Even apparently stable glaciers in Antarctica are at risk of losing large quantities of ice due to warming seas. The warning comes after satellite data showed the Cadman glacier – previously stable for 50 years - retreated by 8 km between November 2018 and May 2021.

The Nature Communications study, led by researchers of the University of Leeds, was among the first to use data from CryoSat’s new Cryo-TEMPO land ice thematic product. CryoSat, ESA’s ice mission, is an Earth Explorer dedicated to monitoring global ice elevation.

The Cryo-TEMPO data, based on CryoSat’s unbroken 13+ year record of land ice, were used to compute the thinning of the Cadman glacier’s ice shelf between 2010 and 2019.

Surrounded by warmer waters, the ice shelf thinned and became ungrounded from the sea floor, meaning it could no longer slow the glacier’s advance.

A doubling of the glacier’s speed increased the amount of ice discharged into the sea as icebergs through a process known as iceberg calving.

The Cadman glacier is now in a state of “substantial dynamic imbalance”, and ice loss from the glacier continues at a rate of around 2.16 billion tonnes of ice -or 20 m of surface elevation- each year.

“This is one of many studies that can benefit from Cryo-TEMPO’s exceptional record of our changing cryosphere,” said Cryo-TEMPO project leader Mal McMillan of Lancaster Environment Centre and the Centre of Excellence in Environmental Data Science (CEEDS). 

“The Antarctic Peninsula has many hundreds of these small and highly dynamic glaciers, which are notoriously hard to monitor. This analysis reinforces the importance of developing new, high resolution satellite observations of ice sheet change, and of investing in long-term satellite programmes, such as Copernicus and its future CRISTAL mission, for monitoring future ice loss.”

Cryo-TEMPO thematic products provide an unbroken, 13+ year record of sea ice, land ice, polar oceans, coastal oceans, and inland waters. The products -which make CryoSat’s unique data record more accessible and user-friendly- launched in 2022, and have since been boosted with extended processing and regional coverage.

The Cryo-TEMPO land ice product used in the recent study covers the grounded and floating parts of the ice sheets blanketing Greenland and Antarctica, with quality-controlled measurements of ice sheet surface elevation.

All-in-all, nine satellites were used to monitor the Cadman glacier’s retreat, including ESA’s CryoSat and Europe’s Copernicus Sentinel-1. NASA’s ICESat-2, part of the groundbreaking CRYO2ICE collaboration with CryoSat to measure snow on ice, also provided data.

“Our study brought together data from three decades, nine different satellite missions, and in-situ oceanographic measurements to understand the changes happening in Antarctica,” said lead author Benjamin Wallis from the University of Leeds. “This demonstrates how important it is to have long-term monitoring of the Earth’s polar regions with a range of sensors which all tell us a different piece of the story.” 

Cryo-TEMPO is developed by a consortium led by the UK Centre for Polar Observation & Modelling (CPOM), and the Lancaster University-UKCEH Centre of Excellence in Environmental Data Science (CEEDS).