Perito Moreno's ice front advances by up to two metres a day, making it one of the few large glaciers on earth that is not in retreat. It ends in a wall roughly five kilometres wide, standing about seventy metres above the surface of Lago Argentino with a further hundred and seventy metres hidden below the waterline.
An El Calafate Glacier Trekking Tour crosses country shaped entirely by that arithmetic. The ice arrives from the Southern Patagonian Ice Field, the third largest reserve of fresh water on the planet, and stops here.
The glacier carries the name of Francisco Pascasio Moreno, born 1852, the surveyor whose fieldwork underwrote Argentina's position in the boundary arbitration with Chile. Perito was a title, not a forename: expert. Los Glaciares National Park was established in 1937, among the oldest protected areas in the country, and covers some 726,000 hectares of ice, moraine and Magellanic subpolar forest. UNESCO inscribed it as a World Heritage site in 1981. El Calafate Glacier Trekking Tour tours now set out from a town that was, within living memory, a wool-trading stop on the shore of the same lake.
The ice is not still. Perito Moreno periodically pushes against the Península de Magallanes and seals the Brazo Rico arm of the lake behind a dam of its own making. Water rises on the southern side, sometimes by tens of metres, until it undercuts the ice and an arch collapses into the Canal de los Témpanos. Those ruptures arrive at irregular intervals, years apart, and are never scheduled. Steel walkways on the peninsula descend through several levels of lenga and ñire forest, holding viewpoints at different heights against the calving front. Below them the water carries brash ice that grinds audibly against the shore.
Perito Moreno is not the park's only ice. Upsala and Spegazzini run longer and reach the lake in more remote arms, while the granite spires of Cerro Fitz Roy and Cerro Torre rise in the northern sector above El Chaltén. Glaciologists track the whole ice field as a single system, and Perito Moreno's stability remains a genuine anomaly within it rather than a sign of health elsewhere. That research context is why Los Glaciares National Park tours carry an interpretive obligation as much as a scenic one. El Calafate Glacier Trekking Tour tour operators work under park concession, roping visitors onto a surface of seracs, mill holes and meltwater channels that redraws itself every season, and the Perito Moreno ice trek remains the only sanctioned way to stand on it.
8 hr
