NASA’s GRACE Satellites Reveal Hidden Deep-Earth Process Behind Gravity Disturbance

Nearly twenty years ago, satellites orbiting Earth captured a mysterious gravity signal near the coast of Africa. This indicates a rare geological disturbance deep within the planet was happening. This specified signal stretched about 7,000 kilometres across the eastern Atlantic Ocean, although it lasted nearly two years, peaking in early 2007. Scientists mention that it is the result of coinciding with a sudden “jerk” in Earth's magnetic field. In addition, as detailed in Geophysical Research Letters on August 28, both events were linked to a previously unknown deep-Earth process which brings changes in the planet's gravitational balance.

GRACE Satellites Reveal Deep Mantle Shift Behind Earth's Mysterious Gravity Anomaly

According to study, researchers discovered the anomaly while reviewing archived data from NASA and Germany's Gravity Recovery and Climate Experiment (GRACE) satellites, which measured variations in Earth's gravity between 2003 and 2015. The signal matched the timing of a geomagnetic “jerk” — a sudden shift in the magnetic field's pattern — implying a rapid redistribution of mass near the planet's core. Study co-author Mioara Mandea from France's National Centre for Space Studies reportedly questioned the signal's validity before recognising its importance.

Twin satellites are part of this GRACE mission. This orbited Earth in tandem to identify subtle gravity changes. As a result of shifting ocean masses or melting ice sheets, these changes generally happen. However, scientists mention that this strange signal originated from deep within the mantle.

The findings suggest that under extreme pressure, transformation occurs in magnesium silicate minerals; a phase shift may have moved huge amounts of material deep below Earth's surface.

Researchers believe this deep mantle activity reshaped local gravitational and magnetic patterns. They say such evidence reveals how dynamic and unpredictable Earth's inner layers remain. Mandea noted that understanding these signals requires integrating different observation methods, emphasising that Earth's internal processes are far more complex than once imagined.