The Salinas Grandes del Noroeste, shared by the provinces of Jujuy and Salta, are the best-known salt flats in Argentina. They extend over an area of 212 km2 at an altitude of 3,450 meters above sea level.
It is a paradoxical landscape, on the one hand extremely inhospitable, but at the same time essential for life, configured by that indispensable element for all living organisms, as is salt.
Salt flat ecosystems are extremely fragile, due to the scarcity of surface water resources. They have their origin in long and complex salinization processes in closed basins (endorheic), with dry geological periods that produce the gradual evaporation of water and the precipitation of salts, alternating with wet periods that cause their redissolution, in addition to volcanic events that distribute and deposit other types of minerals.
In summer the maximum temperature is about 28°C with a huge thermal amplitude between day and night. In winter the temperature drops to several degrees below zero. Rainfall is very low (between 300 and 400 mm per year). When it rains in summer, the salt flats are usually covered with a thin layer of water that produces surprising mirages.
For a long time, it was believed that the polygons on the surface originated when the salt crust cracked, but the regular shapes could not be explained.
Recent studies indicate that during the evaporation process, the water near the surface becomes saltier and therefore heavier than the less salty water below, which produces a convection movement similar to the water in a pan that rises as it heats up, while the water at the surface descends. This process forms convection cells, which are squeezed together and whose boundaries form a hexagonal pattern. When the salt crystallizes at the surface, ridges are formed that trace the hexagonal edges of the convective cells below.
According to universes