A University of Colorado Boulder–led study found that the Hektoria Glacier retreated about 8 kilometres and lost nearly half of its mass between November and December 2022, a rapid collapse researchers linked to the glacier’s grounding geometry and abrupt calving events. Using satellite imagery and seismic records, the team identified a configuration that allowed the glacier to float off its bedrock and break apart quickly, raising concerns that similar conditions elsewhere could accelerate future sea level rise.
The study combined remote sensing and seismological observations to reconstruct the sequence of events during the two-month collapse. Satellite data documented the large-scale retreat and revealed multiple grounding lines beneath Hektoria — the zones where ice transitions from resting on bedrock to floating — suggesting a complex bed geometry that permitted portions of the ice to go afloat. At the same time, seismic instruments registered a series of glacier earthquakes that coincided with episodes of rapid retreat and calving, providing independent evidence of sudden, large-scale iceberg detachment.
Researchers described the glacier’s ice plain resting on comparatively flat bedrock as a critical factor in the event. That flat-bed configuration made it possible for sections of the glacier to lift off rather than remain grounded, after which buoyant forces and mechanical weakness led to rapid calving and disintegration. The combination of multiple grounding lines and a large, flat ice plain, the study concluded, underpinned the unusually fast loss of ice observed in late 2022.
Scientists involved in the work warned that when similar bed and ice geometries exist elsewhere, they could produce comparably fast ice retreat with implications for global sea levels. Ted Scambos, senior research scientist at the University of Colorado Boulder, characterized the event in stark terms:
The researchers emphasized that the scale and speed of Hektoria’s collapse illustrate how local bed conditions can modulate the response of marine-terminating glaciers to environmental forcing.
The study’s use of seismic data alongside satellites highlights an expanding toolkit for monitoring ice-sheet dynamics. Glacier-generated seismicity, sometimes labeled glacier earthquakes, provides a near-continuous record of mechanical activity that satellites can corroborate with imagery of changing ice extent and grounding line position. In the Hektoria case, the concurrence of seismic and optical signals strengthened confidence in the timing and mechanisms of the rapid retreat.
In related Antarctic research, COLDEX investigators reported recovery of the oldest directly dated ice cores to date, extracting material about six million years old from the Allan Hills region of East Antarctica. Those cores were dated using argon isotope techniques, and researchers said they plan further drilling there. The recovery of such ancient ice offers potential new windows into Earth’s climate history and may inform understanding of how Antarctic ice has behaved under past warmer conditions.
Taken together, the two studies underscore a dual focus in polar science: documenting fast-changing contemporary ice dynamics and extending the paleoclimate record to better contextualize those changes. The CU Boulder–led team’s findings draw attention to the vulnerability of glaciers with particular bed geometries to rapid collapse, while the COLDEX drilling effort aims to expand the long-term record that can inform models of ice-sheet sensitivity.
Researchers involved in the Hektoria analysis and the COLDEX project indicated continued observation and additional field work are priorities. The Hektoria results point to the need for targeted monitoring of glaciers that share the same ice plain and grounding-line characteristics, and the COLDEX group has signaled plans to return to Allan Hills for more cores. Scientists warn that understanding where similar configurations exist and how they respond to changing climate and ocean conditions will be critical for anticipating future contributions to sea level rise.