The glacier that marches to its own drummer
As you are probably aware, most of the glaciers in the world are retreating (getting smaller). For example, in Glacier National Park in Montana, the glaciers are expected to be completely gone in the next decade or two. In Argentina’s glacier park (Parque Nacional Los Glaciares), most glaciers are also retreating. But not the Perito Moreno glacier. It steadfastly continues to advance downslope to crash into the Magellanes Peninsula where visitors excitedly wait to see large chunks of ice calve off the front and crash into the adjacent lake.
The Perito Moreno glacier is one of nearly 50 glaciers that are flowing out of the Patagonia Ice Field, the third largest accumulation of continental ice, after Antarctica and Greenland. Below is a photo of Perito Moreno glacier flowing out of the ice field into bodies of water that are arms of Lago Argentina – all formed by glaciers when they flowed farther east during the Last Glacial Maximum. [No, we were not able to fly over the glacier; this is from a postcard!] Other photos below were taken from Peninsula Magellanes – on the postcard photo it is where the front of the glacier touches land and a road leads to viewing platforms.
The next photo is taken from Peninsula Magellanes, looking west into the ice field right at the place where the glacier is touching land. You can see the deep crevasses (ice cracks) that have formed as the ice pushes its way forward. Ice is really a rock – solid water is a mineral composed of the elements hydrogen and oxygen. Like any rock at Earth’s surface, ice behaves brittlely and cracks when pressure is applied. Regular rock, though, remains brittle until it reaches great depths in the Earth; in contrast, ice is only brittle until a depth of about 50 meters, where the weight of overlying rock causes it to behave plastically. So when looking at the front of the glacier it is possible to see the bottom of the crevasses.
The next photo shows several boats in the lake, and gives a sense of the scale of the glacier, whose front is nearly 100 meters high (more than 300 feet).
Viewing this glacier is one of the most popular tourist attractions in Argentina. So there are always buses bringing hordes of people to the site. But with many kilometers of viewing platforms along the edge of the peninsula, it was still possible to have a solitary experience. We spent about 5 hours there Friday and were amazed to see few people along our walk. Still, hanging with others can be part of the overall experience, as people wait excitedly, with cameras poised, and then delightedly scream as another large piece crashes into the water with a loud boom. The next photo may give a sense of the excitement, as people focus intently, waiting for the next action.
During the hour or two that we stood on the viewing platform with the group above, the part of the glacier in front of us was particularly active, and a comradery developed among us as we shared the thrill of each spectacular ice fall. All of the bright blue ice on the photo below was exposed by pieces falling off the front while we watched – sometimes as small pieces and sometimes as huge slabs. The immense sound and the tsunami wave created in the water added to the drama. It was quite a show!
I must thank Anita for supplying the close-up photos of the glacier. My new memory card decided to stop recording photos and to also erase all of the photos it had previously recorded that day (irk!). Yesterday, we climbed about 1000 meters (more than 3000 feet) to the top of Cerro Cristales. The view from the top provided a spectacular view northward across the lakes to the glacier, and a southward view to Torres del Paine in Chile. The photo below shows our path as we begin our descent (amidst raging winds – of course); Perito Moreno glacier is visible flowing out of the mountains in the far background.
