Tourist hotspot Perito Moreno glacier retreats at record speed

A popular tourist glacier in Patagonia, South America is losing mass at the fastest rate and for the most prolonged period in nearly half a century, experts say.

Once considered relatively stable compared to other glaciers, and an attraction for nearly 700,000 visitors annually, the Perito Moreno in Los Glaciares National Park in southwest Santa Cruz Province, Argentina, is now said to be experiencing unusually big ice losses, shrinking by an average of 0.85 metres per year.

In footage filmed from one of Lake Argentina’s viewing platforms and shared on social media site TikTok on 1 May 2025, a vast mountain of ice collapses from the glacier into the country’s largest freshwater lake, overturning and churning up violent, mineral blue waters.

Ice loss outpacing rebound

“Ice calving events of this size haven’t been very common at the Perito Moreno glacier over the past 20 years,” Pablo Quinteros, an official park guide told Reuters in spring 2025, noting that it “It’s only in the last four to six years that we’ve started to see icebergs this big.”

Glaciologist Lucas Ruiz, who works for the public agency CONICET, Argentina’s National Scientific and Technical Research Council, agreed that recent years have seen a change, describing the glacier as “more or less the same position for the past 80 years … However, since 2020, signs of retreat have begun to be seen in some parts of the Perito Moreno glacier’s face.”

Ruiz reported research undertaken by his team that has found a 0.06 degree per decade rise in air temperature around the glacier, leading to it being unable to “rebound” from huge “ice calving” events where skyscraper-sized blocks of ice were sheering off its surface. Essentially, since 2015, the melting and calving on the glacier’s underside is happening faster than the ice can replenish itself at the top.

Vicious circle of melting

Unless reversed quickly, it’s a situation that could compound over time, due to evidence that shows once glacial ice losses begin to occur, they accelerate. This phenomenon is partly due to the so-called “ice-albedo effect”, caused by ice melting to expose darker surfaces which absorb more sunlight. As well as being darker, the surface of melting glaciers is larger than when they are frozen, leading to more exposure to thermal energy from the sun and surrounding surfaces.

In October 2023, tourists were banned from Chile’s Exploradores glacier after an ice fall and subsequent research that revealed “evident risks and uncertainty regarding the behaviour of the glacier” which was deemed to be at an “inflection point.”

Other examples of glacial retreat around the world include the melting of Greenland’s glaciers five times faster in the last two decades than ever before, according to a 2023 study; and the loss of nearly half the volume of Switzerland’s 1,400 glacierssince the early 1930s.