Researchers say it is unprecedented to witness such a shift in glacier ice flow in under 18 years
Scientists say one Antarctic glacier is “stealing” ice from another in a rare phenomenon they are calling “ice piracy.”
A study by researchers at the University of Leeds found that while seven glaciers in West Antarctica have increased their speed of ice flow since 2005, the Kohler West Glacier has slowed by 10%, while the adjacent Kohler East Glacier has accelerated.
Heather Selley, a Leeds PhD researcher and lead author of the study, said satellite data show that ice flow from Kohler West is being diverted into Kohler East.
"This is due to the large change in Kohler West's surface slope, likely caused by the vastly different thinning rates on its neighboring glaciers. Because Kohler East's ice stream is flowing and thinning faster as it travels, it absorbs, or 'steals' ice from Kohler West."
"We think that the observed slowdown on Kohler West Glacier is due to the redirection of ice flow towards its neighbor — Kohler East," she explained in a press release.
Researchers at the University of Leeds say it is unprecedented to directly observe one Antarctic glacier diverting ice from a neighboring glacier to this degree in less than 18 years, marking a key step in understanding Antarctica's potential contribution to future sea level rise.
- Climate change a key factor
Scientific Director of the TerrArctic Mega Grand Project Orhan Ince, who is also an environmental engineering professor at Istanbul Technical University, told Anadolu that the findings show how glacier dynamics — once thought to change slowly over thousands of years — can shift rapidly.
He credited satellite technology such as the European Space Agency's CryoSat with enabling researchers to monitor ice thickness and flow changes in near real-time.
“These satellites allow us to analyze changes in glacier surface slope and flow direction with high precision,” Ince said.
He added that climate change is a driving force behind the observed changes. “The acceleration of glaciers and the thinning of ice masses contribute directly to rising sea levels,” he said. “The difference in movement between Kohler East and West points to the connection between ocean warming and glacier melt.”
According to the EU's Copernicus Climate Change Service, the global average sea level has risen by 10.3 centimeters in the past 30 years. The annual rate of rise increased from 2.1 millimeters between 1993 and 2003 to 4.3 millimeters between 2013 and 2023. Around 30% of that rise is due to ocean warming, while most of the rest comes from melting glaciers and ice sheets.
- Grounding line changes and policy implications
Ince said shifts at the grounding line — the point where glaciers begin to float — are playing a key role in the changing flow speeds. He also pointed to the effects of permafrost melt and surface slope changes.
“The ice piracy seen in Antarctica shows that glacier movement linked to climate change is happening faster than previously thought,” he said. “These findings are critical for improving global sea-level rise projections.”
He said further polar research is essential to understanding and responding to these changes.
“An interdisciplinary approach is needed,” Ince said. “We must expand scientific monitoring, update climate models, reduce carbon emissions and increase investment in polar research.”
