Environment

Ice 'theft' between neighbouring glaciers in Antarctica. The discovery thanks to Copernicus

The research is partly funded by the Science for Society section of Esa's FutureEO programme and the results have been published in Cryosphere

by Davide Madeddu

10 May 2025

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3' min read

Key points

The Kholer East Glacier and the "ice theft"
Ice speed observation
Ice Piracy
Enea climatologist
Data not to be underestimated

3' min read

Esa researchers, thanks to Copernicus Sentinel-1, have discovered that a glacier in Antarctica is rapidly stealing ice from nearby streams, 'at a rate never seen before'. Almost a 'theft' if it were not a natural occurrence, but considered extraordinary, especially in light of ongoing climate change.

'Until now, researchers believed that this process in Antarctica took hundreds or even thousands of years,' writes the European space agency Esa in a note, 'but these latest findings clearly show that this is not always the case'.

The Kholer East Glacier and the "ice theft"

The research, funded in part by the Science for Society section of Esa's FutureEO programme, was published in The Cryosphere and explains that 'the fast-flowing Kohler East glacier in West Antarctica is taking ice from a slower-flowing neighbour'.

As part of this research, a team of scientists, led by the University of Leeds in the UK, examined high-resolution images from satellites such as Sentinel-1, together with other satellite data covering the period from 2005 to 2022, to understand the flow velocity of eight ice streams in the Pope-Smith-Kohler region.

The Kohler glacier, Esa reconstructs, as well as the Pope and Smith glaciers, are among the most rapidly changing glaciers in West Antarctica, with some shifting and thinning more rapidly than others. These glaciers are located upstream of the Dotson and Crosson ice shelves.

Under observation of ice speed

The researchers calculated the speed of the ice using a tracking technique that measures the displacement of visible features, such as crevasses or cracks, on or near the ice surface. The researchers found that, on average, glaciers in the Pope-Smith-Kohler region have accelerated by 51% since 2005. Four glaciers have accelerated between 60% and 87% over the course of 17 years, and six of the streams reached average velocities of more than 700 m in 2022 alone.

The fastest were the Kohler East and Smith West Glaciers, where the ice velocity increased by an average of 32 m per year during the study period.

The Piracy of Ice

For researcher Heather Selley of the University of Leeds, "this is actually an act of 'ice piracy', in which ice flow is being redirected from one glacier to another, and the accelerating glacier is essentially stealing ice from its slowing neighbour. Amazingly, thanks to satellite data, we can see that this is happening in less than 18 years, whereas we always thought it was an extremely long and slow process'. The results, as Esa point out, 'show that there is considerable acceleration in this region of Antarctica, which has the highest recorded rates of landline thinning and retreat'.

Enea's climatologist

For Gianmaria Sannino, ENEA climatologist, "the phenomenon of 'glacial piracy' represents much more than just a scientific curiosity". "It is a fundamental key to understanding the intrinsic instability of Antarctic ice systems in the era of global warming," he argues. "West Antarctica, already identified as an area particularly vulnerable to climate change, shows interactions between adjacent ice flows that reveal complex dynamics, which are essential to incorporate into predictive models of sea-level rise.

Data not to be underestimated

And, according to the expert, the results of this experiment cannot be underestimated. "The direct observation of these rapid glacial reorganisations in such a compressed timeframe (just 18 years) is unprecedented in the history of modern glaciology," Sannino continues. "This accelerated time window forces us to revise our understanding of the reactivity of the polar ice caps. Constant monitoring of these remote regions with state-of-the-art technologies therefore becomes imperative, not only for pure science, but to refine the climate models that drive global policies'. Hence an invitation and a suggestion: 'The data collected unequivocally suggest that the ongoing processes of glacial degradation may be significantly faster and more interconnected than previously estimated, with profound implications for coastal communities across the planet.