The history of the Earth has more than 4.5 billion years and during this time the planet has undergone many visual changes. For centuries, scientists have been trying to explore the bowels of the Earth using all possible technologies. The leading theory suggests that our planet has a fast-flowing and well-mixed mantle, but this theory may now be revised, writes Popular Science.

In a new study, a team from Utrech University in the Netherlands examined a pair of sunken, continent-sized "

U Focus. Technologies has its own Telegram channel. Subscribe so as not to miss the latest and most exciting news from the world of science!

The scientists' study is based on the tones generated during large earthquakes, causing the Earth to vibrate like a giant bell.. Scientists are studying the planet's interior by analyzing the acoustic signatures of these vibrations. Experts can also then identify anomalies based on whether regions are out of tune or are fading in volume.

More than a quarter of a century ago, scientists have discovered that some of their deep earthly audibrations indicate the existence of dual underground " At that time, scientists were not sure whether these formations, located near the boundary of the mantle and core, were temporary or had existed for millions, or even billions of years..

According to the co -author of the study, seismologist Aroven Deuss, these two islands are actually surrounded by a cemetery of tectonic plates, which were moved to the bowels of the planet using subduction. Note that during this process, the tectonic plate shifts under another, forcing it to lower.

Two subcontinents, as well as any other areas that cause a slowdown in seismic waves, are known as large provinces with low seismic speed, or llsvp. Researchers note that one of the main reasons why acoustic deceleration occurs is the higher temperature of the LLSVP compared to the surrounding environment..

During a new study, scientists focused on the ability of LLSVP to “extinguish” seismic waves - forcing them to lose energy. The team also paid special attention to where the tones of seismic waves became upset, as well as on how loud or quiet they became during their trip to the bowels of the planet.

According to another co-author of the study, Sudajania Talavera-Soza, contrary to their expectations with colleagues, scientists discovered a small attenuation of LLSVP, which is why the tones sounded very loudly in these areas. At the same time, scientists discovered a great attenuation in the cemetery of tectonic plates - here the tones sounded extremely quiet.

The results obtained by scientists contrasted with the data obtained from the upper mantle of the Earth. This data looked as expected: the waves were attenuated due to higher temperatures. Scientists compare the difference to running in hot or cold weather: on hot days, runners tend to slow down, and on cool days, the opposite happens..

Further, scientists studied the mineral composition of LLSVP, including the individual sizes of grains. The results of the study indicate that grain size was " Note that plate tectonic graveyards consist of small grains formed after the crystallization of minerals during each downward movement of the formation deep into the planet.

Smaller grains mean a much larger amount of them, as well as a larger number of tiny gaps between them. Any acoustic waves passing through these formations lose energy as they pass through multiple grain boundaries, resulting in greater attenuation. But since the two LLSVPs had very little attenuation, their grain sizes must be much larger.

The study authors note that the larger grain size also indicates that these LLSVPs are likely much older than previously thought.. The team believes that they are at least 500 million years old, and, possibly, more than 1 billion. The results also indicate that these mineral grains are significantly stiffer, allowing them to withstand the flow of Earth's mantle known as mantle convection.

Interestingly, these discoveries contradict the descriptions of a very fluid and well-mixed mantle found in most textbooks..

Such a potentially large seismological revision goes far beyond the composition, age or movement of LLSVP. Scientists believe that understanding how these massive formations grow in size and interact with their environment helps to better shed light on Earth's planetary evolution. This is also important in terms of internal work and mountains.

Previously, Focus wrote that scientists showed the first supercontinent: it disappeared from the face of the Earth 2.8 billion years ago.