Geologists found between the upper and lower mantle of the Earth huge mountain peaks.
A powerful earthquake in Bolivia have helped scientists to study the structure of the boundary between the upper and lower mantle of the Earth and discover that it is covered with huge mountain peaks and deep Rosolini, informs Rus.Media.
Their findings were presented in the journal Science.
“The boundary between layers of the mantle was much rougher than the surface of the planet. Underground hills, figuratively speaking, was higher than the Appalachians or the Rocky mountains. We can’t exactly calculate their height, but they seem higher than any mountain peak on Earth,” said Wenbo Wu (Wu Wenbo) from the Institute of geodesy and Geophysics KAN in brown long-eared bat (China).
The interior of the Earth consists of several layers: solid crust, semi-solid mantle and molten metallic core. The crust is divided into several large pieces – tectonic plates that slowly “float” on the mantle and collide with each other.
They move due to the fact that the mantle is heterogeneous in composition. The process of the exchange of matter in different parts of the mantle occur at exactly the same speed. Due to the high viscosity of mantle material separate sections of the crust begin to “slide” with them. The result of this movement was the “continental drift”, numerous earthquakes and a large number of active volcanoes at the points of contact of the plates.
So far, the geologists didn’t know exactly how to construct the robe that it generates heterogeneity and have their counterparts in the deep regions of this layer of the Earth, given the fact that its matter is in a partially molten state.
Wu and his colleagues uncovered a very unexpected structure of the boundary layer between the lower and upper layers of the mantle, located at a depth of 660 kilometers, thanks to a happy coincidence.
Analyzing archival data, the researchers found that the aftershocks of a powerful earthquake that occurred in Bolivia in June 1994, was so powerful that they reached this boundary layer, reflected and have been recorded dozens seismographic stations.
In the past, scientists could not extract useful data from these records because to do this they simply did not have powerful enough computers. Wu and his colleagues solved this problem and got quite rough topography on this part of the mantle, having considered how the different projections and depressions on the border should influence the movement and reflection of seismic waves.
These calculations are based on a very simple principle – if the boundary between layers of the mantle were smooth, the seismic waves will be reflected from it at the same time and together will return to the Earth’s surface. If there are some irregularities, then of the vibrations is delayed, while others will return earlier than others.
To the surprise of the geologists, the boundary between the upper and lower mantle was not smooth or smooth, and very ragged and rough. Figuratively speaking, some regions were covered with a kind of “mountain peaks” of matter lower mantle, rose to a height of 1-3 km deep into the upper mantle. Similarly, the “gorges” of the matter of the upper layers is etched to the same depth in the lower part of this layer of the Earth.
This structure is the border between the two halves of the mantle, as noted by Wu, contrary to the two generally accepted theories, whose proponents believed that she must either be very clear or non-existent due to the fact that their breed should have been well mixed with each other.
Why this is so, scientists do not yet know, but the presence of such an unusual “terrain” in the lower layer of the mantle, according to them, it says that her breed is practically not mixed with the upper parts of the lithosphere and is preserved in its original form since the formation of the Earth.
Accordingly, their analysis and the creation of analogues in the laboratory will help geologists to understand what was “made” our world in the first moments of the Solar system.