NASA MODIS Image of the Day: November 24, 2010 – Central Andes
Sunlight painted the Central Andes in a varied palette of muted earth tones, while bright white banks of marine stratocumulus clouds shrouded the Pacific Ocean on a spring day in South America.
The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite captured this image on November 13, 2010 when it passed over the region.
In the north, the tan coastal plains of Peru rise to the Altiplano, the most extensive area of high plateau on Earth outside of Tibet. Lake Titicaca, seen in this image as a deep inky blue splotch on the Altiplano, sits on the border of Peru and Bolivia. At 3,811 m (12,500 ft) above sea level, it is the highest commercially navigable lake in the world. To the east the deep greens of the Amazon rainforest are visible, although in some areas a thin blue haze veils the forest. A stark white circular pattern marks the Salar de Uyuni, the world’s largest salt flat. It covers 10,582 square km (4,086 square mi) in southwestern Bolivia near the crest of the Central Andes. Formed as the result of drying of prehistoric lakes, the flat is covered by several meters of salt crust which overlies a pool of brine. The crust is a source of salt, while the brine is estimated to contain 50 to 70% of the world’s lithium reserves. The extensive surface of the salt flat, the normally cloud-free skies and the exceptional uniformity and flatness of the surface make it an ideal object for calibration of instruments aboard Earth observation satellites. In South America, the Andes mountain range blocks Pacific moisture, resulting in rainfall on the western slopes, but an arid climate just downwind on the eastern side of the mountains. In the southern most section of the image this difference in moisture is clearly illustrated. The forests and grasslands of southern Chile are intensely green, while western Argentina, just across the snow-dusted high Andean peaks, appears as a stark, desert-like tan.
