Greenland’s glaciers are falling apart quicker than anyone expected, and it’s happening right beneath our feet. A groundbreaking 3D study has uncovered that cracks in the ice, called crevasses, are widening faster than previously thought. This isn’t just a scientific curiosity—it’s a major problem for global sea levels.

Crevasses are massive fractures in glaciers, some stretching over 300 feet wide and hundreds of feet deep. When meltwater from the surface seeps into these cracks, it reaches the glacier’s base, creating a hidden network of streams. This water isn’t just sitting around—it’s warming the ice from the inside and lubricating the glacier’s movement over bedrock. Both of these processes speed up ice loss, feeding into a vicious cycle of disintegration.

The study, led by glaciologists, found that between 50% and 90% of Greenland’s meltwater flows through these crevasses. And as the climate warms, the problem is only getting worse. Crevasses are spreading faster across the ice sheet, particularly between 2016 and 2021. Researchers used advanced 3D imaging to map these changes, revealing an unprecedented level of detail.

Here’s the kicker: as glaciers speed up due to warmer ocean temperatures, the ice at the surface moves faster than the base, creating even more cracks. It’s a feedback loop that’s hard to stop. Experts say this phenomenon isn’t fully accounted for in current climate models, meaning we might be underestimating how quickly Greenland’s ice could disappear.

The stakes are high. Greenland’s ice sheet loses about 9 billion tons of water every hour—yeah, every hour. If all of Greenland’s ice melted (which would take thousands of years), global sea levels could rise by a staggering 23 feet. Even a partial melt could add 3 feet to sea levels by 2100, threatening coastal communities worldwide.

This study is a wake-up call. It’s the first to map crevasses across Greenland’s entire ice sheet, giving scientists a clearer picture of how climate change is reshaping the planet. As the cracks deepen, so does our understanding of the risks we face. The message is clear: Greenland’s ice is in trouble, and so are we.

This story originally appeared on Inside Climate News.