The Salar de Uyuni salt flat in southwestern Bolivia features massive hexagonal patterns, resulting from the slow disturbance of brine in the ground.
The largest salt flat in the world transforms as nearby overflowing lakes cause its surface to be submerged beneath a thin layer of water, according to IFL Science. Salar de Uyuni is completely flat and spans approximately 10,582 km2, making it a vast reflective surface comparable to the Big Island of Hawaii. From space, it is visible as the larger of two adjacent salt flats, with Salar de Coipasa located to the northwest.
Hexagonal patterns on the surface of Salar de Uyuni. (Photo: iStock).
Salar de Uyuni is located in the Daniel Campos province of the Potosí region in southwestern Bolivia, and is less than a 10-minute drive from Uyuni Airport. It is a halite desert (natural salt mineral) and gypsum. The surface is rich in salt and often displays strange honeycomb patterns that perplex scientists. They are unsure why such geometrically perfect patterns exist, and the honeycomb cells are so large that their widths consistently range from 1 to 2 meters.
In 2023, a research team discovered the answer. According to Dr. Lucas Goehring, an associate professor of physics at Nottingham Trent University, the first and almost only thing visible on the salt desert is endless hexagons and various other shapes. “What we observed is a plausible and straightforward explanation, but it is hidden beneath the ground. The surface patterns reflect the slow disturbance of brine in the ground, a phenomenon akin to convective cells forming within the thin layer of water about to boil,” Goehring explained.
Salar de Uyuni is situated above the ancient Minchin Lake, which covered the plateau thousands of years ago. According to NASA’s Earth Observatory, the lake significantly shrank about 15,000 years ago, creating progressively smaller saltwater basins that eventually evaporated, leaving behind vast amounts of halite and gypsum.
The salt flat attracts millions of visitors each year, with thickness reaching up to 10 meters in some areas, providing stunning backdrops for photographers to compose their shots. During the brief rainy season from December to April, the salt flat receives only a few centimeters of rainfall annually. Water pools on the salt crust, forming a mirror that reflects the sky above.
