Los Glaciers National Park

Founded in 1937, the name of Los Glaciers National Park is derived from the presence of numerous glaciers originating in the great field of Patagonian Ice, the biggest layer of ice after Antarctica. Recognized as a World Heritage Site in 1981, Los Glaciers National Park is truly beautiful. The park is 8,500 square miles, half of which is covered by ice fields that connect over 45 major glaciers. It features the beautiful mount Fitz Roy and two of Argentina's largest lakes (Lago Argentino - the largest lake in Argentina and Lake Viedma) both lakes feeding into the Santa Cruz River, which drains directly into the neighbouring Atlantic Ocean.
 
Seeing the glaciers is one of the most dazzling experiences. Maybe because they are millions of years old, maybe because of the various shades of blue that they acquire when exposed to sunlight, or maybe simply because their whimsical shapes and monumental size make us think of the true beauty of nature. Whatever the reason, thousands of people from all round the world spend considerable amounts of money in order to appreciate them.

The Perito Moreno Glacier

Imagine a fifteen-story tall wall of ice looming over a backdrop of snow-capped mountain peaks, and you'll begin to understand the majesty that is the Perito Moreno Glacier. This glacier, which is one of the largest in the region, is also the most scientifically significant in that it’s still growing in size every day. You can hear the crackles and creaks and gasp as the front wall of the glacier falls away in front of you.
 
Situated 80km (50miles) from El Calafate, Perito Moreno is an enormous glacier (30-60m high x 30km/19 miles x 4km wide with 14Km in sight). It is a stable glacier that has not changed its dimensions in over 100 years. It moves at 1.5 to 2 metres a day and sheds ice at its front wall every day as its front point crashes into the land.

Some years this 18-mile long river of ice advances across Lake Argentina, splitting it in two and creating a natural dam. Eventually water behind the glacier rises and, seeking equilibrium tunnels beneath the glacier. Slowly, the warmer lake waters carve a giant hole through the glacier, leaving only a narrow ice bridge across the top. When the bridge becomes unstable giant chunks of ice begin to calve from the glacier. Towering plumes of water and mist explode from the lake whenever these mini icebergs plunge into the lake, 200 feet below.

Prior to 2004, the bridge had not collapsed for 16 years. Since then, this finger of the glacier has advanced and collapsed three times: in the summer of 2004 and again in the summer of 2006. The most recent occurrence was in the winter of 2008, the first time the bridge has ever fallen during the colder winter months. Some attribute this to global warming, although unlike many glaciers around the world, Perito Moreno is not retreating. In 1988, the ice blocked the channel between the two lakes with the southern lake rising by 22m but when it finally broke through the southern lake emptied into the northern lake in a day.
 
There are many viewing platforms and easy trails (with quite a number of steps) to make the visit and the observation easy and pleasant. You can enjoy a trek on the glacier and take a boat excursion to see this and many other glaciers and places in the Los Glacieres National Park. The colours and shapes of the icebergs floating in the lake are really awesome, making a boat ride on a sunny day a fantastic day out.

Upsala Glacier

This glacier (60-80m high x 60km/38 miles x 5-7km wide) can only be reached by boat, since it is located on the northern side of Lago Argentino. Its main attraction, besides its dimension (much larger than the Perito Moreno glacier), is the size of the blocks that fall from its front. They are enormous blocks, generally larger than the boats used to visit the area. This is probably so because its front goes deeper than Perito Moreno, and there is more water flowing under its base (it is not certain but it is believed that its front is not sitting on the bed but floating), so there is less pressure when moving. It is not common to observe a glacier rupture, but sailing among its icebergs is a fascinating experience. During our visit there had been many large chunks of fallen ice that had totally blocked the river leading up to the front wall of the glacier so we could only sail along the front wall of the large chunks of ice and view Upsala Glacier from a distance.

Spegazzini Glacier

The Spegazzini glacier (80-135m high x 25km/16 miles x 1.5km wide) characterizes by being the highest glacier often visited. It's also unique because it shows no signs of receding, a common phenomenon in large glaciers; on the contrary its front wall seems larger. The glacier is led by both the Mayo Northe and Peineta Glaciers and is one of the most charming ones due to its natural surrounding. The glacier was named after the botanist Carlos Spegazzini who made the first studies of the local flora.

The formation of a Glacier
The formation process of the glacier ice – a bluish crystalline mass — is by the accumulation of successive snowfall that result in the liberation of the air caused by its mere weight: from the “snow crystals” that fuse forming more compressed “granules” which turn into a dense mass, until it turns into a geoid when it reaches more transparency and hardness. The basic conditions are great snowfall and a mean annual temperature that makes the conservation of the snow possible.
 
Icebergs
Icebergs of various shapes and colours are spread over the Lago Argentina by the action of wind and water currents. They show only 15% of their actual size above the level of water "hiding" the other 85% under it. The bluish colour of the ice is given by the degree of compression and the reflected effect of light.