NASA
Two large structures may be complicating the measurements of geologists because they accumulate over the nucleus, slowing down the seismic waves.
There are two strangers mineral structures – one under the Pacific and one under Africa – who resemble in terms of Seismic wavesand it is supposed to have the same composition.
The “large low -speed provinces” are up to 900 kilometers high and thousands wide.
Now, the authors of a new published in Nature this month study the connection of these super-structure “Sunned” next to the nucleus of the earth with the plates on the surface.
“It is fascinating to see the links between the movements of the earth’s surface and the structures 3000 kilometers deep on our planet,” says Oxford University, Paula Koelemeijer, quoted by.
Millions of natural cycles of the crust mixed what was once the surface of the earth in the depths of the cloak. The resulting composition now covers up to 30% of the core, which Sprinkle the seismic waves that geologists use to probe the internal structure of the earth.
“Our cloak circulation models over the past thousand million years demonstrate that large low-speed provinces can develop naturally as a consequence of oceanic crust recycling,” the researchers explain.
“The Pacific Province of great speed and low speed is enriched in underduzed oceanic crust, This implies that the recent history of Earth’s subduction is provoking this difference, ”they report.
“The fact that these two major low -speed provinces differ in terms of composition, but not in terms of temperature, it is fundamental to history and explains why they seem to be the same,” explain the authors of the study.
According to the investigation, the two cloak structures are not allowing the heat of the nucleus dissipates evenly On both sides of our planet, which may be unbalanced our magnetic field.
