The Changing Face of Perito Moreno Glacier: A Spectacle of Calving Ice

The deep cracking sound bursting from within the ice signals the dramatic fall about to happen. Seconds later, a block of ice some 70 meters (230 ft) tall – the size of a 20-story building – collapses from the face of the Perito Moreno glacier into the aquamarine water below.

The sight has attracted visitors to Argentina’s most famous glacier for years. Standing on platforms facing the ice, they wait for the next crack to split the cool Patagonian air.

But recently the size of the ice chunks breaking off – a process called “calving” – has been starting to alarm local guides and glaciologists, already anxious at a prolonged retreat by Perito Moreno, which had bucked the trend in recent decades by maintaining its mass even as warmer climates spurred faster glacial melting worldwide.

Alarming Changes

“Ice calving events of this size haven’t been very common at the Perito Moreno glacier over the past 20 years,” said Pablo Quinteros, an official tourist guide at Los Glaciares National Park in the southern province of Santa Cruz.

The face of the glacier, which flows down from Andean peaks to end in the waters of Lake Argentina, had for decades held more or less steady, some years advancing and others retreating. But in the last five years, there’s been a firmer retreat.

Implications of Climate Change

Argentine glaciologist Lucas Ruiz with state science body CONICET, whose research focus is the future of Patagonian glaciers in the face of climate change, highlighted the concerning trends. He mentioned that the glacier could rebound as it has done before, but that for the moment it was losing between one and two meters of water equivalent per year, which if not reversed could lead to a situation where the loss accelerates.

A state-backed 2024 report, co-authored by Ruiz, showed that while Perito Moreno’s mass has been overall stable for half a century, the period since 2015 has seen the fastest and most prolonged loss of mass in 47 years, on average losing 0.85 meters per year.

Urgent Action Needed

Glaciers around the globe are disappearing faster than ever, with the last three-year period seeing the largest glacial mass loss on record, according to a UNESCO report in March.

Ruiz emphasized the impact of climate change on Perito Moreno, stating that the accumulation of ice at the top of the glacier was being outpaced by melting and calving at the bottom. This disruption in the balance of forces is leading to a loss in both thickness and area of the glacier.

Conclusion

For now, the glacier remains an awe-inspiring attraction for travelers, who board boats to see the calving and the huge icebergs floating around the lake up close. However, the changes in Perito Moreno serve as a stark reminder of the urgent need to address climate change and its devastating effects on our planet’s glaciers.

(Reuters/Production: Bernat Parera, Nicolas Cortes, Juan Bustamante, Liamar Ramos)