Scientists have detected deep within the Earth a quantum phase transition that is pressing on plate tectonics and increasing the frequency of earthquakes and volcanic eruptions on our planet.
Scientists have detected a quantum phase transition more than 1,000 kilometers deep within the Earth's mantle that they assume is related to the increase in earthquakes and volcanic eruptions on the planet.
More specifically, they have detected the unique seismological signature of an electron spin crossover deep within the Earth, as reported in a statement.
Electrons are negatively charged particles that surround the nuclei of atoms and whose behavior governs chemical interactions.
One of the most prominent behaviors that affect the electron clouds that control natural chemistry is the dance of these particles, which occurs spontaneously within some materials.
Electron dance
Electrons can be of two different types, depending on the dynamics of their respective spin or angular momentum: some electrons have upward spin and the other downward.
Both electrons tend to pair up, forming a kind of dance pairs that dance inside the materials that host them, forming unmistakable clouds.
The evolution of these dynamics of the electrons depends on certain circumstances, such as the pressure to which they are subjected, which sometimes causes the dance floor to transform.
This leads the electrons to change gait and dance to another piece, which also causes a kind of pair swapping that is known in physics as "spin crossover" (more specifically, electron spin pairing crossover).
In the lower mantle of the earth
These processes are well known to physicists, who take advantage of them for such everyday things as magnetic recordings.
It has also been known for more than 20 years that such electron dynamics occurs in an iron-rich mineral called ferropericlase (Fp), which is the second most abundant component of the Earth's lower mantle.
The authors of the new research, led by the physicist at Columbia University in the United States, Renata Wentzcovitch, long assumed that this quantum phase transition should also occur in the lower mantle of the Earth, in an area that has a thousand kilometers wide.
And that is what they have now verified, as they show in an article published in the journal Nature Communications: they have identified unmistakable signals of spin cross signals inside the ferropericlase, at a depth between 1,400 and 2,000 kilometers per below the earth's surface.
Earthquakes and volcanic eruptions
Researchers have verified that the spin crossing in this iron ore, located deep within the planet, may be accelerating the movement of tectonic plates, helping to better understand the geological processes that occur below 600 kilometers of depth.
The lower mantle begins at a depth of 660 kilometers and reaches 2,900 kilometers: everything that happens down there we can only know from seismic tomographic images, which sometimes reflect quantum phase transitions.
The authors of this research consider that they have been able to determine one of the keys to the increases that occur in the frequency of seismic events such as earthquakes or volcanic eruptions.
The results of this work are allowing the development of more precise techniques to predict important geological phenomena that may occur in iron-rich regions of the Earth's lower mantle, where temperatures are approaching the melting point.
The authors also note that the techniques developed at work can be applied to materials such as multiferroic and ferroelectrics, where electrons are strongly correlated, as well as materials at high temperatures and pressures generally stands to respect the magazine Physics World .
Reference:
Seismological expression of the iron spin crossover in ferro periclase in the Earth's lower mantle. Grace E. Shephard et al. Nature Communications volume 12, Article number: 5905 (2021). DOI: https: //doi.org/10.1038/s41467-021-26115-z