Eight kilometers in just 2 months: a melt in Antarctica surprises scientists
Satellite images confirm that a glacier disintegrates by almost half in a few weeks
BarcelonaThe rate of Antarctic ice melt continues to surprise scientists. In an article published this Monday in Nature GeoscienceResearchers at the University of Colorado Boulder (United States) have found that in 2023 the Hektoria Glacier, located on the eastern coast of the Graham Peninsula—one of the fastest-warming areas of the Antarctic continent—receded at least 8 kilometers in just two months. Although this ice mass already experienced very rapid ice loss in the 2000s, the rate recorded by this team is the fastest in modern history. The acceleration of the melting was ten times more powerful than previous measurements, to the point that almost half of the glacier disintegrated in just a few weeks.
Glaciers rooted in the ground (non-floating) in polar regions generally do not They retreat more than a few hundred meters per yearbut its loss of ice also contributes significantly to sea level riseHektoria is considered a small glacier by Antarctic standards, covering only about 300 square kilometers, roughly the size of Montseny Natural Park. However, the speed at which it has melted has alarmed researchers, who believe that studying its behavior could help anticipate future collapses of other Antarctic glaciers. And, in a statement, they issue a warning: a collapse of this magnitude in larger masses could have catastrophic effects on global sea level rise.
“When we flew over Hektoria in early 2024, I couldn’t believe the sheer size of the area that had collapsed,” explains Naomi Ochwat, lead author of the study and a researcher at the Cooperative Institute for Research in Environmental Sciences (CIRES) in Colorado. Her team discovered the collapse almost by chance while studying another area affected by an ice shelf breakup via satellite. Upon reviewing the data, the researchers observed that the glacier had practically disappeared in just eight weeks. “The satellite images already showed the change, but seeing it live was breathtaking,” Ochwat says.
A warning for other glaciers
But what happened to Hektoria? According to researchers in Colorado, the main factor behind this accelerated ice loss is the surface on which the glacier rested. Not all ice formations float; some rest on land or the seabed. In Hektoria's case, its surface was a plain of ice and rock located below sea level. With the loss of ice, it detached from the seabed and began to float partially on the water. To put it simply, the ice went from a stable to an unstable location and became more vulnerable to the forces of the ocean. In fact, the water opened cracks from the base, which eventually met those opening from the surface, causing the glacier to completely fracture. Think of a building: if it suddenly loses its foundation, there is a total and catastrophic collapse. And that's what happened to this glacier: the calving was abrupt and massive because it suddenly lost its structural support. To document this behavior, scientists combined images from different satellites and seismic data, achieving a detailed reconstruction of the process. "If we only had one image every three months, we couldn't say that the glacier lost two and a half kilometers in two days. With several satellites, we were able to accurately confirm the speed of the collapse," explains Ochwat. Indeed, seismographs recorded a series of glacial earthquakes coinciding with the retreat period, demonstrating that the glacier was still resting on solid rock, and that its ice loss directly contributed to sea level rise. "The retreat of Hektoria is a warning," says Ted Scambos, also a CIRES researcher. He warns: "Such a rapid collapse completely changes what we thought was possible for other, much larger glaciers. If the same conditions are repeated, sea levels could rise much faster than we predict."
