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Crustal deformation and seismicity in the Levant region are mainly related to the plate-boundary Dead Sea Fault (DSF) and the intraplate Carmel−Gilboa−Faria Fault System (CGFS). The intersection between these two major fault systems is generally treated as a ∼35-km-wide deformation belt stretched between the Faria and Gilboa Faults. Here, we present spatial and temporal analysis of faulting near this intersection. Our analysis is based on new geological mapping, new high-resolution airborne light detection and ranging (LiDAR) data, and seismic reflection profiles and indicates northward migration and localization of the intersection over time since the early Miocene. We discovered and mapped outcrops of Miocene, Pliocene, and Pleistocene rock units as well as faults and reconstructed the evolution of deformation. Three main tectonic phases were identified in this area covering the following periods: the early−middle Miocene, the late Miocene−Pliocene, and the Quaternary. During the first phase, the DSF and the CGFS developed, and the CGFS faulted along a series of subparallel grabens and elongated NW−SE, between the southernmost Faria and the northernmost Gilboa faults, over a belt width of ∼35 km. During the second phase, deformation along the CGFS migrated northward and concentrated at an ∼6-km-wide zone in the northern Faria Anticline. During the third stage, small-scale northward migration and localization of the deformation to a width zone of ∼1−2 km at the southern boundary of the Beit She’an Valley occurred. Faults from the third phase reveal both sinistral and normal faulting. We propose that the currently active intersection between the DSF and the CGFS is located east of this localized deformation zone, near a right step of the DSF and the uplifted area of Tel Al-Qarn in the eastern Jordan Valley. We suggest that the northward migration and localization of this intersection are related to regional tectonic changes, spatial variations in the Sinai-Arabia Euler pole, and the localization of deformation along the DSF.

Thirty-seven sites with fruit tree orchards were found in the arid Negev Highlands of southern Israel. A variety of domesticated fruit trees were planted in these orchards, including date palm, fig, olive, pomegranate, almond, carob, pistachio, grapevine and bitter orange. The orchards were irrigated only by runoff water accumulating in runoff-harvesting systems built during the Byzantine and Early Muslim eras, some 1000–1500 years ago, which, despite their antiquity, are still vivid and occasionally fruit bearing today. The oldest olive trees seem to be direct descendants of trees planted during Byzantine times, whereas the youngest trees were planted by the Bedouin population of the Negev Highlands in the last few decades. The fact that the Bedouin population, with very little experience in agriculture, has succeeded to cultivate a large variety of fruit trees in the present harsh arid climate utilizing the historical agricultural installations has important environmental implications. It indicates that the original builders of the desert agriculture systems were highly sophisticated in transforming desert soil into arable land. However, this was achieved through hard labor, involving the construction of a vast number of stone dams and agricultural terraces to divert channels, and the clearing of rocky surfaces. This huge effort indicates that the climate and environment prevailing during the Byzantine–Early Muslim eras was equally harsh and arid; otherwise, the invested labor would not have been justified. We conclude that the Byzantine farmers, with their greater agricultural experience and long heritage in dry land agriculture, have achieved greater success than today Bedouin population, at cultivating of fruit trees under the harsh conditions of the Negev Highlands. Therefore we deduce that the ancient desert agriculture was not the outcome of better climate; rather, the climate prevailing during the relevant historical times was probably dry and harsh, much like today. The fact that the Bedouin population in that geograghical area is cultivating orchards utilizing the same constructions, and technologies indicates that the present environmental and climatic conditions were are suitable for practicing desert agriculture and have hardly changed since the Byzantine era.

Marine Isotopic Stage 5 is associated with wetter climatic conditions in the Saharo-Arabian deserts. This stage also corresponds to the establishment of Middle Paleolithic hominins and their associated material culture in two geographical provinces in southwest Asia—the Eastern Mediterranean woodland and the Arabian Peninsula desert. The lithic industry of the Eastern Mediterranean is characterized by the centripetal Levallois method, whereas the Nubian Levallois method characterizes the populations of the Arabian desert. The Negev Desert, situated between these regions is a key area to comprehend population movement in correlation to climatic zones. This investigation addresses the nature of the Middle Paleolithic settlement in the Negev Desert during MIS 5 by studying the site of Nahal Aqev. High resolution chronological results based on luminescence dating and cryptotephra show the site was occupied from MIS 5e to MIS 5d. The lithic industries at Nahal Aqev are dominated by centripetal Levallois core method. These data demonstrate that Nahal Aqev is much closer in its cultural attributes to the Eastern Mediterranean Middle Paleolithic than to the Arabian Desert entity. We conclude that Nahal Aqev represents an expansion of Middle Paleolithic groups from the Mediterranean woodland into the desert, triggered by better climatic conditions. These groups possibly interacted with hominin groups bearing the Nubian core tradition from the vast region of Arabia.

Large areas in the arid Southern Levant are dotted with ancient agricultural terraces and runoff harvesting installations. In the Negev Highlands, Israel, they were constructed in the 3rd–4th centuries CE, maintained for 6–7 centuries, and then abandoned after the 10th century. Their design pattern and foundations provide a rare insight to the prevailing environmental conditions during the middle Holocene, while their 600–700 years cultivation tells the story of their maitainance and desert agriculture in these regions. From their abandonment onwards, they documented more than 1000 years of land degradation and soil erosion till present time. In this paper, we follow a complete cycle of desert agriculture of two sites near the UNESCO world-heritage town of Avdat. We reconstruct the landscape at the period pre-dating the first anthropogenic intervention, through the centuries of cultivation, and into a millennium of abandonment until the present erosion phase. We use high-resolution 3-D data to document the erosion and environmental dynamics during these two millennia, and to compute rates of siltation and erosion. Long-term measures of such kind are unique, as it is rare to find a millennium-scale documentation of soil erosion processes. Their study improves our understanding of the long-term environmental change mechanism acting in arid environments. The detailed analysis of these installations also offers insights into methods for soil conservation, for sustainable desert inhabitation, and for strategies to protect world-heritage installations. As the globe-wide struggle to combat soil erosion becomes urgent, this case study becomes even more relevant.

The rise and fall of desert agriculture in the southern Levant has been debated among scholars for the last 200 years, in the chronological, the socio-political and the environmental context. Based on c. 31 OSL ages of sediments from agricultural terraces in various sites in the Negev Highlands, the main phase of ancient desert agriculture was dated to between the 3rd-4th centuries CE and the 10th-11th centuries CE (Avni et al., 2013). Within this longue duree process of agricultural activities, no significant environmental or climatic change was observed coinciding with the Byzantine- Islamic transition in the 7th century CE. Our research, which focused on the natural processes that influenced the rise and fall of the Negev desert agriculture, found that the agricultural installations were sustainable for at least 700 years and parts of these agricultural constructions are still in use today. This long period of usage is a clear indication of their robust design and their good adaptation to the desert environment, despite possible short-term climatic fluctuations. However, continuous flooding, gulling, soil erosion and siltation required constant maintenance of agricultural systems by the local farmers. In addition, the political and economic changes that followed the Byzantine-Islamic transition triggered a gradual decrease in the economic value of the products of desert agriculture, followed by a disruption of the social-political balance between local farmers and herders. These made the desert runoff agriculture less viable, leading to its final demise after the 10th century CE. Therefore, a direct link between the rise and fall of desert runoff agriculture and the claimed climatic changes in the southern Levant seems unlikely.

Farming in drylands has always been challenging, however, modern technologies that allow irrigation by using distant water have sparked renewed interest in desert agriculture. Using imported water liberates the modern farmers from one of the major limitations created by this extreme environment, but the high price of the water, along with natural processes such as salinization and soil erosion, can make modern agriculture unprofitable. In the Negev Highlands desert of the Southern Levant, new agriculture enterprises have recently been established on the same soils that were cultivated for 600–700 years by ancient residents who constantly contended with environmental challenges. Therefore, it makes sense to ask whether the modern farmers can improve their methods using the long-term experience embodied in the remnants of the ancient agricultural systems. Using an interdisciplinary approach combining geomorphology, hydrology, archaeology and sociology, we show that the modern farmers face serious problems of soil erosion, soil salination and high price of water. Surprisingly, rain and floods are considered a negative factor for modern desert agriculture. We conclude that adapting and integrating some of the ancient methods within modern desert agricultural practices may turn the desert precipitation from a burden to a blessing.

Current conventions on the fate of agricultural bench terraces in the mountainous Mediterranean climatic zones, assume that after abandonment terraces undergo rapid degradation and soil loss. First walls crumble, followed by soil washed out of breaches in the walls by runoff, resulting in rapid erosion of soil from the slopes downhill into the streams. Additionally, soil erosion may explain why previous optically stimulated luminescence (OSL) dating of terrace soils in the Judean Highlands, Israel, found mostly young soils dating to the past 700 years, and only occasionally were older ages obtained for soils at the very base of these terraces. In contrast, observations made in the same region show that slopes with degraded terraces appear to still retain much soil even though only faint remains of the terraces exist. To test if terraces and soils indeed erode entirely and how long this might take, a relatively smooth hill slope showing remains of highly degraded sets of terraces was studied. Samples were collected from excavated pits for full OSL dating, in addition to samples densely collected for OSL measurements using a portable OSL reader (PR). Air-born photogrammetry was used to obtain high spatial resolution Digital Elevation Model. Results show that the main body of terraces was first built ∼800 years ago and maintained until 175-100 years age when they were abandoned and subsequently degraded. Since then 30–45% of soil volume was lost to erosion, however steady-state was reached at a relatively high slope of 65%, with stabilization by vegetation. The thick soil present on most of the slope suggests that after the first stage of rapid degradation the slopes reache equilibrium, most likely due to vegetation that reduces direct soil erosion, so most of the soil is retained on the slope. Finally, the PR allows for a much more nuanced understanding of terrace soil history.

Twenty-three olive trees were found to grow in traditional orchard sites in the Negev Highlands desert, southern Israel. Their location was marked on maps, and their growth, morphology, biology, preservation and survival was monitored. Some of them are presently maintained by the Bedouin population of the Negev, whereas others seemed to have survived from earlier periods. The average annual rainfall in this region is 90–130 mm. Most of the orchards were deliberately planted in pre-existing agricultural plots, built during the Byzantine and Early Muslim era (3rd–8th centuries CE). They were irrigated by harvesting runoff water. The Byzantine era was the most populated period in the Negev Highlands, when wine and olive oil were the main horticultural products. A variety of domesticated fruit trees are found in the present abandoned orchards: olive, fig, grapevine, pomegranate, almond, date palm, carob, pistachio and bitter orange. The trees have not been artificially irrigated for at least seven decades. Nevertheless, most of them continue to flourish and bear fruit. We focused on understanding the abandoned olive trees’ survival and adaptation mechanisms. Olive trees growing was a favorite crop to Byzantine farmers due to the significant economic value of olive oil and good adaptation to the environmental conditions in the Negev Highlands.

The recent success in dating dry farming terraces by Optically Stimulated Luminescence (OSL) enables scholars to evaluate for the first time construction events of terraces in their true social and economic context. Presented here are 36 new ages from two study areas located along the Upper Soreq catchment, highlands of Jerusalem, Israel. Field operations were targeted at locating Bronze Age and Iron Age agricultural activities while evaluating possible methodological limitations in using OSL for dating terraces. The results convincingly show that in the Mediterranean highland environment, soil erosion and rebuilding activities have only a mild impact on the resulting OSL dating. When combining the new ages with the ~60 ages that were published previously in the study area, it is possible to conclude that in the more favorable ecological niches of the highlands of Jerusalem terraces began ca 2400–2200 years ago. This was followed by two or three waves of wide-scale terracing, taking place mainly in the last 800 years. Finally, we were able to recognize a unique ecological niche that preserved ancient (ca 2500 years old) pre-terracing activities as it was not densely covered by later terraces.

We study in this paper land degradation processes in arid environments that are leading to a major environmental change. These processes, which are mostly the outcome of gully development, have direct impact on agriculture potential, biomass degradation, and escalating desertification. Three representative sites within the Negev Highland, Israel, are studied by utilizing terrestrial laser scans to gain detailed spatial information, accurate estimations, and concisely document overarching trends. The resulting information allows us to thoroughly characterize and quantify the geomorphic and vegetative changes and to calibrate rates and trends that have only been roughly estimated thus far. The scans, which were taken over a four-year span (2009–2013), cover three different types of hydrological seasons and provide unique insights on development rates and subsequent ramifications. The characteristic progression of natural land degradation in the Negev Highlands and the techniques used to document and analyze it can be extended globally to regions undergoing similar transitions.

The Negev desert is a part of the northern Saharo-Arabian desert belt, a major physical barrier between Africa and southwest Asia. Its location at the crossroads of the two continents makes it a perfect region to trace the presence of early hominins on the route from Africa to the Levant in major dispersal events. Geomorphological mapping in the central Negev region allows a reconstruction of the Plio-Pleistocene landscape, and the processes that shaped the Negev desert. Features that characterize this arid to hyper-arid region are the sequences of alluvial surfaces and wetland deposits, covering the last 2 Ma, now evident in the present-day landscape as a series of abandoned alluvial terraces standing 100-5 m above the active stream channels, containing conglomerates, fine silty sediments and travertines. In this study we integrate alluvial terraces with scattered outcrops of travertines and wetland deposits, marking the locations of past water resources in the central Negev. The environmental reconstruction enabled us to conceive a conceptual model and produce a detailed map that predicts the preferable locations for archaeological sites from the Lower and Middle Paleolithic periods. The outcome of this study is a validated model for tracing Paleolithic sites in their geomorphological contexts and a better understanding of the role of the Negev in Middle Pleistocene hominin dispersals. Likewise, the prediction model for the Negev could be applied to other desert regions globally.

Sparsely vegetated bedrock slopes in deserts coincide with slope parameters, thus they have important implications on biological, chemical, hydrological and geomorphological processes. Spatial variations in these vegetation patterns, density and communities indicates on relatively humid habitats, which correspond with sinks for high runoff. Relations between the bedrock runoff generation and vegetation patterns may imply on the spatial locations of Byzantine – Early Muslim (400-1000 C.E.; 1600-1000 y BP) agriculture installations. These installations are widespread in the Negev Desert, Israel, utilized sophisticated runoff harvesting techniques by the ancient farmers. Applying a multi-disciplinary approach, we tested vegetation patterns as a precursor for runoff generation along bedrock slopes in the Negev Desert Highlands, and correlated them to the spatial distribution of the Byzantine – Early Muslim runoff agriculture installations. Integrating vegetation patterns, geological substrate data and bedrock-runoff generation data on a GIS model on a large scale (160 km2) of the Negev Highlands yields a synthetic potential runoff map. This map is a unique new product conducted for the first time during this study. Basing on it, runoff yield can be predicted for different scales, ranging from that of a single lithology slope to that of a basin of varying lithologies. Utilizing this methodology, we show that high correlation (80 %) exists between vegetation patterns and spatially located Byzantine – Early Muslim runoff-farming installations. This correlation turns the vegetation coverage as a reliable marker for predicting runoff yield in arid bedrock slopes and imply for stable arid climate in the past 1600 years in the Negev Desert.

• Tel Yarmuth is one of the largest Early Bronze Age urban centers in the Land of Israel.

Intense analysis of geological, geophysical and particularly new available biostratigraphic data from the Gulf of Suez (GS), Red Sea (RS) Gulf of Aqaba (GA) and the Eastern Mediterranean significantly clarifies the evolution of these continental rifts toward new accretionary plate boundaries. RS–GS continental rifting started at ~ 28 Ma and experienced occasional sea water floods. The first synchronous flooding of Mediterranean Sea water into both GS–RS and proto-GA tectonic basin prevailed between Late Chattian (~ 24.5 Ma) and Late Aquitanian (~ 20.5 Ma). Contemporaneous flooding of Neotethys sea-water from the east, into the central Dead Sea fault tectonic basins concentrated in Lake Kinneret–Jordan Valley with no connection to the Levant Basin. The second flooding occurred between Late Burdigalian (~ 16.5 Ma) and late Langhian (~ 14.4 Ma). Since then the Mediterranean seaway to GS sealed off by an isostatic uplift of northern Sinai High as a response to increased loading of the Miocene Nile sedimentary cone within the Levant Basin. A compulsory condition for these two flooding events into the RS system was coeval Mediterranean sea-level highstands relative to the Levant continental terrain, represented by onlap of bioclastic and reefal limestones on central Israel foothills. The younger Tortonian highstand flooded only the newly formed Lower Galilee rift in northern Israel. Since the Pliocene, the RS–GS–GA tectonic basins were flooded by the Indian Ocean seaway through the Gulf of Aden. Increased faulting along the GS during the Langhian event coincides with the acceleration of the Dead Sea transform indicating their mutual tectonic activity. Since Mid Miocene time, the Dead Sea transform accommodated most of the plate separation between Africa and Arabia. Cenozoic paleo-seaways and floods portray the structural chronology of continental plate boundaries in the RS–GS–GA–Dead Sea transform, adjacent to the Levant continental margin.

The Miocene Hazeva River was a large fluvial system (estimated catchment size > 100 000 km2) that drained the Arabian Plateau and Sinai Peninsula into the Mediterranean Sea during the Early–Mid Miocene. It was established after rifting of the Red Sea uplifted the Arabian Plateau during the Oligocene. Following late Miocene to early Pliocene subsidence along the Dead Sea Rift, the Hazeva drainage system was abandoned and dissected, resulting in new drainage divides on either side of the rift. We utilized a novel application of cosmogenic 21Ne measurements in chert to compare modern erosion rates with Miocene erosion rates that operated when the Hazeva River was active. We find that modern erosion rates derived from cosmogenic 21Ne, 26Al, and 10Be in exposed in situ chert nodules to be extremely slow, between 2–4 mm/kyr. Comparison between modern and paleo erosion rates, measured in chert pebbles, is not straightforward, as cosmogenic 21Ne was acquired partly during bedrock exhumation and partly during transport of these pebbles in the Hazeva River. However, even with bedrock erosion and maintained transport along this big river, 21Ne concentrations measured in Miocene cherts are lower (range between 3.66 ± 1.9 × 106 and 8.97 ± 1.39 × 106 atoms/g SiO2) compared to 21Ne concentrations measured in the currently eroding chert nodules (8.08 ± 1.48 × 106 and 12.10 ± 2.43 × 106 atoms/g SiO2). 21Ne concentrations in Miocene cherts correspond to minimum erosion rates that are at least twice as fast as rates calculated today. We attribute these faster erosion rates to a combination of continuous uplift and significantly wetter climatic conditions during the Miocene.

Large distribution of historical agricultural installations in the desert zone of the southern Levant, mainly from the Byzantine - Early Muslim periods (1600–1000 y BP) indicates that the region was highly productive in the past. That could have been achieved either because of a more humid climate, or by sophisticated runoff harvesting techniques utilized by the ancient farmers under a desert climate. Among all, the most important factor enabling the existence of the desert agriculture was runoff harvesting. Our study assess a multi-disciplinary approach testing the relationship between diverse geological strata, their ability to cause runoff and the possible preferences made by the ancient farmers to utilize these rock properties. Utilizing GIS methods we generated high-resolution maps, highlighting the present runoff potential both on a single lithology slope level and on the drainage basin scale. By applying this methodology we show that high correlation (80%) exists when testing the spatial emplacement of runoff-farming installations constructed during the Byzantine - Early Muslim periods on the present best runoff yielding drainage basins under the present climatic conditions. This hints at the long stability of the environmental and probably climatic conditions in the southern Levant regions during the late Holocene.

New multidisciplinary research based on geomorphological investigation and soil survey conducted at the slopes of Masada fort enabled us to reevaluate and question the dramatic events that took place there, in 73/74 CE, according to the 1st century CE Jewish historian, Flavius Josephus. The fort, built on a high elevated and isolated rocky block facing the Dead Sea in Israel, is now on the UNESCO list of World Heritage sites. Here, according to Josephus, a group of Jewish rebels occupying Masada chose to kill each other and die as free people rather than go into captivity. This act took place after the rebels realized that the Roman army, laying a complex assault ramp against the fort of Masada, were breaching its walls. The archaeological finds unearthed at Masada, revealing the daily life of the Jewish rebels and the well-preserved remains of the Roman siege apparatus, seem at face value to complement Josephus' description. However, our new geomorphological and soil examination of the assault ramp and the natural terrain in its vicinity enable us to clearly separate between the man-made construction and the natural slope environments, and draw a clear boundary between the two. In addition, we conclude that since their formation, they were not subjected to later modification by processes such as natural erosion, slope sliding, or anthropogenic interruptions. As the Roman assault ramp was found to be an uncompleted structure, we conclude that the final scenario of the siege could not have happened as Josephus described it. This meticulous new research confirms our earlier hypothesis that the assault ramp was never completed and therefore could not have been operational. Such a conclusion challenges the common understanding of how the Roman siege of Masada ended.

Here we present the first results of a new interdisciplinary research project entitled “The Formation of Terraced Landscapes in the Judean Highlands, Israel”. The research traces the socio-economic and historical contexts in which terraces were constructed in the rural periphery of Jerusalem, a thriving political, economic and religious center for four millennia, by using optically stimulated luminescence (OSL) dating of terraces fill in combination with careful analyses of related geomorphological and archaeological records. The first sub-region studied is Mount Eitan, an isolated hilly spur located ca. 12 km west of the ancient city, above the Soreq Valley, the main drainage basin of the region. The results demonstrate a complex history of terrace construction and use, beginning with sporadic activity during the Hellenistic and Roman periods and reaching a zenith during the mid-second millennium CE. The results enable to put to test current paradigms regarding the relation between extensive terracing operations and settlement oscillations and the antiquity of the terrace phenomenon in the Eastern Mediterranean.

We document and analyze the rapid development of a real-time karst system within the subsurface salt layers of the Ze'elim Fan, Dead Sea, Israel by a multidisciplinary study that combines interferometric synthetic aperture radar and light detection and ranging measurements, sinkhole mapping, time-lapse camera monitoring, groundwater level measurements and chemical and isotopic analyses of surface runoff and groundwater. The >1 m/yr drop of Dead Sea water level and the subsequent change in the adjacent groundwater system since the 1960s resulted in flushing of the coastal aquifer by fresh groundwater, subsurface salt dissolution, gradual land subsidence and formation of sinkholes. Since 2010 this process accelerated dramatically as flash floods at the Ze'elim Fan were drained by newly formed sinkholes. During and immediately after these flood events the dissolution rates of the subsurface salt layer increased dramatically, the overlying ground surface subsided, a large number of sinkholes developed over short time periods (hours to days), and salt-saturated water resurged downstream. Groundwater flow velocities increased by more than 2 orders of magnitudes compared to previously measured velocities along the Dead Sea. The process is self-accelerating as salt dissolution enhances subsidence and sinkhole formation, which in turn increase the ponding areas of flood water and generate additional draining conduits to the subsurface. The rapid terrain response is predominantly due to the highly soluble salt. It is enhanced by the shallow depth of the salt layer, the low competence of the newly exposed unconsolidated overburden and the moderate topographic gradients of the Ze'elim Fan.

One of the most significant environmental processes that occurred at the transition from the last glacial phase into the present inter-glacial phase in arid regions was the shift from aggradation to incision in the drainage systems. This is evident by the sharp transition from a fluvial regime depositing fine-grained sediment within the wadis to intensive incision which formed gullies and narrow channels that dissected the late Pleistocene sediments. In order to investigate this transition, we studied three small-scale basins in the arid region of the Negev Highlands, southern Israel. Although the selected basins drain toward different base levels, their geomorphological parameters, particle size distribution of alluvial units and their OSL ages are similar. Sediments from the penultimate glacial cycle are found in patches in the bigger catchments. Fluvial loess was widely deposited since at least 67 ka until after 28 ka, covering valleys and slopes. Between ~ 28 and ~ 24 ka, loess was washed from the slopes into the channels, exposing the underlying colluvium. At ~ 24 ka erosion began with the transport of slope colluvium as gravels into the valleys that eroded the underlying loess sediments. Incision became dominant at ~ 12 ka and is still ongoing and intensifying. Dust and reworked loess continued to be deposited during the main incision stages. It is proposed that the transition from aggradation to incision was controlled by rates of loess supply and removal. Until ~ 24 ka dust choked the drainage system and only after reduction in dust supply was erosion and incision possible. It began first on the slopes and then in the channels. Our results show that an increase in precipitation is not a prerequisite for initiation of incision as is often assumed. Similar processes are described in other arid zones around the world.

More than a hundred abandoned but presently maintained fruit trees are scattered in the Negev Desert Highlands in Southern Israel. Most of the older groves were planted by Bedouins in pre-existing agricultural systems built in the distant past, mainly during the Byzantine era, mostly during the sixth and seventh centuries AD. In these groves a variety of domesticated fruit trees such as date palms, figs, pomegranates, almonds, carobs, pistachios, bitter oranges, grapevines and olives have been planted. The trees growing in these abandoned sites throughout the Negev Highland region are strictly rain-fed and dependent on the amount of runoff water accumulating from the surrounding old runoff harvesting systems with no modern artificial irrigation at least for the past several decades. Despite the lack of active irrigation, some of the trees of all species continue to flourish and even persist in bearing fruit to this day. The trees growing in the Negev Highlands can be divided into several planting periods. The oldest olive trees are apparently descendants of trees planted in the area during the Byzantine period (sixth and seventh centuries AD), while the youngest consist of varieties and species recently planted by Bedouins, until 1948. The factors affecting the survival of the trees are mainly of a geological nature, especially the rock types and their spatial distribution that contribute to the potential of runoff water. Topographic layouts are also critical for enhancing water runoff, as well as various soil parameters, such as water-holding capacity, depth, salinity, and organic matter content. A significant impact on the trees’ condition and survival depends also on the preservation state of the ancient terraces in which they were planted and the level of horticultural expertise of the Bedouins in growing fruit trees. During this study we characterized the geographical, geological and topographical conditions enabling the survival of different fruit trees with no artificially added irrigation in various locations within the Southern Israeli desert. Apparently no specific genotypes were required and involved in the survival of the various fruit trees, but the microconditions at each tree's location were found to be critical.

The June 1991 Pinatubo volcanic eruption perturbed the atmosphere, triggering short-term worldwide changes in surface and lower troposphere temperatures, precipitation, and runoff. The following winter was anomalously wet in the Levant, with a ∼2-m increase in the Dead Sea level that created a distinct morphological terrace along the lake's shore. Given the global radiative and chemical effects of volcanogenic aerosols on climatic systems, we tested the hypothesis that the 1991–92 winter shore terrace is a modern analogue to the linkage between past volcanic eruptions and a sequence of shore terraces on the cliffs around the Dead Sea Basin (DSB). Sixteen shore terraces, detected using airborne laser scanning data, were interpreted as indicating short-term level rises due to episodes of enhanced precipitation and runoff during the dramatic drop in Lake Lisan's (palaeo-Dead Sea) level at the end of the Last Glacial Maximum. The terraces were compared with a dated time series of volcanogenic sulfate from the GISP2 ice core, and similar numbers of sulfate concentration peaks and shore terraces were found. Furthermore, a significant correlation was found between SO 4 concentration peaks and the heights of the terraces. This correlation may indicate a link between the explosivity of past eruptions, the magnitude of stratospheric injection, and their impact on the northern hemisphere water balance. The record of such short-term climato-hydrological effects is made possible by the dramatic desiccation of Lake Lisan. Detailed records of such events, albeit rare because of their vulnerability and short longevity, provide an important demonstration of global climatic teleconnections.

To reveal the development of the stress field near the Arava basin located along the Dead Sea Fault system, we characterized joint sets that were exposed mainly in the Santonian and Eocene chalk rock outcropping in the study area. In total, ~2600 strike orientations of single-layer joints (SLJ) and multilayer joints (MLJ) mirrored four main stress fields: 1) σHNW(J1-326°), 2) σHNNW(J2-343°), 3) σHNNE(J3-033°), and 4) σHN (J4-360°). The results showed that the relatively lower values of the fracture spacing ratio (FSR) and their standard deviations in J1 implied that J1 was formed during the burial stage of the Eocene chalk formations. The inconsistency between the statistical parameters of the log-normal distributions of joint spacing and FSR raised doubt about the applicability of the “saturation joint density model” in our studied area. The joint sets characteristics suggest that the regional σHNW operated during the Eocene. During the Miocene, the regional stress field changed clockwise to σHNNW, probably in association with the early stage of transform motion along the Dead Sea Fault. In the Pliocene-Pleistocene, the σHNNE and σHN local stress fields both operated and were accompanied by a tensional stress field that can be identified in the intensive normal faulting evolved along the western Arava basin margins.

The Dead Sea, the lowest place on the Earth's continents, was at its highest level in 1896, reaching an elevation of ~ 388.4 m below mean sea level (m.b.m.s.l) and ~ 390 m in the early 1920s. Since then it has almost constantly been dropping, reaching the level of 426 m.b.m.s.l in 2013. Since the late 1990s its level has been decreasing by approximately 1 my− 1. The rapid lake retreat accelerates large-scale environmental deterioration, including soil erosion, land degradation, rapid headcut migration and widespread development of collapse sinkhole fields. These geomorphic elements threaten the natural environment and anthropogenic infrastructure. We provide an overview of the geomorphic processes in the form of soil erosion, channel incision, land degradation, and the development of collapse sinkholes. We take advantage of the high-resolution airborne laser scanning technology for three-dimensional detection of surficial changes, quantification of their volumes, and documentation of the present state of the terrain with utmost accuracy and precision. This type of information and the identification of future trends are vital for proper planning of any rapidly-changing environment.

An extensive survey followed by OSL (optically stimulated luminescence) dating of loess accumulation in agricultural terraces at six Byzantine and Early Islamic sites in the Negev Highlands revealed clear stratigraphic and chronological sequences. Traditionally dated to the 1st–7th centuries A.D., results from the present study demonstrate that the construction and use of largescale agricultural systems took place in the 4th–11th centuries A.D. This new chronology provides the framework for a more precise interpretation of the circumstances of construction and demise of largescale agriculture in the Negev Highlands. The agricultural fields were exploited continuously, yet ancient farmers had to confront the environmental hazards of occasional intensive floods, successive years of drought, and a constant process of loess accumulation and erosion. The constant maintenance and repair of fields necessitated an investment of labor. However, it seems that the expansion of ancient agriculture was part of the natural growth and development of Byzantine settlements in the Negev, and not the outcome of planned government enterprise. The agricultural systems were abandoned in the course of the 11th century A.D. and sporadically reused by pastoral nomads.

The paper reviews the dynamic relations between geology, soil mechanics, planning and construction in a desert environment. It claims that misunderstanding environmental processes, disregarding geological properties and climatic uncertainties, while planning for construction and development, can have decisive outcomes of potentially catastrophic implications, such as destabilizing the very terrain on which a project is built. To make this point, it reviews the evolution of a relatively small settlement located in the arid Negev Desert Highlands, Israel, and the way this has affected the very cliff on which it is built.

Exposures of the Menuha Formation (Santonian–Early Campanian, Mount Scopus Group) in the Makhtesh Ramon region of the southern Negev have produced numerous chondrichthyan teeth. The isolated teeth represent at least ten different species: Cretalamna appendiculata, Cretoxyrhina mantelli, Squalicorax falcatus?, S. kaupi, Scapanorhynchus rapax, S. raphiodon?, Carcharias samhammeri, Carcharias cf. C. holmdelensis?, and two other fish (Hadrodus priscus and a pycnodont). This assemblage has important implications for Late Cretaceous chondrichthyan palaeobiogeography. The majority of teeth were contained within a glauconite-rich, yellow-brown, soft chalk that included oysters (Pycnodonte vesicularis?), trace fossils (Planolites, Thalassinoides, and Chondrites), phosphatic peloids, and foraminiferans (globigerinids). The teeth were collected mainly through surface-sampling and sieving. The Menuha Formation probably represents a temperate to subtropical, shallow, open-shelf environment deposited during the formation of the Ramon anticline. Reworked conglomeratic chalks in the western section represent marginal facies derived from this structural uplift. With little to no published material describing the chondrichthyan fauna of the Menuha Formation, these data improve interpretations of its palaeoenvironment. Interpretation of the palaeoenvironment of the formation is important for understanding the larger stratigraphic/tectonic framework of the Ramon monocline region of southern Israel.

The ancient agriculture in the southern Levant is very much dependant on the interaction between the geological and geomorphological characteristics of the desert environment and the arid climatic conditions. Field observations and luminescence dating in the Negev Highlands, southern Israel, indicate that deposition of fluvio-loess sediments occurred mainly during the late Pleistocene glacial period. These sediments, which were transformed into loessy soil, support a high natural biomass and have an agricultural potential. Major soil erosion started after 27 ka, exposing bedrock, increasing runoff and erosion. These feedback processes were intensified during the Holocene. Since the mid Holocene, the co-existence of soil and runoff created a unique setup which enabled the establishment of desert agriculture in the southern Levant, based on runoff-harvesting techniques. Extensive construction of stone terrace walls on top of diachronous middle–late Holocene alluvial units in the less degraded valleys led to the deposition of the anthropogenic unit, consisting of fine grained re-deposited loess as a by-product of the flood irrigation. This process contributed to soil conservation and counteracted the continuous natural soil erosion and desertification. The ability to practice desert agriculture is still preserved in the southern Levant, and historic climate changes are not required to explain the rise and fall of the great farming cultures.

Ancient agricultural systems based on runoff harvesting techniques are abundant in the Negev Highlands. The current study examined traditional classification and investigated the distribution of ancient agricultural systems around the Roman-Byzantine “Negev Towns” Avdat and Shivta, and across the terrain located between these sites and Makhtesh Ramon in the south. It led to an elaboration of the traditional classification of runoff agricultural systems in the Negev desert of southern Israel. We found that the key factors for building these types of agricultural systems were the geological and geomorphological characteristics of the specific site locations and the geographic distance from nearby towns and roads. Depending on these factors, a multitude of types of agricultural systems were constructed in accordance with the physical characteristics of the local desert environment. This clearly indicates the continuation of the current desert climate throughout historical times. Furthermore, the large diversity of agriculture installations indicates that they were constructed by local farmers and not by an external plan imposed by the central government.

A regional truncation surface developed during the Oligocene in the northern Red Sea and southern Levant as a result of the combined effects: (1) the formation of an ∼3000 km × 1500 km crustal dome affecting the northeastern sector of the Afro-Arabian continent above the Afar plume, and (2) widespread fluvial erosion that truncated the northern edge of this dome. The regional truncation surface separates two main stratigraphic divisions: (1) middle Eocene–early Oligocene prerift clastics preserved below the regional truncation surface and (2) late Oligocene–Holocene Red Sea Supergroup deposited after the regional truncation surface developed. The prerifting sequence is composed of two major units: (1) Eocene marine intraformational debris flows (Themed clastics), and (2) fluviolacustrine continental conglomerates, most of them monomictic (Mahatardi Conglomerate). The Red Sea Supergroup is composed of polymictic conglomerates, which include fragments of older rock units, down to the Precambrian. The reconstructed regional truncation surface and its subcrop map shed new light on the initial stages of the Afro-Arabian breakup, indicating two principal phases: (1) an Oligocene slow crustal doming, with reactivation of preexisting faults and the development of the regional truncation surface, all triggered by the upwelling of the Afar plume; and (2) late Oligocene–early Miocene rifting of the Red Sea and Suez rift, which refaulted the region, including the initiation of the Dead Sea Transform along a preexisting suture line. This two-stage model indicates the mutual genetic relationship between the early Oligocene phase of tectonic development following the penetration of the Afar plume and the post-Oligocene rifting and continental breakup of the Afro-Arabian continent.

Dating terraces, the most prominent feature of the agricultural landscape in many parts of the world, is a problem for archaeologists. This study presents an interdisciplinary approach that combines archaeological survey and excavations with direct sediment dating of terrace fill using Optically Stimulated Luminescence (OSL). The study focuses on Ramat Rahel, a multi-period site located in the southern outskirts of modern Jerusalem, Israel, where, on a defined terraced slope chosen for a small-scale landscape archaeology project, three main phases of terrace construction and use were identified. The earliest phase dates to the Late Byzantine/Early Islamic period, the second to medieval times, and the last to the Ottoman period. The results enable a comprehensive reconstruction of the changing local landscape through time and demonstrate the validity of OSL, when combined with archaeological investigations, as a reliable method for terrace dating.

Reworked concretions have been significant substrates for boring and encrusting organisms through the Phanerozoic. They provide large, relatively stable calcareous surfaces in systems where sedimentation is minimal. Diverse sclerobiont communities have inhabited reworked concretions since the Ordovician, so they have been important contributors to our understanding of the evolution of these ecological systems. Here, we describe reworked concretions from southern Israel where they are critical for interpreting the stratigraphy and paleoenvironment of an Upper Cretaceous sedimentary sequence. These cobble-sized concretions (averaging roughly 1,000 cm3) are found at the base of the Menuha Formation (Santonian to lower Campanian, Mount Scopus Group) unconformably above the top of the Zihor Formation (Turonian-Coniacian, Judea Group) exposed in the Ramon region of the Negev Highlands. The concretions are almost entirely composed of micritic limestone, and many are exhumed, cemented burrow-fills apparently from 10–20 m of upper Zihor Formation strata removed by erosion. There are also a few cobbles of dolomitic limestone and rare vertebrate bone. The cobbles are moderately to heavily bored by bivalves (producing Gastrochaenolites) and worms (forming Trypanites), and a few have cemented oysters. They are densely arrayed in a single layer, often touching each other or only a few centimeters apart. The sclerobionts associated with the cobbles, along with their hydrodynamic arrangement, strongly suggest that these cobbles accumulated in very shallow water above normal wave base. Most of them (77%) are encrusted on their top surfaces only, indicating that they were bored in place and not later delivered to a deeper environment by submarine currents. The rest of the Menuha Formation above is a chalk with relatively few macrofossils (primarily shark teeth and oysters) and a few trace fossils (Planolites and Thalassinoides are the most common). These reworked cobbles show that the initial deposits of the Menuha Formation accumulated in very shallow water. This has important implications for the development of the Syrian Arc structures in this region, especially the Ramon Monocline.

To better understand the sedimentary history of the erosional crater of Makhtesh Hazera in the hyper-arid Negev Desert of southern Israel we have measured concentrations of in situ 10 Be in alluvial sediments from the active drainage system and from abandoned alluvial terraces and dated them using optically stimulated luminescence (OSL). These sedimentary sequences suggest changes in the drainage system behavior over time and show a periodic pattern in which periods of sediment aggradation alternate with periods of degradation through incision and erosion. In alluvial terrace sediments, 10 Be concentrations were combined with OSL ages to gain insight of the temporal framework of sediment deposition and shed light on the process of sediment storage. OSL and simple 10 Be exposure ages of terrace sediments give deposition ages between ~ 340 ka to ~ 50 ka, at which time the youngest alluvial terrace was incised. Deposition was interrupted twice, at ~ 300 ka and ~ 160 ka, when periods of rapid incision caused the abandonment of the active fluvial surface and the stabilization of a younger and lower fluvial surface. In the active drainage system, 10 Be concentrations suggest several possible quartz sources, of which the Lower Cretaceous sandstone bedrock exposed at the base of the cliff enclosing the Makhtesh is the most dominant. The results suggest that sediment eroding form these cliffs are conveyed through the active alluvial channels without significant sediment contribution from alluvial terraces or from eroded bedrock exposed within the Makhtesh. In contrast to our measurements in the active drainage system, 10 Be concentrations in alluvial terrace sediments record significant storage within the Makhtesh. We suggest that the geometry of the Makhtesh, mainly the disproportion between the size of the Makhtesh and its narrow outlet, leads to significant accumulation of sediment within the Makhtesh. Episodic breaching of the barrier is followed by rapid and short-lived incision into the stored sediment. The long residence time of sediment within the Makhtesh results in high measured 10 Be concentrations. At the end of each of these short incision episodes, when channels are already carved into the alluvial sediment and terraces are formed, the channels only convey sediment directly eroded from the bounding cliff of the Makhtesh; a situation presently observed.

We present a framework for consistent incorporation of optically-stimulated luminescence dates with cosmogenic radionuclide concentrations measured in a single alluvial section, and apply it on two late Quaternary terraces in the Negev Desert, Israel, to derive constraints on their evolution. We solve an integrated, self-consistent and co-dependant set of equations to reproduce either dataset based on three model parameters of (i) uniform cosmogenic inheritance, (ii) constant terrace aggradation rate and (iii) subsequent exposure time. A subset of all possible parameter combinations, which approximates the measurements within the uncertainties of their best-fits, yields a better constraint of the alluvial history than that obtained by any of these dating proxies alone. The derived set of common solutions indicates similar paleo-inheritances of ∼1 × 10 5 10 Be atoms g −1 in both terraces; progressive deposition of the higher terrace (T2) began at ∼250 ka, lasted for a period of ∼80 ka, was abandoned at ∼170 ka and since that time has remained intact; the lower terrace (T1) was most likely deposited at ∼3 ka and rapidly abandoned by ∼2 ka. In an alternative interpretation for T2, which treats the two geochronometers separately, this terrace might have experienced discrete events of aggradation at (216 ± 13) ka and deep truncation at 118 − 29 + 42 ka, significantly separated in time. In the currently active channel of the Neqarot canyon, contemporary stripping of the lowest terrace located along the stream is suggested by decreasing values of 10 Be downstream along the river channel.

Since the early 1980s, the Dead Sea coast has undergone a near catastrophic land deterioration as a result of a rapid lake-level drop. One conspicuous expression of this deterioration is the formation of sinkholes fields that puncture the coastal plains. The evolution of sinkholes along nearly 70-km strip has brought to a halt the regional development in this well-known and toured area and destroyed existing infrastructures. Great efforts are being invested in understanding the phenomena and in development of monitoring techniques. We report in this paper the application of airborne laser scanning for characterization of sinkholes. We demonstrate first the appropriateness of laser scanning for this task and its ability to provide detailed 3D information on this phenomenon. We describe then an autonomous means for their extraction over large regions and with high level of accuracy. Extraction is followed by their detailed geometric characterization. Using this high-resolution data, we show how sinkholes of 0.5 m radius and 25 cm depth can be detected from airborne platforms as well as the geomorphic features surrounding them. These sinkhole measures account for their embryonic stage, allowing tracking them at an early phase of their creation.

Dating the time of abandonment of geomorphic surfaces in the arid mid latitudes is necessary for studies ranging from tectonics, landscape evolution and paleoclimate. It has often been hampered by the limited material suitable for conventional isotopic methods and the uncertainties inherent in cosmogenic radionuclide methods. We propose luminescence dating as a suitable method for dating the time of abandonment of aggradational geomorphic surfaces in the hyperarid regions. We dated the top of such surfaces with different age ranges and geomorphic settings in a sequence of alluvial fans in Nahal Shehoret in the southern Negev and in a sequence of terraces in Nahal Ze'elim and in Nahal Zin, two adjacent drainage basins in the Judean Desert, Israel. Samples were collected from beneath the gypsic horizon at a depth of 0.3–0.7 m, below which sand grains do not penetrate. Depositional ages for the uppermost beds of the landforms, which are proxies for abandonment, range from ∼90 ka to ∼5 ka. In all three basins, the ages are in morphostratigraphic order and agree well with relative age estimates based on soil chronosequences and on Lake Lisan levels. Abandonment ages for an individual alluvial fan cluster within ±10–20%, therefore it is possible to distinguish between surfaces with ages differing by more than 20%. Thus, in hyperarid areas, the luminescence methods can be used for surface dating.

Early to late Pleistocene 10 Be exposure ages of abandoned surfaces in the Negev desert reveal the regional drainage evolution history and its relationship with the subsidence of the western margin of the Dead Sea Rift. The dated desert paved surfaces have developed over originally westward-flowing rivers, which were abandoned by early Pleistocene and whose relicts are now progressively tilted towards the rift axis. The slow and non-destructive subsidence coupled with extreme hyperaridity enabled the preservation of these ancient surfaces along some of the main water divides in the Negev, nearly irrespective of their distance from the rift axis. Constraints on the tilting history are obtained from analyzing the spatial pattern of the exposure ages, suggesting subsidence rates as low as 120–300 m Ma –1 in the southern Arava Valley since the late Pliocene. It is shown that the transition from the Pliocene to current drainage pattern occurred over a short period during the early Pleistocene, and that the governing fluvial response that followed the delineation of current basins is represented by a continuous spectrum of ages of inset terraces.

Large (−0.6‰ to +2.3‰) δ97/95Mo variations occur in molybdenum-enriched iron oxide veins located in anticlines adjacent to the Dead Sea transform, and are thought to reflect the solutions from which the veins formed because of efficient scavenging of Mo by iron oxides. The wide range of δ97/95Mo values occurs in a paleohydrologic setting in which dense, concentrated, evaporitic marine brines in the Dead Sea Rift valley (δ97/95Mo ~1.6‰) penetrated and interacted with sedimentary rocks of the rift flanks, which included Cretaceous bituminous chalks (δ97/95Mo 0.8‰–1.2‰), before intermixing with Fe-bearing groundwater containing molybdenum of igneous and clastic origin. The δ97/95Mo values higher than seawater (1.6‰–2.3‰) are attributed to Rayleigh isotopic fractionation along the path of the brine migration. Molybdenum isotopes thus reveal a powerful potential to trace the sources and processes governing subsurface metalliferous fluid migration.

Dody, A., Nahlieli, A., Avni, Y., Cohen, H., Weiner, D., and Porat, N. 2008. Late Quaternary deposition and erosion processes along the margins of the Yamin Plain, northeast Negev, Israel. Isr. J. Earth Sci. 57: 199–211. This study presents rates of accumulation and transport of sands as well as rates of incision along the margins of the Yamin Plain, northeastern Negev, and evaluates the stability of the present landscape. Geomorphological mapping, OSL and 14C dating, and sedimentological analyses suggest that rates of erosion range between ~45 mm/year in the eastern side of the study area and 0.05 mm/y on the western side. The calculated erosion rates show that, until recently, geomorphic processes in the eastern part of the plain were dominated by accumulation of sands derived from the Hazeva Group. However, accelerated erosion is observed near the contact between the sand units and the carbonate bedrock of the Judea Group. It appears that the area west of the plain has been stable during the last glacial (circa 73–18 ka). We suggest that the exclusion of domestic grazing from the Yamin Plain in the 1950s changed the balance between erosion and sedimentation and caused accelerated erosion mainly in the eastern part of the Yamin Plain by decreasing infiltration and increasing runoff.