In Greenland, the largest ice mass in the northern hemisphere, the glacial retreat is advancing at a speed that worries the scientific community. Recent observations show an accelerated change that cannot be explained solely by atmospheric warming.
A new international study points to a silent and deep actor: enormous internal waves formed after iceberg calving. These waves remain hidden beneath the surface, moving between layers of water with different densities.
Unlike visible waves, these last much longer and transport energy to the seabed. This persistent movement could be accelerating the ice melt with greater intensity than previously estimated.
The discovery opens an unprecedented window to understand how the ocean and ice interact in Greenland’s fjords. The phenomenon reveals that underwater dynamics play a decisive role in glacial erosion. And it confirms that the surface tells only part of the story.
Fiber optic technology to reveal the hidden movement of the sea
An international team installed a ten-kilometer fiber optic cable in front of a glacier in southern Greenland. Using a technique that measures vibrations in real-time, different types of waves generated by ice calving were identified.
The system allowed recording invisible signals through traditional methods. Each iceberg calving activated a combination of movements: fractures, surface waves, and, above all, internal waves.
These waves reach heights comparable to buildings and continue their movement long after the sea returns to calm. The repeated behavior creates a constant turbulence capable of altering the water temperature.
The collected information shows that the mixing generated in depth is not an isolated event. Internal waves transport warmer water from the bottom to the glacier’s base. This contact accelerates erosion, weakens the ice walls, and promotes future calving.
The multiplier effect of underwater ice melt
The analyzed glacier releases each year a volume of ice much greater than other known alpine systems. This constant loss has direct repercussions on the Greenland ice sheet. And it is part of a process that significantly contributes to the global rise in sea level.
The presence of internal waves acts as an amplifier of the phenomenon. Each calving not only generates new icebergs but also reactivates ocean mixing in depth. The ice melt then becomes a cycle reinforced by its own dynamics.
The study suggests that, until now, the role of underwater forces in the loss of glacial mass has been underestimated. Satellite measurements and surface records did not capture the magnitude of what happens underwater. The new technology allows observing a hidden dimension of climate change in polar regions.
Climatic and environmental consequences of the phenomenon
The acceleration of ice melt in Greenland has global implications. If the entire ice sheet were to melt, sea levels would rise several meters worldwide. This would endanger coastal populations and transform entire ecosystems.
The massive influx of fresh water can also alter essential ocean currents. Among them, the one that regulates much of the climate in the North Atlantic. A modification in this system would affect everything from rainfall patterns to regional temperatures.
Greenland’s fjords are already showing signs of ecological imbalance. Variations in water temperature modify marine life and nutrient availability. The Arctic ecosystems respond quickly to any change, and their fragility makes them especially vulnerable.
