Relationships between lake-level changes and water and salt budgets in the Dead Sea during extreme aridities in the Eastern Mediterranean

Abstract

Thick halite intervals recovered by the Dead Sea Deep Drilling Project cores show evidence for severely arid climatic conditions in the eastern Mediterranean during the last three interglacials. In particular, the core interval corresponding to the peak of the last interglacial (Marine Isotope Stage 5e or MIS 5e) contains ~30 m of salt over 85 m of core length, making this the driest known period in that region during the late Quaternary. This study reconstructs Dead Sea lake levels during the salt deposition intervals, based on water and salt budgets derived from the Dead Sea brine composition and amount of salt in the core. Modern water and salt budgets indicate that halite precipitates only during declining lake levels, while the amount of 2 dissolved Na + and Claccumulates during wetter intervals. Based on the compositions of Dead 24 Sea brines from pore waters and halite fluid inclusions, we estimate that ~12-16 cm of halite 25 precipitated per meter of lake-level drop. During periods of halite precipitation, the Mg 2+ 26 concentration increases and the Na + /Clratio decreases in the lake. Our calculations indicate 27 major lake-level drops of ~170 m from lake levels of 320 and 310 m below sea level (mbsl) 28 down to lake levels of ~490 and ~480 mbsl, during MIS 5e and the Holocene, respectively. 29These lake leves are much lower than typical interglacial lake levels of around 400 mbsl. These 30 lake-level drops occurred as a result of major decreases in average fresh water runoff, to ~40% 31 of the modern value (pre-1964, before major fresh water diversions), reflecting severe droughts 32 during which annual precipitation in Jerusalem was lower than 350 mm/y, compared to ~600 33 mm/y today. Nevertheless, even during salt intervals, the changes in halite facies and the 34 occurrence of alternating periods of halite and detritus in the Dead Sea core stratigraphy reflect 35 fluctuations between drier and wetter conditions around our estimated average. The halite 36 intervals include periods that are richer and poorer in halite, indicating (based on the 37 sedimentation rate) that severe dry conditions with water availability as low as ~20% of present 38 day, continued for periods of decades to centuries, and fluctuated with wetter conditions that 39 spanned centuries to millennia when water availability was ~50-100% of present day. These 40 conclusions have potential implications for the coming decades, as climate models predict 41 greater aridity in the region. 42 3 Mediterranean, reflecting both natural variability and increased anthropogenic greenhouse gas 47 concentrations and predict up to 20% decreases in water availability by the end of the 21 st 48 century (

Evidence for Middle Palaeolithic occupation and landscape change in central Armenia at the open-air site of Alapars-1

“…The most secure examples of H. sapiens ascribed to this phase are found in the Levant and include Qafzeh (Vandermeersch, 1981; Schwarcz et al, 1988; Valladas et al, 1988) and Skhul (McCown and Keith, 1939; Mercier et al, 1993; Grün et al, 2005). However, in recent years, the palaeoclimatic record in the Levant for the later stages of MIS 5 has been interpreted as a period of marked aridity (e.g., Neugebauer et al, 2016; Kiro et al, 2017; Palchan et al, 2017). In contrast to the palaeoclimatic proxies from Lake Lisan (the lacustrine forerunner of the present Dead Sea), the MIS 5 proxies from Lake Van suggest a shift to progressively warmer and wetter conditions within three periods of MIS 5: MIS 5e–d (124.1–111.5 ka); MIS 5c (107.8–87.2 ka), and MIS 5a (84.9–77.5 ka) (Pickarski et al, 2015a, 2015b; Kappenberg et al, 2019).…”

Medieval Climate in the Eastern Mediterranean: Instability and Evidence of Solar Forcing

“…The core comprises sequences of "muds" (mostly primary aragonite and fine detritus material) that were deposited during wet intervals, and salts (halites) that were deposited during hyper-arid periods in the lake's watershed [5]. We emphasize that the salt is possibly the best indicator for extremely arid conditions in the lake watershed and its deposition is associated with a sharp decline in the lake level [52]. The chronology of the core was established by U-Th and radiocarbon methods [53,54].…”

δ13C values in archaeological 14C‐AMS dated charcoals: Assessing mid‐Holocene climate fluctuations and human response from a high‐resolution isotope record (Arslantepe, Turkey)

“…In addition, a long dry period is evident from Jeita Cave, Lebanon . The water‐level record from the Dead Sea basin also shows lower depth from around 3800 to 3600 bc with regard to the later sequence, when the lake level grew consistently (Figure ).…”

“…Comparison between Near Eastern palaeoclimate proxies. From top to bottom: Δ 13 C mean values with standard errors of Arslantepe deciduous oak and juniper charcoal remains; δ 18 O values from Gölhisar Lake; δ 18 O values from Eski Acıgöl Lake; δ 13 C values from Lake Hazar; fluvial sedimentation phases from Upper Tigris valley; δ 18 O and Pistacia pollen % values from Lake Van; Δ 13 C mean values of deciduous oak charcoals from northern Syria sites; δ 18 O values from Soreq Cave speleothem; high‐water level of Dead Sea basin . Shaded rectangles and vertical dotted lines indicate the Rapid Climate Changes (RCC dry events) as singled out and described by Mayeski et al [Color figure can be viewed at wileyonlinelibrary.com]…”