A team of scientists say seawater flowing underneath and into gaps in the Thwaites Glacier in Antarctica is contributing to the melting of the massive ice formation — a potentially ominous sign of the coming effects of human-driven climate change from the world’s widest glacier.

These areas of the glacier may be undergoing “vigorous melting” from warm ocean water caused by climate change, which could lead to even more rapid sea-level rise around the globe.

“The worry is that we are underestimating the speed that the glacier is changing, which would be devastating for coastal communities around the world,” Christine Dow, a professor at the University of Waterloo in Canada and co-author of the study, said in a press release.

But researchers say more work is needed to fully understand what effects the warm water is having beneath the ice formation.