Gravity feels dependable and unchanging, something we rarely question. Yet the planet behaves in strange ways defies intuition.

In reality, gravity is not uniform across Earth’s surface. Its strength shifts from place to place, and once the effects of Earth’s rotation are taken into account, it reaches its lowest point beneath Antarctica.

New research shows that this so called Antarctic gravity hole developed because of extremely slow movements of rock deep within the planet over tens of millions of years. The study also found that changes in this gravity low occurred during the same broad window of time as major shifts in Antarctica’s climate. Scientists say future investigations may determine whether evolving gravity patterns played a role in the expansion of the massive ice sheets that define the continent today.

“If we can better understand how Earth’s interior shapes gravity and sea levels, we gain insight into factors that may matter for the growth and stability of large ice sheets,” said Alessandro Forte, Ph.D., a professor of geophysics at the University of Florida and co-author of the new study recreating the Antarctic gravity hole’s past.