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ABSTRACT The role of freshwater inputs and salinity gradients in hypersaline basins is crucial for understanding the formation of evaporitic sequences. However, this role remains poorly understood, as it involves complex processes such as mixing across density gradients, plume dynamics and air–water interactions. This study addresses this gap by investigating how a diluted buoyant plume, formed by freshwater inflows, affects spatial halite accumulation in the Dead Sea, a modern analogue for ancient evaporitic environments. In situ measurements of halite accumulation rates were conducted along transects extending from nearshore freshwater inflows (discharging ~70 × 10⁶m³year⁻¹), through the diluted plume, and into regions beyond the dilution effect. These measurements were complemented by analyses of spatiotemporal limnological conditions (salinity, temperature, turbidity and halite saturation), which are influenced by wind‐wave action. The diluted plume exhibits a distinct salinity structure, with full dilution at the freshwater spring discharge and exponential decay in both horizontal and vertical directions: horizontally, it decays over ~500 m, with surface dilution extending ~2 km offshore, and vertically it decays over ~0.06 m, creating a thin, highly diluted upper layer of about 1 m thick. Consequently, halite accumulation rates increase along the transect from the freshwater inflows towards deeper areas as the dilution effect diminishes. This process is controlled by (i) the transport of supersaturated brine and halite crystals from the non‐diluted environment under the diluted plume and (ii) direct precipitation of halite when the diluted plume undergoes mechanical mixing. Persistent undersaturation in the upper diluted plume layer prevents halite precipitation and, when combined with the declining lake level, leads to the dissolution of previously deposited halite layers in deeper areas. The absence of halite near the freshwater inflow and the thickening of halite towards the depocenter are observed in early Holocene Dead Sea basin halite sequences and other global halite records. 

Abstract Storm waves transport and sort coarse gravel along coasts. This fundamental process is important under changing sea‐levels and increased storm frequency and intensity. However, limited information on intra‐storm clast motion restricts theory development for coastal gravel sorting and coastal management of longshore transport. Here, we use smart boulders equipped with loggers recording underwater, real‐time, intra‐storm clast motion, and measured longshore displacement of varied‐mass marked boulders during storms. We utilize the unique setting of the Dead Sea shores where rapidly falling water levels allow isolating boulder transport during individual storms. Guided by these observations, we develop a new model quantifying the critical wave height for a certain clast mass mobilization. Then, we obtain an expression for the longshore clast displacement under the fluid‐induced pressure impulse of a given wave. Finally, we formulate the sorting enforced by wave‐height distributions during a storm, demonstrating how sorting is a direct manifestation of regional hydroclimatology. 

The environmental setting of the Dead Sea combines several aspects whose interplay creates flow phenomena and transport processes that cannot be observed anywhere else on Earth. As a terminal lake with a rapidly declining surface level, the Dead Sea has a salinity that is close to saturation, so that the buoyancy-driven flows common in lakes are coupled to precipitation and dissolution, and large amounts of salt are being deposited year-round. The Dead Sea is the only hypersaline lake deep enough to form a thermohaline stratification during the summer, which gives rise to descending supersaturated dissolved-salt fingers that precipitate halite particles. In contrast, during the winter the entire supersaturated, well-mixed water column produces halite. The rapid lake level decline ofO(1 m/year) exposes vast areas of newly formed beach every year, which exhibit deep incisions from streams. Taken together, these phenomena provide insight into the enigmatic salt giants observed in the Earth's geological record and offer lessons regarding the stability, erosion, and protection of arid coastlines under sea level change. 

When a saturated brine layer is cooled from above, both a convective temperature front as well as a front of sedimenting salt crystals can form. We employ direct numerical simulations to investigate the evolution and interaction of these two density fronts. Depending on the ratio of the temperature front velocity and the crystal settling velocity, which is governed by a dimensionless parameter in the form of a Rayleigh number, we find that either two separate fronts exist for all times, two initially separate fronts combine into a single front after some time or a single front exists at all times. We furthermore propose approximate scaling laws for the propagation of the thermal and crystal fronts in each regime and compare them with the simulation data, with generally good agreement.