There is another major source of melting ice that could accelerate sea level rise.

Scientists say a large glacier in northwestern Greenland is interacting with ocean tides, leading to previously unknown melting and the potential for a faster rise in sea levels.

The group of glaciologists from the University of California Irvine (UCI) and NASA’s Jet Propulsion Laboratory published the study in the journal. Proceedings of the National Academy of Sciences.

Observations of the Petermann Glacier revealed that the glacier’s landline—the area where the ice sheet begins to extend into the ocean—can change dramatically as the tides rise each day.

According to Enrico Ciracì, lead author of the study and a UCI scientist, the Petermann ground line “moves between 2 and 6 kilometers as the tide rises and falls”.

This is an important finding: the traditional view among scientists has been that the Earth’s line does not move with the tides – this presents another major source of melt that could accelerate sea level rise.

Between 2016 and 2022, warmer tidal cycles melted an eight-foot hole in the bottom of the glacier along the fill line—large enough that two Statues of Liberty could be stacked on top of each other inside you.

This phenomenon could get worse in the coming years and decades, as the oceans warm. CNN recently reported that sea surface temperatures reached their highest levels on record this spring — a rise that has scientists, who fear it may be part of a worrying new trend.

The study raises further concerns about the already alarming prospect of sea level rise, which threatens coastal regions around the world. According to NASA, the melting of Greenland’s ice cap is the largest contributor to sea level rise, which has accelerated in recent years. But current projections do not account for this new interaction between warming ice and tides.

“These ocean-ice interactions make glaciers more sensitive to ocean warming,” says co-author Eric Rignot, UCI professor and NASA JPL researcher. “These dynamics were not built into the models, and if we did include them, it would increase sea level rise projections by up to 200% – not just for Petermann, but for all glaciers that end in the ocean, i.e. most of northern Greenland and all of Antarctica.”