Dead Sea Research Articles

Adjoint Waveform Tomography for Crustal and Upper Mantle Structure of the Middle East and Southwest Asia for Improved Waveform Simulations Using Openly Available Broadband Data

ABSTRACT We present a new model of radially anisotropic seismic wavespeeds for the crust and upper mantle of a broad region of the Middle East and Southwest Asia (MESWA) derived from adjoint waveform tomography. The new model enables fully 3D simulations of complete three-component waveforms and provides improved fits that were not possible with previous models. We inverted over 32,000 waveforms from 192 earthquakes recorded by over 1000 openly available broadband seismic stations from permanent and temporary networks in the region with highly uneven coverage. Inversion iterations proceeded from the period band 50–100 s in six stages and 54 total iterations reducing the minimum period to 30 s. Our final model, MESWA, improves waveform fits compared to the starting and other models for both the data used in the inversion and an independent validation set of 66 events. Restitution tests indicate that the model resolves features in the central part of the model to depths of about 150 km. The new model reveals tectonic features imaged by other studies and methods but in a new holistic model of anisotropic shear and compressional wavespeeds (VS and VP, respectively) covering a larger domain with smaller scale length and amplified features. Examples include low crustal VS in the Tethyan belt and low mantle VS following divergent (Gulf of Aden, Red Sea) and transform (Dead Sea fault) margins of the Arabian plate. Low VS is imaged below Cenozoic volcanic centers of the Mecca–Madina–Nafud Line, Arabian Peninsula, and the Türkiye–Iran border region. Elevated VS tracks Makran subduction under southeast Iran with near vertical dip. MESWA could be used as a starting model for further improvements, say, using waveforms from in-country seismic networks that are not currently openly available and/or smaller-scale studies targeting a shorter period. The model could be used to improve earthquake hazard studies and nuclear explosion monitoring.

Black Soils in the Eastern Mediterranean: Genesis and Properties

This study investigates the distribution, morphology, and properties of these soils, focusing on areas such as littoral plains, high hilly areas, and rift depression valleys. Black soils occur in the eastern Mediterranean with a limited distribution, and some of them meet the requirements for black soils according to the INBS (International Network of Black Soils), while others do not. Black soils can be categorized into three types based on their genesis and evolution: calcareous black soils (mainly raw rocky rendzina), hydromorphic black soils, and black soil on basalt. While black soils were found in various bioclimatic stages and parent materials, their presence was notably limited in certain areas, contrary to prior indications. A soil morphology analysis revealed distinct color variations and depths, influenced by the accumulation of organic matter for hydromorphic and calcareous black soils and basaltic parent material for black soils on basalt. A particle size analysis indicated texture variations from clay to loam, with no clear indication of illuviation. A chemical analysis showed alkaline pH levels, except in basalt-derived soils, which exhibited a slight acidity. Hydromorphic black soil is the most important in terms of expansion and agricultural use and is only found in limestone marl deposits and lakes in depressions emerging from Dead Sea rifts under conditions of saturation or poor drainage. These soils have a thick, dark moly horizon and a high organic matter content.

Insights into the Dead Sea Transform Activity through the study of fracture-induced electromagnetic radiation (FEMR) signals before the Syrian-Turkey earthquake (Mw-6.3) on 20.2.2023

Observations of fracture-induced electromagnetic radiation (FEMR) were conducted along the Dead Sea Transform (DST) from Sodom to Jericho, coinciding with a magnitude (Mw) 6.3 aftershock earthquake (EQ) in the Turkey-Syrian region on February 20, 2023. The FEMR parameters (“hits,” Benioff strain release, frequency, rise-time, energy) and associated crack dimensions were analyzed, focusing on trends leading up to the EQ. This study investigated the Benioff Strain plot and other parameters in three consecutive earthquake nucleation stages leading to the catastrophe. The first stage showed increased FEMR hits and frequency, decreased rise time (T′), and crack dimensions. In the second stage, FEMR hits and crack width decreased while other parameters continued to rise, accumulating the second-highest energy, likely due to high-stress drop. The third stage exhibited steadily increasing FEMR hits and energy and a notable increase in crack dimensions, suggesting an imminent macro failure event. The cyclic trend in FEMR hits indicates alternating periods of high activity and silence, potentially linked to stress changes during crack propagation. Taken shortly before the earthquake, these measurements offer valuable insights into how FEMR parameters vary before seismic events, bridging the gap between lab-scale studies of rock collapses under stress and large-scale failure phenomena.

Modelling principal stress orientations in the Arabian Plate using plate velocities

Abstract We model maximum principal horizontal stress orientations in the Arabian Plate using a 3D finite element approach in conjunction with plate velocities. To capture the impact of geometry and tectonics, the model considers an accurate plate boundary shape and associated deformations. Three primary geological units represent plate architecture: sedimentary cover, crust and upper mantle. The mesh resolution varies to capture important geometrical features. Subsequently, we calculate the stress field using the force balance equation. Displacement boundary conditions are evaluated as accumulative deformation. NE–SW maximum principal horizontal stress (S Hmax ) azimuths dominate in northeastern Saudi Arabia and Kuwait, whilst NW–SE to NNW–SSE define the Dead Sea area. The Red Sea Basin and Saudi Arabia's interior is characterized by north–south S Hmax azimuths. Iraq's western area shows azimuths from NNW–SSE to NW–SE due to the collision at the Zagros Mountain Range, but changes to NE–SW in the east at the Zagros fold-and-thrust belt. An extensive literature review reveals publicly available S Hmax azimuth data which augment the sparse records compiled in the World Stress Map database. Our simulated S Hmax azimuths are consistent with these data. The results further corroborate ongoing tectonic processes, deepen our understanding of in situ stress variation drivers and inform current elastic deformation mechanisms in the Arabian Plate.

Magnesium of Dead Sea Salts as a Key Factor for the Treatment of Seborrheic and Atopic Dermatitis: A Case Report

Background: Seborrheic and atopic dermatitis are common and chronic inflammatory skin diseases. Conventional treatments are often ineffective and can have significant side effects. Magnesium dead sea salt has a high concentration of magnesium, and previous research shows its potential to help improve skin conditions.
 Case presentation: Patients with chronic seborrheic and atopic dermatitis were treated with topical 5% dead sea salt magnesium for 4 days. Patients experienced significant improvement in their symptoms.
 Conclusion. Dead Sea salt magnesium can be a safe and effective treatment for seborrheic and atopic dermatitis.

Chemical recovery of magnesium from the Dead Sea and its use in wastewater treatment

Abstract The objective of this study was to establish a suitable chemical process to recover magnesium compounds from Dead Sea water using a selective precipitation process. The recovered magnesium hydroxide (Mg(OH)2) and magnesium chloride (MgCl2) are applicable for wastewater treatment processes since they can effectively remove total suspended solids (TSS) and chemical oxygen demand (COD). Magnesium salts recovered from Dead Sea water were compared with cationic polyacrylamide (PAM) and inorganic salts, including aluminum sulfate Al2(SO4)3, ferric chloride (FeCl3), and ferrous sulfate (Fe2SO4) to investigate the removal efficiency of TSS and COD from wastewater using a chemical precipitation method by using coagulation and flocculation process. Results show that Mg(OH)2 yielded the highest TSS and COD removal efficiencies of 59 and 57%, respectively, with a wastewater pH of 11.5. MgCl2 yielded lower removal efficiencies of 46 and 44%, respectively; at pH 10.5, lower magnesium concentration doses were needed. The most effective chemical precipitation method for removal involved cationic PAM coagulants, resulting in an 86% reduction in TSS and a 65% reduction in COD. Combining commercial Fe2SO4 and MgCL2 recovered from Dead Sea water reduced up to 90 and 73% of TSS and COD, respectively.

Shear-Wave Velocity Model for the Dead Sea Transform from Multimode Inversion of Surface Waves Excited by the February 2023 Southeast Türkiye Earthquake Sequence

Abstract The dispersive nature of surface waves can be used for shear-wave velocity inversion at different scales. We show that four large earthquakes from the 2023 Türkiye earthquake sequence generate visible surface waves recorded by a dense strong-motion network deployed along the Dead Sea Transform (DST) in Israel. Thanks to favorable geometrical conditions and source radiation patterns, we observe both Rayleigh and Love waves that travel predominantly parallel to the network. We can reliably compute the dispersion of three Love-wave modes and two Rayleigh-wave modes. Using these dispersion curves, we invert for a 1D S-wave velocity model of the entire DST, outperforming an existing model. Statistical and kernel sensitivity analysis show high certainty down to a depth of 30 km thanks to the multimode joint inversion in the frequency band of 0.03–0.3 Hz. Using a multiwindow approach, we invert for an along-strike laterally varying velocity model of the DST. Although it is limited to the fundamental Love-wave mode, using the 1D model as a constraint allows us to recover a shallow (10 km) velocity structure in agreement with previous studies of the area. Despite the simplicity of our used approach, it can be used as a basis for more advanced studies.

Fluorine in the Waters of Hypersaline Water Bodies: Dead Sea, Lake Urmia

Fluorine in the Waters of Hypersaline Water Bodies: Dead Sea, Lake Urmia

Mechanical and Physical Properties of Concrete Mixed Using Dead Sea Water

Mechanical and Physical Properties of Concrete Mixed Using Dead Sea Water

Composite vertical structures and spatiotemporal characteristics of abnormal eddies in the Japan/East Sea: a synergistic investigation using satellite altimetry and Argo profiles

Mesoscale eddies are omnipresent and play an important role in regulating Earth’s climate and ocean circulation in the global ocean. Here using the combination of satellite altimetry products and Argo float profile data, two types of abnormal eddies are investigated: WCEs(warm cyclonic eddies) and CAEs(cold anticyclonic eddies) with different cores than conventional eddies in the Japan/East Sea. By applying a classification method based on the calculation of the heat content anomalies in the upper ocean, it was found that 10% of the eddies that captured the Argo float profiles exhibited obvious abnormal features. Subsequently, their spatiotemporal distributions and characteristics were analyzed statistically. Three-dimensional structures of abnormal eddies were obtained via the composite analysis method, showing that the warm/cold and light/dense core of the composite WCE/CAE is confined to the upper 100 m of the ocean with a maximum temperature anomaly of approximately +1.0(-1.1)°C. The composite WCE had a double-core salinity structure with a salty core above 50 m and an inferior fresh core. Meanwhile composite CAE had a fresh single-core with a maximum magnitude of -0.05 psu. Abnormal eddies are pervasive in the Japan/East sea, a revaluation of the role of these eddies in ocean circulation and climate systems, such as heat and salt transport, air and sea interaction, and variability in mixed layer depth, is of great importance.

Surface deformations of the 6 February 2023 earthquake sequence, eastern Türkiye.

Two powerful earthquakes struck Türkiye on 6 February 2023. The initial rupture was on the Dead Sea fault zone, yet maximum displacements and energy release [moment magnitude (Mw) 7.8] occurred 24 seconds later when rupture transferred to the East Anatolian fault zone (EAFZ). More than 7 hours later, a Mw 4.5 aftershock at the junction of the EAFZ with the east-west striking Çardak-Sürgü fault was followed 86 minutes later by the second large (Mw 7.5) earthquake, suggesting a causal relationship. We provide quantitative ground and aerial documentation of surface offsets and kinematics from the slipped faults, providing important data on surface deformation during large continental strike-slip earthquakes, rupture propagation mechanisms, and how slip may be transferred between complex fault systems. We also provide insight into how slip along linked fault systems accommodates global plate motions.

From salt to ionic substance: a language‐responsive teaching sequence for discovering salts in the Dead Sea

AbstractViele Schüler:innen stehen im Chemieunterricht vor großen Herausforderungen, wenn von ihnen verlangt wird, fachliches und konzeptionelles Wissen aufzubauen sowie gleichzeitig bildungs‐ und fachsprachliche Kompetenzen zu erwerben. In aller Regel bestimmen die sprachlichen Fähigkeiten in der Bildungs‐ und Unterrichtssprache Deutsch bereits, inwieweit Lernende überhaupt in der Lage sind, am Unterrichtsdiskurs teilzunehmen: Fehlen entsprechende bildungs‐ und fachsprachliche Kenntnisse, so führt das zumeist dazu, dass die fachliche Lernentwicklung hinter den Möglichkeiten der Lernenden zurückbleibt. Der Ansatz Disaggregate Instruction im Chemieunterricht (DICE) nimmt für sich in Anspruch, Schüler:innen mit sprachlichen Förderbedarfen nachweislich darin zu unterstützen, ein solides Verständnis chemiebezogener Fachkonzepte aufzubauen und fachsprachliche Kompetenzen auszubilden. In diesem Artikel stellen wir die Konzeption eines Lehr‐Lern‐Arrangements unter Anwendung von sprachsensiblen DICE‐ und Scaffolding Prinzipien sowie ausgewählte Unterrichtsmaterialien vor.

Anti-aging and rejuvenating effects and mechanism of Dead Sea water in skin.

External environmental stressors and internal factors have a significant impact on the skin, causing inflammation, aging, reduced immunity and other adverse responses. Dead Sea Water (DSW) is well known for its dermatological benefits and has been widely used in dermatological therapy and skin care for conditions such as psoriasis, atopic dermatitis and photoaging. However, the anti-aging and rejuvenating effects of DSW and the related biological pathways involved, which have attracted increasing attention, are not fully understood. The aim of this study is to investigate the anti-aging and rejuvenating effects of DSW and to explore the related potential biological mechanisms of DSW under different environmental conditions. The effects of DSW were investigated using invitro human dermal cells and reconstructed skin models. Extracellular matrix (ECM) components and the morphological changes at the dermal-epidermal junction (DEJ) in a 3D human skin model were evaluated after DSW treatment. RNA sequencing (RNA-seq) analysis of human dermal fibroblast models after DSW treatment was performed to explore the potential mechanisms of action of DSW under normal and UV stress conditions. The novel findings in this work present the biological functions of DSW, including procollagen-1 and elastin secretion, hemidesmosome increase and the epidermal basal cell regeneration. In addition, GO, KEGG and Reactome analyses reveal the activation of pathways related to ion transmembrane transporter activity, ECM component biosynthesis, senescence-associated secretory phenotype (SASP), DNA repair and autophagy, which are associated with the anti-aging activities of DSW. Our work provides new perspectives for understanding the anti-aging and rejuvenating effects and mechanisms of DSW. The new findings also provide a theoretical basis for the further development of age-related strategies.

Stress field and tectonic regime of the Eastern Mediterranean from inversion of earthquake focal mechanisms

The formal stress inversions of 1258 earthquake focal mechanism solutions reveal the presence of six distinct stress regimes. However, the predominant tectonic regimes comprise normal faulting (39%), strike-slip faulting (29%), thrust faulting (25%), and unspecified oblique faulting (7%). The division of the study area into zones based on structural and deformation patterns has provided valuable insights into the variations in the stress field and tectonic processes within this seismically active region. For each designated zone, reduced stress tensors were derived using the improved right dihedron method and the rotation optimization technique implemented by the Win-Tensor software.The stress field derived from the entire dataset is characterized by R′ = 1.0 and an NW-SE SHmax orientation, strongly influenced by the tectonic stress regime of the Hellenic Arc. In specific regions such as CYS, CEM, and WEM, the prevailing tectonic regimes is characterized by a predominant compressive setting with a stress index (R' = 2.0 to 2.5). This pattern aligns with neotectonic deformation associated with the subduction of the African Plate beneath the Eurasian Plate. The EMZ Zone exhibits a strike-slip tectonic regime with an R' of 1.50, primarily influenced by the Dead Sea Transform Fault. This fault accommodates differential motion between the African and Arabian plates in the NNE direction, resulting in left-lateral strike-slip motion along the plate boundary. The mean slip tendency values, varying between 0.62 and 0.66, suggests that the faults in the study area are appropriately oriented for slip or shear displacement, indicating an elevated probability of reactivation.

Extreme fluctuations in ambient salinity select for bacteria with a hybrid “salt-in”/”salt-out” osmoregulation strategy

Abundant microbial biofilms inhabit underwater freshwater springs of the Dead Sea. Unlike the harsh (i.e., over 35% total dissolved salts) yet stable environment of the basin, the flow rate of the springs changes with random amplitude and duration, resulting in drastic shifts in salinity, pH, and oxygen concentrations. This requires the organisms to continuously adapt to new environmental conditions. Osmotic regulation is energetically expensive; therefore, the response of the biofilm organisms to rapid and drastic changes in salinity is interesting. For this purpose, we studied the metagenome of an enrichment culture obtained from a green biofilm-covered rock positioned in a spring. We obtained metagenome-assembled genomes (MAGs) of Prosthecochloris sp. (Chlorobiales), Flexistipes sp. (Deferribacterales), Izemoplasma (Izemoplasmatales), Halomonas sp. (Oceanospirillales), and Halanaerobium (Halanaerobiales). The MAGs contain genes for both the energetically cheaper “salt-in” and more expensive “salt-out” strategies. We suggest that the dynamic response of these bacteria utilizes both osmoregulation strategies, similar to halophilic archaea. We hypothesize that the frequent, abrupt, and variable-in-intensity shifts in salinity, typical of the Dead Sea spring system, select for microorganisms with scalable adaptation strategies.

Seismic anisotropy and stress-field variations along the Dead Sea Fault zone in northern Israel

Geological observations based mainly on stress (strain)-indicating meso-scale markers suggest that the local maximum horizontal compressive stress (SHmax) direction along the Dead Sea Fault (DSF) system in northern Israel changes considerably over short distances from a ∼ N-S, fault-parallel orientation in the south to an ∼E-W, fault-perpendicular orientation in the north. However, the association of the meso-scale markers to the present-day stress field is not well constrained as many of them could have formed at any stage during the DSF evolution. In this study, we use a large dataset of Shear-Wave Splitting (SWS) measurements, taken from local DSF-related earthquakes, to characterize the azimuthal seismic anisotropy of the upper-crust at this critical turning point of the DSF system, near the Lebanese Restraining Bend. The SWS directions commonly align parallel to the local SHmax as revealed by the meso-scale markers, supporting their association with the current stress field. In several stations, SWS fast directions indicate azimuthal anisotropy at high angles to the trace of the master fault, indicating that stress-induced anisotropy represents a more plausible mechanism for SWS than structure-controlled anisotropy. The SWS measurements suggest that a northward counterclockwise rotation of the crustal SHmax is present along this segment of the DSF, supporting previous notation on the transition from divergent to convergent strike-slip faulting in this area. Plain langauge summaryGeological observations based mainly on stress (strain)-indicating meso-scale markers suggest that the local maximum horizontal compressive stress direction along the plate-boundary Dead Sea Fault (DSF) system in northern Israel changes considerably over short distances. However, the association of the meso-scale markers to the present-day local stress field is not well constrained since many of them could have formed at any stage of the DSF evolution. In this study, we use a common method of measuring local seismic anisotropy called “shear wave splitting” (SWS) to characterize the directional-dependent seismic wave speeds in the upper crust. The SWS measurements are obtained from local seismic and micro-seismic DSF-related events, and characterize the upper-crust seismic anisotropy at this critical turning point of the DSF system. The SWS directions commonly align parallel to the maximum compression as revealed by the meso-scale markers, supporting their association with the current stress field. The SWS measurements suggest that a northward counterclockwise rotation of the crustal maximum compression is present along this segment of the DSF.

The Imperative of Establishing the Mediterranean–Dead Sea Channel: Meeting the Demands of Escalating PV Electricity Production

The current landscape of electricity generation in Israel is significantly influenced by a marked increase in solar power output, primarily from photovoltaic (PV) facilities and plants. The rapid growth of solar energy within Israel’s self-sustained energy grid presents challenges for maintaining frequency stability and voltage equilibrium, limiting feasible solar electricity generation to approximately 12–14%. To expand these limits, integrating electrical storage solutions becomes imperative. An optimal proposal, tailored to Israel’s geographic location, involves constructing a conduit linking the Mediterranean and the Dead Sea. This initiative would include the installation of reservoirs and hydroelectric stations along the descent to the Dead Sea. Implementing such hydroelectric stations can help mitigate the impacts on frequency and voltage stability caused by the fluctuating nature of solar electricity production. Additionally, it can facilitate peak consumption management in the evening through hydroelectric generation, capable of delivering up to 320–330 MW of electrical power even in initial project phases. Furthermore, this strategic conduit offers additional benefits, such as enhancing PV electricity generation potential to 25–30% without exacerbating frequency control issues, producing an average of (150–180) × 103 m3 of desalinated water daily, and counteracting the steady decline of the Dead Sea, which currently recedes by about 1 m annually. Moreover, there are ancillary benefits from extensive desert area landscaping and the establishment of recreational health centers and resorts. A thorough analysis is imperative to estimate the potential increase in solar electricity generation, considering the unpredictable nature of PV outcomes. Additionally, it is crucial to explore the feasibility of using the Dead Sea for brine discharge from electrical hydro-storage plants as a key aspect of this comprehensive evaluation.

An investigation of a hybrid solar-mineral disinfection technique using Zeolite and Dead Sea clay

Effluents from water treatment plants (WTP) can often contain a complex mixture of residual micro-contaminants and organisms, not removed during wastewater treatment. A combined trickling filter, activated sludge treatment, ozonation, membrane filtration, and suspended biofilm reactors have been shown to reduce these contaminants in waste effluent but at high capita cost. This study examined an inexpensive method of purifying water, which combines solar water disinfection with natural mineral clays (SOMIN-DIS). The study involved the addition of two types of mineral clays, Zeolite and Dead Sea minerals, to containers of polluted wastewater, at varying concentrations. The containers were then subjected to different durations of sunlight exposure. Then, samples were taken from all of the containers to quantify the overall numbers of Total Coliform, Pseudomonas aeruginosa (P.aeruginosa), and Escherichia coli (E.coli), utilizing the IDEXX system. The findings indicated that incorporating Dead Sea clay and Zeolite into SODIS-treated wastewater decreased the overall number of harmful microorganisms and shortened the disinfection duration, as compared to using natural minerals and solar water disinfection (SODIS) independently. Additionally, the study determined that the most effective concentration of Dead Sea minerals, resulting in the least amounts of harmful microorganisms and shortest purification duration, was 0.001 g/ml. In contrast, the optimum concentration of Zeolite was 0.002 g/ml. In general, the addition of Dead Sea and Zeolite minerals to the wastewater increased the inactivation of bacteria under SODIS from 40% to 65%.

Formulating Dead Sea Mud in Cosmetic Products, Its Effects on Skin, and the Underlying Biological Mechanism: A Review

Formulating Dead Sea Mud in Cosmetic Products, Its Effects on Skin, and the Underlying Biological Mechanism: A Review

3D Interaction of Tectonics and Surface Processes Explains Fault Network Evolution of the Dead Sea Fault

3D Interaction of Tectonics and Surface Processes Explains Fault Network Evolution of the Dead Sea Fault