(ORDO NEWS) — Drying salt lakes are covered with irregular polyhedrons, limited by salt grooves.
Such figures are formed due to the slow mixing of liquids of different densities with the formation of convection cells, similar to granules on the surface of the Sun.
Salt marshes are covered with a crust of dried salt, which cracks, splitting into fragments in the form of irregular hexagons of approximately the same size, from one to two meters in diameter.
So far, there has been no reliable explanation for this process. Scientists from the UK and Austria managed to find it.
It turned out that the drying up of salt lakes on Earth resembles the movement of plasma on the Sun.
“Nature has given us a bright and fascinating riddle that stimulates curiosity and beckons to find a solution,” said Jana Lasser, one of the authors of the new work.
“Even though there is no direct application of this knowledge yet.”
By combining field observations and computer simulations, Yana Lasser and her colleagues described the following mechanism for polygon formation.
The liquid at the surface of the lake is heated by the sun and evaporates, causing the salt content in it to increase.
The higher the concentration of salt, the greater the density of the solution, so that after that it tends to sink down. Conversely, a less concentrated and dense liquid from below rises to the surface.
This leads to the formation of convection cells with a diameter of just over a meter: in the center of each of them, a less dense solution rises, and a more concentrated liquid settles at the edges.
As a result, salt accumulates along the perimeter of such cells and, drying out, forms furrows.
It is curious that similar convection processes associated with the mixing of hot plasma also lead to the appearance of characteristic granules on the Sun (and other stars).
Scientists managed to simulate these mechanisms in laboratory experiments with oversalted soil.
In addition, they demonstrated the formation of polygons using time-lapse photography of Owens Salt Lake in California’s Sierra Nevada desert.
The speed of this process and the size of the resulting figures are in good agreement with the predictions given by the new model.
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