Is Perito Moreno Glacier Growing Or Shrinking?
For half a century this was the glacier that refused to retreat. Recent measurements complicate that story without turning it into a collapse, and the nuance is the interesting part.
Start with the glacier visit you want, then decide how much transport and guiding to add.
At a glance: The balconies work as a visit on their own. Boats add a water-level view, while ice trekking requires a separate guided experience.
Planning update, September 2026: dollar amounts below are earlier estimates, not current quotes. Compare your actual date and full party; admission, pickup, meals and cancellation terms depend on the selected product and option.
For most of the last fifty years, Perito Moreno was the glacier people cited when they wanted an exception to the rule. Its face pushed forward roughly two metres a day, grinding into Lago Argentino while ice elsewhere pulled back. That reputation still leads most travel articles about it. It is now only half the story, and the other half was published in 2025.
Is Perito Moreno Glacier Growing Or Shrinking?
Neither word fits cleanly. For about half a century the glacier held a rough equilibrium, advancing roughly two metres a day at the face while shedding a matching volume of ice into the lake, which made it a famous outlier. Research published in 2025 documents something different: real, accelerating retreat since 2015. The popular version, the glacier that keeps growing, was never quite accurate to begin with. Equilibrium is not growth. Ice moved forward, the face broke away, and the front line stayed roughly where the old photographs show it for decades on end. What has changed is that balance, not the direction the ice flows.
Why Was It Famous For Not Retreating?
Because it stayed put while nearly everything else lost ground. Fed by the Southern Patagonian Ice Field, Perito Moreno advanced fast enough to hold its front against the Magallanes Peninsula, producing a wall close to 5 km wide and up to 70 metres above the lake that looked the same decade after decade. That stability is also what created the glacier's signature event. When the advancing ice touched the peninsula it dammed an arm of the lake, water backed up behind it, and the ice bridge eventually gave way in a rupture Argentina watched live on television. The scale of the thing is easier to grasp in numbers than in photographs, and our page of glacier facts lays them out. Los Glaciares National Park is a UNESCO World Heritage Site, listed in part for exactly this kind of active ice.
What Does The Current Research Actually Show?
Three findings carry it. The glacier retreated more than 800 metres between 2019 and 2024. Thinning accelerated more than sixteenfold, from about 0.34 metres a year historically to somewhere near 5.5 to 6.5 metres a year. And the period since 2015 is the fastest sustained mass loss recorded there in 47 years. Thinning and retreat are not the same thing, which is why the glacier could look unchanged from the balconies for years while the measurements moved. A glacier can lose height across its whole surface long before its front position visibly shifts, and that is roughly the sequence here. The team behind the 2025 work has written up the retreat and thinning data in detail, and it is the source for every figure in this section.
Does That Mean The Glacier Is Disappearing?
Not on any timescale that touches your trip, and the honest reading of the data is a change of direction rather than a collapse. Perito Moreno remains an enormous body of ice, still nearly 5 km across at the face, still up to 70 metres above the water, still dropping ice into the lake. The point researchers make is about decades, not seasons. What ended is the exception: a glacier that held steady while its neighbours retreated is now behaving more like them. If you want a sense of what the more typical Patagonian pattern looks like, compare it with Upsala and Spegazzini in the same park. And the process that made Perito Moreno famous still runs every day, which we cover in how and why the face calves.
Is The Famous Rupture Cycle Changing Too?
The pattern looks less dependable than it once was. Documented ruptures came in 1988, 2004, 2006, 2008, 2012, 2013, 2016 and 2018, roughly every two to five years. The last confirmed major full rupture was 2018, and researchers now suggest a retreating face may not reproduce the same cycle. Sources also disagree about what happened afterwards. Some cite an event in 2019; others describe a brief partial closure in 2022 that lasted about a week rather than a genuine rupture. That disagreement is itself a signal that the clean cycle has loosened. Nobody should time a trip around catching one, and our explainer on the rupture goes through why the ice dam forms and what has to happen for it to break.
Should You See It Now?
If Perito Moreno is already on your list, there is no argument for postponing it. The stability it became famous for is still visible from the balconies: the wall stands where the old photographs put it, the sound carries across the water, and ice still breaks off the face while you stand there. This is not a reason to panic-book. It is a reason to stop deferring. The tour that gets you closest is the trekking and cruise day, which crosses Lago Argentino by boat, puts you on the ice in crampons for about ninety minutes and includes time at the walkways, rated 4.8 across more than 8,551 bookings. Prices shift with season and currency, so see live prices on the listing. Anyone still deciding whether the trip earns its place in a Patagonia itinerary can read our take on whether the glacier is worth visiting, and our comparison of walkways, boat and ice trek covers which format suits which traveller.