CryptoTEPHras in the ICDP Dead Sea deep core to synchronise past eastern MEditerranean hydroclimate (TEPH-ME)

2020 ◽  
Author(s):  
Ina Neugebauer ◽  
Markus J. Schwab ◽  
Simon Blockley ◽  
Christine S. Lane ◽  
Birgit Plessen ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Dead Sea ◽  
Central Anatolia ◽  
Geochemical Data ◽  
Lag Phase ◽  
Deep Basin ◽  
Critical Position ◽  
Global Comparison ◽  
The Dead

<p>The hypersaline Dead Sea is a key palaeoclimate archive in the south-eastern Mediterranean region, situated at a critical position between more humid Mediterranean climate and the hyper-arid Saharo-Arabian desert belt. The ca 450 m long ICDP drill core 5017-1, recovered from the deepest part of the Dead Sea, spans the last ~220,000 years as constrained by radiocarbon, U-Th dating and floating δ<sup>18</sup>O stratigraphy methods. Nevertheless, an independent dating method is much needed because (i) radiocarbon dating is limited to the last ~40,000 years; (ii) U-Th dating of authigenic carbonates requires a complex correction procedure leading to large age uncertainties; and (iii) wiggle matching of oxygen isotope data is not independent and, hence, does not allow the identification of lead- and lag-phase relationships of changing hydroclimate in comparison to other palaeoclimate records.</p><p>Tephrochronology has been demonstrated a powerful tool for dating and synchronisation of palaeoclimate records for regional and global comparison. Due to a lack of visible tephra layers in the Dead Sea sediment record, direct links with the eastern Mediterranean tephrostratigraphical lattice are still absent. Recently, the first cryptotephra ever identified in Dead Sea sediments has been associated with the early Holocene S1-tephra from central Anatolia. This discovery encouraged a systematic search for tephra time-markers in the ICDP deep-basin core 5017-1, with the aim of improving the chronology of the deep record significantly and providing a tool for precise regional synchronisation of proxy records.</p><p>In the first phase of the TEPH-ME project focusing on the early last glacial (ca 100-110 ka) and lateglacial (ca 11-15 ka) time intervals in the ICDP core, we have identified more cryptotephra layers than expected. First glass geochemical data suggest that the majority of volcanic ash in the Dead Sea sediments originates from Anatolian volcanic provinces. Even though proximal Anatolian tephra data for comparison are still limited, the identification of cryptotephra in the long Dead Sea record provides novel opportunities to advance the tephrostratigraphical framework in this region, e.g. through synchronising the Dead Sea and Lake Van (eastern Anatolia) sediment records, but also with archaeological and palaeoenvironmental sites that are currently investigated in the Levant and in Arabia.</p>

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

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

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

scholarly journals Active tectonics of the Eastern Mediterranean region: deduced from GPS, neotectonic and seismicity data

1997 ◽  
Vol 40 (3) ◽  
Author(s):  
A. Barka ◽  
R. Reilinger
Keyword(s):  
Mediterranean Region ◽  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Slip Rate ◽  
Strike Slip ◽  
Central Anatolia ◽  
Western Anatolia ◽  
Eastern Anatolia ◽  
Gps Measurements ◽  
Isparta Angle

This paper reviews the main tectonic features of the Eastern Mediterranean region combining the recent information obtained from GPS measurements, seismicity and neotectonic studies. GPS measurements reveal that the Arabian plate moves northward with respect to Eurasia at a rate of 23 ± 1 mm/yr, 10 mm/yr of this rate is taken up by shortening in the Caucasus. The internal deformation in Eastern Anatolia by conjugate strike-slip faulting and E-W trending thrusts, including the Bitlis frontal thrust, accommodates approximately a 15 mm/yr slip rate. The Northeast Anatolian fault, which extends from the Erzincan basin to Caucasus accommodates about 8 ± 5 mm/yr of left-lateral motion. The neotectonic fault pattern in Eastern Anatolia suggests that the NE Anatolian block moves in an E-ENE direction towards the South Caspian Sea. According to the same data, the Anatolian-Aegean block is undergoing a counter-clockwise rotation. However, from the residuals it appears that this solution can only be taken as a preliminary approximation. The Eulerian rotation pole indicates that slip rate along the North Anatolian fault is about 26 ± 3 mm/yr. This value is 10 mm/yr higher than slip rates obtained from geological data and historical earthquake records and it includes westward drift of the Pontides of a few millimetres/year or more. GPS measurements reveal that the East Anatolian fault accommodates an 11 ± 1 mm/yr relative motion. GPS data suggest that Central Anatolia behaves as a rigid block, but from neotectonic studies, it clearly appears that it is sliced by a number of conjugate strike-slip faults. The Isparta Angle area might be considered a major obstacle for the westward motion of the Anatolian block (Central and Eastern Anatolia). The western flank of this geological structure, the Fethiye-Burdur fault zone appears to be a major boundary with a slip rate of 15-20 mm/yr. The Western Anatolian grabens take up a total of 15 mm/yr NE-SW extension. The fact that motions in Central Anatolia relative to Eurasia, are 15-20 mm/yr while in Western Anatolia and Aegean Sea they are 30-40 mm/yr could suggest that Western Anatolia decouples from Central Anatolia and the Isparta Angle by the Fethiye-Burdur fault zone and Eski?ehir fault. It is also hypothesized that the differentiation of tectonic styles and velocities in the Anatolian-Aegean block are related to differences between the slabs lying under the Cyprus and Hellenic arcs.

Fluctuations of Lake Lisan (the Dead Sea) during the last glacial: Implications for paleoclimatic changes of the Levant.

2020 ◽  
Author(s):  
Shahrazad Abu Ghazleh ◽  
Stephan Kempe
Keyword(s):  
Fresh Water ◽  
Lake Water ◽  
Lake Level ◽  
Eastern Mediterranean ◽  
Xrd Analysis ◽  
Dead Sea ◽  
Climatic Conditions ◽  
Lake Basin ◽  
Fresh Water Input ◽  
The Dead

<p> </p><p>Calcareous stromatolite crusts overgrowing beach gravels and stabilising piles of rocks were observed on shoreline terraces of Lake Lisan along the eastern coast of the Dead Sea. The stromatolite crusts are thick, massive and hard, with a dark-grey or white-grey finely-laminated structure, indicating that they are mostly calcareous organic build-up of cyanobacterial origin. Samples from these stromatolites have been analyzed using Stable Isotopes (δ13C & δ18O), AAS and XRD analysis. The samples range in altitude between -350 m and -19 m, representing the time interval of Lake Lisan (~ 80-19 ka BP) according to our U/Th dating. Since stromatolites grow in shallow water, they are very sensitive to minor shifts in rainfall and evaporation and therefore an excellent tool to track small changes in hydrology, in climate and in paleoenvironmental conditions of the lake basin.</p><p> </p><p>Oxygen and carbon isotopic compositions of these stromatolites show a linear covariant trend with a strong positive correlation (r = 0.8) and large ranges of 7.85 and 6.78‰, respectively. This trend is most typical of primary carbonates formed in closed lakes. Isotopes analyses show low negative values of stromatolites from the lake highest stands at -76 m to -19 m, reflecting fresh water conditions of the lake basin at the last interglacial-glacial boundary (80-76 ka BP). The lowest values were derived from stromatolites at -103 to -119 m associated with the transgression of the lake to these high stands between 55 and 33 ka BP. The heaviest values were derived from stromatolites at -137 to -160 m indicating a change to dry climatic conditions in the Eastern Mediterranean that caused a subsequent drop of the lake level during MIS 2 (31-19 ka BP).</p><p> </p><p>The Mg/Ca ratio and the XRD analysis of the stromatolites correlate also with transgression-regression phases of the lake. Dominance of calcite in stromatolites at -76 to 0 m and inferred low Mg/Ca ratios of the lake water (i.e. ~2) imply a high fresh water input of the lake during the   highest stands period. A high Mg/Ca ratio of the lake water of >7 inferred from low-level stromatolite at -350 m and the existence of aragonite as the sole mineral reflect low fresh water input and high evaporation rates that caused a lake level regression during H6, ~ 60 ka BP.</p><p> </p><p>Inferred low Mg/Ca ratios of stromatolites at -247 to -101 m and the existence of calcite as a main mineral phase indicate wet climatic conditions of the eastern Mediterranean and lake level transgression to higher than -137 during MIS 3. The appearance of more aragonite in stromatolites at -137 to -154 m and the inferred high Mg/Ca ratio of the lake water points to a return to dry climatic conditions that caused a regression of Lake Lisan between 32 to 22 ka BP (MIS 2). However, the change in the mineral composition to pure calcite at -160 m in addition to the inferred low Mg/Ca ratio correlates well with the transgression of the lake to this level by the end of the LGM.</p><p> </p><p> </p>

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

2017 ◽  
Vol 464 ◽  
pp. 211-226 ◽  
Author(s):  
Yael Kiro ◽  
Steven L. Goldstein ◽  
Javier Garcia-Veigas ◽  
Elan Levy ◽  
Yochanan Kushnir ◽  
...  
Keyword(s):  
Lake Level ◽  
Eastern Mediterranean ◽  
Dead Sea ◽  
Lake Level Changes ◽  
The Dead

scholarly journals Precipitation cycles in Turkey

2021 ◽  
Author(s):  
Erkan Yılmaz ◽  
Yılmaz Akdi ◽  
Esra Uğurca ◽  
İhsan Çiçek ◽  
Cemal Atakan
Keyword(s):  
Eastern Mediterranean ◽  
Eastern Mediterranean Region ◽  
Central Anatolia ◽  
The Black Sea ◽  
Short Term ◽  
Air Masses ◽  
Precipitation Regimes ◽  
Annual Total ◽  
Precipitation Cycles

AbstractTurkey is located in the temperate zone; thus, it is influenced by regionally different air masses during summers and winters, resulting in different precipitation regimes. Often, systems with varying masses of air repeatedly affect Turkey; however, at times, these periods are disrupted and difficult to predict. This study analyzes whether a certain periodicity exists in the seasonal and annual total precipitation of 74 meteorological stations in Turkey using periodograms. The analyses conducted herein showed more than one period in the series; therefore, this study was extended, and the first six periods were examined. As a result, we found 2-, 3-, 4-, and 5-year precipitation cycles (PCs) in the short term; 6-, 7-, and 8-year PCs in the medium term; and 11-, 12-, 14-, 17-, and 21-year PCs in the long term in Turkey’s PC. While seasonal distributions exhibited similarities, there were significant differences in the seasonal frequencies owing to seasonal variations in the systems affecting Turkey. The cycles vary by region, and some of these cycles can be found in each region. Three cycles have been identified in Turkey according to frequency and length, namely: (1) short-term cycle across Turkey; (2) Eastern and Central Anatolia, the Black Sea, and Aegean regions; and (3) borders of Central Anatolian and the eastern Mediterranean region. A cluster identifies unrelated locations as the affected local factors. Cycles are connected to the NAO, whereas solar activity is observed throughout Turkey. The analysis showed that certain cycles were repeated and were not dominant in each period, with the best example of this cycle as the 7–14–21 consecutive cycles.

Cenozoic volcanism in the Middle East: petrogenesis of alkali basalts from northern Lebanon

2004 ◽  
Vol 141 (5) ◽  
pp. 545-563 ◽  
Author(s):  
ABDEL-FATTAH M. ABDEL-RAHMAN ◽  
PHILIP E. NASSAR
Keyword(s):  
Mantle Source ◽  
Crustal Contamination ◽  
Eastern Mediterranean Region ◽  
Dead Sea ◽  
Fault System ◽  
Transform Fault ◽  
Alkali Basalts ◽  
Cenozoic Volcanism ◽  
The Dead ◽  
Restraining Bend

The Cenozoic volcanic field of the Akkar region in northern Lebanon consists of a thick succession (200 m) of basaltic lava flows, erupted at the junction between a restraining bend (the Yammouneh transform fault) and its northern extension (the Ghab transform) in Syria. Both faults are part of the Dead Sea transform fault system, which represents the boundary between the Arabian and African plates and the Levantine subplate. The lavas are made up of about 15–25 vol. % olivine (Fo79–84), 30–40 % clinopyroxene (salite), 40–50 % plagioclase (An58–67), and opaque Fe–Ti oxides (∼ 5 %). Geochemically, they exhibit a narrow range of SiO2 (44.6 to 47.0 wt %), and MgO (2.9 to 7.5 wt %), are relatively enriched in TiO2 (2.0 to 2.9 wt %), and are classified as alkali basalts. Mg-numbers range from 0.32 to 0.59, with an average of 0.47. The rocks are enriched in incompatible trace elements such as Zr (98–184 ppm), Nb (16–39 ppm) and Y (25–34 ppm). The REE patterns are fractionated ((La/Yb)N=8.2), and are generally parallel to subparallel. Such compositions are typical of those of HIMU-OIB and plume-related magmas. Elemental ratios such as K/P (2.9), La/Ta (21.8), La/Nb (0.80), Nb/Y (0.92) and Th/Nb (0.35), and the low average SiO2 content (46.1 wt %) suggest that the magma was subjected to minimal crustal contamination. This may be related to a rapid ascent of the parental magma, in agreement with the nature (mafic, oceanic crust-like) and the thickness (only about 12 km) of the crust of the Eastern Mediterranean region. Cenozoic volcanism in this region is interpreted to have occurred in association with an episode of localized extension, particularly at the junction between the Yammouneh restraining bend and the Dead Sea–Ghab Transform (that is, in a transtensional tectonic regime). The 143Nd/144Nd isotopic composition of the basaltic rocks of northern Lebanon ranges from 0.512842 to 0.512934 (εNd=4.0 to 5.8), and 87Sr/86Sr from 0.703317 to 0.703579, suggesting a HIMU-like mantle source. Modelling indicates that the magma was produced by a small degree of partial melting (F=2 %) of a primitive, garnet lherzolitic mantle source, possibly containing a minor spinel component.

Late Holocene climates of the Near East deduced from Dead Sea level variations and modern regional winter rainfall

2003 ◽  
Vol 60 (3) ◽  
pp. 263-273 ◽  
Author(s):  
Yehouda Enzel ◽  
Revital Bookman (Ken Tor) ◽  
David Sharon ◽  
Haim Gvirtzman ◽  
Uri Dayan ◽  
...  
Keyword(s):  
Sea Level ◽  
Lake Level ◽  
Eastern Mediterranean ◽  
Close Association ◽  
Principal Component ◽  
Temporal Variations ◽  
Dead Sea ◽  
Rain Gauge ◽  
The Dead ◽  
Wet Spells

AbstractThe Dead Sea is a terminal lake of one of the largest hydrological systems in the Levant and may thus be viewed as a large rain gauge for the region. Variations of its level are indicative of the climate variations in the region. Here, we present the decadal- to centennial-resolution Holocene lake-level curve of the Dead Sea. Then we determine the regional hydroclimatology that affected level variations. To achieve this goal we compare modern natural lake-level variations and instrumental rainfall records and quantify the hydrology relative to lake-level rise, fall, or stability. To quantify that relationship under natural conditions, rainfall data pre-dating the artificial Dead Sea level drop since the 1960s are used. In this respect, Jerusalem station offers the longest uninterrupted pre-1960s rainfall record and Jerusalem rains serve as an adequate proxy for the Dead Sea headwaters rainfall. Principal component analysis indicates that temporal variations of annual precipitation in all stations in Israel north of the current 200 mm yr−1 average isohyet during 1940–1990 are largely synchronous and in phase (∼70% of the total variance explained by PC1). This station also represents well northern Jordan and the area all the way to Beirut, Lebanon, especially during extreme drought and wet spells. We (a) determine the modern, and propose the past regional hydrology and Eastern Mediterranean (EM) climatology that affected the severity and length of droughts/wet spells associated with multiyear episodes of Dead Sea level falls/rises and (b) determine that EM cyclone tracks were different in average number and latitude in wet and dry years in Jerusalem. The mean composite sea level pressure and 500-mb height anomalies indicate that the potential causes for wet and dry episodes span the entire EM and are rooted in the larger-scale northern hemisphere atmospheric circulation. We also identified remarkably close association (within radiocarbon resolution) between climatic changes in the Levant, reflected by level changes, and culture shifts in this region.

Micro- and macroseismicity of the Dead Sea rift and off-coast eastern Mediterranean

1981 ◽  
Vol 80 (1-4) ◽  
pp. 199-233 ◽  
Author(s):  
Ari Ben-Menahem ◽  
Ezra Aboodi
Keyword(s):  
Eastern Mediterranean ◽  
Dead Sea ◽  
The Dead

scholarly journals Intermediate Bronze Age in Southern Levant (4200–4000 BP) – Why Did Four Cities in Transjordan Survive Urban Collapse?

2016 ◽  
Vol 33 (1) ◽  
pp. 5-10
Author(s):  
Michał E. Bieniada
Keyword(s):  
Bronze Age ◽  
Littoral Zone ◽  
Eastern Mediterranean ◽  
Dead Sea ◽  
Climatic Conditions ◽  
Urban Life ◽  
Dew Point ◽  
Anthropogenic Factors ◽  
Southern Levant ◽  
The Dead

Abstract The first urban culture of southern Levant collapsed and the first period of urbanisation of Canaan (Early Bronze Age I-III) terminated at around 4200 yrs BP. The Canaanites abandoned their walled cities, dispersed and underwent pastoralisation. However, the urban centres of southern Canaan were not destroyed. This fact may point to responsibility of the environmental factor and makes influence influence of anthropogenic factors uncertain, along with the most popular Amorite invasion/destruction hypothesis. A tremendous climatic change occurred at that time in many regions, affecting cultures and civilisations of the Ancient Near East and resulting in abandonment of cities, migrations and great civilizational changes. In southern Levant, virtually all cities were left in ruins with a mysterious exception in Transjordan where four cities: Aroer, Ader, Khirbet Iskander and Iktanu survived and existed throughout the period. Most probably when climatic conditions in Cisjordan excluded possibility of urban life, the ones in Transjordan conditions remained unchanged or altered in a very limited scale. It is now clear that after a period with quite humid and warm climate, the precipitation greatly diminished after 4200 yrs BP in a littoral zone of eastern Mediterranean. A part of Transjordan, probably due to presence of the Dead Sea that somehow created conditions that influenced precipitation, remained a climatic niche with decent rainfall that enabled concentration of population in and around big urban centres and continuation of urban civilisation. Warming in a littoral zone changed dew point temperature preventing formations of clouds above western slopes of Judean and Samarian Hills. Moist air, prevented from condensation was transported eastwards where it could reach ascending currents appearing over the Dead Sea. Masses of air with water vapour moving upwards could form rainy clouds in Transjordan.

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