Every year the Perito Moreno glacier generate expectations in the world relative to its breakup. Some data on its characteristics and its history will help us understand this phenomenon.
Los Glaciares National Park was created in 1937 for the preservation of the glaciers and was declared a World Heritage Site by UNESCO to preserve its flora and fauna in danger of extinction.
Glaciers play an important role in our day, occupy 10% of land surface and account for 90% of the world's freshwater. And with the air and water flow that create, contribute to balance the Earth's climate, which without them would be suffocating.
There are many myths and comments on the Perito Moreno glacier and its behavior that every year surprise and invites tourists from around the world. But to begin to understand, we must ask:
A glacier is often compared to a river of ice because it have tributaries, erosive capacity and greater speed in the middle of the channel than at the edges. But the movement of ice, like all bodies, follow the laws of gravity and very specific behaviors that have little in common with the water.
The ice of glaciers is the result of compression of the snow effect of its own weight. For the formation of a glacier takes large snowfall and the average annual temperature for retaining snow. The snow is compressed and accumulates in layers that are compacted and by the weight it form the ice.
The time required for the formation of ice from the snow varies greatly from one glacier to another depending on two factors: the snowfall and temperature and can range from a dozen years like in the alpine glaciers or glaciers from Patagonia or several hundreds of years like in Antarctica.
The important thing to know about the glacier is that is not only a mass of ice, but above all, a mass of moving ice. And as every body in motion, the ice is influenced by gravity. Because of this similarity with water the glaciers are compare to rivers which, if it is not entirely false, in light of recent studies also doesnt' seem to be quite true.
A glacier is only a glacier if it moves and to start to move the ice needs a certain thickness of about 20 meters. From here, three factors will condition the forward speed of a glacier: the thickness, slope and ice temperature.
The glaciers covered in the last great ice age about 18,000 years ago one third of the landmass, which was 3 times its present size. Sea level then dropped 120 meters, with the result that large areas now covered by sea water, were then dry land. In southern Patagonia, the first ice age that left clear footprints was 3.5 million years ago and at that time, the ice extended at least 60 km east of the Andes today.
The glaciers from Patagonia are named after Perito Moreno since 1899. But the story tells that Perito Moreno has never seen the glacier, despite having been very close his exploration in 1876 because the glaciers are never mention in his report.
In 1879, John Thomas Rodgers, English captain of the Chilean Army, would be the first explorer to mention the glacier and give it a name: he called glacier Francisco Vidal Gormaz in honor of the Director of the Navy Hydrographic Office in Chile. Years late Hauthal attached to the Argentinian Boundary Commission would call it Bismarck in honor of Prussian Chancellor. That name that still appears on some german and chilean maps. But Lieutenant Iglesias in a studio appointed by the Argentine Hydrographic Institute definitely named the glacier Perito Moreno.
The breaking of the Perito Moreno Glacier is one of the most impressive natural phenomena that have been seen in recent times. The various breakdowns show that there is a cyclic parameter in the Perito Moreno:
It is often said that the rupture of Moreno is a phenomenon that repeats cyclically every 3 or 4 years. As discussed above, this only occurred regularly in recent years. Just look at the list of breaks to see how wrong is that idea.
It covers an area of 6,000 km2, covering part of the Continental Ice and all the glaciers that from them descend to the eastern side.
Source and photos: Secretaría de Turísmo de la Provincia de Santa Cruz. www.santacruzpatagonia.gob.ar
Bibliography: Alonso, Miguel Angel (1993) "Manual de Lago Argentino y Glaciar Perito Moreno". Talleres Gráficos de Editorial Acme, S. A. C. I. Buenos Aires