Gravity may feel constant and dependable, but scientists say it varies subtly across Earth’s surface, and one of the most unusual examples lies beneath Antarctica.
Researchers have identified a vast region of slightly weaker gravity under the icy continent, sometimes called the Antarctic “gravity hole,” which may be connected to how Antarctica became covered in massive ice sheets.
The findings come from a recent study published in Scientific Reports, where geophysicists traced the origin of this gravitational anomaly to slow movements of rock deep inside Earth over tens of millions of years.
The research suggests that changes in Earth’s interior may have influenced Antarctica’s climate history.
WHAT IS GRAVITY HOLE?
Gravity differences across the planet are caused by variations in the density of rocks beneath Earth’s surface. These differences are small, but they can affect oceans and landscapes in measurable ways.
In regions where gravity is weaker, ocean water is pulled slightly away toward areas with stronger gravity, lowering the sea surface relative to Earth’s center. Around Antarctica, scientists have observed that sea levels sit slightly lower than they otherwise would because of this gravity anomaly.
Researchers Alessandro Forte, a geophysics professor at the University of Florida, and Petar Gliovi of the Paris Institute of Earth Physics used earthquake data and advanced computer modelling to reconstruct the structure of Earth’s interior and map global gravity patterns.
By analysing how seismic waves travel through the planet, the team effectively created a three-dimensional image of the Earth’s internal structure, similar to a medical CT scan, but using earthquakes instead of X-rays.
Their models closely matched satellite-based gravity measurements, confirming the accuracy of their reconstruction. The scientists then simulated Earth’s geological past, tracking changes in deep rock movement over about 70 million years.
HOW GRAVITY HOLE SHAPES ANTARCTICA?
The simulations showed that the Antarctic gravity hole was once weaker but strengthened between roughly 50 million and 30 million years ago. This period coincides with major climate changes in Antarctica, including the formation of large ice sheets that now define the continent.
Scientists do not yet know whether the gravity changes directly influenced Antarctica’s freezing climate, but the overlap in timing suggests a possible connection between Earth’s interior processes, sea level patterns, and the development of polar ice sheets.
Researchers hope future studies combining gravity, climate, and geological modelling will help answer a fundamental question: how processes deep inside Earth may shape climate systems on the surface.
Understanding these links could improve predictions about ice-sheet stability and global sea-level change, making Antarctica’s mysterious gravity hole an important focus for future research.
