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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.
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This content will become publicly available on May 22, 2026
The impact of a freshwater diluted plume on spatial halite accumulation in a hypersaline lake: Direct observations from the Dead Sea
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.
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- Award ID(s):
- 1936258
- PAR ID:
- 10611181
- Publisher / Repository:
- International Association of Sedimentologists
- Date Published:
- Journal Name:
- Sedimentology
- ISSN:
- 0037-0746
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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