“The Antarctic ice sheet holds 90% of the world’s glacier ice. If it were to melt completely and drain into the ocean, sea levels would rise by about 60 meters,” says Professor Shin Sugiyama of Hokkaido University. In a new study, his team has directly confirmed for the first time that water from melting snow and ice, or meltwater, found at the surface of a glacier can drain down to its base, causing the glaciers in Antarctica to speed up and move towards the ocean.
Drilling boreholes deep into the glacier
In the study, published in Nature Communications, the researchers drilled boreholes more than 550 metres deep into the Langhovde Glacier in East Antarctica. Then, they lowered pressure sensors and cameras to the glacier bed, and captured what satellites could not. “Using a hot-water jet, we could carefully and rapidly drill into the glacier and measure the water pressure right at its base,” explains Sugiyama.
They found that meltwater collecting in lakes and ponds on the glacier’s surface drained down through fractures to its base. This happens through a process called hydrofracturing, in which the sheer weight of surface meltwater—formed naturally by heat exposure—splits the ice underneath it, creating pathways for the water to flow through the glacier.
This drainage raises the water pressure beneath the glacier and partially lifts it off the bedrock that normally bears its weight. The pressurized meltwater lubricates the ice-bed boundary, reduces friction, and accelerates the glacier’s sliding toward the ocean.
“During a spell of intense surface melting, and again after a rare rainfall event in January 2022, meltwater increased the water pressure at the glacier’s base until it was supporting 97% of the weight of the ice above,” says Professor Sugiyama. “The glacier rose slightly and, with less friction to hold it back, its sliding across the bed accelerated by 10–20%.”
This process is well documented in glaciers of Europe, Alaska, and Greenland but whether it happens in Antarctica has long been debated and never before directly confirmed.
“This is the first observation of such kind in Antarctica,” says Sugiyama.
Living underneath the glacier
The boreholes also opened an unexpected window onto life beneath the ice. Cameras captured a sea anemone and a few delicately stalked sponges clinging to a boulder in a seawater layer just three metres thick, sealed beneath 474 metres of ice. This was about several hundred meters beyond the point where the glacier loses contact with the seabed.
“It was very surprising to spot colourful creatures going about their lives in such a cold, dark, and confined environment, revealing a hidden ecosystem under the ice,” says Sugiyama.
The implications extend well beyond a single glacier in Antarctica. “Currently, the ice sheet is losing mass overall because the amount of ice discharged into the ocean exceeds snow accumulation inland. Our study suggests that ice loss will increase as meltwater rises in a warming climate, carrying more and more ice into the ocean. This is especially urgent and relevant for people and societies living in low-elevation areas,” concludes Sugiyama.
Nature Communications
Experimental study
Not applicable
Acceleration of an Antarctic outlet glacier driven by surface meltwater input to the base
6-May-2026