Scientists solve mystery behind strange honeycomb pattern in salt deserts

Scientists have now determined the process that creates the stunning patchwork of hexagons on salt plains. The solution is concealed beneath the shell and functions like a radiator in the form of a doughnut.

Tourists are baffled by the mesmerizing honeycomb designs found in salt deserts like Badwater Basin in California's Death Valley and Salar de Uyuni in Bolivia, which have long served as an inspiration for science fiction film producers. Even scientists have had trouble understanding the process underlying the recognizable patterns.

Now, scientists believe they have discovered the answer to this riddle in nature.

Lucas Goehring, an assistant professor of physics at Nottingham Trent University in England, stated in a statement that "the fantastic scenery requires an answer" . "What we've demonstrated is that there is a straightforward, logical answer, but it is buried beneath the surface."

According to a research that was released in the journal Physical Review X on February 24th, the solution is in the groundwater underneath the salt crust . Researchers explain in the paper how layers of saline and less salty water move upward and downward in donut-shaped currents, which are compressed together horizontally to create the predictable pattern.

Previously, scientists hypothesized that the salt crust swells and dries out, bending and fragmenting under the pressure, causing the fissures and ridges to develop.

The hexagons are always 3 to 6 feet (1 to 2 meters) across, no matter where in the world they are located, according to the experts, who note that earlier efforts to comprehend the famous scenery did not take this into consideration.

The widely held belief that the geometric patterns are created by a process based on fundamental physics, similar to the movement of hot and cold water in a radiator or in a saucepan of boiling water, is confirmed by the new research. "The surface patterns represent the slow overturning of salty water within the soil, a process somewhat like the convection cells that develop in a thin layer of simmering water," Goehring said.

Salt regions are not as parched as they appear to be. Digging with your fingertips will reveal a stratum of highly salty water beneath the salt crust. In the sweltering summer, the water dissipates, leaving behind only a salty coating, some of which dissolves into the subsequent layer of water. Since this layer is now denser than the one beneath it, salty water descends in a ring around fresher, less density water as it rises to take its place. The salt substance that is left behind after the water dissipates dissolves back into the upper water layer. A convection roll, as it is known to experts, is created when the pattern is repeated.

Either these deep currents or the bedrock have been the subject of research on salt deserts. The two characteristics interact and mimic one another, according to the new research, to create the tessellations. 

A convection pastry would typically assume a donut-like form. On a salt flat, however, there are so many of them that they are crammed close together that the rolls press up against one another to create hexagons, according to the experts.

According to Stuart King, a researcher at the University of Edinburgh in Scotland who was not involved in the study and who provided an email response to Live Science, the authors provide a compelling reason for the startling trend. It is well known that convection and evaporation processes lead to hexagonal patterns, but this work makes a connection between those processes and the penetrative convection of the porous layer beneath, which seems very believable as a larger mechanism governing the entire salt formation.

The researchers claim that nothing but interest inspired their research. "Nature provides us with an apparent and intriguing conundrum that awakens our curiosity and thereby motivates us to solve it," said study first author Jana Lasser, a postdoctoral researcher at Graz University of Technology in Austria.