Why are salt flats around the world covered in a similar pattern of ridges?

Source: The post is based on the article “Why are salt flats around the world covered in a similar pattern of ridges?” published in The Hindu on 7th March 2023.

What is the News?

In salt flats across the globe, the salt on the surface forms pentagons and hexagons arranged in a patchwork pattern. These mesmerizing patterns have been captured in Bolivia, Chile, China, India (in the Rann of Kutch), Iran, Tunisia and even United States.

Researchers are puzzled by these patterns of salt flats. Now a study conducted by researchers from Austria, Germany and the United Kingdom may have found an explanation for these patterns of salt flats.

What are Salt Flats?

A salt flat is a natural landscape in which a large area of flat land is covered by salt.

World’s most well-known salt flat is the Salar de Uyuni in Bolivia contains more than half of the planet’s lithium reserves.

A salt flat forms from a natural water body whose recharge rate is lower than the evaporation rate. The underlying soil is highly saline: even if the water table is shallow, the groundwater is too salty for humans to drink.

How are the shapes of Salt Flats formed according to the study?

The study began with the hypothesis that the salt on the surface is influenced by the salt flowing through the soil below. 

Based on this, they found that the salt penetrated deeper into the soil exactly below the ridges and remained shallow under the flat areas. Due to this, salt on the surface forms pentagons and hexagons.

To mitigate the deleterious effects of salt flats, experts have recommended covering salt flats in a shallow layer of water, so that the salt is deposited on the surface more uniformly and less salt is carried away by winds.

What is the significance of this study?

Scientists have proposed a variety of explanations for why the surface of dried salt lakes develops this pattern of polygonal shapes at least since the early 1960s.

The majority of them have either thought about dynamics above or below the surface, but the new study demonstrates that polygons are formed when these two realms interact.