I never tire of Patagonia’s glaciers. For me, they are this region’s most dramatic testaments to the power of nature. They are like living things, endless flowing in frozen rivers down from the Andes, slowly reshaping mountains and carving their way across entire valleys. Many of Patagonia’s most fantastic glaciers reach straight into the sea or some frigid alpine lake, where they shatter with glassy explosions and give birth to an endless stream of icebergs.
I first fell in love with Patagonia’s glaciers when I was completing my training as a mountain guide. Part of the course was held in Tierra del Fuego in the depths of winter, when the sun is low and the days are short and cold. It is also home to some of our most spectacular but least visited glaciers of all – something I was reminded of when I took an adventure cruise around the island recently, ticking off glaciers that can only ever be visited by boat. Pia Glacier, Porter, Águila and Cóndor Glaciers all conspire to make this truly feel like the end of the earth, with nothing left to see except the wild waters of Cape Horn, and perhaps the long voyage to Antarctica.
But why is Patagonia so rich in glaciers?
Pacific snows
Tierra del Fuego’s glaciers are the last hurrah of the Patagonian Ice Field, a vast sheet of ice that once stretched for about 1200 miles (2000 km) along the spine of the Andes, from the Chilean and Argentinian Lakes Districts, past Pucón and Bariloche, all the way south to the tip of the tip of the continent.
It’s been a while since there was that much ice of course – about 21,000 years to be precise – but even today, what remains of the Patagonian Ice Field is the largest sheet of ice in the southern hemisphere that isn’t in Antarctica. Outside the polar regions, it’s only beaten in size by the Greenland ice sheet. When the great Patagonian Ice Field began to melt all those centuries ago, it caused the global sea level to rise by four feet (1.2 metres). Even today, we’ve got over 17,000 glaciers. That’s forty times more ice than the Alps in Europe. It’s a lot of ice.
The ultimate source of all this ice lies out to sea. Not in the crinkly fjords of Tierra del Fuego but in the wide expanses of the Pacific Ocean.
Off South America, the Pacific weather systems are full of strong south westerly winds. They suck endless moist air in at one end and then collide with the great ramparts of the Andes mountains at the other. As the air rises and cools against the granite peaks, it falls on them as snow. A lot of snow: almost 30 feet (10 metres) in some places.
Every year for thousands of years, the snow has piled up in the Andes, compressing itself into ice and forming glaciers. The great weight forces the ice below to move and shift, forming long frozen tongues that slice and groan their way down through the mountains.
Living walls of ice
You only need to visit somewhere like Perito Moreno Glacier in Los Glaciares National Park to see the result. As a guide, it was somewhere I regularly took guests, but however many times I visited it, the show is always spectacular.
The statistics only tell half the story. The face of Perito Moreno is three miles (4.8 km) wide where it pours out of the mountains into the milky blue waters of Lago Argentino. Its cliffs are higher than a 25 storey building.
Whether you take a boat trip, kayak or just watch from the viewing platforms, you don’t have to wait long to see one of nature’s great spectacles. Before long, you’ll hear an explosive boom and watch to see great sheets of ice slicing off its cliff facing and collapsing into the water with a mighty splash. Every day without fail, Perito Moreno advances another two metres, squeezed through the mountains by the endless pressure of the snow and ice high above. No matter how many icebergs calve into the lake, Perito Moreno never stops.
The threat from climate change
Perito Moreno’s size is largely stable. Sadly, that makes it a rare thing in 21st century Patagonia. Climate change is putting its glaciers under severe pressure. Today, it’s estimated that 97% of all Patagonia’s glaciers are in retreat, losing around a metre of ice every year. That’s one of the fastest rates of loss in the world.
What makes many of Patagonia’s glaciers so alluring is sadly also what makes them particularly vulnerable. From Tierra del Fuego to the Chilean Fjords, many of Patagonia’s glaciers extended straight into the sea. As sea temperatures rise, these glacial tongues slowly retreat from the sea.
One of my favourite glaciers is the San Rafael Glacier in the Northern Chilean Fjords. It pours out of the smaller Northern Patagonian Ice Field, tumbling improbably out of a lush temperate rainforest into a wide lagoon. Even in my own lifetime, it has retreated by a mile. Historic photos from a century ago show its face stretching four miles further into the lagoon than it does today.
It’s a sobering thought. Patagonia’s glaciers have always come and gone. The Chilean and Argentinian Lake Districts are both products of a great prehistoric glacial retreat, the ice having once carved its way through the mountains before leaving behind a patchwork of glacial lakes. But to be able to see the change year on year is truly frightening.
The future?
This summer we’ll be taking our daughter to visit Perito Moreno Glacier for the first time. We’ll take the boat trip to its cliffs and hike along its side to where it’s safe to touch its walls and commune with the ice itself. I can’t wait to share it with her and pass on my love of Patagonia’s glaciers.
We’ll sit and watch the icebergs shatter off its cliffs and float into Lago Argentino – and I’ll know that we must work harder than ever to protect these incredible places, so that in years she can bring her own daughter here, and to Pia Glacier and San Rafael and all those special frozen corners I love in Patagonia.
*
