Salt polygons and porous media convection

Abstract

From fairy circles to patterned ground and columnar joints, natural patterns spontaneously appear in many complex geophysical settings. Here, we investigate the origins of polygonally patterned crusts of salt playa and salt pans. These beautifully regular features, approximately a meter in diameter, are found worldwide and are fundamentally important to the transport of salt and dust in arid regions. We show that they are consistent with the surface expression of buoyancy-driven convection in the porous soil beneath a salt crust. By combining quantitative results from direct field observations, analogue experiments and numerical simulations, we further determine the conditions under which salt polygons should form, as well as how their characteristic size emerges.

arXiv comment22 pages, 12 figures

References in corpus (3)

• Development and geometry of isotropic and directional shrinkage crack patterns
• Evolving fracture patterns: columnar joints, mud cracks, and polygonal terrain
• Stability of convection in dry salt lakes

Cited by in corpus (4)

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• Evolution of polygonal crack patterns in mud when subjected to repeated wetting-drying cycles
• Traveling spatially localized convective structures in an inclined porous medium
• Non-invasive imaging of solute redistribution below evaporating surfaces using 23Na-MRI