Almost twenty years ago, satellites circling the Earth picked up a strange gravity signal along the coast of Africa. This piqued the interest of experts. This strange disturbance, which stretched around 7,000 kilometers across the eastern Atlantic Ocean, continued for about two years, with the most activity happening in early 2007. Experts now think that a rare geological event deep inside the Earth caused it, and this event happened at the same time as a violent “jerk” in the Earth’s magnetic field.
A new study published in Geophysical Research Letters on August 28 says that both the gravity anomaly and the magnetic field shift seem to be connected to a mechanism that scientists didn’t know about before that happens deep below Earth’s mantle and changes the planet’s gravitational equilibrium for a short time.
GRACE Satellites Show a Change in the Deep Mantle
Researchers found the discovery by looking at old data from NASA’s and Germany’s Gravity Recovery and Climate Experiment (GRACE) satellites, which were in space from 2003 to 2015. These two satellites flew together around Earth and were meant to pick up tiny changes in gravity produced by moving ocean masses, melting ice sheets, or other big shifts on the planet’s surface.
But this signal was different from anything else that had been seen previously. It didn’t come from changes in the water or the atmosphere; it came from deep below Earth’s mantle. The data showed a substantial link between the timing of this gravitational anomaly and a geomagnetic jerk, which is when the magnetic field’s shape changes suddenly and temporarily.
Mioara Mandea, a co-author of the study and a geophysicist at France’s National Centre for Space Studies (CNES), said, “At first, I wasn’t sure if the signal was even real.” “But as more evidence came in, it became clear that we were seeing something very important happen deep inside the Earth.”
What Went On Deep Below the Surface?
Scientists think that magnesium silicate minerals in the lower mantle may have gone through a phase change under a lot of heat and pressure. This would have caused a large-scale redistribution of material. This change might have caused both the jerk in the magnetic field and the strange behavior of gravity, changing the way gravity and magnetism work in the area as seen from space.
The study’s results show that the Earth’s deep interior is still quite active and hard to anticipate. Researchers stress that these signals provide us a rare look at the hidden processes that shape our planet from the inside.
Mandea also said that to understand these kinds of complicated interactions, you need to use data from a variety of fields, such as gravity measurements, magnetic field research, and seismic investigations.
She said, “The processes inside the Earth are much more complicated than we used to think.” “Only by using a variety of observation methods can we start to understand the whole picture of what’s going on beneath our feet.”
Researchers are still looking at the data from the GRACE satellite. The discovery of this deep-Earth mantle activity could help us learn more about how changes in the planet’s core and mantle affect its magnetic field, gravity, and even the stability of its surface.