Apparently, the Earth’s interior has sprung a leak, with matter erupting from it. A group of researchers from Japan and China, working in the US at Rutgers University, have put forward a very unusual and even alarming hypothesis. Nevertheless, this hypothesis elegantly and simply explains the unusual phenomena detected on Earth. The results of their research were published in the journal Nature. In school problems, students routinely use the standard value for the acceleration due to gravity ($9.83 \text{ m/s}^2$), which characterizes Earth’s gravity—the force of attraction. In reality, the magnitude of this force varies from the poles (where it is higher) to the equator, and more importantly, our planet exhibits significant gravitational anomalies. Some of these have a clear origin, while others remain a mystery. Photo: Aree_S/Shutterstock/Fotodom. One of the latter is a colossal anomaly located beneath South America, the Atlantic Ocean, and South Africa. Gravity is noticeably weakened in this zone. Perhaps one can jump higher there and fly away? Unlikely to that extent, but measuring instruments record this decrease. Remarkably, this gravitational oddity coincides with the known weakening of the Earth’s magnetic field. That is, a defect in the magnetic field is added to the lack of gravitational pull. In these regions, the magnetic field is significantly weaker, and its field lines are oriented incorrectly. Artificial Earth satellites try to avoid this zone: while the magnetic shield usually extends for 600 km, protecting equipment from radiation, in this area open space begins at an altitude of just 200 km. Therefore, flying in this region is unsafe. On the surface, everything still looks relatively normal; no obvious increase in radiation has been recorded. However, a recent study showed that this magnetic “hole” is actively expanding. A serious question arises: does this threaten the inhabitants of South America, and subsequently all of humanity, with inevitable exposure to radiation flows? Geophysicists have long concluded that two massive accumulations of matter deep beneath the surface correlate with these anomalies. These formations look like fragments of the Earth’s core that have migrated upward into the mantle for some reason. It was previously assumed that we are seeing relics of the celestial body that collided with the Earth in time immemorial, giving rise to the Moon. Or perhaps they are very old tectonic blocks that sank deep. Or maybe… “These are not chaotic deviations,” one of the co-authors of the new work, geodynamicist Yoshinori Miyazaki, explained to reporters. “These are traces of the greatest antiquity of the Earth. If we understand the reason for their formation, we can comprehend how our planet formed and why it became habitable.” The new study appears to have definitively settled the matter: the Earth’s core has simply “thinned.” There has been a material leak from it. This is precisely what formed the two deep clusters that caused the gravitational and magnetic anomalies. The positive aspect is that the core, consisting mainly of iron, did not thin out now. The damage likely occurred in the very early stages of Earth’s history. Let’s trace this process. Scientists believe that at the dawn of its existence, the Earth was a molten ocean of magma. Over time, heavier components sank to the center, lighter ones rose, and the surface cooled. Thus, we have an iron core, a viscous mantle, and a relatively thin crust on which civilization managed to develop. Inside, the planet remains molten. Photo: Rost9/Shutterstock/Fotodom. This view is logical, but the “magma ocean” model does not quite match reality. If it were so, the internal structure of the Earth would resemble a perfectly ordered layer cake. In reality, this metaphor is only partially correct. “We decided to proceed from this discrepancy,” says Yoshinori Miyazaki. It turned out that researchers previously overlooked a simple fact: different minerals crystallize and melt at different temperature regimes. This circumstance introduced an element of disorder into the planet formation process. In particular, magnesium oxide and silicon dioxide, mixed with iron, solidified much faster than pure iron. Separating from the iron and moving upward, these substances “breached” the core, which by that time had already acquired its main outlines. Surprisingly, these “breaches” have survived for billions of years, despite the extreme temperatures and monstrous pressure at the planet’s center, and are still functioning today. The authors of the work themselves are delighted: they managed to look billions of years into the past, understand the mechanism of the Earth’s formation, and the scientific community has duly appreciated the work done. But questions remain: if the magnetic anomaly is growing, is the corresponding hole in the core expanding? What are the rates of this growth? Are we facing an eruption of colossal force, against which our current volcanoes will seem insignificant? Perhaps there are no answers to these key questions yet.
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