English: This image was taken by an astronaut looking south-east across the
South American continent when the
International Space Station (ISS) was almost directly over the
Atacama Desert near
Chile’s Pacific coast. The high plains (3000–5000 meters) of the Andes Mountains, also known as the Puna, appear in the foreground, with a line of young
volcanoes facing the much lower Atacama Desert (1000–2000 m elevation). Several
salt-crusted dry
lakes (known as salars in Spanish) occupy the basins between major thrust faults in the Puna. Salar de Arizaro (foreground) is the largest of the dry lakes in this view. The
Atlantic Ocean coastline, where
Argentina’s capital city of
Buenos Aires sits along the
Río de la Plata, is dimly visible at image top left. Near image centre, the transition between two distinct geological zones, the Puna and the Sierras Pampeanas, creates a striking landscape
contrast. Compared to the Puna, the Sierras Pampeanas
mountains are lower in elevation and have fewer young volcanoes. Sharp-crested ridges are separated by wide, low
valleys in this region. The
Salinas Grandes—ephemeral shallow salt lakes—occupies one of these valleys. The general colour change from
reds and
browns in the foreground to
blues and
greens in the upper part of the image reflects the major climatic regions: the deserts of the Atacama and Puna versus the
grassy plains of central Argentina, where
rainfall is sufficient to promote lush prairie grass, known locally as the pampas. The Salinas Grandes mark an intermediate, semiarid region.