A lucky holidaymaker has managed to capture the dramatic moment a huge ice bridge ruptured and fell into the lake below.
The incident occurred in the Los Glaciares National Park at the Perito Moreno Glacier, which, at nearly 20 miles long, is one of the largest in Argentina's Patagonia region.
The glacier's tip extends from the Southern Patagonian Icefield high up in the Andes, and periodically cuts off Lake Argentino's main southern arm, known as Brazo Rico.
According to the Daily Mail, the tip reaches across a narrow section of the lake, connecting to the opposite shoreline, forming a natural dam, which prevents lake water circulating from one side to the other.
The Science Recorder reports that Nasa scientist Jim Foster told OurAmazingPlanet: "This glacier is somewhat unique in that its path takes it across an arm of a large lake.
"Most glaciers don't have such trajectories, so bridging and tunnelling, at least at this scale, is rather rare."
The NASA Earth Observatory points out that meltwater from the south raises water levels in Brazo Rico because of the natural ice dam.
The immense pressure of this water occasionally causes the ice tongue to rupture. Brazo Rico's levels can swell as much as 98 feet higher than those in Lago Argentino before the glacier ruptures, and these repeated ruptures have been a huge tourist attraction in the region for years.
Approximately 2,500 tourists were drawn to the spectacle, and saw a huge chunk of the 97-square-mile glacier crash into the water.
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