A 45 kyr laminae record from the Dead Sea: Implications for basin erosion and floods recurrence

2020 ◽  
Author(s):  
Nicolas Waldmann ◽  
Yin Lu ◽  
Revital Bookman ◽  
Shmulik Marco
Keyword(s):  
High Frequency ◽  
Lake Level ◽  
Dead Sea ◽  
Last Deglaciation ◽  
The Holocene ◽  
Lamina Thickness ◽  
The Last Deglaciation ◽  
The Dead ◽  
Basin Erosion ◽  
The Last Glacial

<p>Recording and analyzing how climate change impacts flood recurrence, basin erosion, and sedimentation can improve our understanding of these systems. The aragonite-detritus laminae couplets comprising the lacustrine formations that were deposited in the Dead Sea Basin are considered as faithful monitors of the freshwater supply to the lakes. We count a total of ~5600 laminae couplets deposited in the last 45 kyr (MIS3-MIS1) at the Dead Sea depocenter, which encompass the upper 141.6 m of the ICDP Core 5017-1. The present study shows that aragonite and detritus laminae are thinner and occur at high frequency during MIS 3-2, while they are much thicker and less frequent during MIS 1. By analyzing multiple climate-connected factors, we propose that significant lake-level drops, enhanced dust input, and low vegetative cover in the drainage basin during the last deglaciation (22-11.6 ka) have considerably increased erodible materials in the Dead Sea watershed. We find a decoupling existed between the significant lake-level drop/lake size reduction and lamina thickness change during the last deglaciation. We argue that during the last glacial and the Holocene, the variation of lamina thickness at the multiple-millennium scale was not controlled directly by the lake-level/size change. We interpret this decoupling implying the transport capacity of flash-floods is low and might be saturated by the oversupply of erodible materials, and indicating a transport-limited regime during the time period. We suggest that the observed thickness and frequency distribution of aragonite-detritus laminae points to the high frequency of small-magnitude floods during the last glacial period, in contrast to low frequency, but large-magnitude floods during the Holocene.</p>

New insights on sediment provenance in the Dead Sea since the last glacial maximum using grain-size distribution

2020 ◽  
Author(s):  
Cecile Blanchet ◽  
Hana Jurikova ◽  
Julia Fusco ◽  
Rik Tjallingii ◽  
Markus Schwab ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Lake Level ◽  
Regional Climate ◽  
Dead Sea ◽  
Sediment Provenance ◽  
Last Deglaciation ◽  
Sedimentary Dynamics ◽  
The Dead

<p>Sedimentary records from the Dead Sea constitute unique paleoclimatic archives that enable investigating the response of environments to climatic changes. Large lake-level fluctuations (>100 m) occurred during the past glacial-interglacial cycles due to reorganizations of the hydroclimatic regime and drastically modified the morphology of the drainage area. We aim here to reconstruct past sedimentary dynamics at times of varying lake level to gain insights into paleoclimate and landscape evolution.</p><p>For this study, we have compared present-day surface sediments (fluvial and soil sediments) retrieved on both the eastern Jordanian and western shores of the present Dead Sea with downcore sediment archives including the ICDP Dead Sea Deep Drilling Program Site 5017-1. Streams originating from various parts of the watershed can be distinguished by their grain-size distribution, with northern and south-western streams having generally finer grain-size modes when compared with streams from the eastern side. We find that all modes identified in the fluvial sediments were present in the ICDP downcore samples from the last deglaciation, when lake levels were up to 250m higher than today. This suggests that the whole watershed contributed to the sediment input at that time. In contrast, Holocene sediments from the deep core and shore deposits are enriched in fluvial particles showing similar grain-size modes as the northern and south-western streams. This suggests that these regions were prime sediment sources during lower lake-level stands. An additional mode, tentatively related to aeolian particles, was also identified in the Holocene samples, pointing to the remobilization of deposited dust in the watershed or to a more arid regional climate.</p><p>Our results provide a first synoptic view on sedimentary dynamics in the Dead Sea watershed and help to relate sediment provenance to the drainage morphology and paleo-hydrological regimes. They constitute a solid basis for further assessment of sedimentary provenance using geochemical indicators.</p>

Changes in hydroclimate during last deglaciation lake-level fall in the Dead Sea sediment record

2020 ◽  
Author(s):  
Markus J. Schwab ◽  
Daniela Müller ◽  
Ina Neugebauer ◽  
Rik Tjallingii ◽  
Yoav Ben Dor ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Lake Level ◽  
Drainage Basin ◽  
Eastern Mediterranean ◽  
Dead Sea ◽  
Laminated Sediments ◽  
Last Deglaciation ◽  
Sediment Record ◽  
Deep Lake ◽  
The Dead

<p>The drainage basin of the Dead Sea is the largest hydrological system in the Levant and spans across the boundary between the sub-humid to semi-arid Mediterranean and the arid to hyper-arid Saharo-Arabian climate zones. As a terminal lake, precipitation changes due to climatic variations result in extensive fluctuations of lake level and sediment deposition.</p><p>A unique sediment record from the deepest part of the Dead Sea Basin was obtained as part of the ICDP Dead Sea Deep Drilling Project. Here we analyze the partially annually laminated sediments of Core 5017-1-A between 88.5-99.2 m core depth, which comprise the period between ~16.5 and ~11 ka and document a lake level drop of ca 160 m. In the sediments of Core 5017-1-A, this marks the transition from MIS2 aad (alternating aragonite and detritus) sediments to MIS1 halite deposits and ld (laminated detrital marl) sediments, coinciding with increased drying in the Dead Sea watershed.</p><p>Microfacies analyses show the occurrence of several lithological facies that accumulated during MIS2: aad, gd (massive gypsum deposit within marl), native sulfur concretions (associated with greenish colored aad), mtd (mass-transport deposits, typically graded) and homogenites consisting of clay and silt. Further, flood layers have been identified, potentially indicating rainstorms associated with specific eastern Mediterranean synoptic systems. To complement the microfacies analyses, XRF scanning provides continuous Ti/Ca and S/Ca records to reconstruct relative detrital input and gypsum occurrence, respectively. Additionally, to study potential early signs of hydroclimatic change, the deep lake sediments are correlated to the Lisan Formation of the marginal Masada outcrop using distinct gypsum marker layers, indicative of pronounced lake level drops. However, due to a significant lake level decline, the Masada outcrop sediments terminate at around 14.5 ka and the subsequent lake level lowering is solely recorded in the deep lake sediments.</p><p>This study was funded by the German Science Foundation (DFG Grant BR 2208/13-1/-2). Further, it is a contribution to the Helmholtz Association (HFG) climate initiative REKLIM Topic 8 “Abrupt climate change derived from proxy data”.</p>

scholarly journals Stratigraphy, depositional environments and level reconstruction of the last interglacial Lake Samra in the Dead Sea basin

2009 ◽  
Vol 72 (1) ◽  
pp. 1-15 ◽  
Author(s):  
N. Waldmann ◽  
M. Stein ◽  
D. Ariztegui ◽  
A. Starinsky
Keyword(s):  
Lake Level ◽  
Dead Sea ◽  
Depositional Environments ◽  
Level Curve ◽  
Last Interglacial ◽  
Mean Sea Level ◽  
Dead Sea Basin ◽  
Arid Conditions ◽  
The Dead ◽  
The Last Glacial

AbstractIn this paper we describe the stratigraphy and sediments deposited in Lake Samra that occupied the Dead Sea basin between ∼ 135 and 75 ka. This information is combined with U/Th dating of primary aragonites in order to estimate a relative lake-level curve that serves as a regional paleohydrological monitor. The lake stood at an elevation of ∼ 340 m below mean sea level (MSL) during most of the last interglacial. This level is relatively higher than the average Holocene Dead Sea (∼ 400 ± 30 m below MSL). At ∼ 120 and ∼ 85 ka, Lake Samra rose to ∼ 320 m below MSL while it dropped to levels lower than ∼ 380 m below MSL at ∼ 135 and ∼ 75 ka, reflecting arid conditions in the drainage area. Lowstands are correlated with warm intervals in the Northern Hemisphere, while minor lake rises are probably related to cold episodes during MIS 5b and MIS 5d. Similar climate relationships are documented for the last glacial highstand Lake Lisan and the lowstand Holocene Dead Sea. Yet, the dominance of detrital calcites and precipitation of travertines in the Dead Sea basin during the last interglacial interval suggest intense pluvial conditions and possible contribution of southern sources of wetness to the region.

Holocene Climate Variability and Cultural Evolution in the Near East from the Dead Sea Sedimentary Record

2006 ◽  
Vol 66 (3) ◽  
pp. 421-431 ◽  
Author(s):  
Claudia Migowski ◽  
Mordechai Stein ◽  
Sushma Prasad ◽  
Jörg F.W. Negendank ◽  
Amotz Agnon
Keyword(s):  
Cultural Evolution ◽  
Lake Level ◽  
Near East ◽  
Eastern Mediterranean ◽  
Sediment Cores ◽  
Dead Sea ◽  
Cultural Development ◽  
The Holocene ◽  
Lake Level Changes ◽  
The Dead

AbstractA comprehensive record of lake level changes in the Dead Sea has been reconstructed using multiple, well dated sediment cores recovered from the Dead Sea shore. Interpreting the lake level changes as monitors of precipitation in the Dead Sea drainage area and the regional eastern Mediterranean palaeoclimate, we document the presence of two major wet phases (∼ 10–8.6 and ∼ 5.6–3.5 cal kyr BP) and multiple abrupt arid events during the Holocene. The arid events in the Holocene Dead Sea appear to coincide with major breaks in the Near East cultural evolution (at ∼ 8.6, 8.2, 4.2, 3.5 cal kyr BP). Wetter periods are marked by the enlargement of smaller settlements and growth of farming communities in desert regions, suggesting a parallelism between climate and Near East cultural development.

Boron isotope systematics of lacustrine carbonates: a new approach for tracing the palaeo-hydroclimatic evolution of the Dead Sea

2020 ◽  
Author(s):  
Hana Jurikova ◽  
Ina Neugebauer ◽  
Birgit Plessen ◽  
Michael Henehan ◽  
Rik Tjallingii ◽  
...  
Keyword(s):  
Lake Level ◽  
Environmental Changes ◽  
Dead Sea ◽  
Human Migration ◽  
Environmental Data ◽  
Boron Isotope ◽  
The Holocene ◽  
Last Glacial ◽  
Lacustrine Carbonates ◽  
The Dead

<p>Sedimentary sequences of the Dead Sea provide a unique high-resolution archive of past climatic changes in the Mediterranean-Levant, a key region for human migration out of Africa at the boundary of hemispheric climate belts. The well-preserved record of the Holocene Dead Sea and its Last Glacial precursor Lake Lisan is characterised by annual laminations – varves – composed of alternate layers of aragonite and detritus. Past lake level reconstructions suggest large fluctuations in the regional hydrological balance driven by abrupt climatic events, including a pronounced transition from lake level high-stand during the Last Glacial Maximum (LGM) to a low-stand at the onset of the Holocene [1]. On millennial timescales these changes have been associated with temperature variations recorded in the Greenland ice core, underscoring the potential of the Dead Sea to offer both regional and global perspectives on high-amplitude climatic events in the past. However, our ability to fully read the Dead Sea record critically depends on reliable extraction of palaeo-climatic and palaeo-environmental data from lacustrine carbonates, and an improved understanding of their formation. Here we present carbon, oxygen, boron isotope and trace element composition of hand-picked authigenic aragonite from a Dead Sea deep-drilling core (ICDP 5017-1; [2]) and shore outcrops. While traditionally used as a pH-proxy [3], we examine the possibility of applying boron geochemistry for reconstructing the source water and brine composition [4]. Using our innovative combined approach, we elucidate the palaeo-hydroclimatic evolution of the Dead Sea during intervals of major environmental changes since the end of the LGM. <br><br>[1] Torfstein A., <em>et al.</em> (2013) <em>Quat. Sci. Rev.</em> <strong>69</strong>, 1–7. <br>[2] Neugebauer I., <em>et al.</em> (2014) <em>Quat. Sci. Rev.</em> <strong>102</strong>, 149–165. <br>[3] Jurikova H., <em>et al.</em> (2019) <em>Geochim. Cosmochim. Acta</em> <strong>248</strong>, 370–386. <br>[4] Vengosh A., <em>et al.</em> (1991) <em>Geochim. Cosmochim. Acta</em> <strong>55</strong>, 1689–1695.</p>

The diatom flora of Lake Lisan (Israel): a preliminary investigation

2020 ◽  
Author(s):  
Hannah Hartung ◽  
Jane M. Reed ◽  
Thomas Litt
Keyword(s):  
Lake Level ◽  
Eastern Mediterranean ◽  
Sediment Cores ◽  
Dead Sea ◽  
Glacial Period ◽  
Last Glacial Period ◽  
Diatom Flora ◽  
Last Glacial ◽  
The Dead ◽  
The Last Glacial

<p>The Eastern Mediterranean, and the southern Levant in particular, is a key region for palaeoclimatological and palaeoenvironmental research due to its highly complex topography and climatic variability. Our understanding of environmental variability and its possible drivers, and the interaction with migration processes of modern <em>Homo sapiens</em> from a source area in Africa to Europe, is still limited. This is partly because continuous sediment records of sufficient age are rare across the Mediterranean Basin. The deposits of the Dead Sea represent an ideal archive to investigate palaeoenvironmental conditions during human migration phases in the Last Glacial period (MIS 4-2). </p><p>Diatoms (single-celled siliceous algae, Bacillariophyceae) have well-recognised potential to generate high-quality palaeolimnological data, especially in closed-basin saline lakes, but they remain one of the least-exploited proxies in Eastern Mediterranean palaeoclimate research. Here, we present preliminary results of a low-resolution diatom study derived from analysis of sediment deposits of Lake Lisan, the last glacial precursor of the Dead Sea. Sediment cores were recovered during an ICDP campaign in 2010/2011 from the centre of the modern Dead Sea. 18 sediment samples were analysed to investigate (a) the preservation of diatom valves in various evaporitic deposits (b) possible shifts in diatom species composition of Lake Lisan during the Last Glacial period, and (c) if diatoms can be used as proxy indicator for lake-level and, thus, palaeoclimate reconstruction. We focus on a prominent lake-level high stand of Lake Lisan at around 28-22 ka BP, which resulted in the merging Lake Lisan and freshwater Lake Kinneret.</p><p>First results show that the diatom preservation is exceptionally good in evaporitic deposits of the sediment cores from Lake Lisan, which is contradictory to the available literature. In contrast to Holocene deposits from the Dead Sea, diatoms are abundant in all analysed samples from laminated deposits from Lake Lisan: the diatom flora is dominated by halophilous benthic diatoms, such as <em>Amphora</em> spp., <em>Halamphora</em> spp. and <em>Nitzschia</em> spp. In phases of lake-level high stands of Lake Lisan, the diatom flora shifts towards a more plankton-dominated freshwater flora containing <em>Aulacoseira</em> spp. and taxa from the <em>Cyclotella-ocellata-</em>species complex.</p>

RADIOCARBON RESERVOIR AGES IN THE HOLOCENE DEAD SEA

Radiocarbon ◽  
2020 ◽  
Vol 62 (5) ◽  
pp. 1453-1473
Author(s):  
Nurit Weber ◽  
Boaz Lazar ◽  
Ofra Stern ◽  
George Burr ◽  
Ittai Gavrieli ◽  
...  
Keyword(s):  
Dissolved Inorganic Carbon ◽  
Dead Sea ◽  
Climate Conditions ◽  
The Holocene ◽  
Radiocarbon Age ◽  
The Past ◽  
Organic Debris ◽  
The Dead ◽  
The Difference ◽  
Continuous Deposition

ABSTRACTThe sources and fate of radiocarbon (14C) in the Dead Sea hypersaline solution are evaluated with 14C measurements in organic debris and primary aragonite collected from exposures of the Holocene Ze’elim Formation. The reservoir age (RA) is defined as the difference between the radiocarbon age of the aragonite at time of its precipitation (representing lakeʼs dissolved inorganic carbon [DIC]) and the age of contemporaneous organic debris (representing atmospheric radiocarbon). Evaluation of the data for the past 6000 yr from Dead Sea sediments reveal that the lakeʼs RA decreased from 2890 yr at 6 cal kyr BP to 2300 yr at present. The RA lies at ~2400 yr during the past 3000 yr, when the lake was characterized by continuous deposition of primary aragonite, which implies a continuous supply of freshwater-bicarbonate into the lake. This process reflects the overall stability of the hydrological-climate conditions in the lakeʼs watershed during the late Holocene where bicarbonate originated from dissolution of the surface cover in the watershed that was transported to the Dead Sea by the freshwater runoff. An excellent correlation (R2=0.98) exists between aragonite ages and contemporaneous organic debris, allowing the estimation of ages of various primary deposits where organic debris are not available.

Late Quaternary Geological History of the Dead Sea Area, Israel

1993 ◽  
Vol 39 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Y. Yechieli ◽  
M. Magaritz ◽  
Y. Levy ◽  
U. Weber ◽  
U. Kafri ◽  
...  
Keyword(s):  
Late Quaternary ◽  
Thick Layer ◽  
Time Frame ◽  
Dead Sea ◽  
Polar Regions ◽  
Geological History ◽  
The Holocene ◽  
History Of ◽  
The Dead ◽  
Sea Area

AbstractA 34.5 m borehole, which was drilled near the Dead Sea coast (altitude -394 m) in the southern part of the fan delta of Wadi Zeelim, reveals the geological history of that area from the latest Pleistocene to present. The depositional time frame is based on six 14C dates and two U-Th dates. An erosional (or nondepositional) period is implied by the hiatus between 21,100 yr B.P. (U-Th age, depth 33 m) and 11,315 yr B.P. (14C age, depth 32 m). A subsequent arid phase is recorded by a 6.5-m-thick layer of halite; based on 14C dates this phase relates to the abrupt Younger Dryas cold period reported in temperate to polar regions. The fragility of the environment in this region is indicated by the fact that the region experienced such a severe, short aridification phase (less than 1000 yr), evidence of which is found widely in the desert fringes of the Middle East and North Africa. The aragonite found in most of the Holocene section indicates that the well site was covered by the lake for most of the Holocene. Exceptions are the intervals at 0-3 and 10-14 m depths which represent low stands of the lake.

scholarly journals Near East Desertification: impact of Dead Sea drying on convective rainfall

2019 ◽  
Author(s):  
Samiro Khodayar ◽  
Johannes Hoerner
Keyword(s):  
Lake Level ◽  
Weather Prediction ◽  
Regional Climate ◽  
Atmospheric Stability ◽  
Lower Boundary ◽  
Heavy Precipitation ◽  
Dead Sea ◽  
Decadal Scale ◽  
The Dead ◽  
The Impact

Abstract. The Dead Sea desertification-threatened region is affected by continual lake level decline and occasional, but life-endangering flash-floods. Climate change has aggravated such issues in the past decades. In this study, the impact of the Dead Sea drying on the severe convection generating heavy precipitation in the region is investigated. Perturbation simulations with the high-resolution convection-permitting regional climate model COSMO-CLM and several numerical weather prediction (NWP) runs on an event time scale are performed over the Dead Sea area. A reference simulation covering the 2003 to 2013 period and a twin sensitivity experiment, in which the Dead Sea is dried out and set to bare soil, are compared. NWP simulations focus on heavy precipitation events exhibiting relevant differences between the reference and the sensitivity decadal realization to assess the impact on the underlying convection-related processes. On a decadal scale, the difference between the simulations points out that in future regional climate, under ongoing lake level decline, a decrease in evaporation, higher air temperatures and less precipitation is to expect. Particularly, an increase in the number of dry days and in the intensity of heavy precipitation is foreseen. The drying of the Dead Sea is seen to affect the atmospheric conditions leading to convection in two ways: (a) the local decrease in evaporation reduces moisture availability in the lower boundary layer locally and in the neighbouring, directly affecting atmospheric stability. Weaker updrafts characterize the drier and more stable atmosphere of the simulations where the Dead Sea has been dried out. (b) Thermally driven wind system circulations and resulting divergence/convergence fields are altered preventing in many occasions convection initiation because of the omission of convergence lines.

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