Hydroclimatic Controls on Salt Fluxes and Halite Deposition in the Dead Sea and the Shaping of “Salt Giants”

As the only deep hypersaline, halite-precipitating lake on Earth today, the Dead Sea is the single modern analog for investigating the mechanisms by which large-scale and thick salt deposits, known as “salt giants”, have accreted in the geological record. We directly measure the hydroclimatic forcing and the physical limnologic processes leading to halite sedimentation, the vertical thermohaline structure, and salt fluxes in the Dead Sea. We demonstrate that changes in these forcing lead to strong seasonal and regional variations in the stratification stability ratio, triggering corresponding spatiotemporal variations in thermohaline staircase formation and diapycnal salt flux, and finally control the thickness of the halite layer deposited. The observed staircase formation is consistent with the mean-field γ instability, causing layering in double-diffusive convection. We show that double diffusion and thermohaline staircase formation drive the spatial variability of halite deposition in hypersaline water bodies, underlying and shaping “salt giants” basin architecture.