Is the Perito Moreno Glacier Growing?

No. The Perito Moreno Glacier is not growing. For decades it was famous for holding its position while the glaciers around it retreated, but a peer-reviewed study published in August 2025 found that this has changed. Near its front, the glacier’s surface lowered by 0.34 m a year between 2000 and 2019 and by 5.5 m a year between 2019 and 2024, and the glacier sped up and its front retreated (Koch and others, Communications Earth & Environment, 2025). The study does not say when, or whether, a larger retreat will come.

What the 2025 study found

The paper is “The state and fate of Glaciar Perito Moreno Patagonia”, by M. Koch and nine co-authors, among them P. Skvarca, published on 7 August 2025 (DOI 10.1038/s43247-025-02515-7). The team flew ground-penetrating radar over the glacier from a helicopter, surveyed the lake bed in front of it, and put together time series of the ice surface and its speed.

Its summary, in the authors’ words: the glacier “has long been considered stable despite widespread regional glacier retreat”, and its frontal position and surface elevation “remained relatively unchanged - until recently”. The measurements are the 0.34 m a year before 2019 and 5.5 m a year after it, “accompanied by glacier acceleration and retreat”.

Koch and others, Communications Earth & Environment 6, 572 (2025).

What it does not predict

The authors ran a simple model that carries the present rate of thinning forward. It shows the potential for a large, buoyancy-driven retreat once the front pulls back past a ridge in the rock under the ice. They are careful about time: rather than “making explicit predictions on a timescale”, they set out stages of retreat based on what they observed. So nobody can tell you from this study that the glacier will look different next summer, or in ten years.

The ice dam and the rupture

The Perito Moreno is famous for something else too. The APN’s leaflet for the walkways explains it: the glacier advances to the shore of the Península de Magallanes, cuts off the water of the Brazo Rico, forms a dam and raises the level of the Brazo Rico; the water then erodes the ice until the dam breaks. The APN calls the rupture periodic and “impossible to predict”.

The 2025 study adds figures: the glacier “has dammed the lake many times in the past”, and in its strong advances of 2003 to 2004 and 2011 to 2012 the dam raised the Brazo Rico by more than 9 m. From that position the front retreated only about 50 to 100 m until 2019. Neither source gives a date for the most recent rupture, and we give none.

The glacier in figures

The APN gives the Perito Moreno a length of about 30 km and a front of 4 to 5 km on Lago Argentino, and its leaflet puts the height of the front at about 70 m. Los Glaciares National Park, which holds it, has been on UNESCO’s World Heritage List since 1981.

What this means for a visit

The walkways face the same front, and nothing in the study or on the APN’s pages says a visit has changed. What you see on the day depends on the weather and on the ice. Nobody can promise you a falling block of ice, and the APN forbids crossing the handrails because falling ice throws splinters tens of metres. The Perito Moreno Glacier from El Calafate has the ways to get there, the hours and the trails.