FAST FACTS
Where is it? Los Glaciares National Park, Argentina [-50.469690266, -73.03391046]
What's in the photo? The point where an unretreating glacier, a turquoise lake and a muddy river meet.
Who took the photo? An unnamed astronaut aboard the International Space Station (ISS).
When was this done? March 2, 2021
This incredible astronaut photo shows an extraordinary point where a huge, unretreating glacier, a pristine turquoise lake and a murky green “river” converge perfectly at the intersection of three valleys in Argentina.
Three hydrological features – the Perito Moreno Glacier, Lake Argentino and Brazo Rico – underlie Glaciers National Parkwhich covers an area of about 2,300 square miles (6,000 square kilometers) in the province of Santa Cruz in southern Argentina, near the country's border with Chile.
The aerial photo doesn't just show these three bodies of water in one frame; if you look closely, you can also see the point where the trio touch in a narrow channel along the western edge of the Magallanes Peninsula, a rocky outcrop said to lie between the lake and the river. NASA Earth Observatory.
In this photo, the waters of Lago Argentino and Brazo Rico are most likely in direct contact with each other (as in the photo below). But their waters do not mix well because they have different densities due to the respective concentrations of suspended particles, according to the study. 2022 study.
But every four to five years, the glacier's tongue moves forward, colliding with the Magallanes Peninsula and temporarily blocking the Brazo Rico River. When this happens, the surface of the murky body of water rises 100 feet (30 meters) until the increase in pressure causes the ice dam to spectacularly “rupture,” the Earth Observatory reports. previously reported.
Perito Moreno is the largest glacier in Patagoniawhich includes parts of Argentina and Chile. It is about 19 miles (30 km) long and the ice is up to 200 feet (60 m) thick. According to preliminary calculations, in total the glacier contains approximately the same amount of water as 360,000 Olympic swimming pools.
The glacier is not “retreating,” meaning it is not shrinking despite rising atmospheric temperatures caused by human activity. climate change. This is extremely rare these days, and Perito Moreno is often referred to as one of the “last large unretreating glaciers in the world.” Nevertheless, recent study hints that it may finally be starting to taper off.
Lago Argentino is the largest freshwater lake in Argentina, with a total area of about 550 square miles (1,425 square kilometers). The part visible in the astronaut's photograph is the southernmost arm of the lake. It contains glacial melt water filled with rocky particles released by the constant movement of glaciers, known collectively as “glacial milk”, which gives the water a striking turquoise color.
The northernmost arm of the lake also connects to the Uppsala Glacier, which is now in full retreat.
Brazo Rico, which means “rich hand” in Spanish, is also technically part of Lake Argentina. However, it has become increasingly isolated from the rest of the lake due to repeated damming by the Perito Moreno Glacier, causing it to behave more like a river than part of a lake.
Frequent ice debris is also responsible for the bland color of Brazo Rico, which is the result of sediment being displaced by movement. The continued rise and fall of the river's surface has also created a boundary along its edges where trees cannot grow.
Eagle-eyed viewers may also have noticed the narrow road that winds its way through the Magallanes Peninsula and along the northern edge of Brazo Rico (just above the tree line): one can only imagine the extraordinary views it offers.
For more incredible satellite photos and images of astronauts, check out our website. Earth from space archives.
