The snow-capped mountains running through the center of this satellite image are part of the Cordillera Blanca – or ‘white range’ – in South America’s Andes. Even though they are part of the typically warm Tropics – the region of Earth surrounding the equator – the mountain range is high enough to be permanently covered in snow and ice.
There are hundreds of glaciers in this range, providing a major source of water for irrigation and hydroelectric power. The glaciers and snow-covered areas ‘collect’ rain and snow during the rainy season and slowly release it during the drier times of the year. Over the last decades, the glaciers have experienced major losses owing to climate change, causing a major threat to water supply during the dry season in the future.
Located near the center of this image, Mount Huascarán is the highest peak in Peru at 6768 m. The summit is one of the farthest points from Earth’s center, meaning it experiences the lowest gravity on the planet.
North of Huascarán, we can see an outlet glacier that meets another outlet from the Chopicalqui mountain to the east. Numerous blue glacial lakes are visible in the valleys between the mountains.
The Huascarán National Park protects this mountainous area, and has been on the UNESCO world heritage list since 1985. The spectacled bear, puma, mountain cat, white-tailed deer and vicuna are important indigenous species, but have all been heavily hunted in the past.
This image, acquired by Japan’s ALOS satellite on 24 August 2010, is featured on the Earth from Space video program.
Image credit: JAXA/ESA
This radar image is one of the first from the Sentinel-1A satellite, acquired on 20 April – less than three weeks after its launch on 3 April.
The image shows the Salar de Uyuni in Bolivia, which is the largest salt flat in the world.
Occupying over 10,000 sq km, the vast Salar de Uyuni lies at the southern end of the Altiplano, a high plain of inland drainage in the central Andes. Some 40,000 years ago, this area was part of a giant prehistoric lake that dried out, leaving behind the salt flat.
While the salt flat appears an almost homogenous white in optical satellite imagery, here we see it in shades of grey, and it looks almost like a lake. This has to do with how the radar signal reacts to different surfaces: areas where the radar signal is absorbed appear darker, while areas where the signal is reflected back to the satellite appear lighter. This gives Earth observation experts an indication of how rough or smooth the surfaces area, differences in salt density or even the presence of water.
But on the whole, the Salar de Uyuni is very flat, with a surface elevation variation of less than 1 m. This makes the area ideal for calibrating satellite radar altimeters – a different kind of radar instrument that measures surface topography. The future Sentinel-3 mission will carry a radar altimeter.
The surrounding terrain is rough in comparison to the vast salt flat and is dominated by the volcanoes of the Andes mountains forming part of the Pacific Ring of Fire.
Sentinel-1A is the first in the two-satellite Sentinel-1 mission for Europe’s Copernicus program. Its radar data will be used for a variety of applications, including the surveillance of the marine environment, monitoring land-surface for motion risks, mapping for forest, water and soil management, and mapping to support humanitarian aid and crisis situations.
This image is featured on the Earth from Space video program.
Image credit: ESA
An unusual view of South America and the Andes mountains, acquired by Proba-V on 23 April 2014.
Image credit: ESA/VITO
On April 28, 2014, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on NASA's Terra spacecraft acquired this image of Ubinas volcano in the Peruvian Andes. The appearance of a new lava dome in March 2014 and frequent ash emissions are signs of increasing activity at this volcano. The left image depicts vegetation in red, and shows a gray plume streaming south from the summit caldera. The right image is a combination of ASTER thermal infrared bands, highlighting the ash-rich composition of the eruptive plume. The image covers an area of 20 by 37 miles (33 by 60 kilometers), and is located at 16.3 degrees north, 70.9 degrees west.
Image credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
The foothills of the Andes mountains near the southern coast of Peru were captured by the Kompsat-2 satellite on 4 May 2011. The Andes stretch about 7000 km from Venezuela down South America’s west coast to the top of Argentina. The mountain range is the result of the Nazca and Antarctic tectonic plates moving under the South American plate – a geological process called ‘subduction’. This process is also responsible for the Andes range’s volcanic activity.
Photo credit: KARI/ESA
