After decades of relative stability, the famous Perito Moreno glacier in southern Argentina is retreating faster than previously thought, according to a study published on Thursday.
While the glacier in the Southern Patagonian Icefields only lost an average of 34 centimetres in thickness per year between 2000 and 2019, it shrank between 5.5 metres and 6.5 metres per year from 2019 to 2024, according to a study led by the University of Erlangen-Nuremberg's Moritz Koch.
In some areas, the world-famous glacier retreated by more than 800 metres over a five-year span to 2024.
The researchers surveyed the 30-kilometre-long glacier using a special radar system and mapped the lakebed beyond the glacier's terminus - its lowest end or edge - and combined these surveys with satellite data to analyse how its surface height and surface velocity changed between 2000 and 2024.
"There is a rocky ridge under the glacier tongue that acts like an anchor point," said lead author Koch. This has kept the glacier in equilibrium for a long time.
"Our data show that the glacier is currently breaking away from its anchor point," said Koch. The retreat of the glacier could then accelerate massively and the ice surface could shrink by 15 square kilometres within a few years.
Perito Moreno, a World Natural Heritage site by UNESCO, is about 250 square kilometres in area, more than the area covered by Buenos Aires. Unlike other glaciers in Patagonia, it has not retreated significantly for a long time.
