Those of us who live in America are increasingly further away from those who live in Europe and Africa.
And we are not referring to a distance political or ideological. Literally, our continents are every day further apart.
Every year, the tectonic plates in those that are America on one side, and Europe and Africa on the other, move about four centimeters apart.
Scientists know that the plates move in opposite directions, and that in the areas bordering between them the densest parts sank and n .
The force that causes that separation, however, is a question that does not yet have a definitive answer.
Now, in a recent investigation, a group of seismologists believe they have a new piece to put together that puzzle.
The finding also provides new clues to better understand the seismic movements that can cause major disasters .
Some experts, although they recognize the importance of the finding, prefer to be cautious with the scope of the investigation.
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A mountain range in the ocean
At the bottom of the Atlantic Ocean stands the Mid-Atlantic Ridge, a extensive mountain range located equidistant between America on one side, and Eurasia and Africa of the other.
This mountain range spans more than 16, 000 km from southern Iceland to southern Africa.
The mountain range reaches up to more than 1. 500 km wide and its mountains can reach protrude above the surface of the ocean , forming islands such as Azores or Tristan da Cunha.
The Mid-Atlantic Ridge is a key area: it is the longest plate border on the planet And it is also a place where new plates are formed.
That is where the boundaries of the North American and South American plates meet, moving away from the Eurasian and African plates.
This separation makes the Atlantic Ocean ever wider, while the Pacific, due to the advance of America, is shrinking.
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A wedge between the plates
In this new study, researchers found that in this cordill It was there are areas where the material from the interior of the Earth rises towards the seabed.
Specifically, they are rocks that come from more than 600 km deep in the mantle , the area located between the core and the earth’s crust.
This phenomenon, according to the authors of the study, causes that material to act as a wedge that gets between the plates and causes them to separate further.
“This work disproves long-held assumptions that mid-ocean ridges could play a passive role in plate tectonics, ”Mike Kendall, a geophysicist at the University of Oxford and co-author, said in a statement. Of the investigation.
“(The study) suggests that in places like the Mid-Atlantic, the forces in the ridge play an important role in the separation of the newly formed plaques. ”
Unexpected signs
The data of this investigation were obtained through 39 seismographs that the researchers submerged on the ocean floor, in an area of the ridge located between South America and Africa.
for almost a year , the movements detected by these sensors allowed the scientists to notice the variations in the structure in the Earth’s mantle to 600 km deep.
Each type of wave that a seismograph records is associated with a different mineral , so with the signals that the researchers received, they could see that there were materials on the surface that came from the mantle.
“The Observed signals were indicative of a deep, slow and unexpected or emergence of the deeper mantle ”, say the authors.
“These results shed new light on our understanding of how the interior of the Earth is connected with plate tectonics”, says Matthew Agius, seismologist at the Università degli studi Roma Tre, and lead author of the study.
Caution
For the geologist Daniel Melnick, who did not participate in the investigation, “the novelty of the article is that it presents for the first time evidence of material transport from the lower mantle (600 km) in an oceanic ridge “.
This research may have implications in the” ent endurance of chemical processes and heat exchanges inside the Earth ”, tells BBC Mundo Melnick, a researcher at the Institute of Earth Sciences of the Austral University in Chile.
Melnick adds that material flow between the mantle and the crust had already been documented in subduction zones, where one plate sinks below another; and also in “hot spots” such as Hawaii and Iceland, but not in oceanic ridges.
Other experts, for their part, also celebrate the study results, but they are cautious in front of its scope.
“These findings add a piece to the puzzle to understand the flow in the mantle of the Earth ”, said to the portal Live Science Jeroen Ritsema, a professor in the Department of Earth Sciences at the University of Michigan, who was not involved in the study.
Ritsema says the authors did a “ excellent ”analysis, but with a limited scope .
The teacher refers to the fact that they observed only a small portion of the bottom of the Atlantic, so it is not clear if the phenomenon occurs along the entire ridge.
“It is difficult to infer the flow of rocks on a global scale in the Earth’s mantle from a single point of observation “, Ritsema told Live Sc ience . “It’s like looking through a keyhole and trying to find out what furniture is in the living room, kitchen and bedrooms.”
Better prepared
The findings of this research may be useful to better understand the movements of tectonic plates, and improve the alarm systems of earthquakes, tsunamis and volcanic eruptions , say the authors.
Tectonic plates also influence sea levels, so studying them allows us to better calculate the effects of change
For Kate Rychert, professor of geophysics at the University of Southampton and study coatura, their findings “have broad implications for the understanding of evolution and habitability of the Earth “.
” It also shows how crucial it is to collect data from the oceans, “says Rychert. “There is much more to explore! “ .
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