MercoPress. South Atlantic News Agency

Considerable shrinking of Antarctic glacier reported

Seismic movements, possibly triggered by ice calving, created waves that reached the Hektoria glacier's fixed ice and fragmented it, the experts believe

Experts have expressed their concern after a study revealed that the Hektoria Glacier in eastern Antarctica retreated by 50% in just two months —between November and December 2022— losing 8.2 kilometers of ice. This rate of ice loss is nearly ten times faster than previously measured for land-based glaciers, setting a new record.

The findings, published in Nature Geoscience, highlight the potential for catastrophic sea-level rise if larger glaciers begin melting at this speed. “This is amazing; the rate of retreat is just incredible,” said Ted Scambos, a co-author of the study and principal research scientist at the University of Colorado Boulder.

Researchers initially stumbled upon the extreme ice loss while investigating the bay where Hektoria is located for other studies. Using satellite data and aerial surveys, they confirmed the rapid disintegration of the glacier, which they noted is located in one of the fastest-warming regions on the planet.

Naomi Ochwat, a researcher at the University of Colorado, recalled the scale of the collapse: “When we flew over Hektoria in early 2024, I couldn't believe the immensity of the area that had collapsed. Even though I had already seen the satellite images, seeing it in person surprised me.”

The discovery is significant because, unlike floating ice shelves, the Hektoria Glacier was resting on bedrock. When ice resting on land melts and flows into the sea, it directly contributes to rising sea levels. Experts calculate Hektoria lost approximately 800 meters of ice per day during the two-month period.

Researchers determined that the astonishing speed of retreat was influenced by a combination of factors related to global warming and local topography. Climate change warmed the ocean, causing the loss of adjacent sea ice and accelerating melting from below. The Hektoria Glacier was resting on a flat plain of bedrock below sea level near the coast. Glaciologists explained that on such flat terrain, small variations in conditions can cause a large surface area of the ice to suddenly float and become exposed to ocean forces.

The study suggests that seismic movements, possibly triggered by ice calving, created waves that reached the glacier's fixed ice and fragmented it. This allowed cracks to open from the bottom, joining with surface cracks and causing half of the glacier's surface to break off and collapse.

Glaciologist Etienne Berthier noted that this phenomenon shows that in periods of very rapid warming, polar ice masses can become unstable, leading to “extraordinary reductions” in ice resting on land.

“The retreat of Hektoria is shocking: this type of ultra-fast retreat would really change the predictions for other larger glaciers in Antarctica,” added Ochwat. Antarctica holds enough ice to raise global sea levels by about 58 meters.