Published:
27 ene 2022 22:40 GMT
The invisible force moving and colliding the plates is not heat from our planet’s core, according to new calculations.
The convection currents generated by the hot core of the Earth are usually pointed out as being responsible for the movement of continents and tectonic plates, which form parts of the Earth’s crust, or lithosphere. However, many geophysicists have questioned the hypothesis that the effect of this heat and its variable distribution produced enough energy to move the outer layer of the planet.
A team of three researchers looked to the sky in search of an explanation for the phenomenon and presumed to have found it in the interaction of the gravitational forces of the Sun, the Moon and the Earth itself.
The key to his hypothesis, exposed on January 27 at the magazine GSA Special Papers (of the US Geological Society), is the so-called ‘center of gravity’, the focus of the masses in a system of orbiting bodies. It is unbalanced, according to the study, and the ‘fault’ is the lunar drift, the same one that causes the tides.
The elongation of the lunar orbit and a monthly radial excursion of the barycentre of approximately 1,000 kilometers are two linked phenomena and due to the gravitational pull of the sun on the moon, which has a value 2.2 times greater than the Earth’s on its own natural satellite. Temperatures in the upper layers of the planet are the result of radiogenic heat leakage from inside into space, but a combination of acceleration and inertia it has much more effect on movements in the lithosphere.
The imbalance generates tensions, which the “warm, thick and strong inner layers of the planet can withstand”, while “the thin, cold and brittle lithosphere responds by fracturing”, as explained by the study’s first author, Anne Hofmeister, a geophysicist at Washington University in St. Louis. Without the Moon and the oscillations that it causes between the barycenter and the physical center of the Earth, we would not see this activity of the plates that we observe.
In this sense, says Hofmeister and picks up a college statement, our Moon is “exceptionally large” and its size and specific distance from the Sun “are essential”.
To validate this idea, the researchers applied their calculations to several rocky planets in the Solar System and their moons, none of which have had confirmed tectonic activity to date.
The study shows that the presence and longevity of volcanism and tectonism depend on a particular combination of the size of the moon, its orbital orientation and proximity to the sun.
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