Mystery discovered near Earth's core thanks to data from gravity satellites

Scientists have discovered strange changes occurring near the boundary between the Earth's core and mantle while analyzing data from the US-German GRACE satellite pair, which operated from 2002 to 2017.

According to Nature, scientists have just discovered strange changes occurring near the boundary between the Earth's core and mantle, thanks to data from gravity measuring satellites.

The phenomenon occurred between 2006 and 2008, but was only recently discovered when the team analyzed data from the US-German GRACE satellite pair, which operated from 2002 to 2017.

These satellites fly in succession, measuring tiny changes in distance caused by gravity, often used to monitor groundwater or melting ice.

This time, the data revealed a strange signal at a depth of nearly 2,900km, off the coast of Africa, which could not be explained by water displacement on the surface.

“At least part of the cause must come from inside the solid Earth, from very deep,” said Dr. Isabelle Panet, Gustave Eiffel University (Paris).

It is hypothesized that perovskite minerals in rocks near the bottom of the mantle changed structure under enormous pressure, causing the rocks to become denser, increasing their mass and causing gravitational disturbances.

Adjacent rocks may have shifted slightly, distorting the core-mantle boundary by about 10 cm. This shift could have affected the flow in the liquid outer core, as evidenced by magnetic anomalies recorded at the same time in 2007.

“This is a completely new observation,” Ms. Panet emphasized.

The research results were published in Geophysical Research Letters.

“For the first time, we have compelling evidence of dynamic processes at the base of the mantle occurring rapidly enough to be studied as they occur,” said seismologist Barbara Romanowicz of the University of California, Berkeley.

The team has not detected any other major gravity signals beyond the 2007 event, but plans to continue monitoring data from the next generation of GRACE satellites to determine whether there are other mysterious changes taking place deep inside the Earth./.

(TTXVN/Vietnam+)

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