Article

Radiocarbon Chronology of the DSDDP Core at the Deepest Floor of the Dead Sea

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

This study establishes the chronological framework of the sedimentary sequence deposited Dead Sea, ICDP 5017-1, Radiocarbon chronology during the past 50 ka at the deepest part of the Dead Sea (the ICDP 5017-1 site), which was recovered by the Dead Sea Deep Drilling Project (DSDDP) under the auspices of the International Continental Scientific Drilling Program (ICDP). The age-depth model is constructed using 38 14C dates of terrestrial plant remains in a composite 150-m-long profile, generated by anchoring 32 marker layers identified in five cores. The sedimentary records at the ICDP 5017-1 site fills gaps in those obtained from the exposed sections at the high margins of the lake, particularly in times of lake-level retreat, and allows for a high-resolution comparison between the lake’s margins and deepest floor.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... During wetter intervals, reflected by lake-level rise, the sedimentary record is dominated by laminated detritus and the occasional occurrence of alternating aragonite and detritus. This study focuses on the section covering the last 11.5 ka (the Holocene), marked by a massive halite deposition at its base ( Fig. 2C) (Neugebauer et al., 2014;Kitagawa et al., 2017). ...
... The cores investigated in this study are from site 5017-1 (31.5083°N, 35.4710°E) of the DSDDP at the deepest point of the Dead Sea basin (Fig. 1). A detailed composite columnar section was established for this study using high-resolution images and μXRF measurements of the core sections 1 to 43 (0-90 m below lake floor), covering the entire Holocene (Neugebauer et al., 2014;Kitagawa et al., 2017), at a 0.5 cm resolution. The sedimentology of the sections was categorized here as either halite or mud (or non-recovery) for the purpose of the following modelling effort (Fig. 2C). ...
... The age model was adapted from Goldstein et al. (2020), who revised the chronology of the core by compiling 14 C, U-Th and 18 O data with lithological considerations. A radiocarbon sample just below the first halite occurrence during the Pleistocene-Holocene transition (89.25 m blf) is dated to ca 11 270 to 11 700 yr cal BP (Kitagawa et al., 2017). This age constrains the selected interval for the following simulations to the last 11.5 ka. ...
Article
Establishing accurate palaeo‐hydroclimatic reconstructions from lacustrine and marine archives is a long‐standing challenge in palaeoenvironment studies. Closed‐basin evaporites, and especially halite, record episodes of extremely arid conditions during rapid climate change. However, the complex limnological behaviour of deep hypersaline water bodies and the stochastic nature of the hydroclimatic regime and its variations limit detailed palaeo‐hydroclimatic interpretations from such records. Therefore, a mass‐balance model was developed to explore hydrology–limnology–sedimentology relationships in hypersaline environments under both deterministic and stochastic approaches that generates synthetic halite–mud sequences. Applying the model to the Holocene Dead Sea halites yields novel insights into palaeoenvironmental conditions in the Levant. The deterministic framework indicates that: (i) under a series of similar hydroclimatic cycles, the thickness of each subsequent halite interval decreases, due to the depletion of dissolved‐ions storage in the brine; (ii) halite deposition requires lake levels to drop below the minimal lake level of the preceding cycle; (iii) the time interval between halite deposition and the hydrological minimum is increasingly longer in subsequent cycles. Thus, counter‐intuitively, halite deposition mostly takes place as water discharge increases, providing that the water balance is still negative. The stochastic approach produced random sequences comparable to the observed Dead Sea sedimentary record. It demonstrates that some hydrological minima are not represented by halite deposition at all. Furthermore, the thickness and number of halite beds at each hydrological cycle vary substantially, depending on the specific hydrological conditions realized. Finally, these results imply that the major Dead Sea level drop at the pre‐Holocene deglaciation ( ca 14 ka bp ), previously assumed to be a record minimum, could not have been as pronounced as suggested, and must have been milder than the subsequent drop at the early Holocene ( ca 11–10 ka bp ).
... BP; e.g. Hajdas 2008; Ramsey et al. 2012;Kitagawa et al. 2017). In lake sediment records older than ~50 ka, U/Th-dating performed on lake carbonates provides the opportunity to date back until ~500 ka cal. ...
... The existing lateglacial chronology for the ICDP core based on radiocarbon (Neugebauer et al. 2014;Kitagawa et al. 2017) and U/Th-dating (Torfstein et al. 2015), as well as stratigraphic correlation of lithological units (Torfstein et al. 2015;Goldstein et al. 2020) is refined by cryptotephrochronology and varve counting. At Masada, a floating varve chronology is established. ...
... In the Lake Gościąż sediment record the here newly constructed chronology is based on varve counting and Bacon age-depth modelling. At the DS, the lateglacial chronologies were thus far based on radiocarbon and U/Th-dating in the ICDP core (Neugebauer et al. 2014;Torfstein et al. 2015;Kitagawa et al. 2017) and at Masada (Prasad et al. 2004;Torfstein et al. 2013a). In this thesis, both DS chronologies are updated by cryptotephrochronology and varve counting (chapters 4 and 5). ...
Thesis
Full-text available
Different lake systems might reflect different climate elements of climate changes, while the responses of lake systems are also divers, and are not completely understood so far. Therefore, a comparison of lakes in different climate zones, during the high-amplitude and abrupt climate fluctuations of the Last Glacial to Holocene transition provides an exceptional opportunity to investigate distinct natural lake system responses to different abrupt climate changes. The aim of this doctoral thesis was to reconstruct climatic and environmental fluctuations down to (sub-) annual resolution from two different lake systems during the Last Glacial-Interglacial transition (~17 and 11 ka). Lake Gościąż, situated in the temperate central Poland, developed in the Allerød after recession of the Last Glacial ice sheets. The Dead Sea is located in the Levant (eastern Mediterranean) within a steep gradient from sub-humid to hyper-arid climate, and formed in the mid-Miocene. Despite their differences in sedimentation processes, both lakes form annual laminations (varves), which are crucial for studies of abrupt climate fluctuations. This doctoral thesis was carried out within the DFG project PALEX-II (Paleohydrology and Extreme Floods from the Dead Sea ICDP Core) that investigates extreme hydro-meteorological events in the ICDP core in relation to climate changes, and ICLEA (Virtual Institute of Integrated Climate and Landscape Evolution Analyses) that intends to better the understanding of climate dynamics and landscape evolutions in north-central Europe since the Last Glacial. Further, it contributes to the Helmholtz Climate Initiative REKLIM (Regional Climate Change and Humans) Research Theme 3 “Extreme events across temporal and spatial scales” that investigates extreme events using climate data, paleo-records and model-based simulations. The three main aims were to (1) establish robust chronologies of the lakes, (2) investigate how major and abrupt climate changes affect the lake systems, and (3) to compare the responses of the two varved lakes to these hemispheric-scale climate changes. Robust chronologies are a prerequisite for high-resolved climate and environmental reconstructions, as well as for archive comparisons. Thus, addressing the first aim, the novel chronology of Lake Gościąż was established by microscopic varve counting and Bayesian age-depth modelling in Bacon for a non-varved section, and was corroborated by independent age constrains from 137Cs activity concentration measurements, AMS radiocarbon dating and pollen analysis. The varve chronology reaches from the late Allerød until AD 2015, revealing more Holocene varves than a previous study of Lake Gościąż suggested. Varve formation throughout the complete Younger Dryas (YD) even allowed the identification of annually- to decadal-resolved leads and lags in proxy responses at the YD transitions. The lateglacial chronology of the Dead Sea (DS) was thus far mainly based on radiocarbon and U/Th-dating. In the unique ICDP core from the deep lake centre, continuous search for cryptotephra has been carried out in lateglacial sediments between two prominent gypsum deposits – the Upper and Additional Gypsum Units (UGU and AGU, respectively). Two cryptotephras were identified with glass analyses that correlate with tephra deposits from the Süphan and Nemrut volcanoes indicating that the AGU is ~1000 years younger than previously assumed, shifting it into the YD, and the underlying varved interval into the Bølling/Allerød, contradicting previous assumptions. Using microfacies analyses, stable isotopes and temperature reconstructions, the second aim was achieved at Lake Gościąż. The YD lake system was dynamic, characterized by higher aquatic bioproductivity, more re-suspended material and less anoxia than during the Allerød and Early Holocene, mainly influenced by stronger water circulation and catchment erosion due to stronger westerly winds and less lake sheltering. Cooling at the YD onset was ~100 years longer than the final warming, while environmental proxies lagged the onset of cooling by ~90 years, but occurred contemporaneously during the termination of the YD. Chironomid-based temperature reconstructions support recent studies indicating mild YD summer temperatures. Such a comparison of annually-resolved proxy responses to both abrupt YD transitions is rare, because most European lake archives do not preserve varves during the YD. To accomplish the second aim at the DS, microfacies analyses were performed between the UGU (~17 ka) and Holocene onset (~11 ka) in shallow- (Masada) and deep-water (ICDP core) environments. This time interval is marked by a huge but fluctuating lake level drop and therefore the complete transition into the Holocene is only recorded in the deep-basin ICDP core. In this thesis, this transition was investigated for the first time continuously and in detail. The final two pronounced lake level drops recorded by deposition of the UGU and AGU, were interrupted by one millennium of relative depositional stability and a positive water budget as recorded by aragonite varve deposition interrupted by only a few event layers. Further, intercalation of aragonite varves between the gypsum beds of the UGU and AGU shows that these generally dry intervals were also marked by decadal- to centennial-long rises in lake level. While continuous aragonite varves indicate decadal-long stable phases, the occurrence of thicker and more frequent event layers suggests general more instability during the gypsum units. These results suggest a pattern of complex and variable hydroclimate at different time scales during the Lateglacial at the DS. The third aim was accomplished based on the individual studies above that jointly provide an integrated picture of different lake responses to different climate elements of hemispheric-scale abrupt climate changes during the Last Glacial-Interglacial transition. In general, climatically-driven facies changes are more dramatic in the DS than at Lake Gościąż. Further, Lake Gościąż is characterized by continuous varve formation nearly throughout the complete profile, whereas the DS record is widely characterized by extreme event layers, hampering the establishment of a continuous varve chronology. The lateglacial sedimentation in Lake Gościąż is mainly influenced by westerly winds and minor by changes in catchment vegetation, whereas the DS is primarily influenced by changes in winter precipitation, which are caused by temperature variations in the Mediterranean. Interestingly, sedimentation in both archives is more stable during the Bølling/Allerød and more dynamic during the YD, even when sedimentation processes are different. In summary, this doctoral thesis presents seasonally-resolved records from two lake archives during the Lateglacial (ca 17-11 ka) to investigate the impact of abrupt climate changes in different lake systems. New age constrains from the identification of volcanic glass shards in the lateglacial sediments of the DS allowed the first lithology-based interpretation of the YD in the DS record and its comparison to Lake Gościąż. This highlights the importance of the construction of a robust chronology, and provides a first step for synchronization of the DS with other eastern Mediterranean archives. Further, climate reconstructions from the lake sediments showed variability on different time scales in the different archives, i.e. decadal- to millennial fluctuations in the lateglacial DS, and even annual variations and sub-decadal leads and lags in proxy responses during the rapid YD transitions in Lake Gościąż. This showed the importance of a comparison of different lake archives to better understand the regional and local impacts of hemispheric-scale climate variability. An unprecedented example is demonstrated here of how different lake systems show different lake responses and also react to different climate elements of abrupt climate changes. This further highlights the importance of the understanding of the respective lake system for climate reconstructions.
... On the other hand, gypsum deposits are indicated by high log(S/Ca) ratios [31][32][33] . Ages in the following refer to the revised age model of the ICDP core using radiocarbon 23 and tephra 22 ages (Fig. 2, Table S1, "Methods"). Lithozone C1 is coeval with the UGU and comprises seven discrete gypsum intervals ( Fig. S1a-h, u) intercalated with mm-to dm-scale, often erosive, MTDs (Fig. S1q-t) and a total of ~ 340 aragonite varves (Fig. S1i-p). ...
... Based on tephrochronological dating (Fig. 2), the AGU coincides with the Younger Dryas/GS-1 22 , thus indicating a generally dry spell in the Levant during this cold Table S1. Ages 1, 7 and 10 denote radiocarbon ages from Kitagawa et al. 23 , and ages 3, 5 and 6 indicate the position of tephra horizons from the Nemrut V-16 and Süphan swarm eruptions V8-V15 from Neugebauer et al. 22 . Tephra ages are from Landmann et al. 30 and Schmincke & Sumita 29 . ...
... Between the AGU low-stand (Fig. 5a) and the onset of halite deposition during the early Holocene (Fig. 5c), which reflects the final lake level fall below the threshold for halite deposition of ~ 400 m bmsl 13 , a short lake level rise lasting ~ 50 years (Fig. 5a) is indicated by the deposition of varves and MTDs in the deep basin (Fig. 5c,d). According to radiocarbon ages ("Methods") this short-term rise occurred during the last glacial to Holocene transition 23 , and sediments associated with this short interval are missing in the littoral zone at Masada due to subsequent erosion or lack of deposition. In a regional context, the negative water budgets that we find in the DS during H1 and GS-1, as well as the positive water budget during GI-1, also appear in lower resolution δ 18 O data from the Soreq speleothem in the Judaean Mountains west of the Dead Sea 18 and from planktonic foraminifera in the Levantine Sea 20 , although less distinct for H1 (Fig. 6a-c). ...
Article
Full-text available
In-depth understanding of the reorganization of the hydrological cycle in response to global climate change is crucial in highly sensitive regions like the eastern Mediterranean, where water availability is a major factor for socioeconomic and political development. The sediments of Lake Lisan provide a unique record of hydroclimatic change during the last glacial to Holocene transition (ca. 24–11 ka) with its tremendous water level drop of ~ 240 m that finally led to its transition into the present hypersaline water body—the Dead Sea. Here we utilize high-resolution sedimentological analyses from the marginal terraces and deep lake to reconstruct an unprecedented seasonal record of the last millennia of Lake Lisan. Aragonite varve formation in intercalated intervals of our record demonstrates that a stepwise long-term lake level decline was interrupted by almost one millennium of rising or stable water level. Even periods of pronounced water level drops indicated by gypsum deposition were interrupted by decades of positive water budgets. Our results thus highlight that even during major climate change at the end of the last glacial, decadal to millennial periods of relatively stable or positive moisture supply occurred which could have been an important premise for human sedentism.
... Accordingly, this approach has also been applied to constrain the chronology of the ICDP deep core 5017-1. For the upper~150 m of the core, the age-depth model is based on 38 14 C dates of terrestrial plant remains that provide a relatively solid chronology for the last~50 ka, i.e. back to the limit of the radiocarbon dating method (Neugebauer et al. 2014(Neugebauer et al. , 2015Kitagawa et al. 2017). Unfortunately, this chronology includes unknown uncertainties because all dated plant remains could only be extracted from the base of turbidites so that reworking and resulting age/ depth reversals cannot be excluded. ...
... B. Dead Sea map with drilling locations of the ICDP 5017 expedition (diamonds; core 5017-1 is analysed in this study) and selected onshore sites studied earlier (circles). C. Core 5017-1 lithostratigraphy (Neugebauer et al. 2014) and selected 14 C (Kitagawa et al. 2017) and U-Th ages (Torfstein et al. 2015); corresponding marine isotope stages (MIS) and Dead Sea sediment formations (Fm.) are also marked. common features in the core (Neugebauer et al. 2014;Kagan et al. 2018) and further add to the uncertainty of the chronology, but this can hardly be quantified. ...
... In the ICDP core, this Early Holocene salt is evident at~71 to 88.5 m sediment depth (Figs 1C,11). No radiocarbon or U-Th ages exist from this section of the core, but a~75-cm-thick turbidite directly below is radiocarbon-dated at its base at 89.25 m b.l.f. to 11 440AE119 cal. a BP (Neugebauer et al. 2014;Kitagawa et al. 2017), supporting an age for the start of the salt sequence of~11 cal. ka BP in the marginal cores (Stein et al. 2010) if significant reworking of the dated sample is excluded. ...
Article
Full-text available
Dueto a lackof visible tephras in theDeadSea record, this unique palaeoenvironmentalarchive is largelyunconnected to the well-established Mediterranean tephrostratigraphy. Here we present first results of the ongoing search for cryptotephras in the International Continental Drilling Program(ICDP)sediment core fromthedeepDeadSeabasin. This study focussesontheLateglacial (~15–11.4 cal.kaBP),whenLake Lisan– the precursorof theDeadSea– shrank from its glacial highstand to the Holocene low levels.We developed a glass shard separation protocol and counting procedure that is adapted to the extreme salinity and sediment recycling of the DeadSea. Cryptotephra is abundant in the Dead Sea record (up to ~100 shards cm�3), but often glasses are physically and/or chemically altered. Six glass samples from five tephra horizons reveal a heterogeneous geochemical composition, with mainly rhyolitic and some trachytic glasses potentially sourced fromItalian, Aegean andAnatolianvolcanoes. Most shards likelyoriginate from the easternAnatolianvolcanic province and can be correlated using major element analyseswith tephra deposits from swarmeruptions of the S€uphan Volcano ~13 ka BP and with ashes from Nemrut Volcano, presumably the Lake Van V-16 volcanic layer at ~13.8 ka BP. In addition to glasses that match the TM-10-1 from Lago Grande di Monticchio (15 820�790 cal. a BP) tentatively correlated with the St. Angelo Tuff of Ischia, we further identified a cryptotephra with glass analyses which are chemically identical with those of the PhT1 tephra in the Philippon peat record (13.9–10.5 ka BP), and also a compositional match for the glass analyses of the Santorini Cape Riva Tephra (Y-2 marine tephra, 22 024�642 cal. a BP). These first results demonstrate the great potential of cryptotephrochronology in the Dead Sea record for improving its chronology and connecting the Levantine region to the Mediterranean tephra framework.
... A ~457 m ICDP composite Core 5017-1 was drilled at the Dead Sea depocenter under ~300 m of water . U-Th and 14 C dating constrain the age of the total penetrated depth at ~220 ka (Torfstein et al., 2015;Kitagawa et al., 2017). (Torfstein et al., 2015). ...
... (Torfstein et al., 2015). In this paper, we focus on the uppermost 141.6 m, whose chronology is constrained by thirty-one 14 C ages with 1σ error (Kitagawa et al., 2017) and one U-Th age with 2σ error (Torfstein et al., 2015) (Fig. 2). The sedimentary sequence spans the last ~45 kyr and is characterized by the alternating aragonite and detritus laminae (aad) facies interbedded with detritus layers, e.g., turbidites and homogenites (Neugebauer et al., 2014;Lu et al., 2017a) (Fig. 2). ...
... B: Generalized lithology column of the core section. C: Age-depth, which was plotted with thirty-two 14 C ages with 1σ error (Kitagawa et al., 2017) and one U-Th age with 2σ error (Torfstein et al., 2015). D: A combination of alternating aragonite and detritus laminae ...
... Recent studies used the ICDP borehole to calculate subsidence and accumulation rates (e.g., Kitagawa et al., 2017;Kagan et al.;2018). As detailed as these calculations are, they represent conditions solely at the location of the borehole, which was cored on the flank of the En Gedi diapir. ...
... Previous sedimentation rates were calculated for the Lisan and Ze'elim formations from the core itself. Kitagawa et al. (2017) showed that the rate increased significantly at the boundary between the Lisan and the Holocene from 2 mm/yr to 10 mm/yr, i.e. an increase of 5 times. This is comparable to our calculations, which also show that sedimentation rates during the deposition of the Ze'elim Fm were five times higher than in the Lisan across the lake (2.9 and 0.5 mm/yr, as can be seen in the left peaks of the black and blue histograms of Fig. 8 respectively) and four times higher in the salt rim syncline (6.2 and 1. 5 mm/yr as can be seen in the right peaks of the black and blue histograms of Fig. 8 respectively). ...
... This is comparable to our calculations, which also show that sedimentation rates during the deposition of the Ze'elim Fm were five times higher than in the Lisan across the lake (2.9 and 0.5 mm/yr, as can be seen in the left peaks of the black and blue histograms of Fig. 8 respectively) and four times higher in the salt rim syncline (6.2 and 1. 5 mm/yr as can be seen in the right peaks of the black and blue histograms of Fig. 8 respectively). Kitagawa et al. (2017) attributed enhanced sedimentation rates throughout the core in part to the chemical deposition of halite during intervals of low lake levels, similar to present-day deposition. Kagan et al. (2018) suggested that the increase in sedimentation rate of the Lisan Fm between the margins of the lake and the ICDP borehole reflect the presence of mass transport deposits in the latter and proposed a modified deposition rate of 0.43 mm/yr (more than 4 times lower than the rate proposed by Kitagawa et al. 2017) for the basin, which could reach as high as 0.53 mm/yr. ...
Article
The Dead Sea is an extensional basin developing along a transform fault plate boundary. It is also a terminal salt basin. Without knowledge of precise stratigraphy, it is difficult to differentiate between the role of plate and salt tectonics on sedimentary accumulation and deformation patterns. While the environmental conditions responsible for sediment supply are reasonably constrained by previous studies on the lake margins, the current study focuses on deciphering the detailed stratigraphy across the entire northern Dead Sea basin as well as syn and post‐depositional processes. The sedimentary architecture of the late Quaternary lacustrine succession was examined by integrating 851 km of seismic reflection data from three surveys with gamma ray and velocity logs and the stratigraphic division from an ICDP borehole cored in 2010. This allowed seismic interpretation to be anchored in time across the entire basin. Key surfaces were mapped based on borehole lithology and a newly constructed synthetic seismogram. Average interval velocities were used to calculate isopach maps and spatial and temporal sedimentation rates. Results show that the Amora Formation was deposited in a pre‐existing graben bounded by two N‐S trending longitudinal faults. Both faults remained active during deposition of the late Pleistocene Samra and Lisan Formations – the eastern fault continued to bound the basin while the western fault remained blind. On‐going plate motion introduced a third longitudinal fault, increasing accommodation space westwards from the onset of deposition of the Samra Formation. During accumulation of these two formations, sedimentation rates were uniform over the lake and similar. High lake levels caused an increase in hydrostatic pressure. This led to salt withdrawal, which flowed to the south and southwest causing increased uplift of the Lisan and En Gedi diapirs and the formation of localized salt rim synclines. This induced local seismicity and slumping, resulting in an increased thickness of the Lisan succession within the lake relative to its margins. Sedimentation rates of the Holocene Ze'elim Fm were 4‐5 times higher than before. The analysis presented here resolves central questions of spatial extent and timing of lithology, deposition rates and their variability across the basin, timing of faulting at and below the lake floor, and timing and extent of salt and plate tectonic phases and their effect on syn and post‐depositional processes. Plate tectonics dictated the structure of the basin, while salt tectonics and sediment accumulation were primarily responsible for its fill architecture during the timeframe examined here. This article is protected by copyright. All rights reserved.
... Previous studies by Torfstein et al. (2015) and Kitagawa et al. (2017) anchor the chronology of core 5017-1 by means of U-Th and 14 C methods, respectively. While the 14 C dating was performed on terrestrial plant remains to avoid a potential hard-water effect (Kitagawa et al., 2017), the U-Th dating was carried out on primary aragonites (aragonite laminae) (Torfstein et al., 2015). ...
... Previous studies by Torfstein et al. (2015) and Kitagawa et al. (2017) anchor the chronology of core 5017-1 by means of U-Th and 14 C methods, respectively. While the 14 C dating was performed on terrestrial plant remains to avoid a potential hard-water effect (Kitagawa et al., 2017), the U-Th dating was carried out on primary aragonites (aragonite laminae) (Torfstein et al., 2015). The age of core 5017-1 ranges from 220.0 ka to the present (Kitagawa et al., 2017;Neugebauer et al., 2014;Torfstein et al., 2015). ...
... While the 14 C dating was performed on terrestrial plant remains to avoid a potential hard-water effect (Kitagawa et al., 2017), the U-Th dating was carried out on primary aragonites (aragonite laminae) (Torfstein et al., 2015). The age of core 5017-1 ranges from 220.0 ka to the present (Kitagawa et al., 2017;Neugebauer et al., 2014;Torfstein et al., 2015). The Lisan Fm interval of~180.0-90.0 ...
Article
Full-text available
We have studied the history of earthquakes over the past 70 kyr by analyzing disturbed sedimentary layers around the margins of the Dead Sea. However, we know little about disturbances in the basin depocenter, where water depth is ~300 m, and accessible only by drilling. In this study, we compare disturbances from the Dead Sea depocenter, with the contemporaneous earthquake record (~56-30 ka) that was recovered on the western margin of the lake. This comparison allows us to discern the characteristics of disturbance in the different subaqueous environments and identify the source and sedimentary process of mass transport deposits. Our observations indicate that (i) the long disturbance sequences in the Dead Sea depocenter are composed of in situ deformation, slump, and chaotic deposits; (ii) earthquake-triggered Kelvin-Helmholtz Instability is a plausible mechanism for the in situ deformation in the lake center; (iii) the slump is slope area sourced; (iv) the unit of chaotic deposits is lakeshore sourced; and (v) earthquake-triggered slope instability is a viable mechanism for the slump and chaotic deposits. We further suggest that long sequences of disturbance in seismically active lake depocenters can be used to infer earthquake clusters.
... In nine intervals, mud layers (ranging in thickness between 10 and 200 cm) are present. As explained above, we interpret these mud layers as representing times when the lake-level rose above the sill and indicate wetter (Kiro et al., 2016;Torfstein et al., 2015) and ages (Kitagawa et al., 2017). The cores are composed of halite (blue), silty-clay (brown), aragonite layers (brown with white lines) and anthropogenic gravel at the top (orange). ...
... The compiled lake-level chronology, derived from the 238 radiocarbon ages from lake-margin exposures, southern basin cores, and from shallow cores from the western margin of the DS, provides a detailed history of the hydrological mass balance of the DS watershed and is the most direct and updated hydrological history of the Levant throughout the Holocene (Fig. 4). Additional important information regarding the DS lake status are derived from the deep core drilled into the depocenter of the northern basin and its lithological and geochemical proxies retrieved by the Dead Sea Deep Drilling Project (DSDDP) Kiro et al., 2020;Kitagawa et al., 2017;Neugebauer et al., 2014;Torfstein et al., 2015). Below, we combine these two sets of records, the levels from the margins and inferences from the core, and provide a hydrological and limnological history of the Holocene DS and discuss its implications. ...
Article
Water availability in the Levant is predicted to decline due to global warming in the upcoming decades and is expected to substantially impact the region. Determining the long-term natural rainfall variability in this region is essential for understanding the regional hydroclimatic response to external climate forcings and for contex-tualizing future hydroclimate changes. The Dead Sea (DS), located in the southern Levant, is a closed-basin lake whose size varies as a function of water availability. Reconstructing DS lake-level variations through time provides a quantitative measure of the natural hydroclimate variability and can inform on the local hydroclimate response to changes in global climate. Here, we constructed an updated lake-level history of the Holocene DS by: 1) studying lake high-stands derived from a series of new cores collected in the DS southern basin, 2) re-dating of the two major Holocene high-stand exposures, and 3) compiling all previously published ages of Holocene DS lake-level markers (n = 296 radiocarbon ages). The results show that the early (10-6.1 kyr cal BP) and late Holocene (3.6-0 kyr cal BP) in the DS were predominantly wet albeit punctuated by dry intervals, whereas the middle Holocene (6.1-3.6 kyr cal BP) was most likely relatively dry. This pattern of two Holocene humid intervals is also evident in distillation records derived from Levant speleothem caves (which represent the integrated magnitude of rainout from the vapor source to the caves), indicating that rainfall intensity and total water availability were correlated throughout the Holocene. These two humid intervals occurred during high and low summer insolation conditions, suggesting that they were modulated by different climatic mechanisms. The predicted future drying in the Levant is of similar magnitude to the natural hydroclimate variability and thus, it is crucial to assess whether the anthropogenic drying is in-or out-of phase with the natural climate variability.
... The recovery rate is about 90% (Neugebauer et al., 2014). The sedimentary sequence covers the past 220 kyr and its age model is built on a combination of 14 C (Kitagawa et al., 2017) and U-Th (Torfstein et al., 2015) dating, and δ 18 O stratigraphy correlation (Goldstein et al., 2020). The recovered sequence comprises seven basic facies which can be classified into four groups, (I) evaporites and related facies: halite, gypsum, and aragonite-detritus laminae (including in situ deformed ones) (Fig. 2), (II) slump facies (Fig. 2), (III) debrite facies (Figs. 2, 3) and graded turbidite facies (Figs. ...
... Thus, we apply linear interpolation to the age calculation of sediment layers between dated horizons. By using 14 C (Kitagawa et al., 2017), U-Th (Torfstein et al., 2015), and δ 18 O stratigraphy correlation (Goldstein et al., 2020) methods, more than 50 dated horizons in the ICDP Core 5017-1 are available for age interpolation during the past 220 kyrs. The dated horizons have been previously summarized in Lu et al. (2020b) (Table S1). ...
Article
Full-text available
In lakes and oceans, links between modern sediment density flow processes and deposits preserved in long-term geological records are poorly understood. Consequently, it is unclear whether, and if so how, long-term climate changes affect the magnitude/frequency of sediment density flows. One approach to answering this question is to analyze a comprehensive geological record that comprises deposits that can be reliably linked to modern sediment flow processes. To address this question, we investigated the unique ICDP Core 5017-1 from the Dead Sea (the largest and deepest hypersaline lake on the Earth) depocenter covering MIS 7-1. Based on an understanding of modern sediment density flow processes in the lake, we link homogeneous muds in the core to overflows (surface flood plumes, ρflow<ρwater), and link graded turbidites and debrites to underflows (ρflow>ρwater). Our dataset reveals (1) overflows are more prominent during interglacials, while underflows are more prominent during glacials; (2) orbital-scale climate changes affected the flow magnitude/frequency via changing salinity and density profile of lake brine, lake-level, and source materials.
... et al. (2020) in order to 1) incorporate the recently-released IntCal20 calibration curve; 2) account for MTDs and 3) provide a Bayesian estimate of age-depth relationship that can be used for uncertainty quantification. Chronological constraints consist of radiocarbon dating of terrestrial plant debris (Kitagawa et al., 2017), U/Th dating of primary aragonite (Torfstein et al., 2015), lithological tie-points to facies in dated outcrops of the Lisan Formation along the lake margins , tiepoints between d 18 O measurements of aragonite and the Soreq Cave speleothem , and, for MIS 6 and 7, tuning of the d 18 O of aragonite to Northern Hemisphere summer insolation . Following Goldstein et al. (2020), we combine this information together to form an updated age model for Hole 5017-1-A. ...
... We use the event-free depth (efd) of Kagan et al. (2018) for age modeling, which omits identified MTDs of greater than 0.5 m thickness from the stratigraphy. From 0 to 158 m below lake floor (mblf; 0e129 efd), we rely on the radiocarbon and U/Th dates, omitting 14 C dates that were previously identified as reversed (Kitagawa et al., 2017) and/or are located within a MTD (Fig. 2). We also omit a 14 C date from 89.25 mblf (88.65 efd) which calibrates to the Younger Dryas 14 C plateau. ...
Article
The eastern Mediterranean is projected to experience increases in drought and extreme rainfall in response to rising greenhouse gas emissions. Paleoclimate records from this region are crucial to further constrain the response of the water cycle to a globally warmer climate. Of these, the Dead Sea lacustrine record, collected by the Dead Sea Deep Drilling Project (DSDDP), provides a detailed history of climate change over the past 200,000 years and documents large-magnitude changes in regional water balance. Here, we analyze leaf wax isotopes (dD wax , d 13 C wax) on DSDDP 5017-1 and compare results to other proxies analyzed on the same core. The dD wax record closely resembles the speleothem d 18 O record from nearby Soreq Cave, suggesting that both record a regionally coherent signature of glacial-interglacial cycles and the interplay between winter season rainfall and large-scale expansion and contraction of the Afro-Asian monsoon system. Principal components analysis of the pollen and core lithology shows that the first-order driver of variability in the Dead Sea paleoclimate record is global temperature, which controls effective moisture by modulating atmospheric evaporative demand. Leaf wax, pollen, and core lithology all suggest radical changes in the annual cycle of precipitation during the peak of the Last Interglacial. We hypothesize that the Dead Sea Basin experienced a dual-rainfall regime during this time, with intensified winter storms and a summer monsoon season. While these changes were driven by the Earth's precessional cycle, model simulations suggest a similar expansion of the African monsoon domain into the Arabian Peninsula under elevated CO 2 levels. The Last Interglacial climate of the DSB provides a glimpse of what future climate in the southeastern Mediterranean region could look like.
... 35°28′15.60″E. The chronology of the investigated sediment sequence for Holocene sediments ( Figure 2a) is based on a linear interpolation of calibrated radiocarbon ages derived from terrestrial plant remains from site 5017-1 (Kitagawa et al., 2017;Neugebauer et al., 2014;Figure 2b). ...
... Additionally, we use a stoichiometric ratio of organic C:SO 4 of 2:1 based on the generalized pathway of MSR (i.e., Equation 1) to obtain a first-order approximation for the amount of organic carbon oxidized (weight %; relative to sediment) by the calculated (Neugebauer et al., 2014 andKitagawa et al., 2017). Green triangles indicate depths where lipid biomarkers were analyzed for this study (samples S17, S18, S19, S21; Figure ...
Article
Full-text available
The hypersaline Dead Sea and its sediments are natural laboratories for studying extremophile microorganism habitat response to environmental change. In modern times, increased freshwater runoff to the lake surface waters resulted in stratification and dilution of the upper water column followed by microbial blooms. However, whether these events facilitated a microbial response in the deep lake and sediments is obscure. Here we investigate archived evidence of microbial processes and changing regional hydroclimate conditions by reconstructing deep Dead Sea chemical compositions from pore fluid major ion concentration and stable S, O, and C isotopes, together with lipid biomarkers preserved in the hypersaline deep Dead Sea ICDP‐drilled core sediments dating to the early Holocene (ca. 10,000 years BP). Following a significant negative lake water balance resulting in salt layer deposits at the start of the Holocene, there was a general period of positive net water balance at 9500–8300 years BP. The pore fluid isotopic composition of sulfate exhibit evidence of intensified microbial sulfate reduction, where both δ34S and δ18O of sulfate show a sharp increase from estimated base values of 15.0‰ and 13.9‰ to 40.2‰ and 20.4‰, respectively, and a δ34S vs. δ18O slope of 0.26. The presence of the n‐C17 alkane biomarker in the sediments suggests an increase of cyanobacteria or phytoplankton contribution to the bulk organic matter that reached the deepest parts of the Dead Sea. Although hydrologically disconnected, both the Mediterranean Sea and the Dead Sea microbial ecosystems responded to increased freshwater runoff during the early Holocene, with the former depositing the organic‐rich sapropel 1 layer due to anoxic water column conditions. In the Dead Sea prolonged positive net water balance facilitated primary production and algal blooms in the upper waters and intensified microbial sulfate reduction in the hypolimnion and/or at the sediment–brine interface.
... The cores of site 5017 were dated by combining 14 C dating of macro-organic debris including seeds and twigs (Neugebauer et al., 2014) with U-Th dating of primary aragonites (Torfstein et al., 2015) and by correlating their δ 18 O with cave deposits (e.g., Lisiecki and Raymo, 2005;Bar-Matthews et al., 1999. The agedepth model for the sections used in this study was established through a Markov chain Monte Carlo procedure utilizing 14 C dates covering ∼ 50 kyr ( Fig. 2; Kitagawa et al., 2017). ...
... The segments com- Torfstein and Enzel, 2017). Bottom: the age-depth model of the ICDP-DSDDP 5017-1 core and the position of the studied segments along the core (after Kitagawa et al., 2017). and earthquakes (Fig. 2;Kagan et al., 2018). ...
Article
Full-text available
Annual and decadal-scale hydroclimatic variability describes key characteristics that are embedded into climate in situ and is of prime importance in subtropical regions. The study of hydroclimatic variability is therefore crucial to understand its manifestation and implications for climate derivatives such as hydrological phenomena and water availability. However, the study of this variability from modern records is limited due to their relatively short span, whereas model simulations relying on modern dynamics could misrepresent some of its aspects. Here we study annual to decadal hydroclimatic variability in the Levant using two sedimentary sections covering ∼ 700 years each, from the depocenter of the Dead Sea, which has been continuously recording environmental conditions since the Pleistocene. We focus on two series of annually deposited laminated intervals (i.e., varves) that represent two episodes of opposing mean climates, deposited during MIS2 lake-level rise and fall at ∼ 27 and 18 ka, respectively. These two series comprise alternations of authigenic aragonite that precipitated during summer and flood-borne detrital laminae deposited by winter floods. Within this record, aragonite laminae form a proxy of annual inflow and the extent of epilimnion dilution, whereas detrital laminae are comprised of sub-laminae deposited by individual flooding events. The two series depict distinct characteristics with increased mean and variance of annual inflow and flood frequency during “wetter”, with respect to the relatively “dryer”, conditions, reflected by opposite lake-level changes. In addition, decades of intense flood frequency (clusters) are identified, reflecting the in situ impact of shifting centennial-scale climate regimes, which are particularly pronounced during wetter conditions. The combined application of multiple time series analyses suggests that the studied episodes are characterized by weak and non-significant cyclical components of sub-decadal frequencies. The interpretation of these observations using modern synoptic-scale hydroclimatology suggests that Pleistocene climate changes resulted in shifts in the dominance of the key synoptic systems that govern rainfall, annual inflow and flood frequency in the eastern Mediterranean Sea over centennial timescales.
... Pore-fluids were extracted from the DSDDP 5017-1-A core that was drilled at the center of the lake at a water depth of 300 m where over 450 m of lake sediment spanning back ca. 220ka was recovered (Neugebauer et al., 2014;Torfstein et al., 2015, Kitagawa et al., 2017. The pore-fluids show that Lake Lisan's hypolimnion was significantly diluted relative to pore-fluids from the previous interglacial, and relative to present day Dead Sea. ...
... Core 5017-3-C was drilled off the shore of Ein Gedi Spa ( Fig. 1) at water depth of~2.5 m. The chronology of the 5017-1-A is given by Torfstein et al. (2015) and Kitagawa et al. (2017). The chronology of core 5017-3-C was constructed by lithological correlation to core 5017-1-A (Coianiz et al., 2019). ...
... Here, we present a new palynological study conducted on sediments of the last glacial Lake Lisan (Lisan Formation). The investigated sediments were recovered in the framework of the International Continental Scientific Drilling Program (ICDP) from the central Dead Sea (Stein et al., 2011a, b) and have an independent chronology based on 14 C and U-Th dating (Neugebauer et al., 2014;Torfstein et al., 2015;Kitagawa et al., 2017). The palynological study provides new and detailed insights into the last glacial vegetation and fire history of the southern Levant in relation to climate changes. ...
... The current chronology of the investigated sediment sequence is based on a linear interpolation of published 14 C and UeTh dates (Table 1). Twelve 14 C dates were conducted from terrestrial plant remains of core 5017-1-A (Neugebauer et al., 2014;Kitagawa et al., 2017). We calibrated the 14 C dates using the calibration dataset IntCal13 (Reimer et al., 2013) within the software OxCal 4.2 (Ramsey, 2009). ...
Article
Full-text available
The southern Levant is a key region for studying vegetation developments in relation to climate dynamics and hominin migration processes in the past due to the sensitivity of the vegetation to climate variations and the long history of different anthropogenic occupation phases. However, paleoenvironmental conditions in the southern Levant during the Late Pleistocene were still insufficiently understood. Therefore, we investigated the vegetation and fire history of the Dead Sea region during the last glacial period. We present a new palynological study conducted on sediments of Lake Lisan, the last glacial precursor of the Dead Sea. The sediments were recovered from the center of the modern Dead Sea within an ICDP campaign. The palynological results suggest that Irano-Turanian steppe and Saharo-Arabian desert vegetation prevailed in the Dead Sea region during the investigated period (ca. 88,000–14,000 years BP). Nevertheless, Mediterranean woodland elements significantly contributed to the vegetation composition, suggesting moderate amounts of available water for plants. The early last glacial was characterized by dynamic climate conditions with pronounced dry phases and high but unstable fire activity. Anatomically modern humans entered the southern Levant during a climatically stable phase (late MIS 4–MIS 3)with diverse habitats, constant moisture availability, and low fire activity. MIS 2 was the coldest phase of the investigated timeframe, causing changes in woodland composition and a widespread occurrence of steppe. We used a biome modeling approach to assess regional vegetation patterns under changing climate conditions and to evaluate different climate scenarios for the last glacial Levant. The study provides new insights into the environmental responses of the Dead Sea region to climate variations through time. It contributes towards our understanding of the paleoenvironmental conditions in the southern Levant, which functioned as an important corridor for human migration processes.
... The dominance of Halobacteriaceae sequences, and more precisely from the genus Salinarchaeum (annotated as Halorhabdus in the NCBI database) is a common feature of the present Dead Sea community, both in the water column (Bodaker et al., 2010;Jacob et al., 2017) and in the halite sediment . It seems that this genus has inhabited the Dead Sea water column for a long time, as similarly affiliated sequences were retrieved in the 48.12 mblf halite, which age is estimated by 14 C at 6640 ± 45 BP (Kitagawa et al., 2017). Salinarchaeum/Halorhabdus members have been acknowledged to be highly versatile and may grow in oxic and anoxic environments, preventing any inference on their environmental niche other than their flexibility. ...
... Two other halophilic bacterial anaerobes were identified through their fluid inclusion 16S rRNA gene sequences: Halanaerobium and Acethothermia. The age of the halite from which Halanaerobium sequences have been recovered is estimated between 4130 ± 40 and 4815 ± 35 BP (Kitagawa et al., 2017), a period during which the lake levels and salinity were comparable to the present (Levy et al., 2017). Similar organisms were previously identified in a microbial mat in the vicinity of the Dead Sea , where salinity was alike the modern Dead Sea. ...
Article
The Dead Sea Deep Drilling Project allowed us to retrieve a continuous sedimentary record spanning the two last glacial cycles. This unique archive, in such an extreme environment, has permitted the development of new proxies and the refinement of already available paleoenvironmental studies. Although life is pushed to its extremes in the Dead Sea environment, several studies have highlighted the impact of microbial activity on this harsh milieu. The identity and means of adaptation of these organisms are however partly ignored. We also know relatively little on the way this extreme ecosystem has evolved with time, and how it will react to growing pressure. In this study, we have used the fluid inclusions trapped in halite, the main evaporitic phase during arid periods in the Dead Sea, to investigate the way the Dead Sea ecosystem has evolved. By extracting ancient DNA from Holocene halite fluid inclusions, we have obtained fossil bacterial and archaeal 16S rRNA gene sequences that suggest that the main microbial actors of the present Dead Sea have been present in the lake for a relatively long period, emphasizing the stability of this extreme environment. This is the case of extreme halophilic archaea of the Salinarchaeum genera. Additionally, we show that current phylotypes of the deep biosphere, such as Acetothermia bacteria are present within the obtained fluid inclusions sequences, which would support seeding of the deep biosphere from the water column. Finally, through the retrieval of sequences assigned to Halodesulfurarchaeum and Desulfovermiculus genera, we shed light on putative new actors of the sulfur cycle involving respectively archaea and bacteria, which could play an unexpected role in the reduction of sulfur species. Together, these data provide new research avenues for both geologists and biologists working in this extreme environment, and help to increase understanding of the evolution of the Dead Sea ecosystem with time.
... 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 [54]. The chronology of the core was established by U-Th and radiocarbon methods [55,56]. The radiocarbon dating of the Holocene segment revealed that a prominent salt unit was deposited between ~800 and ~1100 C.E. ( Figure A1). ...
... To find the dates of the drought-related salt layer, between the depth of 9.2 m and 6.2 m, we use the nearest 14 C dated location, at a depth of 9.49 m (marked by the arrow). This depth location was dated by Kitagawa et al. [56] as having an age of 1300 ± 40 years BP, corresponding to the year of 710 C.E. ± 40 years. We then use a sedimentation rates of ~4 mm/year (the estimated rate for all types of sediments except for salt) to estimate the date at the bottom of the salt layer and a sedimentation rate of ~10 mm/yr for salt to determine the date at the top of the salt layer. ...
Article
Full-text available
This paper examines the hydroclimate history of the Eastern Mediterranean (EM) region during the 10th to 14th centuries C.E., a period known as the Medieval Climate Anomaly (MCA), a time of significant historical turmoil and change in the region. The study assembles several regional hydroclimatic archives, primarily the Dead Sea reconstructed lake level curve together with the recently extracted deep-lake sediment record, the Soreq Cave speleothem record and its counterpart, the EM marine sediment record and the Cairo Nilometer record of annual maximum summer flood levels in lower Egypt. The Dead Sea record is a primary indicator of the intensity of the EM cold-season storm activity while the Nilometer reflects the intensity of the late summer monsoon rains over Ethiopia. These two climate systems control the annual rainfall amounts and water availability in the two regional breadbaskets of old, in Mesopotamia and Egypt. The paleoclimate archives portray a variable MCA in both the Levant and the Ethiopian Highlands with an overall dry, early-medieval climate that turned wetter in the 12th century C.E. However, the paleoclimatic records are markedly punctuated by episodes of extreme aridity. In particular, the Dead Sea displays extreme low lake levels and significant salt deposits starting as early as the 9th century C.E. and ending in the late 11th century. The Nile summer flood levels were particularly low during the 10th and 11th centuries, as is also recorded in a large number of historical chronicles that described a large cluster of droughts that led to dire human strife associated with famine, pestilence and conflict. During that time droughts and cold spells also affected the northeastern Middle East, in Persia and Mesopotamia. Seeking an explanation for the pronounced aridity and human consequences across the entire EM, we note that the 10th–11th century events coincide with the medieval Oort Grand Solar Minimum, which came at the height of an interval of relatively high solar irradiance. Bringing together other tropical and Northern Hemisphere paleoclimatic evidence, we argue for the role of long-term variations in solar irradiance in shaping the early MCA in the EM and highlight their relevance to the present and near-term future.
... The dominance of Halobacteriaceae sequences, and more precisely from the genus Salinarchaeum (named Halorhabdus in the NCBI database) is a common feature of the present Dead Sea community, both in the water column (Bodaker et al., 2010;Jacob et al., 2017) and in the halite sediment . It seems that this genus has inhabited the Dead Sea water column for a long time, as similarly affiliated sequences were retrieved in the 48.12 mblf halite, which age is estimated by 14 C at 6640 ±45 BP (Kitagawa et al., 2016). Salinarchaeum/Halorhabdus members have been acknowledged to be highly versatile and may grow in oxic and anoxic environments, preventing any inference on their environmental niche (Werner et al., 2014). ...
... BP (Kitagawa et al., 2016), a period during which the lake level may have had comparable levels and salinity than today (Levy et al., 2017). Similar organisms were previously identified in a microbial mat in the vicinity of the Dead Sea , where salinity was alike the modern Dead Sea. ...
Preprint
Full-text available
The Dead Sea Deep Drilling Project allowed to retrieve a continuous sedimentary record spanning the two last glacial cycles. This unique archive, in such an extreme environment, has allowed for the development of new proxies and the refinement of already available paleoenvironmental studies. In particular, the interaction of the lake and sediment biosphere with elements and minerals that constitute paleoclimatic proxies has been emphasized. Although life is pushed to its extremes in the Dead Sea environment, several studies have highlighted the impact of microbial activity on this harsh milieu. The paradox is that the identity and means of adaptation of these organisms are largely ignored. We also know relatively little on the way this extreme ecosystem has evolved with time, and how it will react to growing pressure. Constraining this gap should allow to gain precision on the use of paleoenvironmental studies, and also assess the impact of human activity and climate change on a rare ecosystem. In this study, we use halite, the main evaporitic phase during arid periods in the Dead Sea basin and extract ancient DNA from their fluid inclusions, in order to characterize the ancient life of the Holocene Dead Sea. With the aid of an accurately designed protocol, we obtained fossil bacterial and archaeal 16S rRNA gene sequences that illustrate that the main microbial actors of the present Dead Sea have been present in the lake for a relatively long period, emphasizing the stability of this extreme environment. Additionally, we show that current phylotypes of the deep biosphere are present within the obtained fluid inclusions sequences, which would support seeding of the deep biosphere from the water column. Finally, we shed light on putative new actors of the sulfur cycle involving both archaea and bacteria, which could play an unexpected role in the reduction of sulfur species. Together, these data provide new research avenues for both geologists and biologists working in this extreme environment, and help understanding the evolution of the Dead Sea ecosystem with time.
... A general description of the DSDDP core at 5017-1-A is given by Neugebauer et al. (2014) and the chronology of the core is given by Torfstein et al. (2015) and Kitagawa et al. (2017). Detrital sediment samples, 15-30 ml in volume, and numbering 126 in total, were collected during the drilling campaign of 2010/11 at intervals of several centimeters to 14.5 m from core catcher sections, and during 2013 at similar intervals but from accompanying core sections. ...
... The published anchor age model for ICDP core 1A which is based on the integration of radiocarbon ages (on organic debris, Kitagawa et al., 2017) ...
Article
The chemical composition and δ³⁷Cl of pore fluids from the ICDP core drilled in the deepest floor of the terminal and hypersaline Dead Sea, and halites from the adjacent Mount Sedom salt diapir, are used to establish the dynamics of halite precipitation and dissolution during the last interglacial and glacial periods. Between ∼132 and 116 thousand years ago (ka) halites precipitated in the lake resulting in the expulsion of Na⁺ and Cl⁻ from the residual solution. Over 50% of the Cl⁻ reservoir was removed, resulting in a decrease in the Na/Cl ratio from 0.57 to 0.19. This process was accompanied by a decrease in δ³⁷Cl values in the precipitating halites and the associated residual Cl⁻ in the lake. The observed decrease fits a Rayleigh distillation curve with a fractionation factor of Δ(NaCl–Dead Sea solution) = +0.32‰ (±0.12) determined in the present study. This behavior implies negligible contribution of external sources of Cl⁻ to the lake during the main peak of the last interglacial, MIS5e. Subsequently, during the last glacial (ca. 117 to 17 ka) dissolution of halite took place, the Na⁺ and Cl⁻ inventory were replenished, accompanied by an increase in Na/Cl from 0.21 to 0.55 and in the δ³⁷Cl values from −0.46‰ to −0.12‰. While the lake underwent significant dilution during that time, the decrease in salinity was somewhat suppressed by the dissolution of the halite which was mostly derived from Mount Sedom salt diapir.
... Every core depth has a corresponding EFD (event-free depth), on which the age model is based, and the inferred ages of the MTDs is the age at their corresponding EFD. Depths marked "Date (C14 cal)" are dated radiocarbon samples on organic matter from Kitagawa et al. (2017). Depths marked "Date (U-Th)" are dated uranium-thorium aragonite samples from Torfstein et al. (2015). ...
... (a) Correlation of three Lisan Formation outcrop sections (Perazim PZ1, Masada M1, and Beit Ha'Arava BA), and the DSDDP-5017-1-A deep-lake core. Stratigraphic markers are correlated, aided by U-Th dating(Torfstein, Goldstein, Kagan, et al., 2013;Torfstein et al., 2015), radiocarbon dating(Kitagawa et al., 2017) ...
Article
Full-text available
Seismically disturbed sedimentary sequences (seismites) in the last glacial (70-14 ka) Lisan Formation are exposed in the marginal terraces of the Dead Sea and recovered from sedimentary core drilled by the International Continental Scientific Drilling Programs at the depocenter of the lake at water depth of 300 m. The core reveals various types of centimeter- to meter-scale disturbed lake sediments: turbidites, homogenites, slumps, and other deformations, interspersed with undisturbed lamination. The transported sediments comprise a main source of the thickness tripling of the Lisan Formation at the depocenter of the lake compared to the margins. Excluding (mass transport deposits MTDs) from chronology yields a normal, event-free age-depth model for core. Moreover, time intervals of units missing at the exposed sections of the lake margin are synchronous with intervals of mass transport deposits (MTDs) at the deepest lake floors. In the deep core, the recurrence interval range of MTD with thickness > 1 cm is ~ 100-300 years, while that of the thick MTD (>50 cm) is ~ 2,500 years, twice the recurrence interval of the seismites at the lake's margins. The ~1,000 year recurrence at the lake's margins lies within the ranges that have been calculated for ~M6.5-7 earthquakes. The significantly higher figure shown by depocenter core suggests activity on various faults and the response of the lake sediments in the entire Dead Sea basin. Overall, an unprecedented chronology of seismic activity was achieved for the late Pleistocene Lisan Formation providing a framework of earthquake activity in the vicinity of the Dead Sea basin during the period of the last high lake stand.
... Wang et al., 2010). For the last glacial maximum to the present-day, the age model is based on the 14 C data of Kitagawa et al. (2016). Torfstein et al. (2015) discussed the general paleohydrology of the region, based on the lithology of the core, and showed that the last interglacial was characterized by a high degree of climate variability, with a dry interval marked by halite precipitation during the MIS 6/5 transition, followed by wetter conditions during the peak of MIS 5e without halite precipitation, in turn followed by an extreme dry interval characterized by a thick accumulation of halite. ...
... The lake-level curve is from Kushnir and Stein (2010) and Stein et al. (2010), and uses their ages. The halite layers are from the DSDDP stratigraphy, the DSDDP age model for this interval is derived from Kitagawa et al. (2016). There may be some small discrepancies between low lake levels and halite layers due to inconsistencies in the age models. ...
Article
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 the amount of salt in the core. Modern water and salt budgets indicate that halite precipitates only during declining lake levels, while the amount of dissolved Na⁺ and Cl⁻ accumulates during wetter intervals. Based on the compositions of Dead Sea brines from pore waters and halite fluid inclusions, we estimate that ∼12–16 cm of halite precipitated per meter of lake-level drop. During periods of halite precipitation, the Mg²⁺ concentration increases and the Na⁺/Cl⁻ ratio decreases in the lake. Our calculations indicate major lake-level drops of ∼170 m from lake levels of 320 and 310 m below sea level (mbsl) down to lake levels of ∼490 and ∼480 mbsl, during MIS 5e and the Holocene, respectively. These lake levels are much lower than typical interglacial lake levels of around 400 mbsl. These lake-level drops occurred as a result of major decreases in average fresh water runoff, to ∼40% of the modern value (pre-1964, before major fresh water diversions), reflecting severe droughts during which annual precipitation in Jerusalem was lower than 350 mm/y, compared to ∼600 mm/y today. Nevertheless, even during salt intervals, the changes in halite facies and the occurrence of alternating periods of halite and detritus in the Dead Sea core stratigraphy reflect fluctuations between drier and wetter conditions around our estimated average. The halite intervals include periods that are richer and poorer in halite, indicating (based on the sedimentation rate) that severe dry conditions with water availability as low as ∼20% of the present day, continued for periods of decades to centuries, and fluctuated with wetter conditions that spanned centuries to millennia when water availability was ∼50–100% of the present day. These conclusions have potential implications for the coming decades, as climate models predict greater aridity in the region.
... The depths at which samples were collected are provided in the Supplement. The age model for the ICDP core 5017-1 and Ein Gedi was constructed using previously published radiocarbon ages (Neugebauer et al., 2014(Neugebauer et al., , 2015Kitagawa et al., 2017) and modelled with the OxCal Program (Ramsey, 2008). In addition, several samples spanning the late glacial interval were measured from a new profile from the southwestern Masada formation, recovered during a campaign to the Dead Sea in 2018 (Müller et al., 2022). ...
... Core 5017-1 spans the past 220 kyr (Goldstein et al., 2020;Kitagawa et al., 2017), with most dating uncertainty at <±1 kyr (Table S1; Text S2). We constrain the timing of each mass failure event by the age of the first underlying in situ sediment horizon and by linear interpolation. ...
Article
Full-text available
Plain Language Summary Some researchers propose that lowering sea‐level leads to mass failures, while, others suggest that raising sea‐level induces mass failures. In contrast, other researchers conclude that no clear correlation exists between mass failures and sea‐level change as the ages of failure events are random. This dispute is due largely to the lack of comprehensive records of mass failures in the geologic record for which ages, triggers, and preconditioning factors can be reliably constrained, thus preventing the testing of cause‐ and ‐effect relationships. We present a record of mass failures from the Dead Sea center over the last 220 kyr. The high‐resolution dating, combined with well‐constrained trigger and preconditioning factors, makes this a unique archive for testing the different hypotheses. Our analysis indicates that mass failures can occur during seismic shaking at any lake‐level state at the centennial‐to decadal‐scale, but are more frequent during lake‐level high‐stands with large‐amplitude fluctuations at orbital‐ and millennial‐scales. Furthermore, we find that sedimentation rate is not a preconditioning factor for mass failures under seismic shaking at both the orbital‐ and millennial‐scales.
... Varve counting was anchored to the absolute time scale using U-Th and radiocarbon ages of aragonites and organic debris and cover the last glacial maximum from~26 to 18 cal ka BP (Prasad et al., 2004). More recently, micro-facies analyses and microscopic varve counting of two intervals in the long ICDP core, coeval with last glacial Lake Lisan, revealed two floating 700-year varve chronologies recording intervals of rising and falling lake levels anchored by radiocarbon chronology Kitagawa et al., 2017). A~1500-year floating Late Holocene varve chronology from~200 to 1700 cal a BP has been established from the littoral sediment core DSEn at Ein Gedi (Fig. 1E). ...
Article
The sedimentary record of the Dead Sea provides an exceptional high-resolution archive of past climate changes in the drought-sensitive eastern Mediterranean-Levant, a key region for the development of humankind at the boundary of global climate belts. Moreover, it is the only deep hypersaline lake known to have deposited long sequences of finely laminated, annually deposited sediments (i.e. varves) of varied compositions, including aragonite, gypsum, halite and clastic sediments. Vast efforts have been made over the years to decipher the environmental information stored in these evaporitic-clastic sequences spanning from the Pleistocene Lake Amora to the Holocene Dead Sea. A general characterisation of sediment facies has been derived from exposed sediment sections, as well as from shallow-and deep-water sediment cores. During high lake stands and episodes of positive water budget, mostly during glacial times, alternating aragonite and detritus laminae ('aad' facies) were accumulated, whereas during low lake stands and droughts, prevailing during interglacials, laminated detritus ('ld' facies) and laminated halite ('lh' facies) dominate the sequence. In this paper, we (i) review the three types of laminated sediments of the Dead Sea sedimentary record ('aad', 'ld' and 'lh' facies), (ii) discuss their modes of formation, deposition and accumulation, and their interpretation as varves, and (iii) illustrate how Dead Sea varves are utilized for palaeoclimate reconstructions and for establishing floating chronologies.
... The chronology of the deep core 5017-1-A was determined by AMS 14 C and U\ \Th, dating combined with oxygen isotope stratigraphy (Neugebauer et al., 2014;Torfstein et al., 2015;Neugebauer et al., 2016;Kitagawa et al., 2017). The core covers the time interval of the past 220 kyrs including several glacial and interglacial cycles comprising sequences of primary lacustrine aragonite, gypsum and salt that alternate with detritus sediments (Neugebauer et al., 2014(Neugebauer et al., , 2016Torfstein et al., 2015;Palchan et al., 2017;Kiro et al., 2016;Thomas et al., 2016). ...
Article
The sedimentary sequences that accumulated within various lakes that occupied the Dead Sea Basin since the Pliocene, contain a detailed record of the climate and tectonic history of the area. Until recently, most of the information about these paleo-lakes was derived from exposures along the marginal terraces of the current Dead Sea (lake), focusing mainly on the last Glacial Lake Lisan and the Holocene-modern Dead Sea. The International Continental Drilling Program (ICDP) recovered a series of cores in the northern Dead Sea Basin, both in the deep depocenter (300 m water depth) and in shallower waters near the current shore. Here, we present downhole logging measurements that were used to provide continuous records of petrophysical properties at depth and to reconstruct lithological profiles. The study highlights how logging data can overcome gaps in drilled-core recovery and be used to examine subsurface geology on a regional scale. Gamma ray, resistivity and velocity wire logs were examined to infer a log-derived lithofacies. The reconstructed profiles presented in this study constitute a first attempt to link deep central settings of the basin with marginal sedimentary sequences. Three main facies were identified in the boreholes including: (Bartov et al., 2002) Finely laminated sequences of mudstones interbedded with siltstones to sandstones; (Bartov et al., 2003) Medium to thick bedded mudstone to sandstone: and (Bartov et al., 2007) Evaporites (e.g. halite and gypsum with some intervals of detrital sediments). The formations that were previously defined along the marginal terraces of the Dead Sea: the Holocene Ze'elim Formation, the last Glacial Lisan Formation, the last interglacial Samra Formation and the early to mid-Pleistocene Amora Formation are identified in the boreholes. A spatial correlation is established providing the stratigraphic architecture of the sedimentary structure beneath the Dead Sea during the late Quaternary. This paper combines geophysical and lithological data and provides the base for subsequent studies on facies interpretation.
... The chronology of the Dead Sea DSDDP core is based on radiocarbon dating of organic debris, U-Th dating of primary aragonite and d 18 O stratigraphy ( Kitagawa et al., 2017;Torfstein et al., 2015). The chronologies of the Red Sea cores (KL23, KL11) are based on d 18 O values comparison between microfossils of the Red Sea and low latitude speleothems and ice core chronology ( Almogi-Labin et al., 1998;Geiselhart, 1998;Hemleben et al., 1996;Palchan et al., 2013). ...
Article
The sediments deposited at the depocenter of the Dead Sea comprise high-resolution archive of hydrological changes in the lake's watershed and record the desert dust transport to the region. This paper reconstructs the dust transport to the region during the termination of glacial Marine Isotope Stage 6 (MIS 6; ∼135–129 ka) and the last interglacial peak period (MIS5e, ∼129–116 ka). We use chemical and Nd and Sr isotope compositions of fine detritus material recovered from sediment core drilled at the deepest floor of the Dead Sea. The data is integrated with data achieved from cores drilled at the floor of the Red Sea, thus, forming a Red Sea-Dead Sea transect extending from the desert belt to the Mediterranean climate zone. The Dead Sea accumulated flood sediments derived from three regional surface cover types: settled desert dust, mountain loess-soils and loess-soils filling valleys in the Dead Sea watershed termed here “Valley Loess”. The Valley Loess shows a distinct ⁸⁷Sr/⁸⁶Sr ratio of 0.7081 ± 1, inherited from dissolved detrital calcites that originate from dried waterbodies in the Sahara and are transported with the dust to the entire transect. Our hydro-climate and synoptic conditions reconstruction illustrates the following history: During glacial period MIS6, Mediterranean cyclones governed the transport of Saharan dust and rains to the Dead Sea watershed, driving the development of both mountain soils and Valley Loess. Then, at Heinrich event 11, dry western winds blew Saharan dust over the entire Red Sea - Dead Sea transect marking latitudinal expansion of the desert belt. Later, when global sea-level rose, the Dead Sea watershed went through extreme aridity, the lake retreated, depositing salt and accumulating fine detritus of the Valley Loess. During peak interglacial MIS 5e, enhanced flooding activity flushed the mountain soils and fine detritus from all around the Dead Sea and Red Sea, marking a significant “contraction” of the desert belt. At the end of MIS 5e the effect of the regional precipitation diminished and the Dead Sea and Red Sea areas re-entered sever arid conditions with extensive salt deposition at the Dead Sea.
Article
Full-text available
Large earthquakes (magnitude ≥ 7.0) are rare, especially along slow-slipping plate boundaries. Lack of large earthquakes in the instrumental record enlarges uncertainty of the recurrence time; the recurrence of large earthquakes is generally determined by extrapolation according to a magnitude-frequency relation. We enhance the seismological catalog of the Dead Sea Fault Zone by including a 220,000-year-long continuous large earthquake record based on seismites from the Dead Sea center. We constrain seismic shaking intensities via computational fluid dynamics modeling and invert them for earthquake magnitude. Our analysis shows that the recurrence time of large earthquakes follows a power-law distribution, with a mean of 1400 ± 160 years. This mean recurrence is notable shorter than the previous estimate of 11,000 years for the past 40,000 years. Our unique record confirms a clustered earthquake recurrence pattern and a group-fault temporal clustering model, and reveals an unexpectedly high seismicity rate on a slow-slipping plate boundary.
Article
The mineralogical, grain size and geochemical properties (e.g., Nd and Sr isotopes, Mg/Al ratios) of fine detritus that accumulated in the Dead Sea during the late Glacial to early Holocene time (∼22–7 ka) are used to identify its sources and modes of transport and to reconstruct the hydroclimate conditions in the Dead Sea watershed. Samples were retrieved from the DSDDP -5017-1A core that was drilled in the deep floor of the lake, and from various exposures of surface cover in the lake's watershed. The data show that during most of the late glacial, detrital particles were either directly blown mostly from the north Sahara Desert or were washed from the surface cover (loessial soils) of the north Negev Desert and Judea Desert. This picture changed during the end of the last glacial to the early Holocene (∼14 - 7 ka) when the fine detritus showed evidence for contribution from surface cover that contained basaltic soils. The contribution of basaltic soils to the fine detritus inventory of the Dead Sea and to terraces in the Jordan Valley, indicates a period of intense erosion in the northern highlands of the Dead Sea watershed, at an interval that partly coincides with Sapropel S1. In contrast, during the last interglacial Sapropel S5, fine detritus was mostly mobilized to the lake from southern and eastern region of the watershed. The formation and accumulation of terraces from this basaltic-derived material could be an important factor in the establishment of early agriculture settlements in the Jordan Valley.
Article
Full-text available
Archaea and Bacteria that inhabit the deep subsurface (known as the deep biosphere) play a prevalent role in the recycling of sedimentary organic carbon. In such environments, this process can occur over millions of years and requires microbial communities to cope with extremely limited sources of energy. Because of this scarcity, metabolic processes come at a high energetic cost, but the ways heterotrophic microbial communities develop to minimize energy expenses for a maximized yield remain unclear. Here, we report molecular biomarker evidence for the recycling of archaeal cell wall constituents in extreme evaporitic facies of Dead Sea deep sediments. Wax esters derived from the recombination of hydrolyzed products of archaeal membrane lipids were observed in gypsum and/or halite sedimentary deposits down to 243 m below the lake floor, implying the reutilization of archaeal necromass possibly by deep subsurface bacteria. By recycling the building blocks of putatively better-adapted archaea, heterotrophic bacteria may build up intracellular carbon stocks and mitigate osmotic stress in this energy-deprived environment. This mechanism illustrates a new pathway of carbon transformation in the subsurface and demonstrates how life can be maintained in extreme environments characterized by long-term isolation and minimal energetic resources.
Preprint
Full-text available
Archaea and Bacteria that inhabit the deep subsurface (known as the deep biosphere) play a prevalent role in the recycling of sedimentary organic carbon. In such extreme environment, this process can occur over millions of years1 and requires microbial communities to cope with limited sources of energy. Because of this scarcity, metabolic processes come at a high energetic cost, but the ways heterotrophic microbial communities develop to enable the least energy expenses for a maximized yield remain unclear. Here, we report molecular biomarker evidence for the recycling of archaeal cell wall constituents by bacteria in extreme evaporitic facies of the Dead Sea deep sediments. Isoprenoid wax esters (WE) derived from the recombination of hydrolyzed products of archaeal membrane lipids were retrieved in gypsum and/or halite sedimentary deposits down to 243 meters below the lake floor (mblf), implying the reutilization of archaeal necromass by deep subsurface bacteria. By recycling the building blocks of allegedly better adapted archaea, heterotrophic bacteria build up intracellular carbon stocks and gain access to free water in this deprived environment. This strategy illustrates a new pathway of carbon transformation in the subsurface and how life is maintained in extreme environments experiencing long-term isolation and minimal energetic resources.
Article
Full-text available
The Greenland Ice Core Chronology 2005 (GICC05) is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 ka extension of the time scale such that GICC05 continuously covers the past 60 ka. The new section of the time scale places the onset of Greenland Inter-stadial 12 (GI-12) at 46.9±1.0 ka b2k (before year AD 2000), the North Atlantic Ash Zone II layer in GI-15 at 55.4±1.2 ka b2k, and the onset of GI-17 at 59.4±1.3 ka b2k. The error estimates are derived from the accumulated number of un-certain annual layers. In the 40–60 ka interval, the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 ka. Assuming that the Greenland climatic events are synchronous with those seen in the Chinese Hulu Cave speleothem record, GICC05 compares well to the time scale of that record with absolute age differences of less than 800 years throughout the 60 ka period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geo-magnetic excursion, the French Villars Cave and the Austrian Kleegruben Cave speleothem records, suggesting high accu-racy of both event durations and absolute age estimates.
Article
Full-text available
The area surrounding the Dead Sea was the locus of humankind's migration out of Africa and thus has been the home of peoples since the Stone Age. For this reason, understanding the climate and tectonic history of the region provides valuable insight into archaeology and studies of human history and helps to gain a better picture of future climate and tectonic scenarios. The deposits at the bottom of the Dead Sea are a geological archive of the environmental conditions (e.g., rains, floods, dust storms, droughts) during ice ages and warm ages, as well as of seismic activity in this key region. An International Continental Scientific Drilling Program (ICDP) deep drilling project was performed in the Dead Sea between November 2010 and March 2011. The project was funded by the ICDP and agencies in Israel, Germany, Japan, Norway, Switzerland, and the United States. Drilling was conducted using the new Large Lake Drilling Facility (Figure 1), a barge with a drilling rig run by DOSECC, Inc. (Drilling, Observation and Sampling of the Earth's Continental Crust), a nonprofit corporation dedicated to advancing scientific drilling worldwide. The main purpose of the project was to recover a long, continuous core to provide a high resolution record of the paleoclimate, paleoenvironment, paleoseismicity, and paleomagnetism of the Dead Sea Basin. With this, scientists are beginning to piece together a record of the climate and seismic history of the Middle East during the past several hundred thousand years in millennial to decadal to annual time resolution.
Article
Full-text available
The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were ratified at the 21st International Radiocarbon conference in July 2012 and are available as Supplemental Material at www.radiocarbon.org. The database can be accessed at http://intcal.qub.ac.uk/intcal13/. © 2013 by the Arizona Board of Regents on behalf of the University of Arizona.
Article
Full-text available
This work presents a high-resolution lake-level record of the late Holocene Dead Sea, a hypersaline terminal lake whose drainage basin encompasses both Mediterranean and hyperarid climatic zones. The lake-level curve reflects the regional hydrologic variations in the drainage basin, which in turn represent the Levant paleoclimates. The curve is based on 46 radiocarbon ages of organic remains from well-exposed sedimentary sequences along the Dead Sea shores. These sequences record fluvial and lacustrine depositional environments. The paleolakeshores are marked by shore ridges, coarse-sand units, and aragonite crusts; in the modern Dead Sea, such features indicate the exact elevation of the shore. The late Holocene Dead Sea level fluctuated within the range of 390 to 415 m below sea level (mbsl). For most of the time the lake was below the topographic sill (402 mbsl) separating the northern and southern basins of the Dead Sea and was confined to the deep northern basin. Nevertheless, short-term rises in the late Holocene Dead Sea level caused the flooding of the shallow and flat southern basin. Highstands occurred in the second and first centuries B.C. and the fourth century A.D. during the Roman and early Byzantine periods, respectively, in the eleventh and twelfth centuries A.D. during the Crusader period, and at the end of the nineteenth century A.D. The rises mark a significant change in the annual rainfall in the region, which likely exceeded the instrumentally measured modern average. The curve also indicates drastic drops that exposed the sedimentary sequences to erosion. The oldest and probably deepest drop in the lake level culminated during the fifteenth and fourteenth centuries B.C. after a retreat from a higher lake stand. The longest lowstand occurred after the Byzantine period and continued at least until the ninth century A.D. This and period coincided with the invasion of Moslem-Arab tribes into the area during the seventh century A.D. The dramatic fall of the Dead Sea level during the twentieth century is primarily artificial and has been caused by the diversion of runoff water for the drainage basin, but the magnitude is not considered exceptional for the late Holocene. Although the past drops in the lake never exceeded the modern artificial drop rates, they do represent extreme and conditions that occurred frequently over the past several thousand years.
Article
Full-text available
The response of continental climate to the well-documented climate oscillations during the last glacial period has been a subject of intense interest, yet much less is known about the influence on regional continental climates than in the marine or polar realms of Earth. The detailed lake-level history of the closed Lake Lisan (paleo Dead Sea) in the Middle East has been reconstructed from shoreline indications and high-resolution U-Th and 14C chronologies, thus providing data on the response of the lake's catchment area to the climate changes during the corresponding period. We present a correlation between the newly developed Lake Lisan level curve for the past 55 k.y. and the North Atlantic Heinrich events. The correlation indicates a closely connected climate response between these North Atlantic events and the hydrologic conditions that prevailed in the Eastern Mediterranean. Our findings show that although the generally cooler conditions that prevailed during the last glaciation favored high levels of the lake, catastrophic events in the North Atlantic, which are associated with maximum cooling, have been responsible for droughts in the Eastern Mediterranean. We infer that cold-water input to the Mediterranean originating in the collapse of the North Atlantic Deep Water circulation caused the reduction of evaporation and less precipitation in the Eastern Mediterranean.
Article
Full-text available
Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies1, 2 have revealed strong coupling of the largest millennial-scale warm events in Antarctica with the longest Dansgaard–Oeschger events in Greenland3, 4, 5 through the Atlantic meridional overturning circulation6, 7, 8. It has been unclear, however, whether the shorter Dansgaard–Oeschger events have counterparts in the shorter and less prominent Antarctic temperature variations, and whether these events are linked by the same mechanism. Here we present a glacial climate record derived from an ice core from Dronning Maud Land, Antarctica, which represents South Atlantic climate at a resolution comparable with the Greenland ice core records. After methane synchronization with an ice core from North Greenland9, the oxygen isotope record from the Dronning Maud Land ice core shows a one-to-one coupling between all Antarctic warm events and Greenland Dansgaard–Oeschger events by the bipolar seesaw6. The amplitude of the Antarctic warm events is found to be linearly dependent on the duration of the concurrent stadial in the North, suggesting that they all result from a similar reduction in the meridional overturning circulation.
Article
Full-text available
OXYGEN isotope measurements in Greenland ice demonstrate that a series of rapid warm-cold oscillations---called Dansgaard-Oeschger events---punctuated the last glaciation1. Here we present records of sea surface temperature from North Atlantic sediments spanning the past 90 kyr which contain a series of rapid temperature oscillations closely matching those in the ice-core record, confirming predictions that the ocean must bear the imprint of the Dansgaard-Oeschger events2,3. Moreover, we show that between 20 and 80 kyr ago, the shifts in ocean-atmosphere temperature are bundled into cooling cycles, lasting on average 10 to 15 kyr, with asymmetrical saw-tooth shapes. Each cycle culminated in an enormous discharge of icebergs into the North Atlantic (a 'Hein-rich event'4,5), followed by an abrupt shift to a warmer climate. These cycles document a previously unrecognized link between ice sheet behaviour and ocean-atmosphere temperature changes. An important question that remains to be resolved is whether the cycles are driven by external factors, such as orbital forcing, or by inter-nal ice-sheet dynamics.
Article
Full-text available
In 1996/97, we installed a second-generation AMS system (model 4130-AMS) manufactured by HVEE, B.V., The Netherlands. Although we encountered a lot of problems during the installation and tuning up of the machine, our new system has now reached good stability and reproducibility in performing and measurements. According to the reproducibility tests conducted in January 1999, where six graphite targets prepared from HOxII standard material were measured, the standard deviation for reproducibility is around 1.6‰ (comparable with counting statistics) and that for is 0.28‰. The background level of the AMS system was measured using a pure graphite (commercial graphite rod). It lies between 50 and 55 ka BP. We are still on the way to reduce the background. However, we are now prepared to start routine measurements of unknown-age samples.
Article
Full-text available
a b s t r a c t The influence of the northern Atlantic and tropical monsoonal systems, as recorded by the River Nile, on the climate variability of the southeastern Mediterranean was studied in two cores taken by the R/V Marion Dufresne: one core taken SE of Cyprus representing the northern Levantine Basin (core 9501, 980 m water depth) and the other locate 380 km further south, represents the southeastern Levantine Basin in an area influenced by the River Nile plume (core 9509, 884 m water depth). The study was performed at relatively high resolution using several proxies: d 18 O of Globigerinoides ruber, sediment characteristics and index colour parameters in core sections representing the last 86 ka. A low-resolution alkenone sea surface temperature record was also measured. The time frame in both cores was mostly constrained by 'wiggle' matching with the nearby well-dated d 18 O and d 13 C record of the Soreq Cave, which is mainly influenced by the eastern Mediterranean water vapor. The sedimentary record of the southern core is strongly influenced by the River Nile contribution throughout the last 86 ka, as evi-denced by the higher sedimentation rates compared with the northern core (20 cm/ka vs. 5 cm/ka), continuously darker sediment colour, and higher TOC values (0.6–0.9 vs. 0.25 wt% not including sap-ropels). During sapropels S1 and S3, present in both cores, the influence of the River Nile became more widespread, reaching as far as Cyprus. Yet, the influence of the River Nile remained stronger in the south, as evident by the higher TOC values in the southern core throughout the entire 90 ka period and the longer duration of S1 in the southern core. An anomalous low d 18 O interval that is not recorded in western Mediterranean occurred between 58 and 49 ka in the Levantine Basin and is more developed in the northern core. This period correlates with D-O interstadial 14 and maximum northern hemisphere insolation during the lastglacial cycle, suggesting that the warming mainly impacted the northern Levant. The Eastern Mediterranean Sea and land area was considerably warmer than the western Mediter-ranean throughout the LGM – Holocene transition, and the d 18 O G. ruber drop of 4.5& is significantly greater than the 3& shift found for the western Mediterranean d 18 O G. bulloides , both differences reflecting an increased continental effect from the western to eastern Mediterranean. Comparison between the marine and the land d 18 O records suggests that the origin of rain over the land is composed of mixed signal from the southern and northern Levantine Basin. The study of Dd 18 O sea–land variations demon-strates that various factors have influenced the sea–land relationship during the last 90 ka. The 'amount effect' has an important influence on rainfall d 18 O during interglacial periods (particularly sapropel periods), whereas during glacial periods, increased land distances and elevation differences arising from decrease in sea level may have brought about decrease in d 18 O of rainfall due to Rayleigh distillation processes. These influences were superimposed on those of sea surface water d 18 O changes brought about by continental ice melting, and the strong effects felt in the southern Levantine Basin of the high River Nile input during periods of enhanced monsoonal activity. (A. Almogi-Labin), matthews@gsi.gov.il (M. Bar-Matthews), danch@pob.huji.ac.il (D. Shriki), martine.paterne@lsce.cnrs-gif.fr (M. Paterne), bschilman@gsi.gov.il (B. Schilman), ayalon@gsi.gov.il (A. Ayalon), zeev@vms.huji.ac.il (Z. Aizenshtat), alan@vms.huji.ac.il (A. Matthews).
Article
Full-text available
A 1MV AMS was installed in KIGAM (Korea Institute of Geoscience and Mineral Resources). After 4 months of installation, the AMS started normal operation from January 2008. This multi-element AMS was developed by HVEE to measure 14 C, 10 Be, and 26 Al. The results of an acceptance test demonstrate that this machine is capable of routine 14 C age dat-ing and of measurements of other radioisotopes in terms of accuracy and precision as well as the background level. After installation, an investigation aimed at determining the stable operating conditions was conducted, and background levels were determined to be as low as 10 15 for 14 C and 10 14 for 10 Be and 26 Al.
Article
Full-text available
Christoph Heim, Norbert R. Nowaczyk, Jo¨rg F.W. NegendankGeoForschungsZentrum, Bereich 3.3 Sedimente und Beckenbildung,Telegrafenberg A26, D-14473 Potsdam, GermanySuzanne A.G. LeroyCentre for Palaeoecology, School of Geosciences,Queen’s University of Belfast, Northern Ireland, UKZvi Ben-AvrahamDead Sea Research Center, Tel Aviv University, Ramat Aviv, 69978, Israel
Article
Full-text available
Lake Lisan, the late Pleistocene precursor of the Dead Sea, existed from ∼70,000 to 15,000 yr B.P. It evolved through frequent water-level fluctuations, which reflected the regional hydrological and climatic conditions. We determined the water level of the lake for the time interval ∼55,000–15,000 cal yr B.P. by mapping offshore, nearshore, and fan-delta sediments; by application of sequence stratigraphy methods; and by dating with radiocarbon and U-series methods. During the studied time interval the lake-level fluctuated between ∼340 and 160 m below mean sea level (msl). Between 55,000 and 30,000 cal yr B.P. the lake evolved through short-term fluctuations around 280–290 m below msl, punctuated (at 48,000–43,000 cal yr B.P.) by a drop event to at least 340 m below msl. At ∼27,000 cal yr B.P. the lake began to rise sharply, reaching its maximum elevation of about 164 m below msl between 26,000 and 23,000 cal yr B.P., then it began dropping and reached 300 m below msl at ∼15,000 cal yr B.P. During the Holocene the lake, corresponding to the present Dead Sea, stabilized at ca. 400 m below msl with minor fluctuations. The hypsometric curve of the basin indicates that large changes in lake area are expected at above 403 and 385 m below msl. At these elevations the lake level is buffered. Lake Lisan was always higher than 380 m below msl, indicating a significantly large water contribution to the basin. The long and repetitious periods of stabilization at 280–290 m below msl during Lake Lisan time indicate hydrological control combined with the existence of a physical sill at this elevation. Crossing this sill could not have been achieved without a dramatic increase in the total water input to the lake, as occurred during the fast and intense lake rise from ∼280 to 160 m below msl at ∼27,000 cal yr B.P.
Article
Full-text available
A 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.
Article
Full-text available
The Greenland Ice Core Chronology 2005 (GICC05) is a time scale based on annual layer counting of high-resolution records from Greenland ice cores. Whereas the Holocene part of the time scale is based on various records from the DYE-3, the GRIP, and the NorthGRIP ice cores, the glacial part is solely based on NorthGRIP records. Here we present an 18 kyr extension of the time scale such that GICC05 continuously covers the past 60 kyr. The new section of the time scale places the onset of Greenland Interstadial 12 (GI-12) at 46.9±1.0 kyr b2k (before year AD 2000), the North Atlantic Ash Zone 2 layer in GI-15 at 55.4±1.2 kyr b2k, and the onset of GI-17 at 59.4±1.3 kyr b2k. The error estimates are derived from the accumulated number of uncertain annual layers and can be regarded as 1s uncertainties. In the 40–60 kyr interval the new time scale has a discrepancy with the Meese-Sowers GISP2 time scale of up to 2.4 kyr, whereas GICC05 compares well to the dating of the Hulu Cave record with absolute age differences of less than 800 years throughout the 60 kyr period. The new time scale is generally in close agreement with other independently dated records and reference horizons, such as the Laschamp geomagnetic excursion and the Kleegruben speleothem record from the Austrian Alps, suggesting high accuracy of both event durations and absolute age estimates.
Article
Full-text available
230Th-dated oxygen isotope records of stalagmites from Sanbao Cave, China, characterize Asian Monsoon (AM) precipitation through the ends of the third- and fourthmost recent ice ages. As a result, AM records for the past four glacial terminations can now be precisely correlated with those from ice cores and marine sediments, establishing the timing and sequence of major events. In all four cases, observations are consistent with a classic Northern Hemisphere summer insolation intensity trigger for an initial retreat of northern ice sheets. Meltwater and icebergs entering the North Atlantic alter oceanic and atmospheric circulation and associated fluxes of heat and carbon, causing increases in atmospheric CO2 and Antarctic temperatures that drive the termination in the Southern Hemisphere. Increasing CO2 and summer insolation drive recession of northern ice sheets, with probable positive feedbacks between sea level and CO2.
Article
Full-text available
Two deep ice cores from central Greenland, drilled in the 1990s, have played a key role in climate reconstructions of the Northern Hemisphere, but the oldest sections of the cores were disturbed in chronology owing to ice folding near the bedrock. Here we present an undisturbed climate record from a North Greenland ice core, which extends back to 123,000 years before the present, within the last interglacial period. The oxygen isotopes in the ice imply that climate was stable during the last interglacial period, with temperatures 5 degrees C warmer than today. We find unexpectedly large temperature differences between our new record from northern Greenland and the undisturbed sections of the cores from central Greenland, suggesting that the extent of ice in the Northern Hemisphere modulated the latitudinal temperature gradients in Greenland. This record shows a slow decline in temperatures that marked the initiation of the last glacial period. Our record reveals a hitherto unrecognized warm period initiated by an abrupt climate warming about 115,000 years ago, before glacial conditions were fully developed. This event does not appear to have an immediate Antarctic counterpart, suggesting that the climate see-saw between the hemispheres (which dominated the last glacial period) was not operating at this time.
Article
Full-text available
Centennial climate variability over the last ice age exhibits clear bipolar behavior. High-resolution analyses of marine sediment cores from the Iberian margin trace a number of associated changes simultaneously. Proxies of sea surface temperature and water mass distribution, as well as relative biomarker content, demonstrate that this typical north-south coupling was pervasive for the cold phases of climate during the past 420,000 years. Cold episodes after relatively warm and largely ice-free periods occurred when the predominance of deep water formation changed from northern to southern sources. These results reinforce the connection between rapid climate changes at Mediterranean latitudes and century-to-millennial variability in northern and southern polar regions.
Article
Full-text available
A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, ∼800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.
Article
A new radiocarbon accelerator mass spectrometry (AMS) laboratory for carbon cycle studies has been established at the University of California, Irvine. The 0.5MV AMS system was installed in mid-2002 and has operated routinely since October of that year. This paper briefly describes the spectrometer and summarizes lessons learned during the first year of operation. In the process of setting up the system, we identified and largely suppressed a previously unreported 14 C AMS background: charge exchange tails from 14 N beams derived from nitrogen-containing molecular ions produced near the entrance of the accelerator.
Article
The Keck Carbon Cycle accelerator mass spectrometry facility at the University of California, Irvine, operates a National Electronics Corporation 40-sample MC-SNICS ion source. We describe modifications that have increased beam current output, improved reliability, and made the source easier to service.
Article
Thick sequences of salt (halite) have been recovered in a 456-m-long core drilled at the deepest floor of the Dead Sea by the Dead Sea Deep Drilling Project and extending similar to 200 k.y. back in time. The salt sequences were precipitated in the ancient lake that occupied the Dead Sea Basin during the last three interglacials during intervals of extreme aridity in the lake's watershed. The salt layers alternate with "mud" layers that indicate wetter periods in the watershed, when floods transported fine detritus matter to the lake. The salt sources include brine discharge and freshwater runoff that dissolved halite units. Dissolved salts accumulated in the lake during glacials and relatively wet periods when the lake expanded, and precipitated during interglacials when the lake levels dropped. This study establishes for the first time the evaporite facies and sedimentological features of the deep Dead Sea brine during interglacial periods, by using the modern precipitation of halite in the Dead Sea as an analogue for past halite depositional periods as recorded in the drill core. The halite intervals provide a record of facies characterizing a deep-water evaporitic environment. The halite layers consist mainly of two types of crystals: small cumulate crystals containing halite rafts, which indicate precipitation from the surface brine of the lake (epilimnion), and bottom-growth (usually large) halite crystals that precipitated on the lake floor (hypolimnion). The layers of small halite crystals formed during drier periods as compared to the bottom-growth crystals. The bottom-growth halite crystals contain variable quantities of detritus and show mild dissolution structures at the contact between the mud and the halite crystals. These two main types of halite, in combination with "muds" and gypsum, comprise seven categories of salt facies that reflect the hydrological conditions (dry-to-wet), and that display a cyclic (decadal to millennial) pattern along the sampled core intervals. Frequent alternation of these two salt crystal types suggests seasonal changes, whereby the small cumulate crystals were formed during the summer, and the bottom-growth crystals were formed during the winter, when the surface temperatures of the lake were low, and the surface water was less saline and less likely to be saturated with respect to halite. Comparison of the last interglacial halite with the modern halite facies, together with the absence of significant dissolution features within the halite and the cyclic nature of the facies, indicates that the lake was continuously deep (>100 m) during the last 200 k.y.
Article
A 1MV AMS was installed in KIGAM (Korea Institute of Geoscience and Mineral Resources). After 4 months of installation, the AMS started normal operation from January 2008. This multi-element AMS was developed by HVEE to measure 14C, 10Be, and 26Al. The results of an acceptance test demonstrate that this machine is capable of routine 14C age dating and of measurements of other radioisotopes in terms of accuracy and precision as well as the background level. After installation, an investigation aimed at determining the stable operating conditions was conducted, and background levels were determined to be as low as 10-15 for 14C and 10-14 for 10Be and 26Al. © 2010 by the Arizona Board of Regents on behalf of the University of Arizona.
Chapter
During the late Neogene-Quaternary times the tectonic depressions along the Dead Sea transform accomodated several hypersaline to fresh water-bodies: the late Neogene Sedom lagoon and the Quaternary lakes of Amora, Samra, Lisan, Dead Sea and the Sea of Galilee. The sedimentary sections that were deposited at these water-bodies store the environmental conditions that prevailed in their watershed. The lakes are located between the Sahara-Arabia desert belt and the Mediterranean climate zone and their large watershed receives rains and detritus particles from these climatic regions. Thus, the sedimentary sections record the climate –hydrological conditions in the desert belt and Mediterranean climate zone during the late Neogene and the Quaternary Ice Ages. Over the past two decades extensive efforts were devoted to establish a precise and high-resolution chronology for the environmental history of the water-bodies. The chronologies are mainly based on U-series, radiocarbon and oxygen isotope stratigraphy methods and provide the base for detailed geochemical and sedimentological reconstruction of the limnological-hydrological conditions in the watershed. The solutions that filled the lakes are mixtures of Ca-chloride brines that were originally formed in the late Neogene Kinnarot-Sedom lagoon and freshwater from the watershed. The mixing between these solutions is dictated by regional hydrological regime that in turn reflects the changes in the global climate patterns. The water balance in the lakes is reflected in their surface level and salinity. The precise chronology of the lacustrine sedimentary sequences allows the comparison with other global climate archives such as the ice cores and ocean temperatures and opens the way for understanding the global climate connection of hydrological changes in the Levant region. It appears that most of the rains in the lakes watershed are derived from the Mediterranean and reflect the climate – oceanographic conditions in the north Atlantic. Glacial periods were colder and wetter and interglacials were warmer and drier. Episodes of extreme aridity in the Levant region were accompanied by massive salt deposition at the shrinking lakes, e.g. at ~400 ka (MIS11); 130–120 ka (last interglacial MIS5e) and at 14–13 ka (the post-glacial BÖlling-Allerod period). Nevertheless, various lines of evidence indicate on intrusions of wetness from southern sources into the Red Sea region –Arava valley during interglacials that are possibly related to the African monsoon. These wet intrusions could facilitate the migration of humans out of Africa along the rift valley. The lacustrine sedimentary sections indicate also on episodes of abrupt aridities that expanded over the sub-tropical regions from the Sahara to the Mediterranean (e.g. at ~3.5–3.3 ka, coinciding with the late Bronze cultural crisis). These events coincide with ice rafting episodes in the north Atlantic that were linked to solar minima events.
Article
Laminated lake sediments from the Dead Sea basin provide high-resolution records of climatic variability in the eastern Mediterranean region, which is especially sensitive to changing climatic conditions. In this study, we aim on detailed reconstruction of climatic fluctuations and related changes in the frequency of flood and dust deposition events at ca. 3300 and especially at 2800 cal. yr BP from high-resolution sediment records of the Dead Sea basin. A ca. 4-m-thick, mostly varved sediment section from the western margin of the Dead Sea (DSEn – Ein Gedi profile) was analysed and correlated to the new International Continental Scientific Drilling Program (ICDP) Dead Sea Deep Drilling Project core 5017-1 from the deep basin. To detect even single event layers, we applied a multi-proxy approach of high-resolution microscopic thin section analyses, micro-X-ray fluorescence (μ-XRF) element scanning and magnetic susceptibility measurements, supported by grain size data and palynological analyses. Based on radiocarbon and varve dating, two pronounced dry periods were detected at ~3500–3300 and ~3000–2400 cal. yr BP which are differently expressed in the sediment records. In the shallow-water core (DSEn), the older dry period is characterised by a thick sand deposit, whereas the sedimentological change at 2800 cal. yr BP is less pronounced and characterised mainly by an enhanced frequency of coarse detrital layers interpreted as erosion events. In the 5017-1 deep-basin core, both dry periods are depicted by halite deposits. The onset of the younger dry period coincides with the Homeric Grand Solar Minimum at ca. 2800 cal. yr BP. Our results suggest that during this period, the Dead Sea region experienced an overall dry climate, superimposed by an increased occurrence of flash floods caused by a change in synoptic weather patterns.
Article
In 1996/1997, a 14C-AMS system (model 4130-AMS) manufactured by High Voltage Engineering Europe (HVEE), B.V., The Netherlands, was installed at the Center for Chronological Research (CCR), Nagoya University. The system provides highly precise and accurate 14C determinations as well as C values for graphite targets (1.5 mg carbon and 3 mg iron powder) prepared from standards and samples. One sigma errors in 14C ages typically range from ±20 to ±40 yr for materials younger than 8000 BP, depending on absolute 14C ages or 14C counting uncertainties. Standard deviations of 13C/12C ratios range from ±0.1‰ to ±0.9‰. For relatively young samples, accuracies of less than 10‰ are obtained using IAEA reference materials and FIRI test samples. Background levels on the 14C-AMS system range from 52 to 54 ka BP for a pure graphite powder. The HVEE 14C-AMS system at the CCR has been used routinely to date samples with a variety of research applications.
Article
We present a new integrated multi-site chronology for Lake Lisan, which occupied the Dead Sea basin and Jordan Valley during the last glacial period (70–14 kka, Marine Isotope Stages 4, 3, 2). The Dead Sea basin lacustrine deposits are unique among closed basin sediments in that they formed in a deep, hypersaline water body that precipitated primary aragonite which is amenable to radiometric dating by U-series, providing a solid basis for studies of the relationship of Middle East climate to other changes in the high latitudes or the tropics.
Article
The deglacial meltwater pulse in the North Atlantic that induced the Younger Dryas event also prompted climate cooling in East Asian monsoon regions such as Japan and coastal mid-latitude China. However, very little is understood about the mechanism that can transmit changes in the North Atlantic to the Far East. Here we show that the shutdown of the North Atlantic thermohaline circulation brought about significantly lower temperatures and higher precipitation in the Japanese winter, whereas the change in the Japanese summer climate was considerably smaller. The cooling of the Siberian air mass seems to have caused an increased pressure gradient between Siberia and the West Pacific in winter, intensifying the winter monsoon. The Mongolian high-pressure system and the westerly jet stream played an important role in the teleconnection. In contrast, the warming at the onset of the late glacial interstadial (GI-1; Bølling-Allerød) in the West Pacific did not have season-specific features, implying that the principal driving mechanism of this warming event may lie in a pan-hemispheric or global factor, such as insolation changes.
Article
Three modes of reporting ¹⁴ C activities are in use, in part analogous to the internationally accepted (IAEA) conventions for stable isotopes: (1) absolute activity , the specific activity of ¹⁴ C or the activity per gram of carbon; (2) activity ratio , the ratio between the absolute activities of a sample and the standard; and (3) relative activity , the difference between the absolute activities of a sample and standard material, relative to the absolute standard activity. The basic definitions originate from decisions made by the radiocarbon community at its past conferences. Stuiver and Polach (1977) reviewed and sought to specify the definitions and conventions. Several colleagues, however, have experienced inadequacies and pitfalls in the definitions and use of symbols. Furthermore, the latter have to be slightly amended because of the use of modern measuring techniques. This paper is intended to provide a consistent set of reporting symbols and definitions, illustrated by some practical examples.
Article
THE climate system is capable of changing abruptly from one stable mode to another1-3. Rapid climate oscillations-in particular the Younger Dryas cold period during the last deglaciation-have long been recognized from records throughout the North Atlantic region4-14, and the distribution of these records at mostly high latitudes suggests that the changes were caused by rapid reorganizations of the North Atlantic thermohaline circulation6,8,10,15. But events far from the North Atlantic region that are synchronous with the Younger Dryas16-19 raise the possibility that a more global forcing mechanism was responsible20. Here we present high-resolution records of laminated sediments of the last deglaciation from the Cariaco basin (tropical Atlantic Ocean) which show many abrupt sub-decade to century-scale oscillations in surface-ocean biological productivity that are synchronous with climate changes at high latitudes. We attribute these productivity variations to changes in or duration of up-welling rate (and hence nutrient supply) caused by changes in trade-wind strength, which is in turn influenced by the thermo-haline circulation through its effect on sea surface temperature6,21. Abrupt climate changes in the tropical Atlantic during the last deglaciation are thus consistent with a North Atlantic circulation forcing mechanism.
Article
Reconstruction of paleo-shorelines of Lake Lisan, the late Pleistocene precursor of the Dead Sea, is based on sequence stratigraphy of fan-delta and lacustrine deposits that are exposed at the Perazim Valley, southwest of the Dead Sea. The shoreline sediments are physically correlated with lacustrine aragonites, their ages are determined by U-series dating, to establish a lake-level curve for the time interval between 55 and 35kyr. During most of this period, Lake Lisan was at a relatively low level, which fluctuated between 280 and 290m below sea level (m bsl). The minimum lake stand (∼330m bsl) was reached at 47kyr and lasted for 3–4kyr. This episode is marked by a depositional hiatus in the section, and formation of an erosional channel. The studied period correlates with the global marine isotope stage 3. The low stand of Lake Lisan during most of this period indicates relative dry climatic conditions in the region.
Article
Here we present a new algorithm (StalAge), which is designed to construct speleothem age models. The algorithm uses U-series ages and their corresponding age uncertainty for modelling and also includes stratigraphic information in order to further constrain and improve the age model. StalAge is applicable to problematic datasets that include outliers, age inversions, hiatuses and large changes in growth rate. Manual selection of potentially inaccurate ages prior to application is not required. StalAge can be applied by the general, non-expert user and has no adjustable free parameters. This offers the highest degree of reproducibility and comparability of speleothem records from different studies. StalAge consists of three major steps. Firstly, major outliers are identified. Secondly, age data are screened for minor outliers and age inversions, and the uncertainty of potential outliers is increased using an iterative procedure. Finally, the age model and corresponding 95%-confidence limits are calculated by a Monte-Carlo simulation fitting ensembles of straight lines to sub-sets of the age data.
Article
In 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.
Article
Documentation of short-term climate variability during the glacial period has been limited by the availability of well-dated high-resolution archives. Here we present a paleoclimate reconstruction from varved lacustrine sediments of Lake Lisan, Dead Sea Rift, for ca. 26.2 17.7 (calendar) ka. The age is based on a floating varve chronology anchored to radiometric dates. Our reconstruction indicates that small ice-rafting events (a, b, c, and d), as well as Heinrich events in the North Atlantic, are associated with the Eastern Mediterranean arid intervals. Study of seasonal sublaminae yields evidence of several additional decadal- to century-scale arid events that correlate with cooler temperatures at higher latitudes. Analyses in the frequency domain indicate the presence of periodicities centered at 1500 yr, 500 yr, 192 yr, 139 yr, 90 yr, and 50 60 yr, suggesting a solar forcing on climate.
Article
Age–depth models form the backbone of most palaeoenvironmental studies. However, procedures for constructing chronologies vary between studies, they are usually not explained sufficiently, and some are inadequate for handling calibrated radiocarbon dates. An alternative method based on importance sampling through calibrated dates is proposed. Dedicated R code is presented which works with calibrated radiocarbon as well as other dates, and provides a simple, systematic, transparent, documented and customizable alternative. The code automatically produces age–depth models, enabling exploration of the impacts of different assumptions (e.g., model type, hiatuses, age offsets, outliers, and extrapolation).
Article
U-series dating can be an effective means to obtain accurate and precise ages on Quaternary carbonates. However, most samples require a correction for U and Th in admixed detritus. This complication is often addressed through generation of U-Th isochrons, requiring analyses of several coeval samples. In addition, presence of water-derived (hydrogenous) Th in the carbonate can cause inaccuracies in isochron ages.This study reports a high-resolution U-series chronology of sediments deposited by Lake Lisan, the last glacial precursor of the Dead Sea. The strategy employed combines multiple measurements from a few stratigraphic heights and fewer analyses from many heights in a single described and measured section. The resulting chronology is based on ages at 22 heights in a ∼40-m-thick section covering the interval of ∼70–14 calendar ka BP. The effects of admixed detritus are evaluated using trace elements. Nearly pure aragonite samples, indicated by very low abundances of insoluble elements such as Nb and Zr, were found to contain hydrogenous Th, which causes the uncorrected U-230Th age of a modern sample to be ∼2.5 ka. Nevertheless, accurate ages have been obtained by correcting for the detrital and aqueous interferences. The resulting ages are in stratigraphic order, and their accuracy is evidenced by consistency of Lisan Formation U-series and 14C ages with the coral-based calendar-radiocarbon age calibration.The U-Th ages provide a context to unravel the limnological history of Lake Lisan. Boundaries between the Lower, Middle, and Upper stratigraphic units correspond to the MIS 4/3 and 3/2 transitions, respectively. During MIS 2 and 4 the lake generally showed a stable two-layer configuration and a positive fresh-water balance, reflected by deposition of laminated aragonite-detritus. Dry intervals during MIS 2 and 4 are indicated by thick gypsum layers and an inferred depositional hiatus, which are temporally associated with Heinrich events H1 at ∼17 ka and H6 at ∼65 ka, respectively. During MIS 3 the lake level was unstable with intermittent dry periods indicated by abundant clastic layers and a significant hiatus between ∼43–49 ka. Clastic layers are associated with Dansgaard-Oeschger events during MIS 3, and indicate lake level declines during abrupt Northern Hemisphere warmings. Overall, the climate of the Eastern Mediterranean region shows a strong linkage to the Northern Hemisphere climate, with increasing lake size and stability during cold periods, and fluctuations and dessication during warmings and Heinrich events.
Article
A high-resolution Holocene seismic history of the Dead Sea Transform (DST) is established from laminated sedimentary cores recovered at the shores of the Dead Sea. Radiocarbon dating and annual laminae counting yield excellent agreement between disturbed sedimentary structures (identified as seismites) and the historical earthquake record: All recent and historical strong events of the area were identified, including the major earthquakes of A.D. 1927, 1837, 1212, 1033, 749, and 31 B.C. The total of 53 seismites recognized along the entire Holocene profile indicate varying recurrence intervals of seismic activity between a few and 1000 years, with a conspicuous minimum rate at 2100–31 B.C. and a noticeable maximum during the past six to eight centuries. Most of the epicenters of the correlated earthquakes are situated very close to the Dead Sea (within 150 km) or up to 400 km north of it along the DST. Between 1000 B.C. and A.D. 1063, and from A.D. 1600 to recent time the epicenters are all located on the northern segment of the DST, whereas prior to 1000 B.C. and between A.D. 1000 and 1600 they appear to scatter along several segments of the DST. We establish how the local intensity exerts a control on the formation of seismites. At historically estimated intensities greater than VII, all well documented earthquakes are correlated, whereas at intensities smaller than VI none are matching.The periods with enhanced earthquake rate along the DST correlate with those along the North Anatolian Fault as opposed to the intervening East Anatolian Fault. This may indicate some elastic coupling on plate-boundary scale that may also underlie escape and extrusion tectonics, typical of continental collision.
Article
Abrupt arid events in the post-glacial (∼17.4–10 kyr BP) Dead Sea Basin (DSB) were recorded by significant lake level declines in Lake Lisan and massive deposition of gypsum and salt. Between 17.4 and 16 kyr cal BP, the lake level dropped from its late MIS2 stand of ∼260 m below mean sea level (m bmsl) to ∼330 m bmsl, depositing a thick sequence of gypsum. Between ∼16 and 15 kyr cal BP the lake level recovered but dropped abruptly again at ∼14 kyr cal BP to below 465 m bmsl, probably the lowest late Pleistocene stand. Then, between 13 and 11 kyr cal BP (the Younger Dryas time interval) the lake rose above 400 m bmsl and declined at 11–10 kyr cal BP depositing a thick sequence of salt. The abrupt lake level drops and salt deposition coincided with times of ice and meltwater discharges into the North Atlantic (NA): Heinrich event (H1) and Meltwater Pulse – MWP1a. Similar coincidence between ice and meltwater discharges in the NA (e.g., H-events) and arid episodes at the Levant was recorded during the colder last glacial period, demonstrating a persistent effect of the North Atlantic hydrology and sea ice advances on the Levant climate. The climatically “turmoil” post-glacial period was accompanied by significant developments in human culture: the collapse of the Natufian culture during the Bølling–Allerød and the rise of the Pre-Pottery Neolithic cultures, PPN A and B around the 11–10 kyr cal BP salt deposition interval marking the initiation of the “Neolithic revolution” in the region.
Article
The oxygen and carbon stable isotope compositions of cave speleothems provide a powerful method for understanding continental climate change. Here, we examine the question of the regionality of this isotopic record and its linkage with the marine isotopic record in the Eastern Mediterranean (EM) region. The study presents a new, accurately dated 250-kyr δ18O and δ13C record determined from speleothems of the Peqiin Cave, Northern Israel. Its comparison with the continuous 185-kyr isotopic record of the Soreq Cave speleothems from Central Israel reveals striking similarities. Thus, a strong regional climatic signal, brought about by variations in temperature and rainfall amount, is reflected in both cave records. Low δ18O minima in the Peqiin profile for the last 250- to 185-kyr period (interglacial marine isotopic stage 7) match the timing of sapropels 9 to 7 and are indicative of high rainfall in the EM region at these times. The combined Soreq and Peqiin δ18O record for the last 250 kyr excellently matches the published Globigerinoides ruber (G. ruber) marine δ18O record for the EM Sea, with the isotopic compositional difference ΔG.ruber-speleothems remaining relatively constant at −5.6 ± 0.7‰, thus establishing for the first time a robust, exploitable link between the land and the marine isotopic records. The correspondence of low δ18O speleothem values and high cave water stands with low G. ruber δ18O values during interglacial sapropel events indicates that these periods were characterized by enhanced rainfall in the EM land and sea regions. By use of sea surface temperatures derived from alkenone data as a proxy for land temperatures at the Soreq Cave, we calculate the paleorainfall δ18O values and its amounts. Maximum rainfall and lowest temperature conditions occurred at the beginning of the sapropel events and were followed by decrease in rainfall and increase in temperatures, leading to arid conditions. The record for the last 7000 yr shows a trend toward increasing aridity and agrees well with climatic and archeological data from North Africa and the Middle East.
Article
Pollen records from the annually laminated sediment sequence in Lake Suigetsu, Japan, suggest a sequence of climate changes during the Last Termination that resembles that of the North Atlantic region but with noticeable differences in timing. An interstadial interval commenced a few centuries earlier [∼15,000 years before the present (yr B.P.)] than the North Atlantic GI-1 (Bölling) event. Conversely, the onset of a Younger Dryas (YD)–like cold reversal (12,300 to 11,250 yr B.P.) postdated the North Atlantic GS-1 (YD) event by a few centuries. Climate in the Far East during the Last Termination reflected solar insolation changes as much as Atlantic influences.
Article
Isotope and chemical analyses of the GRIP ice core from Summit, central Greenland, reveal that climate in Greenland during the last interglacial period was characterized by a series of severe cold periods, which began extremely rapidly and lasted from decades to centuries. As the last interglacial seems to have been slightly warmer than the present one, its unstable climate raises questions about the effects of future global warming.
Article
This study establishes for the first time the chronology and limnological history of Lake Amora (Dead Sea basin, Israel), whose deposits (the Amora Formation) comprise one of the longest exposed lacustrine records of the Pleistocene time. The Amora Formation consists of sequences of laminated primary aragonite and silty-detritus, Ca-sulfate minerals, halite and clastic units. This sedimentary sequence was uplifted and tilted by the rising Sedom salt diapir, exposing ∼320 m of sediments on the eastern flanks of Mt. Sedom (the Arubotaim Cave (AC) section).
Article
RECENT results1,2 from the Greenland Ice-core Project (GRIP) Summit ice core suggest that the climate in Greenland has been remarkably stable during the Holocene, but was extremely unstable for the time period represented by the rest of the core, spanning the last two glaciations and the intervening Eemian inter-glacial. Here we present the complete oxygen isotope record for the Greenland Ice Sheet Project 2 (GISP2) core, drilled 28 km west of the GRIP core. We observe large, rapid climate fluctuations throughout the last glacial period, which closely match those reported for the GRIP core. However, in the bottom 10% of the cores, spanning the Eemian interglacial and the previous glacia-tion, there are significant differences between the two records. It is possible that ice flow may have altered the chronological sequences of the stratigraphy for the bottom part of one or both of the cores. Considerable further work will be necessary to evaluate the likelihood of this, and the extent to which it will still be possible to extract meaningful climate information from the lowest sections of the cores.
Article
Oxygen isotope records of five stalagmites from Hulu Cave near Nanjing bear a remarkable resemblance to oxygen isotope records from Greenland ice cores, suggesting that East Asian Monsoon intensity changed in concert with Greenland temperature between 11,000 and 75,000 years before the present (yr. B.P.). Between 11,000 and 30,000 yr. B.P., the timing of changes in the monsoon, as established with 230Th dates, generally agrees with the timing of temperature changes from the Greenland Ice Sheet Project Two (GISP2) core, which supports GISP2's chronology in this interval. Our record links North Atlantic climate with the meridional transport of heat and moisture from the warmest part of the ocean where the summer East Asian Monsoon originates.