance are the data obtained by researchers? First of all, the researchers obtained data on how far the core of the planet, which allows the device to better understand the Earth as a whole. Furthermore, the constant melting in one place and crystallization in a different mean a continuous transfer of liquid iron. Local areas of fusion and crystallization, discovered by geophysicists generally agree well with the local peculiarities of the magnetic field of the planet – which is not surprising, since the giant magnetic material flows have been seriously affected the state of the magnetosphere.
Earth’s magnetic field deflects the flow of charged particles from the Sun. The interaction of the magnetic field with solar particles is the basis of magnetic storms, and protects life on Earth from harmful ionizing radiation.
Additional information about the nature of the magnetic field will more accurately predict its long-term changes. Since the magnetic field deflects away from the world’s streams of charged particles from the Sun – for humanity is not an abstract issue. In the past, the magnetic field has changed its orientation, and its complete disappearance is fraught with the sharp increase in background radiation due to cosmic radiation. Looming Do we repeat magnetic cataclysmic, we can say only having enough on his hands full and adequate model of the Earth’s core.