The Perito Moreno Glacier

Listed as one of the Seven Wonders of South America, the Perito Moreno Glacier is indeed a sight and sound to behold. From the viewing deck built up on the slope the view of the glacier is phenomenal. Between the mountain peaks emerges a 30-kilometre-long river of ice that stands on average 60 metres above the waters of Lago Argentina and stretches roughly 5 kilometres from side to side with a total surface area of about 250 kilometres squared. The view is nothing less than mind-boggling and at the same time both awe-inspiring and almost forbidding. It looks as though some frozen hell has breached its restraining barriers and has come flooding into our world. This incredible view has the air charged with sound as tremendous cracks and gunshot booms emanate from the seemingly static towers of ice that are actually slowly advancing forward into the frigid lake waters and bending under their own weight. Large chunks of ice break free and plunge into the lake with a splash that sounds like a semi-trailer truck was dropped in, and if you can watch long enough you might even see a huge section collapse into the lake with a thunderous rumble and a splash that sends tsunami-like waves rolling across the water.

The Perito Moreno issues from the Southern Patagonian Icefield, the third largest freshwater reserve on the planet. It is one of only three Patagonia glaciers that is still growing. Though the articles say that scientists are still not certain why the glacier is growing while most others are retreating, I think it may be a combination of factors such as proximity to the regions of the icefield that receive the most precipitation, wind direction in relation to the surrounding mountains, and the presence of self-produced cloud cover. Icefields tend to make their own climate, cooling the air over them creating clouds when the air is moist and causing rain or snow to fall while neighbouring mountains and plains remain dry.

Aside from its impressive visual appearance, the Perito Moreno glacier is also famous for its spectacular ruptures. The glacier’s trajectory pushes it against the rocky headland where Lago Argentina branches into the main lake and an arm known as Brazo Rico, and once the ice has built up against the rocks, the melt waters in Brazo Rico cannot escape into the rest of the lake. The water level rises and it can reach up to 30 metres before the water forces a way through in with a crashing collapse of ice and an explosion of ice-chocked water. The pent up waters surge through the opening sending icebergs swirling and bobbing into the main body of the lake. This extraordinary event may occur as frequently as once a year to as infrequently as once every several years.