The Arctic is undergoing dramatic changes as global temperatures rise. Scientists have long tracked the shrinking and thinning of sea ice, but a new study reveals another surprising shift - the ice is getting smoother. The rough, ridged terrain that once defined Arctic sea ice is being replaced by flatter, more uniform surfaces.
This change is happening because the Arctic’s older, thicker ice is disappearing. Traditionally, pressure ridges formed when large ice sheets collided and buckled, creating towering structures above and below the water. These ridges played an important role in the Arctic ecosystem, providing shelter for marine life and affecting how ice moves and melts. But as the Arctic transitions to a system dominated by younger, thinner ice, these ridges are forming less frequently, leaving behind a smoother seascape.
Why Is Arctic Ice Becoming Smoother?
Sea ice is constantly shifting due to wind and ocean currents. When pieces of ice push against each other, they sometimes crack and pile up into ridges, similar to how mountains form when tectonic plates collide. These ice ridges are important because they slow down ice movement, help regulate the ocean’s heat balance, and create habitats for marine organisms.
Over the last 30 years, Arctic sea ice has not only become thinner but also more mobile. Scientists initially debated whether this would lead to more ridges forming as ice deformed more easily or fewer ridges as thinner ice struggled to build up large formations. Using decades of aerial surveys, the study confirms that the second scenario is occurring - ice ridges are becoming smaller, less frequent, and spaced farther apart. The loss of older ice means there is simply not enough time for ridges to build up before they melt.
What This Means for the Arctic Ecosystem
While smoother ice may sound like a minor change, it has major consequences. The rough surfaces of pressure ridges trap snow in winter, which later melts into ponds that accelerate ice loss in summer. With fewer ridges, the way Arctic ice melts and refreezes is changing. This could speed up ice retreat and contribute to even more rapid warming in the region.
The loss of ridges also affects marine life. The underwater portions of these ice formations, called keels, create a complex environment where small organisms thrive. These areas act as a refuge for tiny creatures like algae, which serve as the base of the Arctic food chain. Without ridges, many of these organisms may struggle to survive, disrupting the entire ecosystem, from small crustaceans to fish and larger animals like seals and polar bears.
Shipping and industrial activities could benefit from smoother ice, as fewer obstacles mean easier navigation. However, this also raises concerns about increased human activity in previously inaccessible areas, which could further disrupt the fragile Arctic environment.
The Future of Arctic Ice
The shift to smoother ice is part of a broader transformation in the Arctic. Scientists predict that the region will experience more seasonal ice, meaning ice that forms in the winter and melts in the summer, rather than the multi-year ice that used to dominate. This change could make Arctic ice even more dynamic, with larger areas breaking apart and drifting unpredictably.
Researchers are still working to understand all the implications of these changes. Future studies will focus on how smoother ice affects ocean circulation, ice melt rates, and the ability of marine life to adapt.
One thing is clear: the Arctic is changing faster than ever, and the loss of rough, ridged ice is yet another sign of how climate change is reshaping the planet. Understanding these shifts is crucial to predicting what the Arctic will look like in the coming decades - and what that means for the rest of the world.
