Glaciers account for some of the most jaw-dropping scenery on the planet. There are glaciers on every continent on Earth; but the most impressive are usually found in polar and high alpine regions, where cooler temperatures allow them to grow to colossal sizes. The Patagonia glaciers are among the most iconic scenes of life in southern Argentina and Chile. There are countless glaciers in Patagonia, creating a vast adventure playground for anyone with a love for exploring sublime landscapes.
How are Glaciers Formed?
Glaciers are formed when compacted layers of snow accumulate to form glacial ice. This process can only happen in places where snow can remain year-round, when there is more snowfall in winter than water evaporation in summer.
As the layers of snow compress further, their hexagonal flake formation is destroyed and they become rounded, expelling air as they are more densely packed in. The snow then becomes firn, a term used to describe the intermediate state between snow and glacial ice. This stage takes two years to reach.
Pressure builds further, along with brief periods of slight melting, to attain a recrystallization point where glacial ice is now present. This can take decades or even hundreds of years, depending on snowfall and how much of the glacier is lost during warmer months.
New Scientist estimates that the first glaciers on Earth formed around 34 million years ago, on the tops of Antarctica’s mountains. Glaciers in the northern hemisphere, around Greenland and the Arctic, were formed some 3.2 million years ago. Since then, through various ice periods, others across the planet have developed.
There are two main types of glaciers: continental glaciers, which are large sheets of ice that cover landmasses, and valley glaciers, which flow down valleys to sculpt the scenery around them. Numerous classifications for both are used to describe slight variations in their formation, such as ice caps (smaller versions of continental ice sheets) and tidewater glaciers (valley glaciers that flow to meet the sea).
Advancing vs. Retreating Glaciers
The massive weight of a glacier causes it to move at a very slow rate. The top of a glacier will tend to move quicker than the bottom, and sometimes the difference between the two can be very significant. To the human eye glaciers look like they’re standing still, but in actuality they are always moving.
Depending on snowfall and evaporation rates, glaciers will advance and retreat over time. These processes only refer to the position of the snout, a term given to the lowest end of a glacier. It’s not often a drastic change when a glacier advances or retreats. It typically takes years or even decades to notice the shift in position; but rapid retreat has been reported in extreme cases, where this alteration can be witnessed within the course of just a few months.
While the advance and retreat of glaciers is natural to an extent, scientists estimate that the rate at which glaciers are going through these processes is now faster than it has ever been in history. Reports of observed glaciers show that they lose between half a meter and one meter of ice thickness every year. This is two to three times more than the corresponding average of the 20th century.
In terms of the Patagonia glaciers, one of the biggest differences scientists have seen is the retreat of the Southern Patagonian Ice Field, which is the third largest ice cap in the world. It is reported to have retreated around 1km since the 1990s, and 10km since the end of the 19th century.
Many chalk this alarming change up to the large amount of carbon emissions industrialization has sent into our atmosphere over the last 100+ years. At this continuing rate of global warming, some glaciers might disappear entirely within a matter of decades.
Visiting the Patagonia Glaciers
While these studies are undeniably concerning, there’s still ample opportunity to witness the mighty Patagonia glaciers in all their glory. Chile’s Torres del Paine National Park is home to some of the region’s most imposing, including Grey Glacier, which is part of the Southern Patagonian Ice Field. This behemoth encompasses 270 sq km, stretches 28 km end-to-end, and has been photographed from the International Space Station.
One of the more curious Patagonia glaciers is Perito Moreno, which is located in Argentina’s Los Glaciares National Park. Unlike most other glaciers on the planet, Perito Moreno is advancing as opposed to retreating, which has baffled scientists. Research published by National Geographic suggests that one reason is because Perito Moreno’s equilibrium line—the line at which anything above it will increase the glacier’s size, and anything below it will melt—is on a far steeper section than most glaciers. Perito Moreno just doesn’t have as much mass in the melt zone, so it’s thought that climate shifts don’t affect it as much as others.
As the threat of climate change impact grows each year, the glaciers of Patagonia are well worth witnessing for yourself. Zegrahm’s Wild Patagonia tour, led by expert geologist Tom Sharpe, is the perfect way to connect with this mind-boggling scenery. This 8-day expedition begins in Torres del Paine National Park, a 615,000-acre UNESCO Biosphere Reserve. Guests will have a chance to visit the park’s famed glaciers and spot a wealth of wildlife: Around 150 species of animals and over 100 bird species call this majestic landscape home.
The tour’s Perito Moreno river cruise will get you up close to the most massive of the Patagonia glaciers. You’re likely to see the glacier calving—a shedding of enormous chunks of ice that is usually caused by expansion. This fascinating tour will help you further understand the context of glaciers, their advancing or retreating, and what it means for our planet. Nothing can prepare you for your first sighting of one of these majestic natural wonders, and there’s no better place for that moment than the awe-inspiring landscapes of Patagonia.
Emma Higgins is a travel writer who’s been working in the industry since 2010. Her website, Gotta Keep Movin’, documents her travel across the globe through online content, a podcast, and an annual print journal. Her latest book, A Year in Portugal, comes out in September 2017.