scholarly journals Temporal Changes in Radiocarbon Reservoir Age in the Dead Sea-Lake Lisan System

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 649-655 ◽  
Author(s):  
Mordechai Stein ◽  
Claudia Migowski ◽  
Revital Bookman ◽  
Boaz Lazar
Keyword(s):  
Surface Layer ◽  
Late Pleistocene ◽  
Residence Time ◽  
Drainage System ◽  
Dead Sea ◽  
Lower Reservoir ◽  
The Dead ◽  
Reservoir Age ◽  
Mixed Surface Layer

The Holocene Dead Sea and the late Pleistocene Lake Lisan were characterized by varying radiocarbon reservoir ages ranging between 6 and 2 ka in the Dead Sea and between 2 ka and zero in Lake Lisan. These changes reflect the hydrological conditions in the drainage system as well as residence time of 14C in the mixed surface layer of the lake and its lower brine. Long-term isolation of the lower brine led to 14C decay and an increase in the reservoir age. Yet, enhanced runoff input with atmospheric 14C brings the reservoir age down. The highest reservoir age of 6 ka was recorded after the sharp fall of the Dead Sea at ~8.1 ka cal BP. The lower reservoir age of zero was recorded between 36 and 32 ka cal BP, when the Lake Lisan mixed layer was frequently replenished by runoff.

Changes in the Atmospheric Pressure as an Unfavorable Factor of Work in the Deep Open Pits

2021 ◽  
pp. 35-38
Author(s):  
O.N. Dragunskiy ◽  
◽  
M. Rivkin ◽  
Keyword(s):  
Blood Pressure ◽  
Atmospheric Pressure ◽  
Dead Sea ◽  
Open Pit ◽  
Open Pit Mining ◽  
Sharp Change ◽  
Normative Documents ◽  
Dump Trucks ◽  
The Dead

The need in considering changes (including sharp) of the atmospheric pressure during the operation of deep open pits as one of the unfavorable factors is substantiated. It is believed that the atmospheric pressure in a particular region varies slightly-within 30–40 mm Hg per year. But at the present time, when only in Russia there are five open pits with a depth of 500 m and more, it is impossible to ignore changes in the atmospheric pressure in relation to workers moving, for example, by motor transport, from the surface to the bottom of the open pit and back. In this case, it can change by 50 or more mm Hg in half an hour. To solve the related problems, it is required to find out how atmospheric pressure affects the blood pressure of the open pit workers. The experience of the Dead Sea Clinic located in Israel at the Dead Sea at a depth of more than 400 m below the sea level is taken as a basis. Long-term measurements of the blood pressure in patients of the clinic revealed a tendency to decrease it by an average of 10–20 mm Hg. To prevent the adverse effect of a sharp change in the atmospheric pressure on people working in deep open pits, it is required to provide for appropriate measures of a different nature: technological (provide for changes in the characteristics of the open pit roads to ensure smoother descents and ascents of the dump trucks); technical (use of the conveyor and combined transport); organizational (including changes in the work and rest regimes of the working employees); regulatory (amendments to the relevant safety rules and other normative documents). To apply the results obtained in the open pit mining, it is necessary to conduct appropriate research in the operating deep open pits.

Long-term prediction of the water level and salinity in the Dead Sea

2002 ◽  
Vol 16 (14) ◽  
pp. 2819-2831 ◽  
Author(s):  
B. N. Asmar ◽  
Peter Ergenzinger
Keyword(s):  
Water Level ◽  
Dead Sea ◽  
Term Prediction ◽  
The Dead ◽  
Long Term Prediction

Climatic changes during the Pliocene as observed from climate-sensitive rocks and clay minerals of the Sedom formation, the Dead Sea Basin

Clay Minerals ◽  
2009 ◽  
Vol 44 (4) ◽  
pp. 469-486 ◽  
Author(s):  
S. Shoval ◽  
O. Zlatkin
Keyword(s):  
Clay Minerals ◽  
Rock Salt ◽  
Drainage System ◽  
Dead Sea ◽  
Arid Climate ◽  
Humid Climate ◽  
Sea Level Fluctuations ◽  
Dead Sea Basin ◽  
Calcareous Shale ◽  
The Dead

AbstractThe climatic history of the Dead Sea region during the Pliocene and its global connection are observed from climate-sensitive rocks and clay minerals of the Sedom formation. The Sedom formation consists of evaporative halitic rock salt units and calcareous shale units that were deposited in the Dead Sea Basin during the Pliocene. The precipitation of the rock salts took place in the hypersaline sabkha environment of the Sedom Lagoon. The extensive evaporative conditions are related to an extremely dry and warm arid climate at that time. In the arid climate, the influx of meteoric water by the drainage system of the Sedom Lagoon was limited and permitted a large concentration of lagoonal brine as well as a small rate of detritus transportation to the lagoon. Accessory sepiolite found in the rock salt appears to be neoformed from brine enriched with Mg and poor in Al under the extreme salinity condition. The small amounts of Al are in accordance with the small number of detrital minerals in the rock salts. The replacement in the deposition of the rock salt members with the calcareous shale members demonstrates a decrease in the salinity of the brine in the Sedom Basin and an increase in the deposition of detritus. The change in conditions was related to a period of deposition under a more humid climate where the erosion and the transport of detritus by the drainage system to the Sedom Basin was higher, causing the deposition of calcareous shales. Palygorskite found in the calcareous shales appears to be neoformed from brine enriched with Mg and containing Al in conditions of reduced salinity of the Sedom Basin. The larger amounts of Al are in accordance with the abundance of detrital minerals in the calcareous shales.The depositional cycles of the Sedom formation, the cyclic fluctuation of the climatic-hydrologic conditions from an arid to a more humid climate and their correlation with sea-level fluctuations and transgression-regression cycles of the Mediterranean Sea seem to be a response to corresponding global interglacial and glacial periods during the Pliocene.

Long-term (7 Ma) strain fluctuations within the Dead Sea transform system from high-resolution U-Pb dating of a calcite vein

2021 ◽  
Author(s):  
John P. Craddock ◽  
Perach Nuriel ◽  
Andrew R.C. Kylander-Clark ◽  
Bradley R. Hacker ◽  
John Luczaj ◽  
...  
Keyword(s):  
Fault Zone ◽  
Deformation Zone ◽  
Plate Boundary ◽  
Dead Sea ◽  
Mechanical Twinning ◽  
Fault Activity ◽  
Dead Sea Transform ◽  
Calcite Veins ◽  
The Dead

The onset of the Dead Sea transform has recently been reevaluated by U-Pb age-strain analyses of fault-related calcite taken from several fault strands along its main 500-km-long sector. The results suggest that the relative motion between Africa and Arabia north of the Red Sea was transferred northward to the Dead Sea transform as early as 20 Ma and along a ∼10-km-wide deformation zone that formed the central rift with contemporaneous bounding sinistral motion. The Gishron fault is the western bounding fault with normal and sinistral fault offsets that placed Proterozoic crystalline rocks and a cover of Cambrian sandstones in fault contact with Cretaceous-Eocene carbonates. Fault-related calcite veins are common in the Gishron fault zone, and we report the results of a detailed study of one sample with nine calcite fillings. Low fluid inclusion entrapment temperatures <50 °C, stable isotopes values of −3.3−0‰ (δ13C) and −15 to −13‰ (δ18O), and low rare earth element (REE) concentrations within the nine calcite fault fillings indicate that a local, meteoric fluid fed the Gishron fault zone over ca. 7 Ma at depths of <2 km. Laser ablation U-Pb ages within the thin section range from 20.37 Ma to 12.89 Ma and allow a detailed fault-filling chronology with the oldest calcite filling in the middle, younging outward with shearing between the oldest eight zones, all of which are finally crosscut by a perpendicular (E-W) vein. All nine calcite fillings have unique mechanical twinning strain results (n = 303 grains). Shortening strain magnitudes (−0.28% to −2.8%) and differential stresses (−339 bars to −415 bars) vary across the sample, as do the orientations of the shortening (ε1) and extension (ε3) axes with no evidence of any twinning strain overprint (low negative expected values). Overall, the tectonic compression and shortening is sub-horizontal and sub-parallel to the Gishron fault (∼N-S) and Dead Sea transform plate boundary. Most strikingly, the 7 m.y. period of vein growth correlates exactly with the timing of fault activity as evident within the 10-km-wide deformation zone in this evolving plate boundary (between 20 Ma and 13 Ma).

Stable isotopes of a subfossil Tamarix tree from the Dead Sea region, Israel, and their implications for the Intermediate Bronze Age environmental crisis

2009 ◽  
Vol 71 (3) ◽  
pp. 319-328 ◽  
Author(s):  
Amos Frumkin
Keyword(s):  
Stable Isotopes ◽  
Bronze Age ◽  
Nitrogen Isotopes ◽  
Dead Sea ◽  
Environmental Crisis ◽  
Salt Diapir ◽  
Isotopic Enrichment ◽  
Carbon And Nitrogen ◽  
The Dead

AbstractTrees growing on the Mt. Sedom salt diapir, at the southern Dead Sea shore, were swept by runoff into salt caves and subsequently deposited therein, sheltered from surface weathering. A subfossil Tamarix tree trunk, found in a remote section of Sedom Cave is radiocarbon dated to between ∼ 2265 and 1930 BCE. It was sampled in 109 points across the tree rings for carbon and nitrogen isotopes. The Sedom Tamarix demonstrates a few hundred years of 13C and 15N isotopic enrichment, culminating in extremely high δ13C and δ15N values. Calibration using modern Tamarix stable isotopes in various climatic settings in Israel shows direct relationship between isotopic enrichment and climate deterioration, particularly rainfall decrease. The subfossil Tamarix probably reflects an environmental crisis during the Intermediate Bronze Age, which subsequently killed the tree ∼ 1930 BCE. This period coincides with the largest historic fall of the Dead Sea level, as well as the demise of the large regional urban center of the 3rd millennium BCE. The environmental crisis may thus explain the archaeological evidence of a shift from urban to pastoral culture during the Intermediate Bronze Age. This was apparently the most severe long-term historical drought that affected the region in the mid-late Holocene.

scholarly journals Observations of positive sea surface temperature trends in the steadily shrinking Dead Sea

2018 ◽  
Vol 18 (11) ◽  
pp. 3007-3018 ◽  
Author(s):  
Pavel Kishcha ◽  
Rachel T. Pinker ◽  
Isaac Gertman ◽  
Boris Starobinets ◽  
Pinhas Alpert
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Feedback Loop ◽  
Sea Water ◽  
Dead Sea ◽  
Sea Surface ◽  
Positive Feedback Loop ◽  
Temperature Trends ◽  
The Dead

Abstract. Increasing warming of steadily shrinking Dead Sea surface water compensates for surface water cooling (due to increasing evaporation) and even causes observed positive Dead Sea sea surface temperature trends. This warming is caused by two factors: increasing daytime heat flow from land to sea (as a result of the steady shrinking) and regional atmospheric warming. Using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), positive trends were detected in both daytime and nighttime Dead Sea sea surface temperature (SST) over the period of 2000–2016. These positive SST trends were observed in the absence of positive trends in surface solar radiation, measured by the Dead Sea buoy pyranometer. We also show that long-term changes in water mixing in the uppermost layer of the Dead Sea under strong winds could not explain the observed SST trends. There is a positive feedback loop between the positive SST trends and the steady shrinking of the Dead Sea, which contributes to the accelerating decrease in Dead Sea water levels during the period under study. Satellite-based SST measurements showed that maximal SST trends of over 0.8 ∘C decade−1 were observed over the northwestern and southern sides of the Dead Sea, where shrinking of the Dead Sea water area was pronounced. No noticeable SST trends were observed over the eastern side of the lake, where shrinking of the Dead Sea water area was insignificant. This finding demonstrates correspondence between the positive SST trends and the shrinking of the Dead Sea indicating a causal link between them. There are two opposite processes taking place in the Dead Sea: sea surface warming and cooling. On the one hand, the positive feedback loop leading to sea surface warming every year accompanied by long-term increase in SST; on the other hand, the measured acceleration of the Dead Sea water-level drop suggests a long-term increase in Dead Sea evaporation accompanied by a long-term decrease in SST. During the period under investigation, the total result of these two opposite processes is the statistically significant positive sea surface temperature trends in both daytime (0.6 ∘C decade−1) and nighttime (0.4 ∘C decade−1), observed by the MODIS instrument. Our findings of the existence of a positive feedback loop between the positive SST trends and the shrinking of the Dead Sea imply the following significant point: any meteorological, hydrological or geophysical process causing the steady shrinking of the Dead Sea will contribute to positive trends in SST. Our results shed light on continuing hazards to the Dead Sea.

Lake Levels and Sequence Stratigraphy of Lake Lisan, the Late Pleistocene Precursor of the Dead Sea

2002 ◽  
Vol 57 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Yuval Bartov ◽  
Mordechai Stein ◽  
Yehouda Enzel ◽  
Amotz Agnon ◽  
Ze'ev Reches
Keyword(s):  
Water Level ◽  
Sequence Stratigraphy ◽  
Late Pleistocene ◽  
Lake Level ◽  
Dead Sea ◽  
Climatic Conditions ◽  
Water Level Fluctuations ◽  
Time Interval ◽  
Lake Area ◽  
The Dead

AbstractLake 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.

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