In to Atacama we go!
San Pedro de Atacama Travel Blog› entry 6 of 25 › view all entries
The Atacama Desert is the driest non-Arctic place on Earth, and is virtually sterile because it is blocked from moisture on both sides by the Andes Mountains and by the Chilean Coast Range. The cold Humboldt Current and the anticyclone of the Pacific are essential to keep the dry climate of Atacama Desert. The average rainfall in the Chilean region of Antofagasta is just 1 mm per year. Some weather stations in the Atacama have never received rain. Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971. It is so arid that mountains that reach as high as 6,885 meters are completely free of glaciers and, in the southern part from 25°S to 27°S, may have been glacier-free throughout the Quaternary though permafrost extends down to an altitude of 4,400 meters and is continuous above 5,600 meters. Studies by a group of British scientists have suggested that some river beds have been dry for 120,000 years.
Some locations in the Atacama do receive a marine fog known locally as the Camanchaca, providing sufficient moisture for hypolithic algae, lichens and even some cacti. But in the region that is in the "fog shadow" of the high coastal crest-line, which averages 3,000 m height for about 100 km south of Antofagasta, the soil has been compared to that of Mars. Due to its otherworldly appearance, the Atacama has been used as a location for filming Mars scenes, most notably in the television series Space Odyssey: Voyage to the Planets.
In 2003, a team of researchers published a report in Science magazine titled "Mars-like Soils in the Atacama Desert, Chile, and the Dry Limit of Microbial Life" in which they duplicated the tests used by the Viking 1 and Viking 2 Mars Landers to detect life, and were unable to detect any signs in Atacama Desert soil. The region may be unique on Earth in this regard and is being used by NASA to test instruments for future Mars missions.
The Atacama is sparsely populated. In an oasis, in the middle of the desert, at about 2000 meters elevation lies the village of San Pedro de Atacama. Its church was built by the Spanish in 1577. In pre-hispanic times, before the Inca Empire, the super-arid interior was inhabited mainly by the Atacameno tribe. It is most notable for the construction of fortified towns called pucaras, one of which can be seen a few miles from San Pedro de Atacama.
During the 16th, 17th and 18th centuries when under the Spanish Empire towns grew along the coast shipping ports for silver produced in Potosí and other mines. During the 19th century the desert came under control of Bolivia, Chile and Peru and soon became a conflictive zone due to unclear borders and the discovery of nitrate there. After the War of the Pacific in which Chile annexed most of the desert, cities in the zone grew into big international ports, and many Chilean workers migrated there.
We departed at 08.00 to the Atacama Salt Flat which is the largest salt flat in Chile. It is located 55 km south of San Pedro de Atacama and surrounded by mountains and has no drainage outlets. To the east it is enclosed by the main chain of the Andes, while to the west lies a secondary mountain range of the Andes called Cordillera de Domeyko. Large volcanoes dominate the landscape, including the Licancabur, Acamarachi, Aguas Calientes and the Láscar. The latter is one of the most active volcanoes in Chile. All of them are located along the eastern side of the Salar de Atacama, forming a generally north-south trending line of volcanoes that separate it from smaller endorheic basins.
The salt flat encompasses 3,000 km², is about 100 km long and 80 km wide, which makes it the Americas' second largest and is also the second in the world, after Salar de Uyuni in Bolivia (10,582 km²). Its average elevation is about 2,300 m. The topography of the core portion of the salar exhibits a high level of roughness, which is due to that the surface of this area is permanently free of water, unlike the most of the other salt flats, as for example the Salar de Uyuni, which is periodically covered with shallow water.
After lunch we drove through the Callejon Varelas and come to Aguas Calientes Salt Flat and after that we come to the Tuyajto Lagoon. Back on the road again we stopped at Socaire Village to see the 18:00 sunset while we drank coffee and tea. We arrived in San Pedro de Atacama at around 19:00 and were informed that Space Agency had tried to contact us about changing our initial Space Tour that was supposed to be from 21:00 to 22:00 to the next day at 23:00. We reluctantly accepted and went for dinner at El Blanco Restaurant.