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Sample records for western desert egypt

  1. Volatiles in the Desert: Subtle Remote-sensing Signatures of the Dakhleh Oasis Catastrophic Event, Western Desert, Egypt

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Kleindienst, M. R.; Churcher, C. S.; Smith, J. R.; Schwarcz, H. P.; Osinski, G.

    2005-01-01

    Over the past decade members of the Dakhleh Oasis Project have studied enigmatic signatures in the Pleistocene geologic record of portions of the Dakhleh oasis and palaeo-oasis in Egypt's Western Desert [1,2]. In particular, Si-Ca-Al rich glass melt (Dakhleh Glass, Fig. 1) points to a catastrophic event between c.100,000-200,000 years ago [3] in this well-studied African savannah and freshwater lake Middle Stone Age environment [4,5].

  2. Integrated geophysical study to delineate the subsurface structures in Siwa Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, Ahmed; Abd El All, Esmat; Rabeh, Taha; Osman, Salah

    2015-04-01

    Siwa Oasis is located within the Western Desert of Egypt and is a potential candidate for the development. It represents one of the most interesting and distinct region of Egypt. The main goal of the present work is to study the subsurface structures in Siwa Oasis area, Western Desert, Egypt and to determine their effects on surface geologic structures. To achieve this, two geophysical methods (magnetic and geothermal) have been used in this study. A detailed land magnetic survey was performed. The necessary reduction concerning daily variation, the regional gradient and time variation observation were applied. The measured total magnetic field was corrected and reduced to the north magnetic pole. Data analysis was performed using trend analysis, Euler deconvolution, high pass filter, analytical signal. The results indicate that the area is affected by tectonic forces in the NE-SW, NW- SE and E-W directions. Geothermal studies in some places in Siwa Oasis were carried out using the device of thermo-physical properties (Isomet-104) for measuring the subsurface temperature contour map (30 meters below the earth's surface). This map illustrates that there are good geothermal regions have hot groundwater reservoir. The measurements of geothermal properties of some rock samples such as thermal conductivity, thermal diffusivity, volume capacity and thermal values gave us an indication about the geothermal of rocks in the subsurface. Also, geothermal studies gave us an idea about the heat flow and the increasing of the energy and chemical of properties of the predominant subsurface rocks in the study area.

  3. Mesozoic rift basins in western desert of Egypt, their southern extension and impact on future exploration

    SciTech Connect

    Taha, M.A. )

    1988-08-01

    Rift basins are a primary target of exploration in east, central, and west Africa. These intracratonic rift basins range in age from the Triassic to the Neogene and are filled with lagoonal-lacustrine sand-shale sequences. Several rift basins may be present in the Western Desert of Egypt. In the northeastern African platform, the Mesozoic Tethyan strand lines were previously interpreted to have limited southern extension onto the continent. This concept, based upon a relatively limited amount of subsurface data, has directed and focused the exploration for oil and gas to the northernmost 120 km of the Western Desert of Egypt. Recent well and geophysical data indicate a southerly extension of mesozoic rift basins several hundred kilometers inland from the Mediterranean Sea. Shushan/Faghur and Abu Gharadig/Bahrein basins may represent subparallel Mesozoic basins, trending northeast-southwest. Marine Oxfordian-Kimmeridgian sediments were recently reported from wells drilled approximately 500 km south of the present-day Mediterranean shoreline. The link of these basins with the Sirte basin to the southwest in Libya is not well understood. Exploration is needed to evaluate the hydrocarbon potential of such basins.

  4. Pitted and fluted rocks in the Western Desert of Egypt - Viking comparisons

    NASA Technical Reports Server (NTRS)

    Mccauley, J. F.; Breed, C. S.; Grolier, M. J.; El-Baz, F.; Whitney, M. I.; Ward, A. W.

    1979-01-01

    The Western Desert of Egypt is one of the most arid regions on earth and is probably the closest terrestrial analog to the surface of Mars. An expedition to the area in 1978 revealed an abundance of quartzite and basalt rocks that have been pitted and fluted by wind erosion and deflation of the desert surface. These pitted rocks are internally homogeneous, show no internal holes or vesicles, and are considered an important but neglected type of ventifact. They bear a striking resemblance to the pitted and fluted rocks seen by the Viking Landers, rocks that have generally been interpreted as vesicular basalts only slightly modified by wind erosion. Wind tunnel studies of the air flow over and around nonstreamlined hand specimens from the Western Desert show that windward abrasion coupled with negative flow, secondary flow, and vorticity in a unidirectional wind can explain the complex arrays of pits and flutes. These field and laboratory observations suggest that the pitted rocks at the Viking Lander sites are also ventifacts, and thus the Martian surface may be far more wind eroded than previously thought.

  5. Age and isotopic constraints on pleistocene pluvial episodes in the Western Desert, Egypt.

    SciTech Connect

    Crombie, M. K.; Arvidson, R. E.; Sturchio, N. C.; El Alfy, Z.; Abu Zeid, K.; Environmental Research; Washington Univ.; Egyptian Geological Survey and Mining Authority

    1997-01-01

    North Africa has undergone drastic climatic changes over the past several hundred thousand years. The timing of humid intervals called pluvials was investigated by uranium-series disequilibrium dating of travertines from the Kurkur Oasis, Western Desert, Egypt. The youngest and best dated travertines (70-160 ka) are found in Wadi Kurkur and include spring and lacustrine units exposed as 2 to 3 m high terraces. Travertines having an age of approximately 191-220 ka are exposed by differential erosion as linear mounds produced by spring systems over fracture zones in ancient wadis. The oldest travertines, having ages >260 ka, are extensive, cap limestone units above the oasis, and were deposited in paludal and lacustrine environments. Oxygen isotope ratios were measured for the wadi travertines ({delta}{sup 18}O values ranging from 16.7 to 19.1{per_thousand} SMOW) and for spring mound travertines (18.5-20.5{per_thousand}). Equilibrium oxygen isotope fractionation calculations indicate that the Kurkur travertines were deposited from waters having {delta}{sup 18}O values similar to ancient Western Desert groundwaters ({approx} -11{per_thousand}). The ages of the travertines correspond to times of monsoonal maxima, eustatic sea level high stands and interglacial maxima. Rainfall producing these groundwaters (and travertines) was significantly fractionated during atmospheric transport, in contrast to modern meteoric waters (-2.09{per_thousand}), implying a distant source for the pluvial waters. Increased precipitation, recharge of Western Desert groundwaters, and resultant travertine deposition are interpreted to be consequences of Milankovitch insolation cycle forcing, through enhanced Atlantic and Indian Ocean monsoons during interglacial time periods.

  6. Optimal well locations using genetic algorithm for Tushki Project, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalaf, S.; Gad, M. I.

    2014-10-01

    Groundwater depletion is one of the most important problems threaten the national projects in Egypt. The optimal distribution of well locations and pumping rates mitigate this problem. In this paper, a trial to mitigate this problem in Tushki National Project, south western desert, Egypt was carried out via delineating the optimal well locations and optimal pumping rates. The methodology of combination between simulation and optimization techniques was applied. A linked simulation-optimization model for obtaining the optimum management of groundwater flow is used in this research. MODFLOW packages are used to simulate the groundwater flow system. This model is integrated with an optimization model OLGA (Optimal well Location using Genetic Algorithm technique) which is based on the genetic algorithm (GA). Two management cases were considered by running the model in Abu Simbel-Tushki area with adopted steady and transit calibrated parameters. The first case (fixed well location) is found that the optimum value of the objective function (maximum pumping rate). In the second case (flexible well location with the moving well option) locations of wells are to be decided by the OLGA model itself within a user defined region of the model grid until the optimal location is reached. Also, the prediction of the future changes in both head and flow were made in steady and transient states.

  7. Remote sensing and geophysical investigations of Moghra Lake in the Qattara Depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khan, Shuhab D.; Fathy, Mohamed S.; Abdelazeem, Maha

    2014-02-01

    The Western Desert covers two-thirds of the land area of Egypt and occupies one of the driest regions of the Sahara. Seven depressions within the desert - Siwa, Qattara, Fayum, Bahariya, Farafra, Dakhla, and Kharga - may represent parts of old drainage systems with deflation, extensive erosion, and possibly, some tectonic activity. Oases with freshwater exist in these depressions. Geological and geophysical investigations in the Qattara Depression indicate the presence of buried fluvial channels with southeast to northwest flow directions from the highland areas. The origin of these fluvial systems, as well as the origin of the depressions themselves, is still unresolved, and many ideas have been suggested. Moghra Lake at the northeastern tip of the Qattara basin may be a remnant of a larger paleolake, including the mouth of a paleo-river. We present here the results of our recent work in this area using ALOS PALSAR radar remote sensing data, which indicated the presence of buried channels that may have fed the larger Moghra paleolake. Ground penetrating radar (GPR) data along 2D profiles were acquired; the migrated GPR sections identified a major paleochannel with numerous minor channels at its margins. GPR interpretations are verified by field observations, trenching, and stratigraphic information from outcrop data. Potential field analyses identify possible aquifers that are controlled by regional structures. Density contrasts within the sedimentary units, physical boundaries of uplifted basement blocks and depths to causative sources were also identified. This work contributes to the reconstruction of paleodrainage of this region and helps in understanding processes involved in the formation of the Qattara Depression.

  8. Habitat of oil in Abu Gharadig and Faiyum basins, Western Desert, Egypt

    SciTech Connect

    Awad, G.M.

    1984-05-01

    The Abu Gharadig and Faiyum basins are areas which have some of the greatest hydrocarbon potential in the Western Desert of Egypt. Several extensive cycles of marine transgression and regression occurred in these territories through geologic time. The depositional cycles combined with at least 3 tectonic cycles - (1) the Hercynian orogeny at the end of the Paleozoic, (2) from Late Jurassic to early Tertiary, and (3) from Late Cretaceous to middle Tertiary - resulted in a highly deformed, thick sedimentary sequence. This organic-rich Jurassic-Upper Cretaceous-lower Tertiary sequence in large areas of these basins was subjected to enough heat and depth to generate hydrocarbons. The Abu Gharadig and Faiyum basins are separated structurally by a major ridge. Both basins are bounded on the north by another major ridge associated with Cretaceous and Tertiary faulting. A major platform with tin sedimentary cover forms the southern boundary. The hydrocarbon potential exists in cyclic sequences of sandstone, shale, and carbonate, having moderate porosities and permeabilities. An important hydrologic phenomenon prevails in major parts of the basins; fresh water has flushed the early Cenomanian and older reservoirs. Exploration efforts should be concentrated on deep structures close to the main depocenters and inside or very close to the main depocenter and inside or very close to the 150/sup 0/F (65/sup 0/C) geothermal contour.

  9. Habitat of oil in Abu Gharadig and Faiyum basins, Western Desert, Egypt

    SciTech Connect

    Awad, G.M.

    1984-05-01

    The Abu Gharadig and Faiyum basins are areas which have some of the greatest hydrocarbon potential in the Western Desert of Egypt. Several extensive cycles of marine transgression and regression occurred in these territories through geologic time. The depositional cycles combined with at least 3 tectonic cycles--the Hercynian orogeny at the end of the Paleozoic, from Late Jurassic to early Tertiary, and from Late Cretaceous to middle Tertiary--resulted in a highly deformed, thick sedimentary sequence. This organic-rich Jurassic-Upper Cretaceous-lower Tertiary sequence in large areas of these basins was subjected to enough heat and depth to generate hydrocarbons. It is evident from recent discoveries that these source rocks generated large amounts of highquality oil and gas. Exploration efforts should be concentrated on deep structures close to the main depocenters and inside or very close to the 150/sup 0/F geothermal contour. Contemporaneous structures on the northern rims of the basins should have high potential, resulting from migration of hydrocarbons from the south across major faults. The Jurassic in the northeastern part of the Abu Gharadig basin may provide good hydrocarbon potential. The lower Tertiary sequence present in the troughs also may have large amounts of oil entrapped in situ or resulting in shortdistance migration to the northern structures or to the Late Cretaceous-early Tertiary Syrian arc traps.

  10. Paleomagnetism of Abu Aggag and Sabaya Formations at Kalabsha, South Western Desert of Egypt.

    NASA Astrophysics Data System (ADS)

    Mostafa, Reem; Khashaba, Ahmed; El-Hemaly, Ibrahim; Takla, Emad; Abdel Aal, Mohamed; Odah, Hatem

    2015-04-01

    Two profiles have been sampled from the Nubia Sandstone at Aswan, south Western Desert: The 1st profile has been taken from Abu Aggag Formation and the 2nd one was from Sabaya Formation (23.25 oN, 32.75 oE). 136 oriented cores (from 9 sites) have been sampled. Abu Aggag Formation is of Late Cretaceous (Turonian) and Sabaya Formation is of Early Cretaceous (Albian-Cenomanian). The studied rocks are subjected to rock magnetic measurements as well as demagnetization treatment. It has been found that hematite is the main magnetic mineral in both formations. Four profile sections (normal polarity) from Abu Aggag Formation, yielded a magnetic component with D = 352.7°, I = 36.6° with ?95 = 5.2° and the corresponding pole lies at lat. = 82.8 °N and long. = 283.1 °E. Five profile sections (normal polarity) from Sabaya Formation, yielded a magnetic component with D = 348.6°, I = 33.3° with ?95 = 5.8° and the corresponding pole lies at lat. = 78.3 °N and long. = 280.4 °E. The obtained paleopole for the two formations lies at lat. = 80.5 °N and long. = 281.7 °E. The obtaind components are considered primary and the corresponding paleopole reflects the age of Nubia Sandstone when compared with the previously obtained Cretaceous poles for Egypt.

  11. Reconstructing Quaternary pluvial episodes and paleohydrology using travertines from Egypt's Western Desert

    NASA Astrophysics Data System (ADS)

    Jimenez, G.; Crossey, L. J.; Karlstrom, K. E.; Ricketts, J. W.; Tafoya, A. J.; Anan, T.; Mohammed, A.; Asmerom, Y.; Polyak, V.; Farouk, S.

    2012-12-01

    Quaternary climate in North Africa was marked by multiple wet periods overprinting extreme aridity, but pluvial drivers, as well as their timing and geographic extent, are poorly constrained. We address these factors in the first comprehensive analysis of travertine from Egypt's Western Desert, which represents a unique and under-utilized record of paleoclimate and paleohydrology. We infer large-volume travertine mound deposition along faults near the area's central limestone plateau to reflect times of high discharge (high groundwater head) from springs of the Nubian aquifer, likely associated with so-called Green Sahara pluvial episodes. Similarly, we assume that travertine platforms in depressions (oases) represent related marsh and lake deposition, including a widespread late Cenozoic dolostone of probable lacustrine origin in Farafra Oasis, which needs additional mapping. We present the results of uranium-series analysis of travertines from oasis areas spanning a north-south gradient through the Western Desert; we dated the tops and bottoms of inset deposits at different wadi (wash) elevations to resolve the inception and termination of high spring heads/pluvials as well as regional aggradation or incision patterns. Our dates, combined with published literature ages, suggest wet intervals around 100-115, 125-140, 180-200, 350-360, 450, and 600 ka. Heights of inset terrace travertines in wadis are potentially correlative between sites and are seen as approximately 5, 10, and 25 m above the modern wadi levels. Assuming that paleohydrological changes reflect paleoclimate changes, we examine correlations between times of travertine deposition, relative to glacial cycles or to more specific orbital forcings, acting on the North African summer monsoon. Initial comparison of travertine occurrence to glacial cycles shows no obvious correlation, although there are major travertine deposition episodes at important paleoclimate transitions such as MIS 6 to 5, 7 to 6, and 11 to 10. Perhaps the best preliminary association is to orbital forcing, particularly precession, consistent with the hypothesis that orbital forcing is a driver of the North African monsoon and thus pluvials.

  12. Remote Sensing and Shallow Geophysical Investigations on Moghra Lake in Northeastern Qattarra Depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khan, S. D.; Fathy, M. S.; Azeem, M. A.

    2012-12-01

    The Western Desert of Egypt encompasses two thirds of the land area of Egypt and constitutes one of the driest regions of the Sahara. This desert has seven depressions; Siwa, Qattara, Fayium, Bahariya, Farafra, Dakhla and Kharga. These depressions may be the manifestation of old drainage basins with extensive erosion and possibly some tectonic activity. Several oases with freshwater can be found in these depressions. Geological and geophysical investigations in Qattara Depression indicate several buried fluvial channels with flow direction from highlands in southeast to northwest. Moghra Lake at the northeastern tip of Qatarra basin may be a small remnant of a larger paleo-lake including the mouth of a paleo-river. This study probed this area for presence of buried channels that may have fed the larger Moghra paleo-lake. We have used ALOS - PALSAR radar remote sensing data to identify the surface features in this region, such as channels, channel fills, and fractures. In addition, dual polarization PALSAR data (HV, HH) allowed analysis of the near surface geology and assisted in delineating areas of interest for GPR surveys. GPR data along 2D profiles were acquired using the GSSI SIR-3000 system with a 400 MHz antenna that provided images to approximately three meters in depth. All the GPS data were processed using RADAN 6.6 software. A conventional processing flow was used for data processing: The positional correction tool removed the air wave. A range-gain balanced the amplitudes and a final band-pass (50 kHz to 500 kHz) filter was applied to the data. Deconvolution was also applied for highlighting the finer details. In addition, spatial filters were used to attenuate continuous vertical noise. The migrated sections of GPR identified a major paleochannel distributary with two minor channels at the margins. The bedrock of the studied area consists of the Lower Miocene Moghra Formation (sandstone and shale intercalations). The area around the present lake is covered by about 2 m of lacustrine sediments of post-Miocene age in the east side and by recent eolian dunes in the west. These sediments are characterized by shallowing upward, horizontal to cross-bedded with an unconformity in between. The eastern end of the paleochannel surveyed by GPR is covered by recent sand dunes followed by an ephemeral stream that feeds the current lake. Field observations suggest that the movement of sand dunes in the northeast direction may have blocked the paleo-channel. A two meters deep trench was dug to confirm the GPR findings. Regional gravity mapping of this area also shows major gravity anomalies. More work is planned to carry out additional high resolution potential field surveys in conjunction with remote sensing and GPR studies to understand the paleo-drainage of this area. Identifying the exact track of the paleo-channels will help reconstructing of paleo drainage of this region and may help in mapping groundwater, this will be very important for the development of this rapidly expanding desert area.

  13. The geochemistry of uranium and thorium isotopes in the Western Desert of Egypt

    SciTech Connect

    Dabous, A.A.

    1994-11-01

    The concentrations of {sup 238}U, {sup 234}U, {sup 232}Th, and {sup 228}Th have been measured in the groundwaters of the Bahariya and Farafra oases of the Western Desert of Egypt. These waters are characterized by normal amounts of U, but unusually high concentrations of Th. The pattern of variation of the parent isotopes, {sup 238}U and {sup 232}Th, as well as the daughter isotopes, {sup 234}U, {sup 230}Th, and {sup 228}Th, is systematic within and between the two oases. From the unusually consistent distribution of the {sup 234}U/{sup 238}U activity ratios one can conclude that the samples from both oases are representative of a two-component mixing system. One component, characterized by low U content and a high {sup 234}U/{sup 238}U activity ratio, is typical of deep artesian systems and probably represents flowthrough water derived from the Nubian highlands to the south. The second component is characterized by a greater U concentration and a low activity ratio. This signature is hypothesized as being derived by leaching of downward infiltrating water during pluvial times. The source of the U may be the uraniferous phosphate strata that overly the sandstone aquifer in both oasis areas. Higher Th values are associated with the artesian flow component of the mixing system and suggests that Th-bearing minerals may be abundant in the Nubian sandstone aquifer. The distribution of {sup 230}Th and {sup 228}Th in the water samples supports this interpretation.

  14. Origin of the gypsum-rich silica nodules, Moghra Formation, Northwest Qattara depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El Khoriby, Essam M.

    2005-06-01

    Gypsum rich-silica nodules appear in two shale horizons of the Moghra Formation (early Miocene) northwestern Qattara Depression, Western Desert, Egypt. These nodules are gray to milky white in colour, mostly botroidal and rose-like in shape and range in diameter from 2 to 7.5 cm. The silica nodule-bearing shale is composed mainly of smectite with a little minor kaolinite. The silica nodules consist mainly of quartz and are composed of gypsum-free matrix and gypsum-rich megacrystalline quartz. The matrix consists of microflamboyant quartz (less than 36 ?m in diameter) and chalcedony. The megacrystalline quartz occurs as lenticular and prismatic forms (length: 90-250 ?m; width: 30-90 ?m). The microprobe, petrographic and SEM examinations confirmed the occurrence of gypsum relics (diameter; 2-16 ?m) within the megacrystalline quartz. The chalcedony and mosaic microcrystalline quartz occurs as pore-lining and pore-filling cements. The structure of the silica nodules begins with quartzine in its outer rim, then gypsum-free microcrystalline quartz in the middle part and ends with gypsum-rich lenticular to prismatic megaquartz in the center. Field study, petrographic examination and microprobe analysis reveal that the silica nodules were formed by silicification of precursor gypsum nodules deposited in a marginal sabkha environment under an arid climate. The silicification selectively affected the gypsum nodules rather than the surrounding shale and occurred both through gypsum replacement and void filling. Transformation of isopachous chalcedony into mosaic microcrystalline quartz also occurred. The texture of the silica minerals reflects the different physico-chemical conditions under which they crystallized. Spherical nodules grew chiefly by the diffusive supply of the silica, and elongated ones grew by pore water advection. The integrated effect of climate, pH, salinity, crack systems within the sediment and oscillation in the groundwater level and its chemical composition contributed to the formation of the nodules.

  15. Geochemistry and microprobe investigations of Abu Tartur REE-bearing phosphorite, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Awadalla, Gamal S.

    2010-07-01

    Phosphorites in Egypt occur in the Eastern Desert, the Nile Valley and the Western Desert at Abu Tartur area and present in Duwi Formation as a part of the Middle Eastern to North African phosphogenic province of Late Cretaceous to Paleogene age (Campanian-Maastrichtian). The Maghrabi-Liffiya phosphorite sector is considered as the most important phosphorite deposits in the Abu Tartur area due to its large reserve thickness and high-grade of lower phosphorite bed beside high content of REE. Back scattered electron (BSE) images show framboidal pyrite filling the pores of the phosphatic grains, suggesting diagenetic reducing conditions during phosphorites formation. Electron Probe Micro Analyzer (EPMA) chemical mapping was conducted to examine the variation and distributions of selected elements (P, F, La, Fe, Yb, Si, Ce, W, Eu, S, Ca, Y and Er) within the shark teeth, coprolites and bone fragments. In the teeth W, S, Fe are concentrated along the axis of the teeth, the bone fragments show high concentration of W, Yb, Er and Eu, whereas coprolites are nearly homogenous in composition contains S, Er with some Si as micro-inclusions. Fluorapatite is considered as main phosphate mineral whereas pyrite occurs as pore-filling within the phosphatic grains and cement materials. Maghrabi-Liffiya samples show a wide range in the P 2O 5 content, between 19.8 wt.% and 29.8 wt.% with an average of 24.6 wt.% and shows low U content ranging from 15 ppm to 34 ppm with an average of 22 ppm. The total REE content in nine samples representing the Maghrabi-Liffiya ranges from 519 to 1139 ppm with an average of about 879 ppm. The calculation of LREE (La-Gd) show indeed a marked enrichment relative to the HREE (Tb-Lu) where LREE/HREE ratio attains 8.4 indicating a strong fractionation between the LREE and HREE. Chondrite-normalized REE patterns of the studied phosphorite samples show a negative Eu anomaly.

  16. Diagenetic origin of ironstone crusts in the Lower Cenomanian Bahariya Formation, Bahariya Depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Afify, A. M.; Sanz-Montero, M. E.; Calvo, J. P.; Wanas, H. A.

    2015-01-01

    In this paper, a new interpretation of the ironstone crusts of the Bahariya Formation as late diagenetic products is provided. The siliciclastic Lower Cenomanian Bahariya Formation outcropping in the northern part of the Bahariya Depression (Western Desert, Egypt) is subdivided into three informal units that are mainly composed of thinly laminated siltstone, cross-bedded and massive sandstone, fossiliferous sandstone/sandy limestone and variegated shale. Abundant ironstone crusts occur preferentially within its lower and upper units but are absent in the middle unit. The ironstone crusts show selective replacement of carbonate components, including calcretes, by iron oxyhydroxides. More permeable parts of the terrigenous beds such as burrow traces, subaerial exposure surfaces, concretionary features and soft-sediment deformation structures led to heterogeneous distribution of the iron oxyhydroxides. A variety of diagenetic minerals, where goethite and hematite are the main end-products, were characterized by mineralogical analysis (XRD), petrography and SEM observation, and geochemical determinations (EMPA). Other diagenetic minerals include Fe-dolomite/ankerite, siderite, manganese minerals, barite, silica, illite/smectite mixed-layer, and bitumen. These minerals are interpreted to be formed in different diagenetic stages. Some minerals, especially those formed during eodiagenesis, show features indicative of biogenic activity. During burial, dolomite and ankerite replaced preferentially the depositional carbonates and infilled secondary porosity as well. Also during mesodiagenesis, the decomposition of organic matter resulted in the formation of bitumen and created reducing conditions favorable for the mobilization of iron-rich fluids in divalent stage. Telodiagenesis of the Cenomanian Bahariya deposits took place during the Turonian-Santonian uplift of the region. This resulted in partial or total dissolution of Fe-dolomite and ankerite which was concomitant to iron oxyhydroxide precipitation upon mixing with shallow oxygenated water. Circulation of reducing iron-rich fluids through fractures and inter and intrastratal discontinuities is proposed as an alternative model to explain the controversial source of iron for the ironstone crusts of the Bahariya Formation. The origin of iron-rich fluids is probably related to the basement rocks. The provided model relates the fluid movements through fractures and discontinuities with the preferential replacement of carbonates. This combination of processes is consistent with the heterogeneous geometries and the wide distribution of the ironstones.

  17. Environmental impact and natural hazards on Kharga Oasis monumental sites, Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Salman, A. B.; Howari, F. M.; El-Sankary, M. M.; Wali, A. M.; Saleh, M. M.

    2010-09-01

    Kharga Oasis monumental sites are important to the cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The studied sites include the Hibis, EI-Nadura, EI-Ghueita and El-Zayyan temples as well as El-Bagawat Cemetery. The present study found that natural hazards have remarkable impacts on these sites. The impact of weathering processes, encroachment of sand dunes, stability of foundation beds and shallow groundwater seepage were documented. The present study found that humidity, temperature, sunlight and water content conditions seem to be favorable for biodegradation as evidenced by the presence of algae, bat blood and bird excretions. The radioactivity levels at the investigated sites are also measured via gamma-ray spectrometry. Sand dunes in the area pose a serious natural threat to the monumental sites. Active sand dunes are rapidly encroaching upon the components of these monuments, partially covering some monuments such as El-Ghueita Temple. These dunes load wind storms with fine sand particles. This causes wind erosion through sand blasting of these sites. Some monuments, such as EI-Nadura, EI-Ghueita and El-Zayyan temples were constructed on a suitable hard sandstone ground, whereas others, such as the Hibis Temple, were constructed on unsuitable soft shale ground in relatively topographically low area. The impact of the unstable foundation and shallow groundwater levels have caused severe structural damage as evidenced by tilted columns, cracked walls and salt-crystal growth in the porous building stones. These destructive elements threaten some other temples in Kharga Oasis and will eventually cause total physical collapse. Although rain is rare in this area, it can form a real threat to mud brick monuments such as El-Bagawat Cemetery. The natural radioactivity sources resulted in an annual effective dose equivalent values averaging 0.20, 0.13, 0.09 and 0.07 mSv/year for the monumental sites at Hibis, El-Nadura, El-Ghueita and El-Zayyan, respectively.

  18. Eolian features in the Western Desert of Egypt and some applications to Mars.

    USGS Publications Warehouse

    El-Baz, F.; Breed, C.S.; Grolier, M.J.; McCauley, J.F.

    1979-01-01

    Relations of landform types to wind regimes, bedrock composition, sediment supply, and topography are shown by field studies and satellite photographs of the Western Desert. This desert provides analogs of Martian wind-formed features and sand dunes, alternating light and dark streaks, knob 'shadows' and yardangs. Surface particles have been segregated by wind into dunes, sand sheets, and light streaks, that can be differentiated by their grain size distributions, surface shapes, and colors. Throughgoing sand of mostly fine to medium grain size is migrating S in longitudinal dune belts and barchan chains whose long axes lie parallel to the prevailing W winds, but topographic variations such as scarps and depressions strongly influence the zones of deposition and dune morphology. -from Authors

  19. Sedimentary cover in the South Western Desert of Egypt as deduced from Bouguer gravity and drill-hole data

    NASA Astrophysics Data System (ADS)

    Senosy, M. M.; Youssef, M. M.; Abdel Zaher, M.

    2013-06-01

    The Western Desert, Egypt includes the major groundwater aquifer in the country. It is apart from the Major Sahara Nubian Aquifer which is present in Sudan, Chad, Egypt and Libya. Thickness of this aquifer is changed laterally from south to north and also from west to east. The changes may structurally or litheologicalley control. The present study is focused on using of Bouguer gravity anomaly mapped at a scale of 1:500,000 and the lithological logs of about 120 deep wells used to determine the thickness of the sedimentary sequence containing the main Nubian sandstone water aquifer in important area of Egypt. The area is located in the southern part of the Western Desert bounded by the latitudes 22°00'-26°30'N, and longitudes 28°30'-33°00'E. The predominant structures affecting the basement rocks and the sedimentary cover were traced and analyzed. The gravity stripping approach was applied to eliminate the gravity effects caused by sedimentary sequence and to separate density anomalies within the sedimentary fill from the influence of rocks at deeper levels in the crystalline crust. The study indicated that the surface of the basement rocks is highly rugged and mostly controlled by structures which have a direct effect on thickness variation of the sedimentary cover all over the area. Regionally the area is characterized by two major intracratonic basins (the Dahkla Basin and the Nile valley Basin) separated by a NE-SW trending swell of the Kharga uplift and bounded at the south by the Oweinat-Bir Safsaf-Aswan uplift. These major tectonic units are controlled by fault structures trending in N-S, E-W, NE-SW, NW-SE, which cut the basement rocks and extend upward in the sedimentary cover. The maximum thickness of sandstone formations is recorded at west Oweinat, west Kurkur, southwest of Aswan, Gramashin, Dakhla oasis and some localities west of Sohag and Qena towns. At these localities the thickness ranges between 600 and 900 m. As this formation is the main water aquifer in the study area, therefore these localities are characterized by the presence of big amount of ground water. Accordingly, these areas must take the priority in the sustainable development programs of southern Egypt.

  20. Geoenvironmental assessment of the SIWIA area Oasis, Western Desert, Egypt, using geographical and hydrological information systems

    NASA Astrophysics Data System (ADS)

    Faid, A.; Ismail, E.; Birk, S.

    2012-04-01

    Overpopulation of Egypt has put pressure on the government for horizontal expansion for food security. Therefore, horizontal expansion in the desert for agricultural purposes is one of the solutions. Groundwater represents the main source of water supply in Siwa Oasis. The sedimentary succession comprises different water bearing formations. These aquifers bear groundwater ranging in its salinity from fresh water to brine one. These aquifers are the Quaternary deposits, the Miocene carbonate, the Eocene carbonate, the Upper Cretaceous, the Cretaceous Nubian sandstone beside Carboniferous, Devonian, Silurian and Cambrian-Ordovicean sandstone aquifers. The Paleozoic sandstone has brine water but the Mesozoic one (Cretaceous Nubian sandstone) has fresh one. The Cretaceous Nubian sandstone represents the source of exploited water in the area, where it recharges the overlying carbonate aquifers. Fifty seven wells are included in the present study to reveal the hydrogeologic conditions of the oasis. The fractured carbonate aquifers represent the main exploitable aquifers due to their availability for the farmers in spite the low water quality. The water of this aquifer has a wide range of salinity ranging from 2377 ppm to > 17000 ppm depending on the depth of aquifer and the nature of facies and fracturing of the rock. The Nubian sandstone aquifers represent the main source of water in the area where it bears fresh water (< 1000 ppm). The flow within the Nubian sandstone is directed to the area of high discharge, i.e. to the west. The groundwater of the Quaternary and the fractured carbonates reflects leaching processes (secondary salinity) and that of the Nubian sandstone reflects meteoric origin and recharge during the pluvial period. The groundwater resources are evaluated with respect to their suitability for different purposes. Depending on the present geomorphological and hydrogeological studies and the previous pedological studies a landuse map was constructed.

  1. Subsurface geology of Tertiary rocks of northeastern district of Western Desert, Egypt

    SciTech Connect

    Elzarka, M.H.; Radwan, I.A.

    1983-03-01

    The lithofacies analysis of the Tertiary rocks reveals two ancient subbasins at the north and southeast of the northeastern district, Western Desert. The lithofacies of the Paleocene and early and middle Eocene sections are mainly calcareous. Shale predominates in the late Eocene rocks. The Paleocene rocks seem to have accumulated in a lagoonal environment of epineritic depths. The Paleocene rocks of the northern subbasin indicate accumulation on an unstable shelf. The Paleocene environmental conditions seem to have prevailed during the early and middle Eocene. During the late Eocene, rocks of shallow-water and current-agitated environments accumulated. The lower clastic layers of the Oligocene, having a sand/shale ratio less than one, indicate a clastic shoreline environment-lagoonal subenvironment. The Oligocene clastics are overlain by a basaltic sheet at the eastern part of the district. The middle Miocene lithofacies indicate rock accumulation in a contemporaneously subsiding basin under lagoonal or delta-front conditions at the southern part of the district. Marine stagnant-bottom-water conditions prevailed during the accumulation of the middle Miocene rocks at the norther parts. The Pliocene rocks seem to have accumulated in lagoons, where the inflow exceeded evaporation and alternating periods of exposure and flooding by either fresh or saline water of poor circulation prevailed. The tectonic instability of the district was initiated by volcancity during the late Oligocene.

  2. Precipitation source inferred from stable isotopic composition of Pleistocene groundwater and carbonate deposits in the western desert of Egypt.

    SciTech Connect

    Sultan, M.; Sturchio, N.; Hassan, F. A.; Abdel, M.; Hamdan, R.; Mahmood, A. M.; Alfy, Z. E.; Stein, T.; Environmental Research; Univ. Coll. London; Cairo Univ.; Ain Shams Univ.; Egyptian Geological survey and Mining Authority; Washington Univ.

    1997-01-01

    An Atlantic source of precipitation can be inferred from stable isotopic data (H and O) for fossil groundwaters and uranium-series-dated carbonate spring deposits from oases in the Western Desert of Egypt. In the context of available stable isotopic data for fossil groundwaters throughout North Africa, the observed isotopic depletions ({delta}D -72 to -81{per_thousand}; {delta}{sup 18}O -10.6 to -11.5{per_thousand}) of fossil ({ge}32,000 yr B.P.) groundwaters from the Nubian aquifer are best explained by progressive condensation of water vapor from paleowesterly wet oceanic air masses that traveled across North Africa and operated at least as far back as 450,000 yr before the present. The values of {delta}{sup 18}O (17.1 to 25.9{per_thousand}) for 45,000- to >450,000-yr-old tufas and vein-filling calcite deposits from the Kharga and Farafra Oases are consistent with deposition from groundwaters having oxygen isotopic compositions similar to those of fossil groundwaters sampled recently at these locations.

  3. 3D slicing of radiogenic heat production in Bahariya Formation, Tut oil field, North-Western Desert, Egypt.

    PubMed

    Al-Alfy, I M; Nabih, M A

    2013-03-01

    A 3D block of radiogenic heat production was constructed from the subsurface total gamma ray logs of Bahariya Formation, Western Desert, Egypt. The studied rocks possess a range of radiogenic heat production varying from 0.21 ?Wm(-3) to 2.2 ?Wm(-3). Sandstone rocks of Bahariya Formation have higher radiogenic heat production than the average for crustal sedimentary rocks. The high values of density log of Bahariya Formation indicate the presence of iron oxides which contribute the uranium radioactive ores that increase the radiogenic heat production of these rocks. The average radiogenic heat production produced from the study area is calculated as 6.3 kW. The histogram and cumulative frequency analyses illustrate that the range from 0.8 to 1.2 ?Wm(-3) is about 45.3% of radiogenic heat production values. The 3D slicing of the reservoir shows that the southeastern and northeastern parts of the study area have higher radiogenic heat production than other parts. PMID:23291561

  4. Palynostratigraphy and paleoenvironmental significance of the Cretaceous succession in the Gebel Rissu-1 well, north Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El Beialy, Salah; El-Soughier, Maher; Mohsen, Sayed Abdel; El Atfy, Haytham

    2011-02-01

    Palynological investigation of the Cretaceous Abu Roash, Bahariya, Kharita, Alamein, Alam El Bueib and Betty formations, encountered in the Gebel Rissu-1 well, north Western Desert, Egypt yielded 27 species of pteridophytic spores, 24 of gymnosperm pollen, 25 of angiosperm pollen and 11 of dinoflagellate cysts in addition to some acritarchs, foraminiferal test linings and freshwater algae. This enabled us to recognize five miospore biozones arranged from youngest to oldest as: Classopollis brasiliensis- Afropollis cf. kahramanensis- Dichastopollenites ghazalataensis Assemblage Zone (Late Cenomanian); Elaterosporites klaszii- Sofrepites legouxae- Afropollis jardinus Assemblage Zone (Middle/Late Albian-Early Cenomanian); Pennipollis peroreticulatus- Duplexisporites generalis-Tricolpates Assemblage Zone (Early Aptian-Early Albian); Tucanopollis crisopolensis- Afropollis sp. Assemblage Zone (Barremian) and Appendicisporites cf. tricornitatus- Ephedripites spp. Assemblage Zone (Late Neocomian). The Early Cretaceous Kharita, Alam El Bueib and the Betty formations encountered in the Gebel Rissu-1 well are interpreted to indicate oxic proximal and distal shelf deposits, characterized by type III/IV, V kerogen, which is gas prone but having little potential to produce hydrocarbons. The Upper Cretaceous Abu Roash and Bahariya formations are characterized by a distal suboxic-anoxic and marginal dysoxic-anoxic environment, and their kerogen type III/II indicates gas/oil prone nature. The Bahariya and Kharita Albian-Cenomanian sediments in the present study witnessed the onset of a semi-arid to arid climate, with local or seasonal humid conditions, based on the continuous high abundance of the elaterates pollen and Afropollis-producing plants that inhabited the paleotropical humid coastal plains.

  5. Correlation of Aerogravity and BHT Data to Develop a Geothermal Gradient Map of the Northern Western Desert of Egypt using an Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Mohamed, Haby S.; Abdel Zaher, Mohamed; Senosy, Mahmoud M.; Saibi, Hakim; El Nouby, Mohamed; Fairhead, J. Derek

    2015-06-01

    The northern part of the Western Desert of Egypt represents the second most promising area of hydrocarbon potential after the Gulf of Suez province. An artificial neural network (ANN) approach was used to develop a new predictive model for calculation of the geothermal gradients in this region based on gravity and corrected bottom-hole temperature (BHT) data. The best training data set was obtained with an ANN architecture composed of seven neurons in the hidden layer, which made it possible to predict the geothermal gradient with satisfactory efficiency. The BHT records of 116 deep oil wells (2,000-4,500 m) were used to evaluate the geothermal resources in the northern Western Desert. Corrections were applied to the BHT data to obtain the true formation equilibrium temperatures, which can provide useful constraints on the subsurface thermal regime. On the basis of these corrected data, the thermal gradient was computed for the linear sections of the temperature-versus-depth data at each well. The calculated geothermal gradient using temperature log data was generally 30 °C/km, with a few local high geothermal gradients in the northwestern parts of the study area explained by potential local geothermal fields. The Bouguer gravity values from the study area ranged from -60 mGal in the southern parts to 120 mGal in the northern areas, and exhibited NE-SW and E-W trends associated with geological structures. Although the northern Western Desert of Egypt has low regional temperature gradients (30 °C/km), several potential local geothermal fields were found (>40 °C/km). The heat flow at each well was also computed by combining sets of temperature gradients and thermal conductivity data. Aerogravity data were used to delineate the subsurface structures and tectonic framework of the region. The result of this study is a new geothermal gradient map of the northern Western Desert developed from gravity and BHT log data.

  6. Palaeoenvironment and Holocene land use of Djara, Western Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Kindermann, Karin; Bubenzer, Olaf; Nussbaum, Stefanie; Riemer, Heiko; Darius, Frank; Pöllath, Nadja; Smettan, Ursula

    2006-07-01

    The results of the interdisciplinary project ACACIA support the assumption of a more humid climate at Djara, on the Egyptian Limestone Plateau, which is a hyper-arid desert today, during the early and mid-Holocene. The ancient plant and animal inventories give new impetus for the suggestion of an interfingering of two climatic regimes, the winter rains from the north and west and the summer monsoonal rains from the south, on the latitude of Djara. A playa sediment sequence, the composition of plant and animal taxa as well as the reconstructed settlement patterns indicate a semi-arid climate with alternating more humid and drier conditions. The concentration of prehistoric sites in the Djara depression points to locally favourable conditions in contrast to the surrounding plateau surface. The widespread catchment and a distinct system of palaeochannels offered fresh water over a period of time due to the run-off from the plateau surface after rain events. Although the ecological conditions were better during the Holocene humid phase than they are today, a sedentary way of life was improbable. The hydrological constraints require altogether highly mobile subsistence strategies. Shells of the Nile bivalve Aspatharia sp. ( Spathopsis sp.) give evidence for contacts between Djara and the Nile Valley, which remains beside the Egyptian oases an important retreat area with perennially available water. The decrease of radiocarbon dates and related archaeological sites around 6300 BP (c. 5300 cal BC) indicate the depopulation of the Djara region as a consequence of the drying trend. While the drop off of the 14C-dates can also be observed in other desert research areas of the ACACIA-project, we date the end of the Holocene humid phase about 300 years earlier than previously suggested.

  7. Larger benthic foraminiferal turnover across the Eocene-Oligocene transition at Siwa Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Orabi, H.; El Beshtawy, M.; Osman, R.; Gadallah, M.

    2015-05-01

    In the Eocene part of the Siwa Oasis, the larger foraminifera are represented by the genera Nummulites, Arxina, Operculina, Sphaerogypsina, Asterocyclina, Grzybowskia, Silvestriella, Gaziryina and Discocyclina in order of abundance. Operculina continues up to the early Oligocene as modern representatives in tropical regions, while the other genera became extinct. Nevertheless, the most common larger foraminiferal genus Lepidocyclina (Nephrolepidina) appears only in the lowermost Oligocene. In spite of the Eocene-Oligocene (E/O) transition is thought to have been attended by major continental cooling at northern middle and high latitudes, we discover that at the Siwa Oasis, there is a clear warming trend from the late Eocene (extinction level of Nummulites, Sphaerogypsina, Asterocyclina, Grzybowskia, Silvestriella and Discocyclina) to the early Oligocene is observed due to the high abundance of Operculina and occurrence of kaolinite and gypsiferous shale deposits in both Qatrani and El Qara formations (Oligocene) at this transition. The El Qara Formation is a new rock unit proposed herein for the Oligocene (Rupelian age) in the first time. Several episodes of volcanic activity occurred in Egypt during the Cenozoic. Mid Tertiary volcanicity was widespread and a number of successive volcanic pulses are starting in the late Eocene. The release of mantle CO2 from this very active volcanic episode may have in fact directly caused the warm Eocene-Oligocene greenhouse climate effect.

  8. Cosmogenic, radiogenic, and stable isotopic constraints on groundwater residence time in the nubian aquifer, western desert of egypt

    SciTech Connect

    Patterson, Leslie J.; Sturchio, Neil C.; Kennedy, B.Mack; van Soest, Matthias C.; Sultan, Mohamed; Lu, Zheng-Tian; Lehmann, Bernhard; Purtschert, Roland; El Alfy, Zeinhom; El Kaliouby, Baher; Dawood, Yehia; Abdallah, Ali

    2004-06-01

    Measurements of radiochlorine ({sup 36}Cl), radiogenic noble gases ({sup 4}He and {sup 40}Ar), and stable chlorine isotope ratios were obtained to assess the residence time of groundwater in the Nubian Aquifer of the Western Desert of Egypt. Measured {sup 36}Cl/Cl ratios yield apparent residence times from {approx}0.2 to 1.2 x 10{sup 6} years in the deep (600-1200 m) groundwater (assuming constant Cl) and {le} 0.16 x 10{sup 6} years in the shallow (<600 m) groundwater. Values of {delta}{sup 37}Cl in the groundwater strengthen the application of the {sup 36}Cl dating method by constraining Cl sources and identifying groundwater mixing. Dissolved gases were measured in some of the deep groundwater samples. Measured {sup 4}He concentrations indicate accumulation of radiogenic {sup 4}He that is qualitatively consistent with the age progression indicated by the {sup 36}Cl/Cl ratios, but the flux of external {sup 4}He from the underlying crust has not been quantified and is not constant throughout the aquifer. Concentrations of {sup 40}Ar range from 3.3 to 6.7 x 10{sup -4} ccSTP/g and indicate excess air incorporation at recharge. Measured {sup 40}Ar/{sup 36}Ar ratios do not exceed the atmospheric ratio. A two-dimensional numerical hydrodynamic transect of the aquifer was modeled from the area of the Uweinat Uplift to the northern Bahariya Oasis. Predicted groundwater velocities in the deep portion of the aquifer are 0.5-3.5 m/yr with groundwater residence times up to 9 x 10{sup 5} years; residence times up to 1.3 x 10{sup 6} years are predicted in the confining shale. Aquifer properties are estimated by using the model to fit the measured {sup 36}Cl/Cl ratios. Under these conditions, hydrodynamic residence times are within about 30 percent of those calculated from {sup 36}Cl when mixing of Cl{sup -} is accounted for in the highest-Cl{sup -} deep groundwaters. By mutually calibrating multiple methods (hydrodynamic, {sup 36}Cl, and {sup 4}He), a consistent picture of the Nubian Aquifer has emerged in which lateral flow from a southern recharge area dominates the deep horizons, while shallow horizons contain younger, autochthonous recharge.

  9. A Study of Hydrogeological Conditions of the Nubian Sandstone Aguifer in the Area between Abu Simbel and Toschka, Western Desert, Egypt.

    NASA Astrophysics Data System (ADS)

    Dahab, K. A.; Ebraheem, A. M.; El Sayed, E. A.

    2001-05-01

    A Study of Hydrogeological Conditions of the Nubian Sandstone Aquifer in the Area between Abu Simbel and Toschka, Western Desert, Egypt. By K. A. Dahab*, A. M. Ebraheem**, and E. El Sayed*** *Geology Department, Faculty of Science, Menofia University, Shibin El Kom, Egypt. ** Geology Department, Faculty of Science, Assiut University, Assiut, Egypt. *** Geology Department, Faculty of Science, Minia University, Minia, Egypt. The Nubian Sandstone Aquifer in the area between Toschka and Abu Simbil is small portion of the very well known Nubian Sandstone Aquifer System in the Eastern Sahara, which covers the entire area of southwest Egypt, southeast Libya, northeast Chad, and northern Sudan. Toscha area is currently the site of intensive drilling and development for a huge land reclamation project. The drilling information was used to study the hydrogeological setting of the Nubian Sandstone aquifer in the area. The obtained results indicate that the lithological characteristics and tectonic setting is strongly affecting the groundwater flow pattern as well as the aquifer potentiality of the nubian sandstone aquifer in the area. The aquifer potentiality in this area is low if compared to that of east Oweinat or Dakhla areas. The aquifer is mainly composed of hard ferruginous sandstone with great shale and clay intercalation with a thickness ranging from 140 to 230 meters. Groundwater in this aquifer belongs to fresh to slightly brackish type (salinity is ranging from 240 to 1300 ppm). Ion dominance ordering reveals that sodium cation is mostly predominating over calcium and magnesium whereas chloride is predominant over sulfate and bicarbonate. The groundwater is related to meteoric origin. The high concentration of sodium, chloride, and sulfates reflect leaching and dissolution processes of gypsiferous shales and clay as well as long residence time of water.

  10. Thermal Performance of Building Envelope in Very Hot Dry Desert Region in Egypt (Toshky) 

    E-print Network

    Khalil, M. H.; Sheble, S. S.; Helal, M. A.; El-Demirdash, M.

    2010-01-01

    of Building Envelope in Very Hot Dry Desert Region in Egypt (Toshky Region) S.S. Sheble* M. H. Khalil M. A. Helal Prof. M. El- Demirdash3 Asso. Prof. Building Physics Institute (HBRC) Asso. Prof. Building Physics Institute (HBRC) Prof. & head... of Building Physics Institute (HBRC) Prof. & Chairman of HBRC Housing & Building National Research Center (HBRC) Cairo, Egypt * Author ABSTRACT Toshky region is a desert region located in the south east of Egyptian western desert...

  11. The Climate and its Impacts on deterioration and weathering rate of EI-Nadura Temple in El- Kharga Oasis, Western Desert of Egypt.

    NASA Astrophysics Data System (ADS)

    Ismael, Hossam

    2015-04-01

    Undoubtedly, El-Kharga Oasis monumental sites are considered an important part of our world's cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The Roman stone monuments in Kharga represent cultural heritage of an outstanding universal value. Such those monuments have suffered weathering deterioration. There are various elements which affect the weathering process of stone monuments: climate conditions, shapes of cultural heritages, exposed time periods, terrains, and vegetation around them, etc. Among these, climate conditions are the most significant factor affecting the deterioration of Archeological sites in Egypt. El- Kharga Oasis belongs administratively to the New Valley Governorate. It is located in the southern part of the western desert of Egypt, lies between latitudes 22°30'14" and 26°00'00" N, and between 30°27'00" and 30°47'00" E. The area of El Kharga Oasis covers about 7500 square kilometers. Pilot studies were carried out on the EI-Nadura Temple, composed of sandstones originating from the great sand sea. The major objective of this study is to monitor and measure the weathering features and the weathering rate affecting the building stones forming El-Nadora Roman building rocks in cubic cm. To achieve these aims, the present study used analysis of climatic data such as annual and seasonal solar radiation, Monthly average number of hours of sunshine, maximum and minimum air temperatures, wind speed, which have obtained from actual field measurements and data Meteorological Authority of El-Kharga station for the period 1977 to 2010 (33 years), and from the period 1941-2050 (110 years) as a long term of temperature data. Several samples were collected and examined by polarizing microscopy (PLM), X-ray diffraction analysis (XRD) and scanning electron microscopy equipped with an energy dispersive X-ray analysis system (SEM-EDX). The results were in agreement with the observed values in the study area. The deterioration of El-Nadora temple is above 45 % of original temple (138-161 BC), these deteriorations have occurred not only due to the age of the structures, but also due to the climate elements. It was found that the climate is the most important elements influencing weathering. El-Nadora temple is highly influenced by wind action because it was built on a hill top 180 meter in hyper arid climate and exposed to wind without any obstruction. Finally, El-Nadora Temple has lost about 42.46 % of its original size. And if the rate of deterioration continues, the major landmarks, symbols and inscriptions will fully disappear in 2150.

  12. RETRACTED: Thickness variation of the sedimentary cover in the south Western Desert of Egypt as deduced from Bouguer gravity and drill-hole data

    NASA Astrophysics Data System (ADS)

    Senosy, M. M.; Youssef, M. M.; Abdel Zaher, M.

    2013-01-01

    Bouguer gravity anomaly mapped at a scale of 1:500,000 and the lithological logs of about 120 deep wells were used to determine the thickness of the sedimentary sequence containing the main sandstone water formation in important area of Egypt. The area is located in the southern part of the Western Desert bounded by the latitudes 22°00'-26°30' N, and longitudes 28°30'-33°00' E. The predominant structures affecting the basement rocks and the sedimentary cover were also studied. The gravity stripping approach was applied to eliminate the gravity effects caused by sedimentary sequence and to separate density anomalies within the sedimentary fill from the influence of rocks at deeper levels in the crystalline crust. The present study indicated that the surface of the basement rocks is highly rugged and mostly controlled by structures which have a direct effect on thickness variation of the sedimentary cover all over the area. Regionally the area is characterized by two major intracratonic basins (the Dahkla Basin and the Nile valley Basin) separated by a NE-SW trending swell of the Kharga uplift and bounded at the south by the Oweinat-Bir Safsaf-Aswan uplift. These major tectonic units are controlled by fault structures trending in N-S, E-W, NE-SW, NW-SE, which cut the basement rocks and extend upward in the sedimentary cover. The maximum thickness of sandstone formations is recorded at west Oweinat, west Kurkur, southwest of Aswan, Gramashin, Dakhla oasis and some localities west of Sohag and Qena towns. At these localities the thickness ranges between 600 and 900 m. As this formation is the main water aquifer in the study area, therefore these localities are characterized by the presence of big amount of groundwater. Accordingly, these areas must take the priority in the sustainable development programs of southern Egypt.

  13. The contribution of geographic information systems and remote sensing in determining priority areas for hydrogeological development, Darb el-Arbain area, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Elewa, Hossam H.; Fathy, Rafik G.; Qaddah, Atef A.

    2010-08-01

    The Darb el-Arbain study area is in the southern Western Desert of Egypt and has been attracting increasing developmental interest in the last few decades, especially since agricultural development of the southern Baris area, where the groundwater resources of the Nubian Sandstone Aquifer System (NSAS) have been utilized for the cultivation of valuable lands. Due to the proven high potential of both groundwater and land resources, determining the priority areas for sustainable hydrogeological development becomes a necessity. A geographic information system, as a platform for geospatial modeling techniques, has been built, which depends on the recently collected data about the NSAS, in addition to the published databases. Certain criteria of practical value, like depth to groundwater, hydraulic conductivity, groundwater salinity, sodium adsorption ratio, and the safe yield of wells, were selected as decisive parameters for hydrogeological prioritization. The model pinpoints areas characterized by favorable hydrogeological conditions, which could be used for future development and implementation of an artificial storage and recovery (ASR) program. The designated priority areas for hydrogeological development occur at the southern, middle southern and some localized northern parts of the Darb el-Arbain area. The newly formed Tushka Lakes represent a suitable and excellent natural source of freshwater for implementing an ASR program.

  14. Characterization of magnetic spherical fractions in sand deposits for interpretation of environmental change around the El- Zayyan temple, Kharga Oasis, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Watanabe, Makiko; Koizumi, Natsuko; Kato, Sayuri; Kikuchi, Ryohei; Kamei, Hiroyuki

    2014-05-01

    Desertification in North Africa has rapidly advanced over the last 6,000 years. Such environmental changes began in the Early Dynastic Period of Egypt (4200 - 3150 BC), and the occupation of Achaemenid Persian and Roman cultures in Egypt occurred under even drier climates. Kharga is the largest oasis of the five oases, located in the western desert of Egypt that contains a treasure trove of archaeological resources. This oasis has been highlighted to promote resource exploration and development of archaeological tourism since the 1980's. The El-Zayyan temple is located 27 km south of the central Kharga oasis. Zayyan was once called 'Tchonemyris', which has connection with the means of 'huge well' in Greek. Although major portions of the temple were rebuilt in 140 AD during the rule of the Roman Emperor Antoninus Pius, this temple is considered to be originally built in the Ptolemaic period (4c-1c BC). It is likely that the area had a sufficient water supply in the past as the El-Zayyan temple stands at the lowest point (-18 m a.s.l.) in the Kharga oasis. Furthermore, the El-Ghueita temple that stands on a hill top at 68.5 m a.s.l., 4 km northward from the El-Zayyan temple, has given name that means 'beautiful garden' in Greek. From these facts, we can imagine that the past landscape of this area contained green surroundings. The El-Ghueita temple was well known as a production centre of high quality wine since the mid-Dynastic age (2050 -1786 BC). As this area is currently arid, it is expected that there were irrigation facilities to maintain the vast farm land during the ancient period. To deepen our knowledge of how people developed their technologies and conducted their life within the natural environment of a drastic drying period, understanding the process of environmental change on a region scale is necessary. The aim of this study was to extract proxies from sand deposits in the western desert area to estimate the change in the environment. We examined the sand layers with a focus on the spherical magnetic fractions having relations with accumulation of free iron oxides, condition of water and microbial activities. The study sites were located west of the El-Zayyan temple, and six and seven samples were collected every 10 cm from the two sand profiles, Zy-R and Zy-6, respectively. AMS 14C dating was conducted using fine fractions of an organo-mineral complex; date ranges 5,000-8,400 yBP and 5,500-7,800 yBP were assigned to Zy-R and Zy-6, respectively. Spherical fractions, separated into six colored-types, were extracted using a neodymium magnet, and then characterized by SEM observation, EDX elemental analysis (FE-SEM S4700, Hitachi, Genesis, EDAX), and X-ray micro-crystal structural analysis (D8-Discover, Bruker axs) to discuss their origins. The vertical change in the density of each fraction by weight and counts in sand revealed the environmental change.

  15. Hydrogeological aspects and environmental concerns of the New Valley Project, Western Desert, Egypt, with special emphasis on the southern area

    NASA Astrophysics Data System (ADS)

    Assaad, Fakhry A.

    1988-12-01

    The New Valley Project has been given much attention in the past 20 years especially from the hydrogeological point of view concerning groundwater utilization for the reclamation of a large area of the Western Desert. Lithological, petrophysical, and petrographical studies were conducted on four wells south of Beris Oasis, namely Beris 20, Beris 15, Beris 14, and Beris 13, and are defined by latitudes 24°25'E and 24°35'E and longitudes 30°30'N and 30°46'N. The Nubian sedimentation is of Posttectonic deposition that took place over the uplifted Precambrian granitic basement and is Lower Cretaceous, whereas the upper most variegated shales of the cap rock are Upper Cretaceous. The Nubian sandstones in the area south of Beris Oasis contain hematitic stains and/or fine granular authigenic hematite, thin laminae of brown ferruginous quartzite is also recorded denoting oxidizing conditions in the basin of deposition. Thin streaks of carbonaceous shales are met with in different depths to the south of Beris area, may be taken to denote oscillations in the sea level and accordingly its depths, and are responsible for the change in the oxidation-reduction potential during the deposition of the corresponding beds. Lithologic logs were interpreted together with the electric and micro-logs for adjustment of the shale breaks and showed that there are five water-bearing zones, named from bottom to top: A, B, C, D, and E, and are mainly unfossiliferous orthoquartzites, separated from each other by impervious beds of siltstones, shales, and clays of varying thicknesses. This zoning had been found valid in other parts of the Kharga Oases and could be applied locally in the Kharga Oases area. Mechanical analysis was performed mainly on 39 samples, of which 18 were core samples and 21 were cuttings, that were raised from four wells dug in the area south of Beris Oasis, Kharga Oases. Porosity and permeability tests were carried out on the 18 core samples only. The implication of these data on the environment of deposition of the Nubia Sandstone is discussed. Petrographic examination of a thin section of the subsurface Nubia sandstones in the South of Beris Oasis showed that the lithified rocks fall into three types depending on the nature of cement being, silicious or ferruginous, and on the amount of primary matrix, which at present is reorganized into iron oxides, microquartz, and muscovite flakes, thus reaching the phyllomorphic stage of diagensis. Rounding of the quartz grains shows that transportation had a minor effect on the grain morphology and favor a fluviatile transporting agent.

  16. ORIGINAL PAPER Neoproterozoic diamictite in the Eastern Desert of Egypt

    E-print Network

    Stern, Robert J.

    ORIGINAL PAPER Neoproterozoic diamictite in the Eastern Desert of Egypt and Northern Saudi Arabia in Wadi Kareim and Wadi Mobarak in the Eastern Desert of Egypt and the Nuwaybah formation in NW Saudi intrusions (Abdel Naby et al. 2002; Shalaby et al. 2005). Such lithologies are well- exposed in the Eastern

  17. Thermochronometric Investigation of Multiple Unconformities and Post-depositional Thermal History of a Fault Block in the Northern Western Desert, Egypt

    E-print Network

    Glauser, Travis Robert

    2010-12-13

    .1 Proterozoic Formation of Gondwana and Proterozoic Effects of 7 Gondwanan Suture Zones 3.2 Paleozoic Evolution and Neotethys Formation 8 3.3 Mesozoic Evolution and Supercontinental Breakup 9 4. Northern Western Desert Stratigraphy 10... 5. Methodology 12 5.1 Sampling 12 5.2 (U-Th)/He Thermochronology 13 vii 5.3 Detrital Zircon (U-Th)/He Thermochronology 14 5.4 Detrital Zircon Complexities 15 5.4.1 Abrasion 15 5.4.2 Sample Bias 16 5.5 Radiation Damage 16...

  18. Neoproterozoic tectonothermal evolution of the Central Eastern Desert, Egypt: a slow velocity tectonic process

    E-print Network

    Fritz, Harald

    Neoproterozoic tectonothermal evolution of the Central Eastern Desert, Egypt: a slow velocity in the Central Eastern Desert of Egypt is constraint by 40 Ar/39 Ar ages of hornblende and muscovite from Meatiq

  19. Precambrian Research 136 (2005) 2750 The Wadi Mubarak belt, Eastern Desert of Egypt

    E-print Network

    Fritz, Harald

    2005-01-01

    Precambrian Research 136 (2005) 27­50 The Wadi Mubarak belt, Eastern Desert of Egypt System in the Central Eastern Desert of Egypt. The belt therefore appears to be a structural feature Mubarak belt can be correlated with the accepted scheme of deformation events in the Eastern Desert

  20. Mineralization, origin and age classification of ferruginized sandstone in the Bahariya Oasis, Western Desert, Egypt: A contribution to the origin of red beds

    NASA Astrophysics Data System (ADS)

    Mücke, A.; Agthe, Ch.

    1988-09-01

    The Bahariya Oasis is a depression and the topography of it is mainly controlled by anticlines. It lies in the Egyptian Western Desert and is characterized by isolated, cone-shaped residual hills which are aligned parallel to anticline axes in the southern part of the depression. These hills are capped by ferruginized sandstone of nearly black colour with an average iron content of 20 wt.%. The existence of a humid, warm climate with heavy rainfalls and a strong influence of vegetation during the Cretaceous-Tertiary transition provided reducing and weakly acid conditions. They enabled the mobilization of Fe and Mn out of manganese-bearing ilmenite and magnetite, primarily present in the sandstone. The existence of an oxidation barrier accompanied by an increase in pH value resulted in the precipitation of these elements. There is a definite correlation between the position of iron enrichment and tectonics in that area. The fracture planes, formed in the crestal region of the anticlines, exposed the deeper parts of the sandstone. As a consequence the oxygen of the air gained access to the subjacent sandstone strata, resulting in the formation of oxidation barriers in relatively deep-seated parts of the sandstone. The enrichment of iron and manganese was furthermore controlled by: (1)The process of up-arching during the formation of the anticlines, the thick sedimentary sequences in the crestal region of the fold, thus facilitating the penetration of supergene solutions. (2)Apart from the predominant supergene nature of the iron enrichment, a lateral one, though on a subordinate scale, also took place. (3)The oxidation barrier is supposed to be coincident partly with an evaporation barrier. The iron horizons therefore constitute an epigenetically mineralized sandstone of the Bahariya Formation. The former term Radwan Formation for this type of ferruginized sandstone, now preserved in the form of residual hills, is therefore invalid.

  1. Epidemiology and clinical presentation of stroke in Upper Egypt (desert area)

    PubMed Central

    El Tallawy, Hamdy N; Farghaly, Wafaa M; Badry, Reda; Hamdy, Nermin A; Shehata, Ghaydaa A; Rageh, Tarek A; Metwally, Nabil A; Hassan, Enas M; Elsayed, Sayed S; Yehia, Mohamed A; Soliman, Wael T

    2015-01-01

    Background Stroke is a common cause of morbidity and mortality worldwide. Four out of five strokes occur in the low- and middle-income countries. This study aims to find lifetime prevalence of stroke in Upper Egypt and to identify clinical presentations and possible risk factors of stroke in this population. Methods This is a door-to-door (every door) study conducted on all inhabitants in Al Kharga district (representative of western desert) and Al Quseir city (representative of eastern desert). The study was conducted in two stages, and every stage consisted of three phases (screening, diagnostic, and investigatory). Results The total lifetime prevalence of stroke was 8.5/1,000 in the population aged 20 years and more. It increased with advancing age and was higher among males than females among all age groups except in the childbearing period (20 years to <40 years of age). Lifetime prevalence of ischemic stroke (7.2/1,000) was higher than hemorrhagic stroke (1.1/1,000). Hemiparesis and hemiplegia were the commonest presentation of stroke. Headache, vomiting, and vertigo were found to be significantly more common accompaniments of hemorrhagic stroke. The most common risk factor was hypertension, followed by hyperlipidemia and diabetes mellitus. Conclusion The total lifetime prevalence of stroke in the population aged 20 years and more in Upper Egypt (desert area) lies within the range that is recorded in developing countries. Clinical presentation and risk factors are similar to those recorded from developing and developed countries. PMID:26346729

  2. Sites with Holocene dung deposits in the Eastern Desert of Egypt: Visited by herders?

    E-print Network

    Marinova, Elena

    Sites with Holocene dung deposits in the Eastern Desert of Egypt: Visited by herders? V. Linseele a in the Egyptian Eastern Desert with stratified archaeological deposits. In Middle Holocene contexts of both sites Cave site is situated approximately 40 km Northeast of Quseir, in the Egyptian Eastern Desert

  3. Aeolian erosional lineations in the Libyan Desert, Dakhla Region, Egypt

    NASA Astrophysics Data System (ADS)

    Brookes, Ian A.

    2001-08-01

    This paper presents results of a study of aeolian erosion at the landscape scale. There have been few such studies in desert geomorphology compared to those focused on individual landforms and on rock surface sculpture. The present study area lies in the southern part of the Libyan Desert in south-central Egypt, between 25° and 27°N, 29° and 30°E. Bedrock comprises Paleogene limestone of various lithologies. Climate is hyperarid. The following topics are treated. (i) Correspondences between rock outcrop belts and belts of terrain lineated by aeolian erosion and unlineated terrain. (ii) The effect of lithology on aeolian lineation, which works through the presence or absence of chert in the limestones. Lineation is produced by aeolian erosion in chert-free/poor rocks, whereas erosion of chert-rich rocks produces a desert pavement that armors the surface, suppressing erosion. (iii) The effect of large valleys eroded upwind of lineated terrain, which deflect winds and trap sand, ending erosion, so that downwind lineations are reduced and finally erased by weathering. (iv) Sample lineated landscapes in the area show stages of evolution, arranged in the time domain into a proposed cycle of aeolian erosion; the cycle progresses from initial smooth plain to grooves separating long, blade-shaped ridges, to segmentation of ridges into shorter blades along diagonal joints, to streamlining of shorter blades and size reduction, to final planation. In any one wind-parallel swath of lineated terrain, stages in the cycle progress downwind in the space domain, so that upwind landscapes are more advanced in the cycle. (v) The structure of air flow responsible for lineation is still uncertain, but initial grooving may respond to stable longitudinal horseshoe vortices, or self-organized regularity of erosion by random vortices; subsequently, the erosion pattern is fixed by evolving relief. (vi) Large, smooth basins within the lineated terrain were carved by aeolian erosion before Oxygen Isotope Stage (OIS) 5 (70-130 ka), as were similar basins along the Dakhla piedmont below the scarp; little geomorphic change has occurred since, so in this field of aeolian erosional lineations (AELs) the aeolian erosion cycle may have occupied 10 times as long. Since continental scale aridity set in at ca. 2.4 Ma, there have been only two cycles in this area. A completed cycle earlier than the current incomplete one is indicated by rare small yardangs riding 'piggyback' on larger ones.

  4. Carrion insects of the Egyptian western desert.

    PubMed

    Hegazi, E M; Shaaban, M A; Sabry, E

    1991-09-01

    A general survey was made on the zoosaprophagous insects and their associates in a natural ecosystem in the Egyptian western desert (80 km west of Alexandria, 12 km from the Mediterranean Sea shore). Two types of traps were used, one for flying insects and the other for soil-burrowing insects. Two types of decaying media were used as baits: the common freshwater fish (Tilapia zilii Gerv.) and the desert snail (Eremina desertorum). More than 30 insect species were trapped. The following orders and families were represented: Diptera (Calliphoridae, Sarcophagidae, Muscidae); Coleoptera (Histeridae, Scarabaeidae, Dermestidae, Tenebrionidae); Hymenoptera (Chalcididae, Pteromalidae, Eulophidae, Formicidae). Monthly totals of numbers trapped in each of these groups are presented. PMID:1941945

  5. The El Mayah molasse basin in the Eastern Desert of Egypt A. Shalaby a,b,*, K. Stuwe a,*, H. Fritz a

    E-print Network

    Fritz, Harald

    The El Mayah molasse basin in the Eastern Desert of Egypt A. Shalaby a,b,*, K. Stu¨we a,*, H. Fritz: Molasse basin; Eastern Desert of Egypt; Pan-African evolution 1. Introduction Molasse basins occur of the adjacent orogen (e.g. White et al., 2002; Spiegel et al., 2000). Molasse type sediments have been described

  6. Origin and recharge rates of alluvial ground waters, Eastern Desert, Egypt.

    SciTech Connect

    Sultan, M.; Gheith, H.; Sturchio, N. C.; El Alfy, Z.; Danishwar, S.

    2002-04-12

    Stable isotope and tritium analyses of shallow ground waters in the Eastern Desert of Egypt showed that the waters were derived largely by evaporation of regional precipitation and at least partly from precipitation in the past 45 y. To estimate the ground water recharge rate, we developed an integrated hydrologic model based on satellite data, geologic maps, infiltration parameters, and spatial rainfall distribution. Modeling indicated that during a severe 1994 storm, recharge through transmission loss in Wadi El-Tarfa was 21% of the precipitation volume. From archival precipitation data, we estimate that the annual recharge rate for the El-Tarfa alluvial aquifer is 4.7 x 10{sup 6} m{sup 3}. Implications for the use of renewable ground waters in arid areas of Egypt and in neighboring countries are clear.

  7. Soil seed bank in different habitats of the Eastern Desert of Egypt

    PubMed Central

    Gomaa, Nasr H.

    2012-01-01

    The floristic composition and species diversity of the germinable soil seed bank were studied in three different habitats (desert salinized land, desert wadi, and reclaimed land) in the Eastern Desert of Egypt. Moreover, the degree of similarity between the seed bank and the above-ground vegetation was determined. The seed bank was studied in 40 stands representing the three habitats. Ten soil samples (each 25 × 20 cm and 5 cm depth) were randomly taken per stand. The seed bank was investigated by the seedling emergence method. Some 61 species belonging to 21 families and 54 genera were identified in the germinable seed bank. The recorded species include 43 annuals and 18 perennials. Ordination of stands by Detrended Correspondence Analysis (DCA) indicates that the stands of the three habitats are markedly distinguishable and show a clear pattern of segregation on the ordination planes. This indicates variations in the species composition among habitats. The results also demonstrate significant associations between the floristic composition of the seed bank and edaphic factors such as CaCO3, electrical conductivity, organic carbon and soil texture. The reclaimed land has the highest values of species richness, Shannon-index of diversity and the density of the germinable seed bank followed by the habitats of desert wadi and desert salinized land. Motyka’s similarity index between the seed bank and the above-ground vegetation is significantly higher in reclaimed land (75.1%) compared to desert wadi (38.4%) and desert salinized land (36.5%). PMID:23961181

  8. Neoproterozoic post-collisional granitoids in the Central Eastern Desert of Egypt: Petrological and geochemical constraints

    NASA Astrophysics Data System (ADS)

    Osman, Ali F.; El Kalioubi, Baher A.

    2014-11-01

    The Um Had and Um Effein (UHUE), Central Eastern Desert of Egypt, are elliptical and circular bodies of monzogranite to syenogranite with subordinate alkali feldspar granite. The UHUE granites are quite evolved (SiO2 = 67-74 wt.%), and have characteristics of high-K calc-alkaline peraluminous rocks. They are relatively enriched in K, Ba, La, Rb, Zr and total REEs, while are depleted in Sr, Y, Ti, HREE. The rocks have LREE-enriched patterns with significant negative Eu anamolies suggesting post-collision granites. The gradual increase of Rb/Sr and Rb/Ba ratios from the monzogranite to the alkali feldspar granites indicates that these granites are genetically related. The various geochemical discrimination diagrams strongly suggest that the studied granitoids were generated from crustal sources through fractional crystallization with some crustal contamination which have played a major role during the magmatic evolution of the plutons. These granites display transitional character from orogenic calc-alkaline arc-type up to subsequent anorogenic within-plate environments, suggesting continuous crystallization of magma in a transitional “post-collision” tectonic setting. This transition from compression to extension was controlled mainly by lithospheric delamination following continental collision in the Eastern Desert of Egypt.

  9. Genetic Aspects of Gold Mineralization at Some Occurrences in the Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Abd El Monsef, M.; Slobodník, M.; Salem, I. A.

    2012-04-01

    The Eastern Desert of Egypt is well known as a gold-mining area since ancient times, there're more than 95 gold deposits and occurrences spread the whole area covered by the basement rocks of Precambrian age. The basement rocks of the Eastern Desert of Egypt constitute the Nubian Shield that has formed a continuous part of the Arabian-Nubian Shield before the opening of Red Sea (Oligocene-Early Miocene). Commonly, the system of gold-bearing quartz veins in the Eastern Desert is clearly structural controlled related to brittle-ductile shear zones that mostly developed during late deformational stages of the evolution history for basement rocks in the Eastern Desert. This running study principally aims to contribute the mineral resource potential of the gold deposits in Egypt, so particularly Fatira, Gidami and Atalla occurrences have been involved into a comprehensive study based on field, structural, mineralogical, geochemical and genetic investigations. It is intended to better understanding for the characteristics, distribution controls, conditions and age of mineralization in relation to the age of the hosting rocks intrusion to find if there're genetic links between the gold mineralization and the evolution of the host intrusive complex. Several authors suggested that the gold mineralization was related to the intrusion of the (postorogenic) Younger granites. Other authors interpret these deposits as products of hydrothermal activity induced either by metamorphism or cooling effects of early Paleozoic magmatism or as combined metamorphic/magmatic episodes. The prime focus will be directed to the ore itself and the associated hydrothermal alteration zones based on detailed maps and well-distributed samples network and geochemical anomalies distribution. The laboratory studies included microscopic examination (reflecting and transmitting microscopy) to allow for determination of the hosting rocks types and mineralogical changes related to the gold mineralization in each area and revealing the ore mineralogy and the ore textures, geochemical analyses (including rare earth elements) are to be used in order to determine the tectonic setting and magmatic evolution of the host intrusions, scanning electron microscope, microprobe analysis, stable isotopes and fluid inclusions will serve as a new part of this study in detection of the origin and the physico-chemical conditions (P-T condition) for the gold precipitation, Age dating of the host intrusion and mineralization will be based on K-Ar for dating potassium-bearing minerals in fresh host rocks and hydrothermal mineral phases.

  10. Holocene freshwater carbonate structures in the hyper-arid Gebel Uweinat region of the Sahara Desert (Southwestern Egypt) q

    E-print Network

    Gilli, Adrian

    Desert (Southwestern Egypt) q Margarita M. Marinova a,b , A. Nele Meckler c , Christopher P. McKay b Zurich, 8092 Zurich, Switzerland a r t i c l e i n f o Article history: Received 24 May 2013 Received

  11. Natural radioactivity and rare earth elements in feldspar samples, Central Eastern desert, Egypt.

    PubMed

    Walley El-Dine, Nadia; El-Shershaby, Amal; Afifi, Sofia; Sroor, Amany; Samir, Eman

    2011-05-01

    The pegmatite bodies of the Eastern Desert of Egypt are widely distributed especially along the Marsa-Alam-Idfu road. The Abu Dob area covers about 150km(2) of the Arabian Nubian shield at the central part of the Eastern Desert of Egypt. Most of the pegmatite is zoned; the zonation starts with milky quartz at the core followed by alkali feldspar at the margins. The feldspars vary in color from rose to milky and in composition from K-feldspar to Na-feldspar, sometimes interactions of both types are encountered. Thirteen feldspar samples were collected from different locations in the Abu Dob area for measuring the natural radioactivity of (238)U, (232)Th and (40)K using an HPGe detector. The variation in concentration of radionuclides for the area under investigation can be classified into regions of high, medium and low natural radioactivity. The average concentration in BqKg(-1) has been observed to be from 9.5 to 183675.7BqKg(-1) for (238)U, between 6.1 and 94,314.2BqKg(-1) for (232)Th and from 0 to 7894.6BqKg(-1) for (40)K. Radium equivalent activities (Ra(eq)), dose rate (D(R)) and external hazard (H(ex)) have also been determined. In the present work, the concentration of rare earth elements are measured for two feldspar samples using two techniques, Environmental Scanning Electron microscope XIL 30 ESEM, Philips, and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The existence of rare earth elements in this area are very high and can be used in different important industries. PMID:21324705

  12. Mapping of serpentinites in the Eastern Desert of Egypt by using Landsat thematic mapper data

    SciTech Connect

    Sultan, M.; Arvidson, R.E.; Sturchio, N.C.

    1986-12-01

    Serpentinites in the Eastern Desert of Egypt were mapped from Landsat thematic mapper (TM) data by using procedures that take advantage of the distinctive spectral reflectance of these rocks caused by the abundance of antigorite, lizardite, clinochrysotile, and magnetite. The method employs a threshold classifier based on three reflectance ratios: (1) band 5/7 for estimating the abundance of hydroxyl-bearing phases, (2) band 5/1 for magnetite content, and (3) the calculated value of reflectance for band 4, based on a linear interpolation between bands 3 and 5, divided by the observed band-4 reflectance. The third ratio was used to identify rocks in iron-bearing aluminosilicates and thereby to distinguish mafic rocks containing substantial amounts of magnetite and hydroxyl-bearing phases from serpentinites. The method was first successfully tested over the Meatiq dome and Wadi Ghadir areas, where serpentinites and ophiolitic melanges dominated by serpentinites have been mapped during the course of field work. A TM-based map was then generated; the map covered about 60,000 km/sup 2/ in the Eastern Desert. Results demonstrate that TM data can be used with reliability to distinguish serpentinites from surrounding rocks in arid regions and to generate detailed maps over wide regions by using quantitative, reproducible mapping criteria. Possibilities for locating suture zones over the less well known parts of arid continents are clear.

  13. Age constraints on the formation and emplacement of Neoproterozoic ophiolites along the AllaqiHeiani Suture, South Eastern Desert of Egypt

    E-print Network

    Stern, Robert J.

    ­Heiani Suture, South Eastern Desert of Egypt K.A. Ali a,d, , M.K. Azer b , H.A. Gahlan c , S.A. Wilde d , M the Gabgaba­Gebeit­Hijaz terranes to the south and the SE Desert­Midyan terranes to the north occurred

  14. Technologies Applied in the Toshka Project of Egypt

    ERIC Educational Resources Information Center

    Wahby, Wafeek S.

    2004-01-01

    The Toshka Project, located in Egypt, involves excavating a canal to carry about 380 billion ft[supercript 3] of water every year from Lake Nasser to the Toshka Depression, southwest of Aswan. This will eventually create a new valley to the River Nile in the western desert of Egypt in addition to the currently existing prehistoric river course.…

  15. Apparent weekly and daily earthquake periodicities in the western United States, and evolution of Wadi Kubbania in Egypt

    NASA Astrophysics Data System (ADS)

    Atef, Ali Hadi

    The dissertation consists of two separate sections. The first section is on apparent daily and weekly periodicities in earthquake occurrence in the western United State. Analysis of Apparent Seismicity Rate (ASR) in the western United States confirmed the existence of prominent spectral peaks with a period of 1 and 7 days. The number of recorded earthquakes on Sundays for the duration of 1963-2008 is about 5% higher than that on weekdays, and, more significantly, there is a 9% increase of ASR in the early morning compared with that in the middle of the days. Significant similarities between the spatial distributions of the weekly and daily variations suggest that the two types of variations have the same sources and both originate from periodic variations in cultural noise that lead to periodic variations in the detectability of the seismic networks. The second section of the dissertation reports results from an active-source seismic experiment conducted in southern Egypt. The ancient Nile River (pre-Eonile) is believed to have flowed west-northwest from the Red Sea Hills due to the Nubian uplift in the Eastern Desert. It continued over Wadi Abu Subeira in the Eastern Desert and across the modern Nile to the Western Desert over the valley known today as Wadi Kubbania. This study addresses two hypotheses. The first hypothesis advocates that Wadi Kubbania was a morphologically incised valley of the pre-Eonile River where uplift of the Nubian swell may have forced rapid erosion forming Wadi Kubbania. The second hypothesis argues that Wadi Kubbania is a northwest trending graben formatted as a result of regional tectonic effects of the rifting of the Red Sea and the associated uplift in form of graben structure prior to the flowing of the pre-Eonile River. Analysis of seismic refraction data indicated that the Wadi Kubbania formed as a result of tectonic events.

  16. Greenstone-hosted lode-gold mineralization at Dungash mine, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Zoheir, Basem; Weihed, Pär

    2014-11-01

    The auriferous quartz ± carbonate veins at Dungash mine, central Eastern Desert of Egypt, are confined to ?E-trending dilation zones within variably foliated/sheared metavolcanic/volcaniclastic rocks. The vein morphology and internal structures demonstrate formation concurrent with a dextral shear system. The latter is attributed to flexural displacement of folded, heterogeneous rock blocks through transpression increment, late in the Neoproterozoic deformation history of the area. Geochemistry of the host metavolcanic/metavolcaniclastic rocks from the mine area suggests derivation from a low-K, calc-alkaline magma in a subduction-related, volcanic arc setting. In addition, chemistry of disseminated Cr-spinels further constrain on the back-arc basin setting and low-grade metamorphism, typical of gold-hosting greenstone belts elsewhere. Mineralogy of the mineralized veins includes an early assemblage of arsenopyrite-As-pyrite-gersdorffite ± pyrrhotite, a transitional pyrite-Sb-arsenopyrite ± gersdorffite assemblage, and a late tetrahedrite-chalcopyrite-sphalerite-galena-gold assemblage. Based on arsenopyrite and chlorite geothermometers, formation of gold-sulfide mineralization occurred between ?365 and 280 °C. LA-ICP-MS measurements indicate the presence of refractory Au in arsenian pyrite (up to 53 ppm) and Sb-bearing arsenopyrite (up to 974 ppm). Abundant free-milling gold associated with the late sulfide assemblage may have been mobilized and re-distributed by circulating, lower temperature ore fluids in the waning stages of the hydrothermal system. Based on the isotopic values of vein quartz and carbonate, the calculated average ?18OH2O values of the ore fluids are 5.0 ± 1.4‰ SMOW for quartz, and 3.3 ± 1.4‰ for vein carbonate. The measured carbonate ?13C values correspond to ore fluids with ?13CCO2 = -6.7 ± 0.7‰ PDB. These results suggest a mainly metamorphic source for ore fluids, in good agreement with the vein morphology, textures and hydrothermal alteration. The calculated ?34SH2S values for early, transitional, and late sulfide assemblages define three distinct ranges (?1.5-3.6‰), (?0.4-1.0‰), and (-3.7‰ to -1.9‰), respectively. The systematic evolution towards lighter ?34S values may be attributed to recrystallization, or to ore fluid buffering under variable physicochemical conditions. The shear zone-related setting, mineralogy and isotopic characteristics of gold mineralization in Dungash mine are comparable with other orogenic gold deposits in the region (e.g., Barramiya deposit), which may suggest a regional setting controlling gold metallogeny of the region. This setting should guide future exploration programs in the central Eastern Desert province.

  17. Chemical and isotopic constraints on the origin of Wadi El-Tarfa ground waters, Eastern Desert, Egypt.

    SciTech Connect

    Sultan, M.; Sturchio, N. C.; Abdel Hady, Y.; El Anbeawy, M.; Environmental Research; Cairo Univ.

    2000-10-01

    We evaluated the use of the renewable ground water resources of the Eastern Desert to develop sustainable agriculture in Upper Egypt, an alternative that could alleviate some of Egypt's dependence on water from the Nile River. Ground water from shallow aquifers in the Eastern Desert of Egypt, near the intersection of Wadi El-Tarfa and the Nile River, was analyzed for chemical compositions, stable isotope ratios, and tritium activities. The ground water has a range in total dissolved solids of 300 to 5000 mg/L. Values of {delta}D and {delta}{sup 18}O range from -10 to +34 %o and -2 to +5.2 %o, respectively, and defines a line having a slope of 5.7 that intersects the meteoric water line at about {delta}D = -15% on a plot of 8D versus {delta}{sup 18}O. These findings indicate that the water might have been derived by a combination of evaporation of and salt addition to regional precipitation. Only one sample could have been derived directly by evaporation and transpiration of modern Nile River water. Salinization of the ground water could have occurred through dissolution of marine aerosol dry fallout, carbonate minerals, gypsum, and other trace evaporitic minerals at and near the ground surface. Tritium activities ranged from 0.04 to 12.9 TU (tritium unite), indicating that all but one of the samples were derived at least partly from precipitation that occurred within the last 45 years. These data indicate that Nubian Aquifer paleowater is not a significant component of the shallow aquifers of this portion of the Eastern Desert. The most likely source of this ground water is sporadic flash flood events yielding locally voluminous recharge that accumulates in coarse sediments and fractured rock beneath alluvial channels. The magnitude of this renewable ground water resource and its potential for supporting sustainable agriculture require further investigation.

  18. The Neoproterozoic Abu Dahr ophiolite, South Eastern Desert, Egypt: petrological characteristics and tectonomagmatic evolution

    NASA Astrophysics Data System (ADS)

    Gahlan, Hisham A.; Azer, Mokhles K.; Khalil, Ahmed E. S.

    2015-10-01

    The Neoproterozoic Abu Dahr ophiolite, South Eastern Desert, Egypt, is one of the best preserved and least dismembered ophiolite successions in the Arabian-Nubian Shield. It contains a Penrose-type ophiolite sequence from mantle section below mafic crust upward to oceanic sedimentary cover overlying mafic volcanics, although the original magmatic (stratigraphic) contact between the mantle and crustal sections is disrupted by tectonism. The Abu Dahr ophiolite is metamorphosed under greenschist facies conditions, and low-temperature alteration is widespread. Petrography reveals that: (i) the mantle is homogenous, serpentinized, and dominated by harzburgite and less abundant dunite; (ii) the cumulate ultramafics are represented by wehrlite and pyroxenite; and (iii) the crustal section is represented by metagabbros, meta-anorthosites and metabasalts. The Abu Dahr serpentinized peridotites show high Mg# (0.92-0.93), with enrichment of Ni, Cr and Co, and depletion of Al2O3 and CaO, and nearly flat and unfractionated REE chondrite-normalized pattern. Major and trace element characteristics of the Abu Dahr metagabbro and metabasalt (crustal section) indicate a tholeiitic to calc-alkaline affinity. Units of the crustal section have low-Nb and Zr concentrations, low Dy/Yb and relatively elevated La/Yb ratios, high U/Yb and Th/Yb ratios, and LREE enriched chondrite-normalized pattern. All of the Abu Dahr ophiolite units have trace-element signatures characterized by enrichment of LILE over HFSE. Rare and trace element patterns indicate a genetic link between the Abu Dahr mantle, cumulate ultramafics, and crust. Chromian spinel has survived metamorphism and is used as a petrogenetic indicator in the Abu Dahr serpentinized peridotites. The spinel is homogeneous with a limited composition, and shows high-Cr# (>0.6) combined with low-TiO2 character (mostly <0.1 wt.%). The Abu Dahr ophiolite is interpreted as a fragment of depleted oceanic lithosphere that experienced high degrees of partial melting (up to 35 %) and originated in a fore-arc setting. Such interpretation contributes to the body of evidence suggesting that tectonomagmatic processes of the Neoproterozoic were largely similar to those of the Phanerozoic, implying little, or no significant, change in the geothermal regime of Earth since the Neoproterozoic.

  19. Red Sea Rift-Related Quseir Basalts, Central Eastern Desert, Egypt: Petrogenetic and Geodynamic Evolution

    NASA Astrophysics Data System (ADS)

    Farahat, Esam; Ali, Shehata; Hauzenberger, Christoph

    2015-04-01

    Mineral and whole rock chemistry of Tertiary Red Sea rift-related basalts occurred in south Quseir city, Central Eastern Desert, Egypt has been presented to investigate their petrogenetic and geodynamic evolution. The South Quseir basalts (SQB) have been classified as high-Ti tholeiitic lava (TiO2 >2 wt. %) emplaced in anorogenic tectonic setting. Their Mg# varies from 48 to 53. Pearce element ratios (PER) suggest that the SQB magmas have evolved through fractional crystallization of olivine + clinopyroxene ± plagioclase assemblages, however, the absence of Eu-anomaly argues against plagioclase fractionation. The clinopyroxene compositions provide evidence for polybaric fractionation of the parental mafic magma. Estimated temperatures of crystallization range from 1143 to 1323 oC for olivines, 1031 to 1207 oC for clinopyroxenes, 600 to 900 oC for feldspars, and 638 to 787 oC for Fe-Ti oxides. Oxygen fugacity (ƒO2) values range from -15.16 to -19.5. The incompatible trace element signatures of the SQB (La/Ba = 0.08-0.10 and La/Nb = 0.89-1.04) are similar to those of ocean island basalts (OIB) generated from asthenospheric mantle source unaffected by subduction components. Modelling calculations indicate that the SQB primary magmas were derived from 4-5% partial melting of a garnet-bearing lherzolite mantle source which had a potential temperature (Tp= 1334-1432 °C; based on olivine liquid equilibria) corresponding to ambient temperature of MORB (i.e. passive rifting). This ambient mantle would have to rise to shallower depths (< 100 km) in the upper mantle to cross the dry mantle solidus and stimulate adiabatic partial melting. These estimates along with absence of HIMU (high ? refers to high 238U/204Pb) components (based on trace element data) show that the SQB volcanism isn't associated with thermally driven mantle plumes. Thus, the SQB magma generation is related to extensional regime through passive upwelling and adiabatic decompression melting of an asthenospheric mantle source associated with Red Sea rifting.

  20. Rare metal-bearing and barren granites, Eastern Desert of Egypt: geochemical characterization and metallogenetic aspects

    NASA Astrophysics Data System (ADS)

    Mohamed, F. H.

    1993-11-01

    Three "younger granite" plutons from the Eastern Desert of Egypt are studied: petrographic and geochemical characteristics of the barren pink granites at Wadi Sikait and Wadi Nugrus are similar, of alkaline, mildly peraluminous nature and are enriched in LIL-elements and LREE with moderate negative Eu anomalies. In contrast, the Sn-Ta-W-bearing albite granite of Abu Dabbab is alkaline, peraluminous muscovite granite; its chemical specialization is manifested by the pronounced enrichment in Ta, Sn, W, F, Rb and Li coupled with marked depletion in Ca, Ti, Mg, Sr and Ba. Elemental ratios (e.g., K/Rb, Rb/Sr, Ba/Rb) discriminate the albite granite and the pink granites into "mineralized and barren granites", respectively. The albite granite is derived from Na-rich magma of within-plate characteristics. Fluorine was an important complexing anion during magmatic evolution history. The albite granite is emplaced at shallow depth (<100 MPa) and at the intersection of structural weaknesses. The pink granites might have a crustal and/or LIL-element enriched mantle sources, in which the subduction-related fingerprints are partly obliterated. For both types, reactivation of regional structures played a significant role in magma generation. Acid metasomatism is mainly manifested by the development of thin greisen veins along fracture systems in the albite granite. The chemistry of greisenization using mass balance approach reveals that the process is accompanied by dramatic increase in SiO 2, Fe 2O 3, MnO, F, Sn and Li as well as significant loss in Na 2O, K 2O, Ba, Nb and Zn. The process causes a significant increase in volume (30%). Changes in chemical components are consistent with the observed mineralogical changes. Microprobe results reveal that the wolframite crystals are typically huebnerite with Fe-rich cores and Mn-rich rims. Compositional variations in wolframite crystals are attributed to the physicochemical conditions (pH, T, etc.) and chemistry of the ore-bearing fluids.

  1. Genesis of the Abu Marawat gold deposit, central Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Zoheir, Basem A.; Akawy, Ahmed

    2010-06-01

    Gold mineralisation at the Abu Marawat mine, central Eastern Desert of Egypt, is related to a system of massive and sheared, milky quartz veins cutting a sequence of Neoproterozoic island arc metavolcanic/volcaniclastic rocks and related banded iron formation (BIF). Sulphide-bearing quartz veins and related hydrothermal breccia bodies display a range of textures including sheared, boudinaged and recrystallised quartz, open space filling and microbreccia. These variable textures imply a complex history of crack-seal mechanism characterising the relation between mineral deposition and a major N-S-trending shear zone, during a late brittle-ductile deformation event which affected the area at about 550 Ma. Gold-base metal mineralisation is associated with brecciation and fracturing of the iron ore bands, close to silicified shears and related quartz veins. The auriferous quartz lodes are characterised by the occurrence of visible pyrite-chalcopyrite ± pyrrhotite ± sphalerite ± galena mineralisation. Gold is refractory in pyrite and chalcopyrite, but rare visible gold/electrum and telluride specks were observed in a few samples. Hydrothermal alteration includes pervasive silicification, pyritisation, sericitisation, carbonatisation confined to a delicate set of veins and altered shears, and a more widespread propylitic alteration assemblage (quartz + chlorite + pyrite + calcite ± epidote). Fluid inclusion petrography and microthermometric studies suggest heterogeneous trapping of a low-salinity (1.4-6.7 wt.% eq. NaCl) aqueous solution and a carbonic fluid. Evidence for fluid immiscibility during ore formation includes variable liquid/vapour ratios in inclusions along individual trails and bulk inclusion homogenisation into liquid and occasionally to vapour at comparable temperatures. The trapping conditions of intragranular aqueous-carbonic inclusions approximate 264-378 °C at 700-1300 bar. Similar temperature estimates have been obtained from Al-in-chlorite geothermometry of chlorite associated with sulphides in the mineralised quartz veins. Fracturing enhanced fluid circulation through the wallrock and related BIF, allowing reaction of the S-bearing ore fluid with iron oxides. This caused pyrite formation and concomitant Au precipitation, enhanced by fluid immiscibility as H 2S partitioned preferentially into the carbonic phase. The ore fluids may have originated from granitoid intrusions (likely the post-Hammamat felsites, whereas gold and base metals might have been leached from the Abu Marawat basic metavolcanics.

  2. The paleomagnetism of certain Late Precambrian and Early Paleozoic rocks from the Red Sea Hills, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Davies, J.; Nairn, A. E. M.; Ressetar, R.

    1980-07-01

    A stable remanence was isolated from three groups of rocks collected in the Eastern Desert of Egypt. Two groups of dikes, one collected north of the Qena-Safaga road and the other about 200 km to the south near the Um Rus gold mine, gave paleomagnetic pole positions of 87°N, 304°E and 86°N, 185°E, respectively. Both have K/Ar ages in the range 480-530 m.y. The results are compatible with data reported from other Gondwana cratonic areas for this time period. The third group of rocks were samples of the Dokhan Volcanic Series collected at seven sites along the Qena-Safaga road. The paleomagnetic pole position of the higher-coercivity component, 36°S, 17°E, acquired about 600 m.y. ago is not easily reconciled with established polar wander paths. The younger component, however, with a paleomagnetic pole lying at 54°N, 327°E, suggests a Cambro-Ordovician age.

  3. Impact of consecutive extreme rainstorm events on particle transport: Case study in a Sonoran Desert range, western USA

    E-print Network

    Dorn, Ron

    Desert range, western USA Ronald I. Dorn School of Geographical Sciences & Urban Planning, Arizona State Keywords: Desert geomorphology Erosion rate Overland flow Threshold Quantifying erosion rates in different Sonoran Desert mountain range were placed prior to every precipitation event over a three-year period

  4. Thermal Performance of Exposed Composed Roofs in Very Hot Dry Desert Region in Egypt (Toshky) 

    E-print Network

    Khalil, M. H.; Sheble, S.; Morsey, M. S.; Fakhry, S.

    2010-01-01

    is considered the major part of the building envelop which exposed to high thermal load due to the high solar intensity and high outdoor air temperature through summer season which reach to 6 months. In Egypt the thermal effect of roof is increased as one go...

  5. Extending the western North American Proterozoic and Paleozoic continental crust through the Mojave Desert

    SciTech Connect

    Martin, M.W.; Walker, J.D. )

    1992-08-01

    Data supporting the existence of Proterozoic basement in the central and western Mojave Desert include U-Pb zircon geochronology and Nd, Sr, and Pb isotopic values of quartzofeldspathic gneisses, detrital zircon provenance ages, and the presence of basement clasts in Paleozoic and Mesozoic conglomerates. These data corroborate existing isotopic data from Mesozoic and Tertiary intrusive rocks that suggest involvement of Proterozoic crust in their genesis. Exposures of Proterozoic basement and Late Proterozoic and Paleozoic transitional miogeoclinal-cratonal facies trends in the central and western Mojave Desert consistently imply that cratonal North America continues westward uninterrupted through this region to the San Andreas fault. These data place geographic limits on the position of several pre-Tertiary tectonic elements speculated to exist in the Mojave Desert.

  6. Desert landforms of southwest Egypt: A basis for comparison with Mars

    NASA Technical Reports Server (NTRS)

    El-Baz, F. (editor); Maxwell, T. A. (editor)

    1982-01-01

    Geologic interpretations of The Gilf Kebir-Uweinat of Apollo-Soyuz photographs were verified. The photographs and LANDSAT images showed features reminiscent of those depicted by Mariner and Viking missions to Mars. These features were to better understand their morphologic analogs on Mars. It is indicated that climate change played a significant role in the formation of the eastern Sahara. It is also revealed that correlations between the eolian features in southwestern Egypt and the wind blown patterns on the surface of Mars result in a better understanding of eolian activity on both planets.

  7. Ground-water quality and geochemistry, Carson Desert, western Nevada

    USGS Publications Warehouse

    Lico, Michael S.; Seiler, R.L.

    1994-01-01

    Aquifers in the Carson Desert are the primary source of drinking water, which is highly variable in chemical composition. In the shallow basin-fill aquifers, water chemistyr varies from a dilute calcium bicarbonate-dominated water beneath the irrigated areas to a saline sodium chloride- dominated water beneath unirrigated areas. Water samples from the shallow aquifers commonly have dissolved solids, chloride, magnesium, sulfate, arsenic, and manganese concentrations that exceed State of Nevada drinking-water standards. Water in the intermediante basin-fill aquifers is a dilute sodium bicarbonate type in the Fallon area and a distinctly more saline sodium chloride type in the Soda Lake-Upsal Hogback area. Dissolved solids, chloride, arsenic, fluoride, and manganese concen- trations commonly exceed drinking-water standards. The basalt aquifer contains a dilute sodium bicarbonate chloride water. Arsenic concentrations exceed standards in all sampled wells. The concen- trations of major constituents in ground water beneath the southern Carson Desert are the result of evapotranspiration and natural geochemical reactions with minerals derived mostly from igneous rocks. Water with higher concentrations of iron and manganese is near thermodynamic equilibrium with siderite and rhodochrosite and indicates that these elements may be limited by the solubility of their respective carbonate minerals. Naturally occurring radionuclides (uranium and radon-222) are present in ground water from the Carson Desert in concen- tratons higher than proposed drinking-water standards. High uranium concentrations in the shallow aquifers may be caused by evaporative concentration and the release of uranium during dissolution of iron and manganese oxides or the oxidation of sedimentary organic matter that typically has elevated uranium concentrations. Ground water in the Carson Desert does not appear to have be contaminated by synthetic organic chemicals.

  8. Seismic hazard studies in Egypt

    NASA Astrophysics Data System (ADS)

    Mohamed, Abuo El-Ela A.; El-Hadidy, M.; Deif, A.; Abou Elenean, K.

    2012-12-01

    The study of earthquake activity and seismic hazard assessment of Egypt is very important due to the great and rapid spreading of large investments in national projects, especially the nuclear power plant that will be held in the northern part of Egypt. Although Egypt is characterized by low seismicity, it has experienced occurring of damaging earthquake effect through its history. The seismotectonic sitting of Egypt suggests that large earthquakes are possible particularly along the Gulf of Aqaba-Dead Sea transform, the Subduction zone along the Hellenic and Cyprean Arcs, and the Northern Red Sea triple junction point. In addition some inland significant sources at Aswan, Dahshour, and Cairo-Suez District should be considered. The seismic hazard for Egypt is calculated utilizing a probabilistic approach (for a grid of 0.5° × 0.5°) within a logic-tree framework. Alternative seismogenic models and ground motion scaling relationships are selected to account for the epistemic uncertainty. Seismic hazard values on rock were calculated to create contour maps for four ground motion spectral periods and for different return periods. In addition, the uniform hazard spectra for rock sites for different 25 periods, and the probabilistic hazard curves for Cairo, and Alexandria cities are graphed. The peak ground acceleration (PGA) values were found close to the Gulf of Aqaba and it was about 220 gal for 475 year return period. While the lowest (PGA) values were detected in the western part of the western desert and it is less than 25 gal.

  9. Evidence for Early and Mid-Cryogenian glaciation in the Northern ArabianNubian Shield (Egypt, Sudan, and western Arabia)

    E-print Network

    Stern, Robert J.

    (Egypt, Sudan, and western Arabia) ROBERT J. STERN1*, PETER R. JOHNSON2, KAMAL A. ALI1,3 & SUMIT K. MUKHERJEE1,4 1 Geosciences Department, U Texas at Dallas, Richardson TX 75080-3021, USA 2 Johnson and Vranas-mail: rjstern@utdallas.edu) Abstract: Evidence of Early- to Mid-Cryogenian (c. 780 Ma and c. 740 Ma) glacial

  10. Heat production rate from radioactive elements in igneous and metamorphic rocks in Eastern Desert, Egypt.

    PubMed

    Abbady, Adel G E; El-Arabi, A M; Abbady, A

    2006-01-01

    Radioactive heat-production data of Igneous and Metamorphic outcrops in the Eastern Desert are presented. Samples were analysed using a low level gamma-ray spectrometer (HPGe) in the laboratory. A total of 205 rock samples were investigated, covering all major rock types of the area. The heat-production rate of igneous rocks ranges from 0.11 (basalt) to 9.53 microWm(-3) (granite). In metamorphic rocks it varies from 0.28 (serpentinite ) to 0.91 microWm(-3) (metagabbro). The contribution due to U is about 51%, as that from Th is 31% and 18% from K. The corresponding values in igneous rocks are 76%, 19% and 5%, respectively. The calculated values showed good agreement with global values except in some areas containing granites. PMID:16120480

  11. Diversity of bacteria nesting the plant cover of north Sinai deserts, Egypt

    PubMed Central

    Hanna, Amira L.; Youssef, Hanan H.; Amer, Wafaa M.; Monib, Mohammed; Fayez, Mohammed; Hegazi, Nabil A.

    2012-01-01

    North Sinai deserts were surveyed for the predominant plant cover and for the culturable bacteria nesting their roots and shoots. Among 43 plant species reported, 13 are perennial (e.g. Fagonia spp., Pancratium spp.) and 30 annuals (e.g. Bromus spp., Erodium spp.). Eleven species possessed rhizo-sheath, e.g. Cyperus capitatus, Panicum turgidum and Trisetaria koelerioides. Microbiological analyses demonstrated: the great diversity and richness of associated culturable bacteria, in particular nitrogen-fixing bacteria (diazotrophs); the majority of bacterial residents were of true and/or putative diazotrophic nature; the bacterial populations followed an increasing density gradient towards the root surfaces; sizeable populations were able to reside inside the root (endorhizosphere) and shoot (endophyllosphere) tissues. Three hundred bacterial isolates were secured from studied spheres. The majority of nitrogen-fixing bacilli isolates belonged to Bacillus megaterium,Bacillus pumilus, Bacillus polymexa,Bacillus macerans,Bacillus circulans and Bacillus licheniformis. The family Enterobacteriaceae represented by Enterobacter agglomerans,Enterobacter sackazakii, Enterobacter cloacae, Serratia adorifera,Serratia liquefaciens and Klebsiella oxytoca. The non-Enterobacteriaceae population was rich in Pantoae spp., Agrobacterium rdiobacter, Pseudomonas vesicularis, Pseudomonas putida, Stenotrophomonas maltophilia, Ochrobactrum anthropi, Sphingomonas paucimobilis and Chrysemonas luteola.Gluconacetobacter diazotrophicus were reported inside root and shoot tissues of a number of tested plants. The dense bacterial populations reported speak well to the very possible significant role played by the endophytic bacterial populations in the survival, in respect of nutrition and health, of existing plants. Such groups of diazotrophs are good candidates, as bio-preparates, to support the growth of future field crops grown in deserts of north Sinai and irrigated by the water of El-Salam canal. PMID:25685397

  12. Late Carboniferous macrofauna from Wadi Araba, Eastern Desert, Egypt, and their paleoecological implications

    NASA Astrophysics Data System (ADS)

    El-Shazly, Soheir H.

    2011-12-01

    The Upper Carboniferous rocks at Wadi Araba are highly rich in macrofaunal content. The systematic description of these macrofauna reveals the identification of 34 species, 17 species of which are recorded for the first time from the Carboniferous rocks of Egypt, among them the trilobite Cummingella ( C.) carringtonensis carringtonensis (Etheridge). Moreover, the paleoeclogic study on some crinoid and brachiopod specimens shows predation and commensal relations with some endo and epibionts fauna. The study presents also crinoidal infestation by Oxytoma ( Palmoxytoma) cygnipes (Young and Bird) species, a relation which is recorded for the first time. Evidences of crushing or biting damages on some brachiopod shells that have been attributed to nautiloids or conchostracan arthropods are also reported. The microfacies study of the carbonate rocks in this area reveals the identification of five microfacies types indicating that the rocks were deposited in an environment ranging from restricted inner to outer shelf lagoonal environments with open circulation. The microfacies study indicates also the presence of two types of microorganisms, the filamentous microorganisms and the fossilized microbial carbonate communities, which played an important role in iron oxide precipitation and rock diagenesis.

  13. Construction of a hydrologic model for estimating Wadi runoff and ground water recharge in the Eastern Desert, Egypt.

    SciTech Connect

    Gheith, H.; Sultan, M.; Environmental Research

    2002-06-10

    We constructed a hydrologic model to estimate the groundwater recharge rate for alluvial aquifers of the Eastern Desert from sporadic precipitation over the Red Sea hills. To estimate initial losses over sub-basins, transmission losses through channel routing, and downstream runoff, we developed an integrated model combining spatial rainfall distribution, an appropriate basin unit hydrograph, and appropriate infiltration parameters. Watersheds and stream networks identified from digital terrain elevation data were verified by comparison with co-registered Landsat thematic mapper scenes and geologic maps. Records of a November 1994 storm event acquired from rain gauges along the Nile River and the Red Sea shore were used to generate a spatial precipitation distribution for the study area. A 2 hour design hyetograph was adopted from rain gauge data for the 1994 flood event. The model was tested against records from the November 1994 flood event at the outlets of the Tarfa and Hammamat watersheds. Groundwater recharge rates were estimated for the alluvial aquifers within the major watersheds of the north Eastern Desert. We estimated that during the 1994 flood event, the ground water recharge through transmission losses ranged from 21 to 31% (Tarfa: 15.8 x 10{sup 6} m{sup 3}; Asyuti: 20 x 10{sup 6} m{sup 3}, Qena: 49 x 10{sup 6} m{sup 3}, Hammamat: 59 x10{sup 6} m{sup 3}) of the precipitated volume. The initial losses ranged from 65 to 77%. Only 3-7% of the precipitation reached the watershed outlets. Archival data show that rainfall events of the size of the November 1994 storm or larger occur every 40 months; thus, the annual recharge rates for the Tarfa, Asyuti, Qena, and Hammamat alluvial aquifers are estimated at 4.7 x 10{sup 6} m{sup 3}, 6 x 10{sup 6} m{sup 3}, 14.7 x 10{sup 6} m{sup 3}, and 17.7 x10{sup 6} m{sup 3}, respectively. Implications for the use of these renewable ground waters and similar water resources in other arid areas of Egypt and in neighboring countries are clear.

  14. Integration of geophysical and geological data for delimitation of mineralized zones in Um Naggat area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Gaafar, Ibrahim

    2015-06-01

    An integrated approach for geophysical, geological and mineralogical data was followed for Um Naggat area, Central Eastern Desert, Egypt, in order to delineate its mineralized zones. The albitized granites are well-defined on the Th- and U-channel images, by their anomalous shapes, reaching 150 ppm and 90 ppm respectively, beside low K content. Interpretations of the aeromagnetic maps delineated four regional structural trends oriented due NNW, NW, ENE and E-W directions. They are identified as strike-slip faults, which coincide well with field observations, where NW-trending faults cut and displace right laterally ENE-trending older ones. The interaction between these two strike-slip fault systems confining the albite granite is easily identified on the regional data presenting longer wavelength anomalies, implying deep-seated structures. They could represent potential pathways for migration of enriched mineralized fluids. Geochemically, albite granites of peraluminous characteristics that had suffered extensive post-magmatic metasomatic reworking, resulted into development of (Zr, Hf, Nb, Ta, U, Th, Sn) and albite-enriched and greisenized granite body of about 600 m thick, and more than 3 km in strike length. The albite granite is characterized by sharp increase in average rare metal content: Zr (830 ppm), Hf (51 ppm), Nb (340 ppm), Ta (44 ppm), and U (90 ppm). Thorite, uranothorite, uraninite and zircon are the main uranium-bearing minerals of magmatic origin within the enclosing granite. However, with respect to Zr, Nb, and Ta, the albitized granite can be categorized as rare metal granite. The integration of airborne geophysical (magnetic and ?-ray spectrometric), geological, geochemical and mineralogical data succeeded in assigning the albite granite of Um Naggat pluton as a mineralized zone. This zone is characterized by its high thorium and uranium of hydrothermal origin as indicated by its low Th/U ratio, with rare metals mineralization controlled by two main structural trends in the NW- and ENE-directions.

  15. Full year cycle of desert dust spectral optical thickness and precipitable water vapor over Alexandria, Egypt

    NASA Astrophysics Data System (ADS)

    Sabbah, I.; Ichoku, Charles; Kaufman, Yoram J.; Remer, Lorraine

    2001-08-01

    We study the annual cycle of dust loading in Alexandria, Egypt. Observations were performed from December 1997 to November 1998, including during the Kamaseen storms of March 1998. A ground-based, manual Sun photometer was used to measure aerosol optical thickness (?a) at four spectral bands in the 340-870 nm wavelength range (namely 340, 440, 675, 870). Total precipitable water vapor (W) was also measured simultaneously, based on the 936 nm channel measurements and extrapolations of the aerosol optical thickness from the neighboring 675 and 870 nm channels. Aerosol optical thickness ?a at all the four spectral bands were very high (averaging 2.0-4.0) during the Kamaseen storms of late March 1998. Correspondingly, the Ångström wavelength exponent ? of the optical thickness fell close to zero during that time, implying a substantial increase in dust. Overall, the monthly mean and median aerosol optical thickness were highest during January-May and lowest in June-October. During the January-May period total precipitable water vapor and Ångström exponent were lower than during the June-October period. There is a high correlation between the Ångström exponent and the optical thickness (r = 0.63), with a ranging from 0.0 to 0.5 for ?a > 1.0, indicating high dust concentration. Trajectory analysis shows that the presence of dust was associated with air masses arriving predominantly from the Sahara or North Africa. No significant correlation was found between the optical thickness and the precipitable water vapor. These basic systematic observations are vital for assessing dust climatology in this important part of the world and also for validating satellite observations and dust transport models.

  16. Stratigraphy, facies architecture, and palaeoenvironment of Neoproterozoic volcanics and volcaniclastic deposits in Fatira area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalaf, Ezz El Din Abdel Hakim

    Fatira area in the Central Eastern Desert, Egypt, is a composite terrane consisting of Neoproterozoic volcanics and sediments laid down in submarine to subaerial environment, intruded by voluminous old to young granitic rocks. The various lithofacies of the study area can be grouped in three distinct lithostratigraphic sequences, which are described here in stratigraphic order, from base to top as the Fatira El Beida, Fatira El Zarqa and Gabal Fatira sequences. Each depositional sequence, is intimately related to volcanic activity separated by time intervals of volcanic inactivity, such as marked hiatuses, reworked volcaniclasts, and or turbidite sedimentation. Four submarine facies groups have been recognized within the oldest, folded eruption sequence of Fatira El Beida. The southern part of the study area is occupied by sheet lava (SL), pillow lavas (PL), pillow breccias (PB), and overlying Bouma turbiditic volcaniclastites (VC). The four facies groups of Fatira El Beida sequence occur in a predictable upward-deepening succession, essentially from base to top, an SL-PL-PB-VC stacking pattern. The coeval tholeiitic mafic and felsic volcaniclastic rocks of this sequence indicate an extensional back-arc tectonic setting. The El Beida depositional sequence appears to fit a submarine-fan and slope-apron environment in an intra-arc site. The Fatira El Zarqa sequence involves a large volume of subaerial calc-alkaline intermediate to felsic volcanics and an unconformably overlying siliciclastic succession comprising clast-supported conglomerates (Gm), massive sandstone sheet floods (Sm) and mudstones (FI), together with a lateritic argillite paleosol (P) top formed in an alluvial-fan system. The youngest rock of Gabal Fatira sequence comprises anorogenic trachydacites and rhyolites with locally emergent domes associated with autobrecciation and sill-dyke rock swarms that could be interpreted as feeders and subvolcanic intrusions. Unconformity and lithofacies assemblages define seven events and three unconformity-bounded tectonic stages that record uplift-subsidence cycles in the study area. A proximal-distal relationship has been established within the depositional products, based on the relative dominance of erosional and depositional features.

  17. Morphodynamic implications for shoreline management of the western-Mediterranean sector of Egypt

    NASA Astrophysics Data System (ADS)

    Frihy, Omran E.

    2009-09-01

    Although the western-Mediterranean coast of Egypt between Sallum and Alexandria, ~550 km long, has maintained a considerable equilibrium throughout history, developers have built traditional protective structures in an effort to form sheltered recreational beaches without taking into consideration its geomorphologic characteristics, coastal processes and their harmful impact on the coastal environment and human safety. The improper practices in this environmentally valuable region have induced us to undertake an initiative to carry out a morphodynamic analysis to provide a framework for understanding the relationship between coastal morphology and the prevailing dynamic forces. Based on the degree of natural protection or wave sheltering, the study shoreline can be categorized into four distinct morphotypical stretches: (1) high-energy wave-exposed shores and the outer margins of the rocky headlands, (2) moderate to high wave-energy beaches along semi-exposed embayments and bays mostly downdrift of the rocky headlands, (3) low-wave energy at semi-exposed headland lee-sided and pocket beaches, and (4) calm wave-sheltered enclosing water basins for safe anchorages, moorings and recreation beaches. The results deducted will have practical applications for shoreline management initiatives regarding sustained sites suitable for future beachfront development such as safe swimming conditions, sport facilities, water intakes and sheltered areas for vessels. In addition, benefits realized by the understanding of the morphodynamic processes would enhance our awareness of the significance of the role of western coast morphodynamics in supporting sustainable development via shoreline management. As far as sustainability is concerned, the selection of appropriate sites would help avoiding or minimizing the formation of the hard structures needed for creating safe recreation beaches. On a national scale, results reached could provide reliable database for information that can be used in establishing a sustainable shoreline management plan, which is, in turn, an essential part when implementing an Integrated Coastal Zone Management Plan for this region of attraction.

  18. Northeast Egypt as seen from STS-58

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This oblique view, looking northeast from central Egypt, shows great expanses of the sand covered and rocky Western Desert in the foreground (bottom). The dark patches bottom right are the Dakhla Oases on the south side of an escarpment. The northern half of Egypt's Nile appears here, from about the latitude of Luxor to the delta. Green colors indicate the small area of crops which feed Egypt's population of 55 million. The Nile Delta is partly obscured by a band of clouds, but can be discerned at the coast as a flattened triangle of green. The smaller triangle close by is the Falyum Basin, a depression irrigated by water from the Nile. The coast of the Mediterranean Sea appears left.

  19. Pan-African adakitic rocks of the north Arabian-Nubian Shield: petrological and geochemical constraints on the evolution of the Dokhan volcanics in the north Eastern Desert of Egypt

    NASA Astrophysics Data System (ADS)

    Obeid, Mohamed A.; Azer, Mokhles K.

    2015-04-01

    The Precambrian basement of Egypt is part of the Red Sea Mountains and represents the north-western part of the Arabian-Nubian Shield (ANS). Five volcanic sections are exposed in the Egyptian basement complex, namely El Kharaza, Monqul, Abu Had, Mellaha and Abu Marwa. They are located in the north Eastern Desert (ED) of Egypt and were selected for petrological and geochemical studies as they represent the Dokhan volcanics. The volcanics divide into two main pulses, and each pulse was frequently accompanied by deposition of immature molasse type sediments, which represent a thick sequence of the Hammamat group in the north ED. Compositionally, the rocks form a continuum from basaltic andesite, andesite, dacite (lower succession) to rhyodacite and rhyolite (upper succession), with no apparent compositional gaps. These high-K calc-alkaline rocks have strong affinities to subduction-related rocks with enriched LILEs (Rb, Ba, K, Th, Ce) relative to high field strength elements (Nb, Zr, P, Ti) and negative Nb anomalies relative to NMORB. The lower succession displays geochemical characteristics of adakitic rocks with SiO2 >53 wt%, Al2O3 >15 wt%, MgO >2.5 wt%, Mg# >49, Sr >650 ppm, Y <17 ppm, Yb <2 ppm, Ni >25 ppm, Cr >50 ppm and Sr/Y >42.4. They also have low Nb, Rb and Zr compared to the coexisting calc-alkaline rhyodacites and rhyolites. The highly fractionated rhyolitic rocks have strong negative Eu anomalies and possess the geochemical characteristics of A-type suites. Trace element geochemical signatures indicate a magma source consistent with post-collisional suites that retain destructive plate signatures associated with subduction zones. The adakitic rocks in the northern ANS are generated through partial melting of delaminated mafic lower crust interacting with overlying mantle-derived magma. The Dokhan volcanics were likely generated by a combination of processes, including partial melting, crystal fractionation and assimilation.

  20. Benefits of protective fencing to plant and rodent communities of the western Mojave Desert, California

    NASA Astrophysics Data System (ADS)

    Brooks, Matthew L.

    1995-01-01

    Human disturbance in the western Mojave Desert takes many forms. The most pervasive are livestock grazing and off-highway vehicle use. Over the past few decades several areas within this region have been fenced to preclude human disturbance. These areas provide opportunities to study the impact of human activities in a desert ecosystem. This paper documents the response of plant and small mammal populations to fencing constructed between 1978 and 1979 at the Desert Tortoise Research Natural Area, Kern County, California. Aboveground live annual plant biomass was generally greater inside than outside the fenced plots during April 1990, 1991, and 1992. The alien grass Schismus barbatus was a notable exception, producing more biomass in the unprotected area. Forb biomass was greater than that of alien annual grasses inside the fence during all three years of the study. Outside the fence, forb biomass was significantly higher than that of alien grasses only during spring 1992. Percent cover of perennial shrubs was higher inside the fence than outside, while no significant trend was detected in density. There was als more seed biomass inside the fence; this may have contributed to the greater diversity and density of Merriam's kangaroo rats ( Dipodomys merriami), long-tailed pocket mice ( Chaetodipus formosus), and southern grasshopper mice ( Onychomys torridus) in the protected area. These results show that protection from human disturbance has many benefits, including greater overall community biomass and diversity. The significance and generality of these results can be further tested by studying other exclosures of varying age and configurations in different desert regions of the southwestern United States.

  1. Remote sensing based improvement of the geological map of the Neoproterozoic Ras Gharib segment in the Eastern Desert (NE-Egypt) using texture features

    NASA Astrophysics Data System (ADS)

    Jakob, Sandra; Bühler, Benjamin; Gloaguen, Richard; Breitkreuz, Christoph; Eliwa, Hassan Ali; El Gameel, Khaled

    2015-11-01

    Geological mapping in the Eastern Desert is impeded by difficult accessibility. We improve the existing geological maps by including texture features in a classification scheme of ASTER and Landsat 8 data. We tested the improvement of support vector machine classification using band ratios, principal component analysis (PCA) and texture analysis in the Ras Gharib segment (NE Egypt). A very high classification overall accuracy of 99.85% was achieved. We demonstrate that the input of textures provide valuable additional data for lithological mapping. With the gained information, the existing geological map of the study area was improved distinctly in precision and resolution, but also in terms of correction of yet wrong or inaccurate locations and of lithological unit extents.

  2. Application of LANDSAT satellite imagery for iron ore prospecting in the western desert of Egypt

    NASA Technical Reports Server (NTRS)

    Elshazly, E. M.; Abdel-Hady, M. A.; Elghawaby, M. A.; Khawasik, S. M. (principal investigators)

    1977-01-01

    The author has identified the following significant results. The delineation of the geological units and geological structures through image interpretation, corroborated by field observations and structural analysis, led to the discovery of new iron ore deposits. A new locality for iron ore deposition, namely Gebel Qalamun, was discovered, as well as new occurrences within the already known iron ore region of Bahariya Oasis.

  3. Groundwater development, Kharga Oases, Western Desert of Egypt: A long-term environmental concern

    NASA Astrophysics Data System (ADS)

    Lamoreaux, Philip E.; Memon, Bashir A.; Idris, Hussein

    1985-09-01

    The groundwater reserves in Kharga Oases have been studied for the long-term socioeconomic development in the area. The Nubian Sandstone, which consists of a thick sequence of coarse clastic sediments of sandstone, sandy clay interbedded with shale, and clay beds, forms a complex aquifer system. The Nubian Aquifer has been providing water to artesian wells and springs in the Kharga Oases for several thousand years. Groundwater in the Kharga Oases is withdrawn from springs and shallow and deep artesian wells Nearly all the wells originally flowed, but with the exploitation of ground-water from deep wells for irrigation beginning about 1959. the natural flows declined as more and more closely spaced deep wells were drilled By 1975 many deep wells had ceased to flow The water demand in the area has been met by pumping both shallow and deep wells The total annual extraction from deep wells has fluctuated over the year, however, the annual withdrawal from deep wells has exceeded extraction from shallow wells About 17 billion m3 of water was withdrawn from the combination of shallow and deep wells during the period 1960-1980 The Nubian complex aquifer in the Kharga Oases has a very large groundwater potential that could be exploited and beneficially used for a long-term agricultural development in the area, provided proper well spacing and management are implemented Other major environmental considerations for which precise hydrogeologic data are needed include 1 Determination of the long-term yield available from properly constructed and producing artesian wells that will support a planned migration of population from the overcrowded Nile delta and flood plain areas

  4. Water Management Strategy in Assessing the Water Scarcity in Northern Western Region of Nile Delta, Egypt

    NASA Astrophysics Data System (ADS)

    Mabrouk, Badr; Arafa, Salah; Gemajl, Khaled

    2015-04-01

    Sustainable development in the Nile Delta of Egypt is retarded by serious environmental problems, where land-use and land-cover of the region are subjected to continuous changes; including shoreline changes either by erosion or accretion, subsidence of the delta, as well as by sea level rise due to climate change. The current research attempts to; (1) study the vulnerability of the northern western region of the Nile Delta coastal zone to climate change/sea level rise while setting basic challenges, review adaptation strategies based on adaptation policy framework, and highlight recommended programs for preparedness to climate change, (2) study the scarcity of water resources in the area of study with review of the socioeconomic impacts and the critical need of establishing desalination plants with new standards assessing the environmental situation and population clusters, and (3) monitor of the brine water extracted from the desalination plants and injected to subsurface strata. This monitoring process is divided into 3 main directions: 1) studying the chemical characteristics of water extracted from the water desalinations plants qualitatively and quantitatively. 2) mapping the subsurface of which that brine water will be injected to it and the flow directions and effects using resistivity data, and 3) using GIS and suitable numerical models in order to study the effect, volume, flow of the brine water and its long term environmental impacts on the area. The results indicate that the area is particularly vulnerable to the impact of SLR, salt water intrusion, the deterioration of coastal tourism and the impact of extreme dust storms. This in turn will directly affect the agricultural productivity and human settlements in coastal zones. The paper presents different scenarios for water management and recommends the most suitable scenarios in order to establish a core for water management strategy in the region according to existing socio-economic and environmental situations. Key words: Nile Delta, climate change, socioeconomic, sea level rise, groundwater monitoring, GIS

  5. Habitat invasibility and dominance by alien annual plants in the western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.L.

    1999-01-01

    Patterns of habitat invasibility and alien dominance, respectively measured as species richness and biomass of alien annual plants, were evaluated in association with four habitat factors at the Desert Tortoise Research Natural Area (DTNA) in the western Mojave Desert, USA. Habitat factors varied in levels of disturbance outside (high) and inside (low) the DTNA, and in levels of soil nutrients in washlet (high) and hummock (low) topographic positions, in Larrea-north (high), Larrea-south (medium), and interspace (low) microhabitats near creosote bushes (Larrea tridentata), and during 1995 when rainfall was 207% (high) and 1994 when rainfall was 52% (low) of the long-term average. Dominant alien plants included the annual grasses Bromus rubens, Bromus trinii, and Schismus spp., and the forb Erodium cicutarium. Species richness and dominance of alien annual plants were slightly higher where disturbance was high, and much higher where soil nutrients were high. B. rubens and B. trinii were most dominant in washlets and in the Larrea-north microhabitats during both years. These two species evolved in mesic ecosystems, and appeared to be particularly limited by soil nutrients at this site. Schismus spp. and E. cicutarium were also most dominant in washlets, but their dominance varied between interspaces in 1994 and the Larrea-south microhabitat in 1995. Monitoring to detect the invasion of new annual plants should focus on regions of high rainfall and nitrogen deposition and on washes and beneath-canopy microhabitats. The ecological range of each alien species should be evaluated separately, because their evolutionary origins may greatly affect their patterns of invasion and dominance in the Mojave Desert.

  6. Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alien grass invasions are resulting in ecosystem-level transformations of entire landscapes in arid and semi-arid ecosystems. The cold desert of western US is undergoing such a transformation, and is considered one of the most imperiled large ecosystems in the US. To address the rapid and complex ch...

  7. Bi-Static Deep Electromagnetic Soundings for Martian Subsurface Characterization: Experimental Validation in the Egyptian Western Desert

    NASA Astrophysics Data System (ADS)

    Ciarletti, V.; Le Gall, A.; Berthelier, J. J.; Corbel, Ch.; Dolon, F.; Ney, R.; Reineix, A.; Guiffaud, Ch.; Clifford, S.; Heggy, E.

    2007-03-01

    A bi-static version of the HF GPR TAPIR developed for martian deep soundings has been operated in the Egyptian Western Desert. The study presented focuses on the retrieval of the direction of arrival of the observed echoes on both simulated and measured d

  8. Nest site characteristics and nesting success of the Western Burrowing Owl in the eastern Mojave Desert

    USGS Publications Warehouse

    Longshore, Kathleen M.; Crowe, Dorothy E.

    2013-01-01

    We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species.

  9. Prospecting cold deserts of north western Himalayas for microbial diversity and plant growth promoting attributes.

    PubMed

    Yadav, Ajar Nath; Sachan, Shashwati Ghosh; Verma, Priyanka; Saxena, Anil Kumar

    2015-06-01

    Microbial communities in different samples collected from cold deserts of north western Himalayas, India, were analyzed using 16S rRNA gene sequencing and phospholipid fatty acids (PLFA) analysis. A total of 232 bacterial isolates were characterized employing 16S rDNA-Amplified Ribosomal DNA Restriction Analysis with the three restriction endonucleases Alu I, Msp I and Hae III, which led to formation of 29-54 groups for the different sites, adding up to169 groups. 16S rRNA gene based phylogenetic analysis, revealed that 82 distinct species of 31 different genera, belonged to four phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. PLFA profiling was performed for concerned samples which gave an estimate of microbial communities without cultivating the microorganisms. PLFA analysis led to characterization of diverse group of microbes in different samples such as gram-negative, gram-positive bacteria, actinomycetes, cyanobacteria, anaerobic bacteria, sulphate reducing bacteria and fungi. The representative strains were screened for their plant growth promoting attributes, which included production of ammonia, HCN, gibberellic acid, IAA and siderophore; solubilization of phosphorus and activity of ACC deaminase. In vitro antifungal activity assay was performed against Rhizoctonia solani and Macrophomina phaseolina. Cold adapted microorganisms may serve as inoculants for crops growing under cold climatic conditions. To our knowledge, this is the first report for the presence of Arthrobacter nicotianae, Brevundimonas terrae, Paenibacillus tylopili and Pseudomonas cedrina in cold deserts and exhibit multifunctional PGP attributes at low temperatures. PMID:25575970

  10. Desert varnish and environmental change near Broken Hill, Western New South Wales

    NASA Astrophysics Data System (ADS)

    Dragovich, D.

    1988-12-01

    Desert varnish is widespread in arid Australia, and occurs as a thin often discontinuous manganese-enriched surface coating near Broken Hill, western New South Wales. Radiocarbon dating of calcium carbonate associated with this varnish indicated that major varnishing took place before about 10,000 years B.P., with varnish-forming conditions continuing during the Holocene. Small patches of varnish on secondary carbonate, on non-varnished rock and sometimes on existing varnish suggest that current environmental conditions allow for some varnish formation. Loss of varnish has resulted from within-channel abrasion, weathering by lichens, minor breakdown of varnish substrates, and localized weathering, possibly related to a previously higher soil surface.

  11. Upper Oligocene evaporites in basin fill of Sevier Desert region, western Utah ( USA).

    USGS Publications Warehouse

    Lindsey, D.A.; Glanzman, R.K.; Naeser, C.W.; Nicholas, D.J.

    1981-01-01

    The basin fill beneath the Sevier Desert of western Utah contains evaporites that were deposited in a broad closed basin. All of the basin fill penetrated by the Gulf Oil 1 Gronning contains abundant volcanic detritus and its alteration products of Cenozoic age. Fission-track dating of tuffaceous sandstone yields ages of 26-28 m.y. Fossil pollen from mudstone in the evaporite-bearing strata includes forms no older than late Oligocene, in good agreement with the fission-track ages. Thus the age of evaporites is late Oligocene and younger. Anhydrite is present throughout approximately 900m of volcaniclastic rocks in the lower part of the section cut by the Gulf hole. Fossil pollen are indicative of an arid to semiarid flora.-from Authors

  12. Trace elements assessment in agricultural and desert soils of Aswan area, south Egypt: Geochemical characteristics and environmental impacts

    NASA Astrophysics Data System (ADS)

    Darwish, Mohamed Abdallah Gad; Pöllmann, Hebert

    2015-12-01

    Determination of chemical elements, Al, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, Sc, Sr, Ti, Y, and Zn have been performed in agricultural and desert soils and alfalfa (Medicago sativa) at Aswan area. Consequently, the pollution indices, univariate and multivariate statistical methods have been applied, in order to assess the geochemical characteristics of these elements and their impact on soil environmental quality and plant, and to reach for their potential input sources. The investigation revealed that the mean and range values of all element concentrations in agricultural soil are higher than those in desert soil. Furthermore, the agricultural soil displayed various degrees of enrichment and pollution of Cd, Zn, Mo, Co, P, Ti, Pb. The geochemical pattern of integrated pollution indices gave a clear image of extreme and strong pollution in the agricultural soil stations, their poor quality with high risk to human health and considered as a tocsin for an alert. In contrast, the desert soil is the good environmental quality and safe for plant, animal and human health. Alfalfa is tolerant plant and considered as a biomarker for P and Mo in polluted agricultural soil. Four geochemical associations of analyzing elements in agricultural soil and three ones in desert soil have been generated, and their enhancements were essentially caused by various anthropogenic activities and geogenic sources. The investigation also revealed that the broad extended desert soil is fruitful and promising as cultivable lands for agricultural processes in the futures.

  13. Finite strain analysis of metavolcanics and metapyroclastics in gold-bearing shear zone of the Dungash area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Kassem, Osama M. K.; Abd El Rahim, Said H.

    2014-11-01

    The Dungash gold mine area is situated in an EW-trending quartz vein along a shear zone in metavolcanic and metasedimentary host rocks in the Eastern Desert of Egypt. These rocks are associated with the major geologic structures, which are attributed to various deformational stages of the Neoproterozoic basement rocks. Field geology, finite strain and microstructural analyses were carried out and the relation-ships between the lithological contacts and major/minor structures have been studied. The R f/? and Fry methods were applied on the metavolcano-sedimentary and metapyroclastic samples from 5 quartz veins samples, 7 metavolcanics samples, 3 metasedimentary samples and 4 metapyroclastic samples in Dungash area. Finite-strain data show that a low to moderate range of deformation of the metavolcano-sedimentary samples and axial ratios in the XZ section range from 1.70 to 4.80 for the R f/? method and from 1.65 to 4.50 for the Fry method. We conclude that finite strain in the deformed rocks is of the same order of magnitude for all units of metavolcano-sedimentary rocks. Furthermore, the contact between principal rock units is sheared in the Dungash area under brittle to semi-ductile deformation conditions. In this case, the accumulated finite strain is associated with the deformation during thrusting to assemble nappe structure. It indicates that the sheared contacts have been formed during the accumulation of finite strain.

  14. Zr-Y-Nb-REE mineralization associated with microgranite and basic dykes at EL Sela shear zone, South Eastern Desert, Egypt.

    PubMed

    Shahin, Hassan Abd El-Razek Aly

    2014-01-01

    El Sela shear zone occurs in the younger granite rock of Gabal El Sela area, south Eastern Desert, Egypt near the Sudan Frontier. It comprises lines-arranged intrusions trending ENE-WSW and extend for about 1.5 km in length and reach up to 40 meters in width. These lines-arranged intrusions include multi-phase quartz veins, altered microgranite and altered basic dykes. These dykes hosting or acting as a source for uranium, rare metals (Zr, Y, Nb and Ga) and light rare earths (La, Ce, Sm and Nd) mineralizations. They show highly alteration, uranium enrichment and a strong enrichment in some rare metals and light rare earths contents (Zr?=?644, Y?=?133, Nb?=?136, Ga =184, La?=?50.19, Ce?=?105.47, Sm?=?24.81, Nd?=?78.91 ppm and and ? LREEs?=?259.38.). The chondrite normalised rare earth elements trends indicate strongly fractionated rare earth elements pattern with significant enriched of LREE according to HREE in both altered microgranite and altered basic dykes. Field radiometric measurements of the studied altered microgranite dyke revealed that eU reach up to 359 ppm with an average 78 ppm, while in the altered basic dyke reach up to 1625 ppm with an average 144 ppm. PMID:25332873

  15. An assessment of the external radiological impact in granites and pegmatite in central Eastern Desert in Egypt with elevated natural radioactivity.

    PubMed

    Uosif, M A M; Abdel-Salam, L M

    2011-11-01

    The contents of natural radionuclides ((226)Ra, (232)Th and (40)K) were measured in investigated samples (granite Gabal Ras Barud, Eastern Desert in Egypt) by using gamma spectrometry (NaI (Tl) 3?×3?). The activities of (226)Ra, (232)Th series and (40)K are between (3.8±0.5 and 172.8±1135.1±56.8 8.6), (2.3±0.3 and 103.8±5.2) and (53.1±2.7 and 1135.1±56.8) Bq kg(-1), respectively. With average total annual dose being only 67.2 ?Sv y(-1), this value is about 6.72 % of the 1.0 mSv y(-1) recommended by the International Commission on Radiological Protection (ICRP-60, 1990) as the maximum annual dose to members of the public. Geochemical studies revealed that Gabal Ras Barud is formed from a highly fractionated biotite granite, with SiO(2) >75 % and generally enriched in alkali with K/Na >8 %. PMID:21131664

  16. Neoproterozoic diamictite in the Eastern Desert of Egypt and Northern Saudi Arabia: evidence of ~750 Ma glaciation in the Arabian-Nubian Shield?

    NASA Astrophysics Data System (ADS)

    Ali, Kamal A.; Stern, Robert J.; Manton, William I.; Johnson, Peter R.; Mukherjee, Sumit K.

    2010-06-01

    The Neoproterozoic Atud diamictite in Wadi Kareim and Wadi Mobarak in the Eastern Desert of Egypt and the Nuwaybah formation in NW Saudi Arabia consist of poorly sorted, polymictic breccia, with clasts up to 1 m of granitoid, quartz porphyry, quartzite, basalt, greywacke, marble, arkose, and microconglomerate in fine-grained matrix. Stratigraphic relations indicate that the diamictite was deposited in a marine environment. Integrated field investigation, petrographic study and U-Pb SHRIMP zircon ages demonstrate that the Atud and Nuwaybah are correlative. The distribution of zircon ages indicate that ~750 Ma ages are dominant with a significant component of older materials, characterized by minor Mesoproterozoic and more abundant Paleoproterozoic and Neoarchean ages. Some matrix and metasedimentary clast zircons yield ages that are a few 10s of Ma younger than the age of the youngest clast (754 ± 15 Ma), suggesting Atud/Nuwaybah diamictite deposition ~750 Ma or slightly later, broadly consistent with being deposited during the Sturtian glaciation (740-660 Ma). The Paleoproterozoic and Neoarchean clasts have no source within the ensimatic Arabian-Nubian Shield. The distribution of the pre-Neoproterozoic ages are similar to the distribution of the pre-Neoproterozoic ages in Yemen and Saharan Metacraton, suggesting that these clasts have been transported hundreds of kilometers, maybe by ice-rafting. The Atud diamictite may represent important evidence for Cryogenian “Snowball Earth” in the Arabian-Nubian Shield.

  17. Upper Oligocene evaporites in basin fill of Sevier Desert region, western Utah

    SciTech Connect

    Lindsey, D.A.; Glanzman, R.K.; Naeser, C.W.; Nichols, D.J.

    1981-02-01

    The basin fill beneath the Sevier Desert of western Utah contains evaporites of late Oligocene age that were deposited in a broad closed basin. All of the basin fill penetrated by the Gulf Oil 1 Gronning (2458 m TD), one of only three deep holes in the basin, contains abundant volcanic detritus and its alteration products of Cenozoic age, when volcanism was intense in western Utah. Fission-track dating of tuffaceous sandstone, interbedded with evaporite minerals and representative of sandstone in the lower formations penetrated, yields ages of 26 to 28 m.y.; concordance of ages indicates no thermal resetting. Fossil pollen from mudstone in the evaporite-bearing strata includes forms no older than late Oligocene, in good agreement with the fission-track ages. Thus the age of the evaporites, and of all the basin fill penetrated by drilling, is late Oligocene and younger; previous work had assigned them ages ranging from Triassic to Eocene. Evaporite-bearing rocks were deposited during late Oligocene time in a broad closed basin under arid or semiarid conditions much like those of the Great Basin today. Anhydrite is present throughout approximately 900 m of volcaniclastic rocks in the lower part of the section cut by the Gulf hole, and more than 1500 m of anhydrite and halite is present in possibly equivalent strata in the nearby Argonaut dry hole. Fossil pollen from anhydrite-bearing rocks in the Gulf hole are indicative of an arid to semiarid flora, including plants similar to Mormon tea and possibly saltbush or buffalo berry. Evaporite minerals formed in the basin during dry periods; tuff was erupted from nearby volcanic centers, reworked by water, and deposited in the basin.

  18. Geothermal resources of the western arm of the Black Rock Desert, northwestern Nevada. Part I. Geology and geophysics

    SciTech Connect

    Schaefer, D.H.; Welch, A.H.; Maurer, D.K.

    1983-01-01

    Studies of the geothermal potential of the western arm of the Black Rock Desert in northwestern Nevada included a compilation of existing geologic data on a detailed map, a temperature survey at 1-meter depth, a thermal-scanner survey, and gravity and seismic surveys to determine basin geometry. The temperature survey showed the effects of heating at shallow depths due to rising geothermal fluids near the known hot spring areas. Lower temperatures were noted in areas of probable near-surface ground-water movement. The thermal-scanner survey verified the known geothermal areas and showed relatively high-temperature areas of standing water and ground-water discharge. The upland areas of the desert were found to be distinctly warmer than the playa area, probably due to the low thermal diffusivity of upland areas caused by low moisture content. Surface geophysical surveys indicated that the maximum thickness of valley-fill deposits in the desert is about 3200 meters. Gravity data further showed that changes in the trend of the desert axis occurred near thermal areas. 53 refs., 8 figs., 3 tabs.

  19. Effects of protective fencing on birds, lizards, and black-tailed hares in the Western Mojave Desert

    USGS Publications Warehouse

    Brooks, M.

    1999-01-01

    Effects of protective fencing on birds, lizards, black-tailed hares (Lepus californicus), perennial plant cover, and structural diversity of perennial plants were evaluated from spring 1994 through winter 1995 at the Desert Tortoise Research Natural Area (DTNA), in the Mojave Desert, California. Abundance and species richness of birds were higher inside than outside the DTNA, and effects were larger during breeding than wintering seasons and during a high than a low rainfall year. Ash-throated flycatchers (Myiarchus cinerascens), cactus wrens (Campylorhynchus brunneicapillus), LeConte's thrashers (Toxostoma lecontei), loggerhead shrikes (Lanius ludovicianus), sage sparrows (Amphispiza belli), and verdins (Auriparus flaviceps) were more abundant inside than outside the DTNA. Nesting activity was also more frequent inside. Total abundance and species richness of lizards and individual abundances of western whiptail lizards (Cnemidophorous tigris) and desert spiny lizards (Sceloporus magister) were higher inside than outside. In contrast, abundance of black-tailed hares was lower inside. Structural diversity of the perennial plant community did not differ due to protection, but cover was 50% higher in protected areas. Black-tailed hares generally prefer areas of low perennial plant cover, which may explain why they were more abundant outside than inside the DTNA. Habitat structure may not affect bird and lizard communities as much as availability of food at this desert site, and the greater abundance and species richness of vertebrates inside than outside the DTNA may correlate with abundances of seeds and invertebrate prey.

  20. Mesozoic evolution of northeast African shelf margin, Libya and Egypt

    SciTech Connect

    Aadland, R.K.; Schamel, S.

    1989-03-01

    The present tectonic features of the northeast African shelf margin between the Nile delta and the Gulf of Sirte are products of (1) precursory late Paleozoic basement arches, (2) early Mesozoic rifting and plate separation, and (3) Late Cretaceous structural inversion. The 250 km-wide and highly differentiated Mesozoic passive margin in the Western Desert region of Egypt is developed above a broad northwest-trending Late Carboniferous basement arch. In northeastern Libya, in contrast, the passive margin is restricted to just the northernmost Cyrenaica platform, where subsidence was extremely rapid in the Jurassic and Early Cretaceous. The boundary between the Western Desert basin and the Cyrenaica platform is controlled by the western flank of the basement arch. In the middle Cretaceous (100-90 Ma), subsidence accelerated over large areas of the Western desert, further enhancing a pattern of east-west-trending subbasins. This phase of rapid subsidence was abruptly ended about 80 Ma by the onset of structural inversion that uplifted the northern Cyrenaica shelf margin and further differentiated the Western Desert subbasin along a northeasterly trend.

  1. Bistatic GPR Measurements in the Egyptian Western Desert - Measured and Simulated data

    NASA Astrophysics Data System (ADS)

    Ciarletti, V.; Le Gall, A.; Berthelier, J.; Ney, R.; Corbel, C.; Dolon, F.

    2006-12-01

    The TAPIR (Terrestrial And Planetary Investigation Radar) instrument has been designed at CETP (Centre d'etude des Environnements Terrestre et Planetaires) to explore the deep Martian subsurface (down to a few kilometers) and to detect liquid water reservoirs. TAPIR is an impulse ground penetrating radar operating at central frequencies ranging from 2 to 4 MHz operating from the surface. In November 2005, an updated version of the instrument working either in monostatic or in bi-static mode was tested in the Egyptian Western Desert. The work presented here focuses on the bi-static measurements performed on the Abou Saied plateau which shows a horizontally layered sub-surface. The electromagnetic signal was transmitted using one of the two orthogonal 70 m loaded electrical dipole antennas of the transmitting GPR. A second GPR, 50 or 100 meters apart, was dedicated to the signal reception. The received waves were characterized by a set of 5 measurements performed on the receiving GPR : the two horizontal components of the electric field and the three composants of the magnetic field. They were used to compute the direction of arrival of the incoming waves and to retrieve more accurately their propagation path and especially to discriminate between waves due to some sub-surface reflecting structure and those due to interaction with the surface clutter. A very efficient synchronization between the two radars enabled us to perform coherent additions up to 2^{31} which improves dramatically the obtained signal to noise ratio. Complementary electromagnetic measurements were conducted on the same site by the LPI (Lunar and Planetary Institute) and the SwRI (Southwest Research Institute). They provided independent information which helped the interpretation of the TAPIR data. Accurate simulations obtained by FDTD taking into account the information available are presented and used for both the interpretation of the measured data and the validation of the instrument.

  2. Multi-stage emerald formation during Pan-African regional metamorphism: The Zabara, Sikait, Umm Kabo deposits, South Eastern desert of Egypt

    NASA Astrophysics Data System (ADS)

    Grundmann, G.; Morteani, G.

    2008-02-01

    The genesis of gem-quality deep green emeralds of Zabara, Sikait and Umm Kabo (South Eastern Desert, Egypt) is to date a controversial topic. The emerald-bearing biotite schists and quartz lenses are interpreted alternatively as a product of (i) thrust-fault-shear zone - controlled large scale alkali-metasomatism driven by post-magmatic fluid flow or of (ii) a large scale interaction between syntectonic pegmatitic magma or hydrothermal fluids with pre-existing basic to ultrabasic rocks, or of (iii) a syn- to post-tectonic regional metamorphism and small scale blackwall metasomatism. Detailed microstructural and chemical analyses of the Egyptian emeralds and their host rocks show that three generations of beryl can be distinguished: a colourless pegmatitic beryl; a pale green Cr-poor beryl crystallized from pegmatite-related hydrothermal fluids; and a deep green Cr- and Mg-rich emerald. The crystallization of the Cr- and Mg-rich emerald was controlled by the very local availability of Cr, Mg and Be-rich metamorphic fluids during the Pan-African tectono-thermal event. Emerald-rich quartz lenses demonstrate that those fluids locally did mobilize quartz, too. The pale green emeralds found within the pegmatites in association with colourless beryl are the product of a mobilization of colourless pegmatitic beryl and/or phenakite by late pegmatitic fluids slightly enriched in Cr by an interaction with the Cr-rich country rocks. The late pegmatitic fluids are typically Na-rich as is demonstrated by the pervasive albitization of the pegmatites. The complex interplay of magmatic and regional metamorphic events during the genesis of the Egyptian emeralds/beryls makes it impossible through stable oxygen isotope data to relate their genesis to the one or the other event.

  3. Schematic relief of the near-surface and deep-seated magnetic basement, using local-power spectra, Gabal El-Erediya area, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Ammar, Ahmed A.; Rabie, Said I.

    1992-01-01

    The use of Fourier's transformation and the representation of magnetic anomalies in the form of frequencies (power-spectra) have enabled a thorough analysis of the magnetic anomalies and the estimation of depths at which their source exit. The method applied computes the spectrum of anomalies in the potential (magnetic) field from the data of a profile and of a two-dimensional map. The average interpreted depths from the power spectrum are assigned to the centre of the profile and to the center of the map. As an example, the interpretation of the total aeromagnetic survey of Gabal (G.) El Erediya area, Eastern Desert, Egypt was tried. The two average depths estimated for the near-surface and deep-seated interfaces using the profiles in both the N-S and E-W directions are 0.55 and 1.60 km, while those estimated using the two-dimensional map are 0.59 and 1.31 km respectively. It was found that the area under study consists of a series of simple and complex alternating NW-SE and ENE-WSW trending horsts (or uplifted blocks) and grabens (or downfaulted blocks). The previous trend parallels the Red Sea and some segments of the River Nile, while the latter trend parallels the shear zone of Safaga-Qena. The shorter wavelength (ENE) seems to suffer rejuvenation, i.e., more than one tectonic event and is consequently more ancient. Meanwhile, the longer wavelength (NW) appears to undergo only one tectonic event and is accordingly more recent.

  4. Early Cretaceous counterclockwise rotation of Northeast Africa within the equatorial zone: Paleomagnetic study on Mansouri ring complex, Southeastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Lotfy, Hamza I.

    2015-06-01

    The Mansouri ring complex (132 Ma) is, paleomagnetically, studied to shed light on the paleo-tectonic position of Northeast Africa during the Early Cretaceous. Progressive thermal demagnetization of all samples verified a general bi-vectorial decay of the natural remanence. After the removal of the present-day field overprint, the decaying anchored component was either: A dual-polarity, shallow NW-SE directed component residing in magnetite (400-585 °C) of shiny fresh samples, or, A normal-polarity, medium-inclination, north-oriented component stored in haematite of few reddish ferruginous sites. This component was considered as chemical remagnetization carried by secondary haematite. Due to its steady stability, overwhelming existence in most sites, positive reversal test and its residence in fresh-samples' magnetite, the first dual-polarity, shallow NW-SE component, was considered as the characteristic remanent magnetization [ChRM] representing the paleomagnetic field during cooling of the Mansouri ring complex. The mean paleomagnetic pole of the isolated ChRM was at 47°N/259°E, Dp/Dm = 3.4°/6.6°. This Hauterivian pole from Egypt shows reasonable consistency with its coeval poles rotated from the main tectonic units to Northeast Africa. It reveals that in Early Cretaceous: Northeast Africa was equatorial, lying just south the Equator. Cairo, which is now at 30°N, was at -1.5° paleo-latitude. The Azimuth of the African Plate was NE-SW, about 30° clockwise with respect to the present-day N-S trend. Comparing this Hauterivian pole to that of the Wadi Natash basalts [107 ± 4 Ma], which was at [55°N/250°E] during the Albian, the African Plate seems to have rotated counter-clockwise about 10° with Northeast Africa moving northwards [Cairo was moving from 1.5°S to 1.5°N] within the equatorial zone, during the Early Cretaceous.

  5. Holocene freshwater carbonate structures in the hyper-arid Gebel Uweinat region of the Sahara Desert (Southwestern Egypt)

    NASA Astrophysics Data System (ADS)

    Marinova, Margarita M.; Meckler, A. Nele; McKay, Christopher P.

    2014-01-01

    The eastern part of the Sahara is at present the driest region of the desert. Yet the extensive animal rock art in the area, presumed to depict real activities in the lives of the painters, suggests that environmental conditions were significantly different when the rock art was produced. Here we report on exploration of the area, which led to the discovery of morphologically-distinct carbonate structures that line the walls of two valleys in Gebel Uweinat, and were likely formed in standing water. The carbonate structures comprise what appear to be shoreline carbonate formations, and date back to 8100 and 9400 years BP. The chemical and morphological similarity of these formations to carbonate structures from modern lakes suggests that these lakes contained fresh, standing water suitable for human and animal use. However, the significant quartz content suggests that windblown sand was pervasive, and thus the vegetation cover may have been sparse. This discovery supports the possibility of grasslands in the area, which may have been able to support human habitation, and adds to the evidence for a wetter climate in the area in the early Holocene.

  6. Correlation between the radiometric analysis and the surface geology of Abu Zawal area, Central Eastern desert, Egypt

    NASA Astrophysics Data System (ADS)

    Bakhit, F. S.; Meleik, M. L.; El Taher, M. A.

    Abu Zawal area is located north of the Qena-Safaga road. It consists of igneous and metamorphic rocks of late Precambrian age. It has been subjected to geological, radiometric and structural investigations to reveal the structural setting of the area and its relation to the trends of mineralization, as well as the distribution of the radioactivity in the different rock units. Each rock units has been characterized statistically by a certain radiometric background through the radiometric survey traverses. Application of certain statistical inference tests found the relation between the different rock types of Abu Zawal area and their equivalents in other studied areas. It is found that least radioactivity is associated with basic metavolcanic rocks, while the highest values are associated with the late orogenic plutonites and related rocks, while granodiorites have moderate levels of radioactivity. The study suggests that the late orogenic plutonites of Abu Zawal area may be younger than plutons of similar composition in the north of the Eastern Desert.

  7. Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California

    USGS Publications Warehouse

    Ball, J.W.; Izbicki, J.A.

    2004-01-01

    About 200 samples from selected public supply, domestic, and observation wells completed in alluvial aquifers underlying the western Mojave Desert were analyzed for total dissolved Cr and Cr(VI). Because Cr(VI) is difficult to preserve, samples were analyzed by 3 methods. Chromium(VI) was determined in the field using both a direct colorimetric method and EPA method 218.6, and samples were speciated in the field for later analysis in the laboratory using a cation-exchange method developed for the study described in this paper. Comparison of the direct colorimetric method and EPA method 218.6 with the new cation-exchange method yielded r2 values of 0.9991 and 0.9992, respectively. Total dissolved Cr concentrations ranged from less than the 0.1 ??g/l detection limit to 60 ??g/l, and almost all the Cr present was Cr(VI). Near recharge areas along the mountain front pH values were near neutral, dissolved O2 concentrations were near saturation, and Cr(VI) concentrations were less than the 0.1 ??g/l detection limit. Chromium(VI) concentrations and pH values increased downgradient as long as dissolved O 2 was present. However, low Cr(VI) concentrations were associated with low dissolved O2 concentrations near ground-water discharge areas along dry lakes. Chromium(VI) concentrations as high as 60 ??g/l occurred in ground water from the Sheep Creek fan alluvial deposits weathered from mafic rock derived from the San Gabriel Mountains, and Cr(VI) concentrations as high as about 36 ??g/l were present in ground water from alluvial deposits weathered from less mafic granitic, metamorphic, and volcanic rocks. Chromium(III) was the predominant form of Cr only in areas where dissolved O2 concentrations were less than 1 mg/l and was detected at a median concentration of 0.1 ??g/l, owing to its low solubility in water of near-neutral pH. Depending on local hydrogeologic conditions and the distribution of dissolved O2, Cr(VI) concentrations may vary considerably with depth. Samples collected under pumping conditions from different depths within wells show that Cr(VI) concentrations can range from less than the 0.1 ??g/l detection limit to 36 ??g/l in a single well and that dissolved O2 concentrations likely control the concentration and redox speciation of Cr in ground water.

  8. Chromium, chromium isotopes and selected trace elements, western Mojave Desert, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Ball, J.W.; Bullen, T.D.; Sutley, S.J.

    2008-01-01

    Chromium(VI) concentrations in excess of the California Maximum Contaminant Level (MCL) of 50 ??g/L occur naturally in alkaline, oxic ground-water in alluvial aquifers in the western Mojave Desert, southern California. The highest concentrations were measured in aquifers eroded from mafic rock, but Cr(VI) as high as 27 ??g/L was measured in aquifers eroded from granitic rock. Chromium(VI) concentrations did not exceed 5 ??g/L at pH < 7.5 regardless of geology. ??53Cr values in native ground-water ranged from 0.7 to 5.1??? and values were fractionated relative to the average ??53Cr composition of 0??? in the earth's crust. Positive ??53Cr values of 1.2 and 2.3??? were measured in ground-water recharge areas having low Cr concentrations, consistent with the addition of Cr(VI) that was fractionated on mineral surfaces prior to entering solution. ??53Cr values, although variable, did not consistently increase or decrease with increasing Cr concentrations as ground-water flowed down gradient through more oxic portions of the aquifer. However, increasing ??53Cr values were observed as dissolved O2 concentrations decreased, and Cr(VI) was reduced to Cr(III), and subsequently removed from solution. As a result, the highest ??53Cr values were measured in water from deep wells, and wells in discharge areas near dry lakes at the downgradient end of long flow paths through alluvial aquifers. ??53Cr values at an industrial site overlying mafic alluvium having high natural background Cr(VI) concentrations ranged from -0.1 to 3.2???. Near zero ??53Cr values at the site were the result of anthropogenic Cr. However, mixing with native ground-water and fractionation of Cr within the plume increased ??53Cr values at the site. Although ??53Cr was not necessarily diagnostic of anthropogenic Cr, it was possible to identify the extent of anthropogenic Cr at the site on the basis of the ??53Cr values in conjunction with major-ion data, and the ??18O and ??D composition of water from wells.

  9. The hydrochemical evolution of brackish groundwater in central and northern Sinai (Egypt) and in the western Negev (Israel)

    NASA Astrophysics Data System (ADS)

    Rosenthal, E.; Zilberbrand, M.; Livshitz, Y.

    2007-04-01

    SummaryCretaceous trans-boundary aquifers in the central and northern parts of Sinai (Egypt) and the Negev (Israel), are geographically and geologically both contiguous and continuous. Hydrogeological and hydrochemical studies of these aquifers, with disregard to political boundaries, are scarce. The Lower Cretaceous Kurnub Group aquifer in Sinai and the Negev hosts paleowater mostly replenished during the Pleistocene. The objectives of this study are to elucidate the relationship between regional structural elements and the salinization of groundwater in the Kurnub Group in Sinai and further downstream in the Negev. The stable plateaus in southern Sinai and the fold structures in the north continuing into the Negev are separated by the W-E striking Minshara-Ramon shear zone. With the exception of higher salinities in the north, the chemical composition of Kurnub Group groundwater north and south of the shear zone is similar. Similarly, groundwater in the overlying Upper Cretaceous aquifer differs from Kurnub groundwater only within and north of the shear zone and is characterized by higher Cl concentrations, lower Mg/rCa ratios (due to high Ca in the calcareous aquifer) and by a "heavier" isotopic signature. Inverse hydrogeochemical modeling using PHREEQC indicates that the increase in salinity of Kurnub groundwater within the shear zone and in adjacent areas could be due to two different sources: First, the salinization process could be the result of mixing with sulfate-rich brackish groundwater occurring in Jurassic formations, which are in fault-controlled lateral contact with the Kurnub Group aquifer. Second, the salinity differences could be from unflushed seawater in the subsurface of the northern Sinai and western Negev, i.e. possible remnants of the post-Messinian (Lower Pliocene) transgression, which penetrated into northern Sinai, the western Negev and the Coastal Plain of Israel both through erosional channels, which were incised during the Neogene, and by flooding over outcrops of permeable formations.

  10. Mid-Eocene alluvial-lacustrine succession at Gebel El-Goza El-Hamra (Shabrawet area, NE Eastern Desert, Egypt): Facies analysis, sequence stratigraphy and paleoclimatic implications

    NASA Astrophysics Data System (ADS)

    Wanas, H. A.; Sallam, E.; Zobaa, M. K.; Li, X.

    2015-11-01

    This study aims to provide the depositional facies, sequence stratigraphic and paleoclimatic characteristics of the Mid-Eocene (Bartonian) continental succession exposed at Gebel El-Goza El-Hamra (Shabrawet Area, NE Eastern Desert, Egypt). The studied succession consists of siliciclastic rocks followed upward by carbonate rocks. Detailed field observation and petrographic investigation indicate accumulation in floodplain-dominated alluvial and shallow lacustrine systems. The floodplain-dominated alluvial facies (45 m thick) is composed mainly of carbonate nodules-bearing, mottled mudrock with subordinate sandstone and conglomerate beds. The conglomerate and pebbly sandstone bodies interpreted as ephemeral braided channel deposits. The massive, laminated, planner cross-bedded, fine- to medium-grained sandstone bodies interlayered within mudstone reflect sheet flood deposits. The mudrocks associated with paleosols represent distal floodplain deposits. The shallow lacustrine facies (15 m thick) is made up of an alternation of marlstone, micritic limestone, dolostone and mudrock beds with charophytes and small gastropods. Both the alluvial and lacustrine facies show evidence of macro-and micro-pedogenic features. Pollen assemblages, stable ?18O and ?13C isotopes, and paleopedogenic features reflect prevalence of arid to semi-arid climatic conditions during the Bartonian. The sequence stratigraphic framework shows an overall fining-upward depositional sequence, consisting of Low- and High-accommodation Systems Tracts (LAST, HAST), and is bounded by two sequence boundaries (SB-1, SB-2). Conglomerate and pebbly sandstone deposits (braided channel and sheet flood deposits) of the lower part of the alluvial facies reflect a LAST. Mudrock and silty claystone facies (distal floodplain deposits) of the upper part of alluvial facies and its overlying lacustrine facies correspond to a HAST. The LAST, HAST and SB were formed during different accommodation-to-sediment supply (A/S) ratio phases. The variation in A/S ratios was mainly controlled by sea-level change as well as by local tectonic subsidence and uplift of the basin coincident with the reactivation of the Syrian Arc System during the Bartonian.

  11. Petrogenesis of carbonated meta-ultramafic lenses from the Neoproterozoic Heiani ophiolite, South Eastern Desert, Egypt: A natural analogue to CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Gahlan, Hisham A.; Arai, Shoji; Almadani, Sattam A.

    2015-02-01

    Among a set of peculiar meta-ultramafics, carbonate-orthopyroxenites are observed for the first time in the Heiani ophiolite belt, South Eastern Desert, Egypt. They form massive lensoidal masses up to 50 m long and 20 m wide. The lenses show a marked structural concordance with their neighboring country rocks. The typical country rocks are represented by the following high-grade metamorphic rocks: kyanite-muscovite schists, amphibolites, kyanite-bearing biotite gneisses, migmatites, granite gneisses and mobilizates. The studied carbonate-orthopyroxenites consist mainly of metamorphic orthopyroxene + magnesite, among other metamorphic, relict primary and retrograde secondary minerals. According to primary chromian spinel (Cr#, 0.7-0.84) chemistry and morphology, absence of clinopyroxene and presence of primary mantle olivine (Fo89-91) as relicts in the metamorphic orthopyroxene, the Heiani carbonate-orthopyroxenites seem to have formed from a highly depleted mantle peridotite precursor. At a late collisional stage during the Pan-Africa terrane accretion and the E-W crustal shortening (ca. 650-620 Ma), high-grade (upper amphibolite facies) low-P/high-T regional metamorphism (ca. 660 Ma) accompanied by CO2-metasomatism resulted in formation of the Heiani carbonate-orthopyroxenites. Mostly the carbonate-bearing shelf sediments beneath and/or in juxtaposition with the Heiani ophiolite are considered to be the proven source of the CO2-rich fluids. Although, a mixed sedimentary-mantle C source is not unlikely. A mineral paragenetic correlation with experimental data for the system MgO-SiO2-H2O-CO2 suggests metamorphic conditions consistent with those of the high-grade country rocks; i.e. 630-650 °C, 6-7 kbar (20-23 km depth) and high-XCO2 (0.6-0.7). The CO2-bearing fluids discharging along faults gave rise to regionally widespread carbonate-bearing assemblages. Accordingly, the Heiani carbonate-orthopyroxenites are considered the by-products of natural carbon sequestration by an ultramafic rock.

  12. Bacterial diversity of Drass, cold desert in Western Himalaya, and its comparison with Antarctic and Arctic.

    PubMed

    Gupta, Puja; Sangwan, Naseer; Lal, Rup; Vakhlu, Jyoti

    2015-08-01

    Drass is the coldest inhabited place in India and the second coldest, inhabited place in the world, after Siberia. Using the 16SrDNA amplicon pyrosequencing, bacterial diversity patterns were cataloged across the Drass cold desert. In order to identify the ecotype abundance across cold desert environment, bacterial diversity patterns of Drass were further compared with the bacterial diversity of two other cold deserts, i.e., Antarctic and Arctic. Acidobacteria, Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria and Gemmatimonadetes were among the highly abundant taxonomic groups present across all the three cold deserts and were designated as the core phyla. However, Firmicutes, Nitrospirae, Armatimonadetes (former candidate division OP10), Planctomycetes, TM7, Chloroflexi, Deinococcus-Thermus, Tenericutes and candidate phyla WS3 were identified as rare phyla in Drass, Antarctic and Arctic samples. Differential abundance patterns were also computed across all the three samples, i.e., Acidobacteria (32.1 %) were dominant in Drass and Firmicutes (52.9 ± 17.6 %) and Proteobacteria (42 ± 1.3 %) were dominant in Antarctic and Arctic reference samples, respectively. Alpha diversity values Shannon's (H) and Simpson's (1-D) diversity indices were highest for Antarctic samples, whereas richness estimators (ACE and Chao1) were maximum for Drass soil suggesting greater species richness in bacterial communities in Drass than the Antarctic and Arctic samples. PMID:26055487

  13. Morphologic-anthropological investigations in tomb K93.12 at Dra' Abu el-Naga (Western Thebes, Egypt).

    PubMed

    Lösch, Sandra; Moghaddam, Negahnaz; Paladin, Alice; Rummel, Ute; Hower-Tilmann, Estelle; Zink, Albert

    2014-01-01

    In this study we present the analysis of the human remains from tomb K93.12 in the Ancient Egyptian necropolis of Dra' Abu el-Naga, located opposite the modern city of Luxor in Upper Egypt on the western bank of the Nile. Archaeological findings indicate that the rock tomb was originally built in the early 18th dynasty. Remains of two tomb-temples of the 20th dynasty and the looted burial of the High Priest of Amun Amenhotep have been identified. After the New Kingdom the tomb was reused as a burial place until the 26th dynasty. The skeletal and mummified material of the different tomb areas underwent a detailed anthropological and paleopathological analysis. The human remains were mostly damaged and scattered due to extensive grave robberies. In total, 79 individuals could be partly reconstructed and investigated. The age and sex distribution revealed a male predominance and a high percentage of young children (< 6 years) and adults in the range of 20 to 40 years. The paleopathological analysis showed a high prevalence of stress markers such as cribra orbitalia in the younger individuals, and other pathological conditions such as dental diseases, degenerative diseases and a possible case of ankylosing spondylitis. Additionally, 13 mummies of an intrusive waste pit could be attributed to three different groups belonging to earlier time periods based on their style of mummification and materials used. The study revealed important information on the age and sex distribution and diseases of the individuals buried in tomb K93.12. PMID:24818442

  14. Implications of high altitude desert dust transport from Western Sahara to Nile Delta during biomass burning season.

    PubMed

    Prasad, Anup K; El-Askary, Hesham; Kafatos, Menas

    2010-11-01

    The air over major cities and rural regions of the Nile Delta is highly polluted during autumn which is the biomass burning season, locally known as black cloud. Previous studies have attributed the increased pollution levels during the black cloud season to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. Here we show, for the first time, the evidence of long range transport of dust at high altitude (2.5-6 km) from Western Sahara and its deposition over the Nile Delta region unlike current Models. The desert dust is found to be a major contributor to the local air quality which was previously considered to be due to pollution from biomass burning enhanced by the dominant northerly winds coming from Europe. PMID:20797813

  15. Structural controls, temperature-pressure conditions and fluid evolution of orogenic gold mineralisation at the Betam mine, south Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Zoheir, Basem A.

    2008-01-01

    The Betam gold deposit, located in the southern Eastern Desert of Egypt, is related to a series of milky quartz veins along a NNW-trending shear zone, cutting through pelitic metasedimentary rocks and small masses of pink granite. This shear zone, along with a system of discrete shear and fault zones, was developed late in the deformation history of the area. Although slightly sheared and boudinaged within the shear zone, the auriferous quartz veins are characterised by irregular walls with a steeply plunging ridge-in-groove lineation. Shear geometry of rootless intra-folial folds and asymmetrical strain shadows around the quartz lenses suggests that vein emplacement took place under a brittle-ductile shear regime, clearly post-dating the amphibolite-facies regional metamorphism. Hydrothermal alteration is pervasive in the wallrock metapelites and granite including sericitisation, silicification, sulphidisation and minor carbonatisation. Ore mineralogy includes pyrite, arsenopyrite and subordinate galena, chalcopyrite, pyrrhotite and gold. Gold occurs in the quartz veins and adjacent wallrocks as inclusions in pyrite and arsenopyrite, blebs and globules associated with galena, fracture fillings in deformed arsenopyrite or as thin, wire-like rims within or around rhythmic goethite. Presence of refractory gold in arsenopyrite and pyrite is inferred from microprobe analyses. Clustered and intra-granular trail-bound aqueous-carbonic (LCO2 + Laq ± VCO2) inclusions are common in cores of the less deformed quartz crystals, whereas carbonic (LCO2 ± VCO2) and aqueous H2O-NaCl (L + V) inclusions occur along inter-granular and trans-granular trails. Clathrate melting temperatures indicate low salinities of the fluid (3-8 wt.% NaCl eq.). Homogenisation temperatures of the aqueous-carbonic inclusions range between 297 and 323°C, slightly higher than those of the intra-granular and inter-granular aqueous inclusions (263-304°C), which are likely formed during grain boundary migration. Homogenisation temperatures of the trans-granular H2O-NaCl inclusions are much lower (130-221°C), implying different fluids late in the shear zone formation. Fluid densities calculated from aqueous-carbonic inclusions along a single trail are between 0.88 and 0.98 g/cm3, and the resulting isochores suggest trapping pressures of 2-2.6 kbar. Based on the arsenopyrite-pyrite-pyrrhotite cotectic, arsenopyrite (30.4-30.7 wt.% As) associated with gold inclusions indicates a temperature range of 325-344°C. This ore paragenesis constrains f S2 to the range of 10-10 to 10-8.5 bar. Under such conditions, gold was likely transported mainly as bisulphide complexes by low salinity aqueous-carbonic fluids and precipitated because of variations in pH and f O2 through pressure fluctuation and CO2 effervescence as the ore fluids infiltrated the shear zone, along with precipitation of carbonate and sericite. Wallrock sulphidation also likely contributed to destabilising the gold-bisulphide complexes and precipitating gold in the hydrothermal alteration zone adjacent to the mineralised quartz veins.

  16. Zonation of primary haloes of Atud auriferous quartz vein deposit, Central Eastern Desert of Egypt: A potential exploration model targeting for hidden mesothermal gold deposits

    NASA Astrophysics Data System (ADS)

    Harraz, Hassan Z.; Hamdy, Mohamed M.

    2015-01-01

    The Atud gold mine located in the Neoproterozoic diorite and metagabbro of the Central Eastern Desert of Egypt has been initially excavated during Pharaonic times. Between 1953 and 1969, the Egyptian Geological Survey and Mining Authority performed underground prospection in the auriferous quartz vein and metasomatic alteration zones in the main Atud area, estimating a principal gold lode of 19,000 tones (16.28 g/ton), and 1600 tons of damp (1.24 g/ton). Yet the potentiality of the deposit has not been exhausted. However, for exploration of hidden ore, quantitative characterization using trace elements zoning of mineralization haloes with 280 samples from surface and three underground mining levels is applied. This was through multivariate statistical analysis (Factor analysis) of 11 selected trace elements. Axial (vertical) extents of primary haloes above and beneath gently dipping orebody are also visualized to interpret the level of erosion, determine the direction of mineralizing solutions as well as to examine whether the hidden orebody is promising at the Atud mine. Axial zones of primary dispersion aureoles of trace elements are: Ag, As, S and U around the auriferous quartz veins; Cu, and Pb in the surface horizons; and Zn, Ni, Co, and U along the lower margin of mineralization zone. Gold contents in bedrock and quartz vein samples from level-42M are the highest (5.7 and 40.3 ppm, respectively). In the transverse (lateral) direction, the maximum relative accumulation of Au and Zn occurs at the Northern Shaft; Pb, Cu, As, and U at the Main Shaft; and Ag, S, Co, and Ni at the Southern Shaft. The estimated axial zonation sequence of indicator elements using the variability index is Pb ? Cu ? Ag ? Au ? As ? S ? Ni ? Co ? U ? Zn. According to this zonation, an index such as (Pb × Cu)D/(U × Zn)D can be a significant for predicting the Au potentiality at a particular depth. In addition, the Pb/U zonality index is an appropriate indicator for the degree of erosion at the Atud gold mine. The degree of surficial zonality of the mineralization as deduced from geochemical maps and the level of erosion of the geochemical anomalies as well as the decreasing of gold content with depth recorded throughout the different underground mine workings make it necessary for the prospection model to evaluate the drainage patterns dissecting the mineralized zone. The application of R-mode factor analysis estimated seven statistical factors, and factor score maps are portrayed. Factors 1 (Ag, Au, As, Co, S, U and Zn) and 2 (Zn, U, Co and S) significantly reflect the Au-mineralization (ore-controlled), and their score maps enable a more precise delineation of auriferous quartz veins and the area which may contain primary gold mineralization. The other factors reveal the distribution of Cu- and Pb-bearing minerals (supergene alteration factors), and Ba and Ni in the host diorite (lithologically-controlled). These are consistent with the calculated maximum relative accumulation of trace elements, proposing a potential model of exploration based on integrating underground geochemical data from old gold mine workings with spatial information from R-mode factor score maps.

  17. Paleohydrology of flash floods in small desert watersheds in western Arizona

    NASA Astrophysics Data System (ADS)

    House, P. Kyle; Baker, Victor R.

    2001-06-01

    In this study, geological, historical, and meteorological data were combined to produce a regional chronology of flood magnitude and frequency in nine small basins (7-70 km2). The chronology spans more than 1000 years and demonstrates that detailed records of flood magnitude and frequency can be compiled in arid regions with little to no conventional hydrologic information. The recent (i.e., post-1950) flood history was evaluated by comparing a 50-year series of aerial photographs with precipitation data, ages of flood-transported beer cans, anthropogenic horizons in flood sediments, postbomb 14C dates on flotsam, and anecdotal accounts. Stratigraphic analysis of paleoflood deposits extended the regional flood record in time, and associated flood magnitudes were determined by incorporating relict high-water evidence into a hydraulic model. The results reveal a general consistency among the magnitudes of the largest floods in the historical and the paleoflood records and indicate that the magnitudes and relative frequencies of actual large floods are at variance with "100-year" flood magnitudes predicted by regional flood frequency models. This suggests that the predictive equations may not be appropriate for regulatory, management, or design purposes in the absence of additional, real data on flooding. Augmenting conventional approaches to regional flood magnitude and frequency analysis with real information derived from the alternative methods described here is a viable approach to improving assessments of regional flood characteristics in sparsely gaged desert areas.

  18. Extension of the Najd Shear System from Saudi Arabia to the central eastern desert of Egypt based on integrated field and LANDSAT observations

    NASA Astrophysics Data System (ADS)

    Sultan, Mohamed; Arvidson, Raymond E.; Duncan, Ian J.; Stern, Robert J.; El Kaliouby, Baher

    1988-12-01

    The Najd Shear System in Saudi Arabia extends over 1200 km in a NW-SE direction and has a width of approximately 300 km. A digital color mosaic, compiled from seven Landsat thematic mapper scenes, was used to delineate characteristic structural features of the Najd System in the Midyan region of Saudi Arabia and to search for similar features in the Egyptian Eastern Desert. The digital mosaic was generated using ratios of Landsat thematic mapper bands (bands 5/4 × 3/4, 5/1, 5/7) that are sensitive to the rock content of Fe-bearing aluminosilicates, spectrally opaque phases, and hydroxyl-bearing or carbonate minerals, respectively. The mosaic covers approximately 130,000 km² of late Proterozoic exposures of the Arabian-Nubian Shield and has the Eastern Desert and the Midyan region placed in their approximate pre-Red Sea locations. The Ajjaj Shear Zone (AJZ) marks the termination of the Najd System against the eastern margin of the Red Sea in the Midyan region. The AJZ aligns with the central Eastern Desert, based on analysis of pre-Red Sea locations. Analyses of Landsat data and field observations show that the Ajjaj Shear Zone and the central Eastern Desert exhibit the following features in common: (1) outcrops that are generally elongate in a NW-SE direction as a result of folding, with fine-scale lithologic heterogeneity at the outcrop scale related to deformation associated with faulting; (2) NW trending left-lateral faults and ductile shear zones; (3) subhorizontal, NW trending mineral lineations, and variably dipping NW trending foliations, with local changes in attitude around large competent (e.g., granitic) bodies; and (4) lithologic contacts that are generally tectonic in nature and related to faulting. These features are less common to the north and south of both the Ajjaj Shear Zone and the central Eastern Desert. Results are consistent with the Najd Shear System extending into the Eastern Desert and dominating the structural patterns within the central part of the Eastern Desert.

  19. The meaning of desert color in earth orbital photographs

    NASA Technical Reports Server (NTRS)

    El-Baz, F.

    1978-01-01

    The color of desert surfaces as seen in earth orbital photographs is indicative of soil composition. Apollo-Soyuz photographs of the Sturt and Simpson Deserts of Australia confirm that sand grains become redder as the distance from the source increases. Reddening is caused by a thin iron-oxide coating on individual sand grains and can be used, in some cases, to map relative-age zones. Photographs of the Western (Libyan) Desert of Egypt indicate three distinct and nearly parallel color zones that have been correlated in the field with: (1) arable soil composed of quartz, clay, and calcium carbonate particles; (2) relatively active sand with or without sparse vegetation; and (3) relatively inactive sand mixed with dark (desert-varnished) pebbles. The youngest sands are in the form of longitudinal dunes, which are migrating to the south-southeast along the prevailing wind direction. Some of the young dune fields are encroaching on the western boundary of the fertile Nile Valley.

  20. Three-dimensional structure of Conrad and Moho discontinuities in Egypt

    NASA Astrophysics Data System (ADS)

    Abdelwahed, Mohamed F.; El-Khrepy, Sami; Qaddah, Atef

    2013-09-01

    The three-dimensional structures of Conrad and Moho discontinuities beneath Egypt are investigated by local earthquake travel time inversion. A number of 2513 events with 24,696 arrival time data recorded by the Egyptian National Seismic Network (ENSN) are used. The station corrections of P- and S-waves and the hypocentral parameters are simultaneously estimated with the Conrad and Moho depths. The results of this study show that the discontinuities form patterns of shallow and deep structures getting shallow toward the northern and eastern coast, and deeper toward western Desert and northeastern Sinai. The Conrad and Moho discontinuities are located within the depth range 9-17 km and 27-41 km, respectively. The depth ranges of Conrad and Moho discontinuities are respectively: 15-16 km and 31-33 km in greater Cairo and Dahshour; 15-18 km and 32-35 km in Sinai; 16-17 and 33-35 km along the Nile River; 9 and 30 km near the Red Sea coast; 15 and 39 km toward the western desert. The comprehensive comparison with previous crustal studies suggests that the main patterns of Moho undulations and the range of Moho depths are in good agreement with the previous crustal models in Egypt, as well as with the Bouguer gravity anomalies that well explain the Nile River sediments, Red Sea mountain belts and Western Desert depression and Oasis. The model of the Moho and Conrad discontinuities improves knowledge of the three dimensional structure of the crust beneath Egypt in wide areas where geophysical data is sparse.

  1. Present groundwater status in Egypt and the environmental impacts

    NASA Astrophysics Data System (ADS)

    Idris, Hussein; Nour, S.

    1990-11-01

    This article is an attempt to give a brief review on the status of groundwater studies in Egypt, their results, and the present plans for groundwater development that are usually based on the hydrogeological characteristics of the groundwater resources as well as on the environmental control of the discharge area. In terms of groundwater hydrology, Egypt can be divided into the following groundwater provinces: (1) the Western Desert, (2) the Eastern Desert, (3) the Nile Valley including the delta, (4) the Sinai Peninsula, (5) the Northern Coastal Zone, and (6) Wadi El-Natrun. The studies of volume and nature of groundwater and the environmental impact studies that were carried out in each of these provinces differed according to the importance given to development of projects in areas of interest and to the availability of funds. Recent studies and the surveys conducted for groundwater hydrological research by local and international organizations are described separately for each province. Special reference is made to groundwater hydro-geological setting, groundwater resources evaluation, and present and future utilization. The New Valley is the largest Egyptian irrigated agricultural development project that is solely dependent on groundwater resources. An outline showing its nature, objective, and size is included as an example of groundwater development.

  2. Remote sensing and geochemical investigations of selected surface processes in Egypt and Missouri

    NASA Astrophysics Data System (ADS)

    Crombie, Mary Katherine

    This thesis consists of three studies of surface processes on Earth: 1. Age and isotopic constraints of pluvial episodes in the Western Desert of Egypt. North Africa has undergone drastic climatic change over the past several hundred thousand years. Timing of humid intervals called pluvials was investigated by uranium- series disequilibrium dating of travertines from the Kurkur Oasis, Western Desert, Egypt. Stable oxygen isotopes of the travertines were used in equilibrium oxygen isotope fractionation calculations indicating the Kurkur travertines have ?18O values similar to ancient Western Desert groundwaters (~[- ]11/perthous). The ages of the of the travertines correspond to times of monsoonal maxima, eustatic sea level high stands and interglacial maxima. Increased precipitation, recharge of Western Desert groundwaters, and resultant travertine deposition are interpreted to be consequences of Milankovitch cycle forcing, through enhanced Atlantic and Indian Ocean monsoons during periods of enhanced northern summer insolation. 2. Identification of soil moisture as an environmental risk factor for filariasis in Egypt. Bancroftian filariasis is a deforming illness transmitted by mosquitoes (Culex. pipiens) and caused by the parasite Wuchereria bancrofti (WHO technical report 821; Neva and Brown, 1994). Environmental variables, such as humidity, play an important role in the transmission cycle of filariasis. Landsat Thematic Mapper data were used to model the surface soil moisture conditions of the southern Nile Delta region of Egypt as a proxy for environmental humidity. Filariasis infection rates were found to be negligible for areas with low surface soil moisture availability (>20%). Variable infection rates were observed for regions with higher surface soil moisture content, possibly due to anthropogenic influences such as insect control and the use of anti- filarial drugs. 3. Monitoring of Pb aerosol fallout in the vicinity of the Glover smelter, Southeastern Missouri. Pb ore smelting in Southeastern Missouri is a point source for heavy metal particulates that are dispersed over a wide region. Pb ratios of the ores are distinct from local bedrock and background atmospheric Pb. A feasibility study to determine the usefulness of Sector Field ICP-MS analysis of Pb isotopes and heavy metal concentrations of leaves sampled at increasing distance from the smelter was initiated. The goal was to develop an inexpensive and relatively simple means of mapping the impact of heavy metals on the ecosystem surrounding the smelter.

  3. Combining molecular-marker and chemical analysis of Capparis decidua (Capparaceae) in the Thar Desert of Western Rajasthan (india).

    PubMed

    Kumar, Sushil; Sharma, Ramavtar; Kumar, Vinod; Vyas, Govind K; Rathore, Abhishek

    2013-03-01

    The Thar Desert, a very inhospitable place, accommodates only plant species that survive acute drought, unpredictable precipitation, and those can grow in the limited moisture of sandy soils. Capparis decidua is among one of the few plants able to grow well under these conditions. This species is highly exploited and has been naturally taken, as local people use it for various purposes like food, timber and fuel, although, no management or conservation efforts have been established. The present study was conducted in this arid area of Western Rajasthan (India) with the aim to obtain preliminary molecular information about this group of plants. We evaluated diversity among 46 samples of C. decidua using chemical parameters and random amplified polymorphic DNA (RAPD) markers. Fourteen chemical parameters and eight minerals (total 22 variables) of this species fruits were estimated. A total of 14 RAPD primers produced 235 band positions, of which 81.27% were polymorphic. Jaccard's similarity coefficients for RAPD primers ranged from 0.34 to 0.86 with a mean genetic similarity of 0.50. As per observed coefficient of variation, NDF (Neutral Detergent Fiber) content was found to be the most variable trait followed by starch and soluble carbohydrate. The Manhattan dissimilarity coefficient values for chemical parameters ranged between 0.02-0.31 with an average of 0.092. The present study revealed a very low correlation (0.01) between chemical parameters and RAPD-based matrices. The low correlation between chemical- and RAPD-based matrices indicated that the two methods were different and highly variable. The chemical-based diversity will assist in selection of nutritionally rich samples for medicinal purpose, while genetic diversity to face natural challenges and find sustainable ways to promote conservation for future use. PMID:23894984

  4. Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas

    PubMed Central

    Aschenbach, Katrin; Conrad, Ralf; ?eháková, Klára; Doležal, Ji?í; Janatková, Kate?ina; Angel, Roey

    2013-01-01

    Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~103 gdw?1 soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts. PMID:24348469

  5. Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas.

    PubMed

    Aschenbach, Katrin; Conrad, Ralf; Reháková, Klára; Doležal, Ji?í; Janatková, Kate?ina; Angel, Roey

    2013-01-01

    Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~10(3) gdw(-1) soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts. PMID:24348469

  6. The significance of gneissic rocks and synmagmatic extensional ductile shear zones of the Barud area for the tectonics of the North Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Fowler, Abdel-Rahman; Ali, Khaled G.; Omar, Sayed M.; Eliwa, Hassan A.

    2006-10-01

    The mainly tonalitic gneissic rocks, amphibolites, schists and rarer migmatites of the Barud area, at the southern margin of the Egyptian North Eastern Desert (NED) have previously been viewed as products of ultrametamorphism or granitization of pre-PanAfrican basement. The Qena-Safaga Line of approximately NW-striking steeply dipping faults was also regarded as marking the boundary between these NED rocks and the low grade metavolcanics and ophiolitic melange of the Central Eastern Desert (CED). Detailed investigation of the Barud area indicates that the amphibolites, schists and migmatites formed by shearing and medium grade metamorphism of similar arc metavolcanics to those of the CED in normal shear sense extensional ductile shear zones heated by numerous syn-kinematic dolerite, gabbro, diorite, granodiorite, tonalite and granite dykes. They are thus hot sheared equivalents of the CED metavolcanics and basic arc plutonites, accompanied by sheared mafic and felsic intrusive rocks, and are not deep-seated crystalline basement rocks. The shear zones are interpreted as having formed by arc-rifting, not necessarily reaching the stage of marginal basin formation. Arc-accretion structures and those produced by later orogen squeezing are also described. The somewhat gneissic Barud Tonalitic is found to be entirely magmatic. Following intrusion of the Barud Tonalite, and before or during Hammamat and Dokhan deposition, the NED experienced a rapid uplift relative to the CED (˜620-600 Ma) that was not achieved by thrusting along the Qena-Safaga Line.

  7. Nile River, Lake Nasser, Aswan Dam, Egypt

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

  8. PIXE micro-mapping of minor elements in Hypatia, a diamond bearing carbonaceous stone from the Libyan Desert Glass area, Egypt: Inheritance from a cold molecular cloud?

    NASA Astrophysics Data System (ADS)

    Andreoli, M. A. G.; Przybylowicz, W. J.; Kramers, J.; Belyanin, G.; Westraadt, J.; Bamford, M.; Mesjasz-Przybylowicz, J.; Venter, A.

    2015-11-01

    Matter originating from space, particularly if it represents rare meteorite samples, is ideally suited to be studied by Particle Induced X-ray Emission (PIXE) as this analytical technique covers a broad range of trace elements and is per se non-destructive. We describe and interpret a set of micro-PIXE elemental maps obtained on two minute (weighing about 25 and 150 mg), highly polished fragments taken from Hypatia, a controversial, diamond-bearing carbonaceous pebble from the SW Egyptian desert. PIXE data show that Hypatia is chemically heterogeneous, with significant amounts of primordial S, Cl, P and at least 10 elements with Z > 21 (Ti, V, Cr, Mn, Fe, Ni, Os, Ir) locally attaining concentrations above 500 ppm. Si, Al, Ca, K, O also occur, but are predominantly confined to cracks and likely represent contamination from the desert environment. Unusual in the stone is poor correlation between elements within the chalcophile (S vs. Cu, Zn) and siderophile (i.e.: Fe vs. Ni, Ir, Os) groups, whereas other siderophiles (Mn, Mo and the Platinum group elements (PGEs)) mimic the distribution of lithophile elements such as Cr and V. Worthy of mention is also the presence of a globular domain (Ø ? 120 ?m) that is C and metals-depleted, yet Cl (P)-enriched (>3 wt.% and 0.15 wt.% respectively). While the host of the Cl remains undetermined, this chemical unit is enclosed within a broader domain that is similarly C-poor, yet Cr-Ir rich (up to 1.2 and 0.3 wt.% respectively). Our data suggest that the pebble consists of shock-compacted, primitive carbonaceous material enriched in cold, pre-solar dust.

  9. Spatial association of Neoproterozoic continental arc I-type and post-collision A-type granitoids in the Arabian-Nubian Shield: The Wadi Al-Baroud Older and Younger Granites, North Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    El-Bialy, Mohammed Zaky; Omar, Mohamed M.

    2015-03-01

    The Neoproterozoic basement of Wadi Al-Baroud area located at the northern Eastern Desert (ED) of Egypt, at the northernmost segment of the Arabian-Nubian Shield (ANS), is comprised of two different granite suites. A large batholith ascribed to the Older Granite suite, extends across the boundary between the northern and central ED, and is intruded by two isolated plutons of the Younger Granite suite. The Older Granite suite includes gray-colored, massive to gneissose, granodiorites to tonalites typically containing microgranular mafic enclaves. These are calc-alkaline, magensian, metaluminous I-type granitoids, with high Sr contents, and depleted in Rb, Nb, Y and REE. The Younger Granite suite plutons are pink to red, biotite and two-mica monzogranites. These are peraluminous A-type granites exhibiting a high-K calc-alkaline nature, and varying between ferroan and magnesian type granites. The A-type granites of the Younger Granite suite are enriched in Ga, Y, HFSE and REE elements, and depleted in the LILE elements Ba, Sr and Rb and transition metals Cr, Ni, Co, Sc and V. Magmatic saturation temperatures indicate early crystallization of apatite at high temperature in the metaluminous I-type Older Granite suite, while in the peraluminous A-type Younger Granites its crystallization occurs later after separation of zircon and monazite. The plutons of the Younger Granite suite were generated during the post-collisional stage of the northern ANS, following collision between the juvenile ANS crust and the pre-Neoproterozoic continental blocks of west Gondwana. The emplacement of the Older Granite suite took place earlier, within a normally mature continental arc prior to the collision. These pre-collision granitoids evolved through assimilation-fractional crystallization processes from mantle-derived parental magmas, which have interacted with crustal materials during ascent and storage. The post-collisional Younger Granite suite seems to have been derived by high degree, partial melting of metasedimentary sources, particularly psammitic and pelitic metasediments.

  10. Spectroscopy of olivine basalts using FieldSpec and ASTER data: A case study from Wadi Natash volcanic field, south Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Madani, Ahmed

    2015-10-01

    This paper aims at revealing the spectral characteristics of the olivine basalts exposed at Wadi Natash area, Egypt, using FieldSpec spectroradiometer. It also evaluates band ratios and fusion techniques for mapping purposes using ASTER data. Several volcanic episodes occurred during Early- to Late-Cretaceous are recorded in the study area. Early-Cretaceous olivine basalts are highly carbonated. Late-Cretaceous eruptions took place throughout several volcanic cones aligned in NW direction. Based on FieldSpec measurements and petrographic data, two groups of olivine basalt namely `A' and `B' are recognized. Fresh olivine basalt (group A) is characterized by low flat spectral profile with overall low reflectance values (˜20%). Spectral profile of altered olivine basalt (group B) shows moderate reflectance values (˜37%) with four little absorption features around the 1.10, 1.40, 2.00 and 2.35 ?m wavelength regions. These absorption features are attributed mainly to the presence of chlorite and carbonate alteration products as indicated by petrographic examination. ASTER false colour composite band ratio image (3/2:R, 8/1:G and 8/5:B) discriminates easily the fresh and altered basalts by deep blue and reddish blue colours respectively. Image fusion between previously mentioned FCC ratios image and high spatial resolution ASTER panchromatic image are carried out using brovey and HSV transformation methods. Visual and statistical assessment methods proved that HSV fusion image yields better image interpretability results compared to brovey image. It improves the spatial resolution of original FCC ratios image with acceptable spectral preservation. The present study proved the usefulness of FieldSpec spectral profiles and the processed ASTER data for discriminating different olivine basalt groups exposed at the study area.

  11. Spectroscopy of olivine basalts using FieldSpec and ASTER data: A case study from Wadi Natash volcanic field, south Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Madani, Ahmed

    2015-09-01

    This paper aims at revealing the spectral characteristics of the olivine basalts exposed at Wadi Natash area, Egypt, using FieldSpec spectroradiometer. It also evaluates band ratios and fusion techniques for mapping purposes using ASTER data. Several volcanic episodes occurred during Early- to Late-Cretaceous are recorded in the study area. Early-Cretaceous olivine basalts are highly carbonated. Late-Cretaceous eruptions took place throughout several volcanic cones aligned in NW direction. Based on FieldSpec measurements and petrographic data, two groups of olivine basalt namely `A' and `B' are recognized. Fresh olivine basalt (group A) is characterized by low flat spectral profile with overall low reflectance values (˜20%). Spectral profile of altered olivine basalt (group B) shows moderate reflectance values (˜37%) with four little absorption features around the 1.10, 1.40, 2.00 and 2.35 ?m wavelength regions. These absorption features are attributed mainly to the presence of chlorite and carbonate alteration products as indicated by petrographic examination. ASTER false colour composite band ratio image (3/2:R, 8/1:G and 8/5:B) discriminates easily the fresh and altered basalts by deep blue and reddish blue colours respectively. Image fusion between previously mentioned FCC ratios image and high spatial resolution ASTER panchromatic image are carried out using brovey and HSV transformation methods. Visual and statistical assessment methods proved that HSV fusion image yields better image interpretability results compared to brovey image. It improves the spatial resolution of original FCC ratios image with acceptable spectral preservation. The present study proved the usefulness of FieldSpec spectral profiles and the processed ASTER data for discriminating different olivine basalt groups exposed at the study area.

  12. Geology and organic geochemistry of Dakla Shale, Egypt

    SciTech Connect

    Robison, V.D.; Troeeger, U.

    1983-03-01

    The Dakla Formation is late Campanian to Paleocene in age and, in eastern Egypt, is overlain by the Nubian Sandstone and underlain by the phosphate-bearing Duwi Formation. Lithologically, samples of the Dakla shale member collected in the Red Sea area consist of marls to marly clays, range from brown to black in color, and are bounded at the top and bottom by phosphate-bearing strata. Organic carbon and extractable C/sub 15+/ hydrocarbon concentrations for samples from Quseir, Hamrawein, and Safaga ranged from 3.8 to 5.9% C/sub org/ and 550 to 2400 ppM HC, and may be petroleum source rocks in areas where burial and thermal conditions are adequate. Shale samples from the Quseir region yielded Fischer assay results of 40 gal/ton, and thus have considerable potential as oil shales. Samples from the Sibaiya region in the Nile Valley are light to dark gray shale and average 0.2% C/sub org/. In this area, the phosphate deposits associated with the Dakla Formation are presently being exploited. The Dakla shale samples from the Abu Tartur region, in the Western Desert, contain organic carbon concentrations in excess of 4.0%. Such values are considered suitable for potential petroleum source rocks where other conditions are satisfied. Recent exploration activity in the Western Desert region may make petroleum source rock studies of the Dakla shales increasingly important.

  13. Effect of the temperature variation between Mediterranean Sea and Syrian deserts on the dust storm occurrence in the western half of Iran

    NASA Astrophysics Data System (ADS)

    Amanollahi, Jamil; Kaboodvandpour, Shahram; Qhavami, Samira; Mohammadi, Bakhtiyar

    2015-03-01

    Recent dust storms have caused crises in western Iran, which necessitate the prediction of these storms a few days before their occurrence. This is the first study of its type that analyzes the effect of temperature differences between the Mediterranean Sea surface and Syrian deserts (creation zone of the dusts storms) on the formation of dust storms in the west of Iran. The study also seeks to identify any changes in the atmospheric temperature created by the extreme dust storm of July 5, 2009 in west of Iran (Sanandaj City). In this study, the MODIS images from 2000 to 2008, and particulate matter data of the Sanandaj station from 2008 to 2012 were utilized to identify the dust storm days. The Mediterranean Sea surface temperature data were extracted from NOAA satellites for dust storm days up to four days preceding them. The web site of world weather was used to obtain the temperature of Damascus, Syria station as the selected land station. According to the results, significant differences were acquired between surface temperatures of Damascus station and the Mediterranean Sea in the dust storm days and up to three days before them. As the dust storm days approached, a rising trend was observed in changes of the temperature difference between land and sea. Thermal map analysis of the atmosphere of the Syrian deserts on July 5, 2009 showed significant decrease in the levels of 1000 hPa and 500 hPa but for the days preceding it no significant changes were observed. It can be concluded that the temperature difference between the Mediterranean Sea surface and the Syrian deserts four days before the dust storm occurrences is the important factor in predicting this event.

  14. 76 FR 59682 - Desert Southwest Customer Service Region-Western Area Lower Colorado Balancing Authority-Rate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-27

    ..., DSW-EI2, DSW- SPR2, and DSW-SUR2 on June 26, 2006 (Rate Order No. WAPA-127, 71 FR 36332).\\1\\ These..., Extension of Rate Order No. WAPA-127 through September 30, 2013. 76 FR 28767, May 18, 2011. Desert Southwest... published on September 18, 1985 (50 FR 37835). Under Delegation Order Nos. 00-037.00 and 00-001.00C, 10...

  15. Solar Energy for Rural Egypt

    NASA Astrophysics Data System (ADS)

    Abdelsalam, Tarek I.; Darwish, Ziad; Hatem, Tarek M.

    Egypt is currently experiencing the symptoms of an energy crisis, such as electricity outage and high deficit, due to increasing rates of fossil fuels consumption. Conversely, Egypt has a high solar availability of more than 18.5 MJ daily. Additionally, Egypt has large uninhabited deserts on both sides of the Nile valley and Sinai Peninsula, which both represent more than 96.5 % of the nation's total land area. Therefore, solar energy is one of the promising solutions for the energy shortage in Egypt. Furthermore, these vast lands are advantageous for commissioning large-scaled solar power projects, not only in terms of space availability, but also of availability of high quality silicon (sand) required for manufacturing silicon wafers used in photovoltaic (PV) modules. Also, rural Egypt is considered market a gap for investors, due to low local competition, and numerous remote areas that are not connected to the national electricity grid. Nevertheless, there are some obstacles that hinder the progress of solar energy in Egypt; for instance, the lack of local manufacturing capabilities, security, and turbulent market in addition to other challenges. This paper exhibits an experience of the authors designing and installing decentralized PV solar systems, with a total rated power of about 11 kW, installed at two rural villages in at the suburbs of Fayoum city, in addition to a conceptual design of a utility scale, 2 MW, PV power plant to be installed in Kuraymat. The outcomes of this experience asserted that solar PV systems can be a more technically and economically feasible solution for the energy problem in rural villages.

  16. Atom Trap, Krypton-81, and Egypt

    NASA Astrophysics Data System (ADS)

    Lu, Zheng-Tian

    2003-10-01

    We are developing the Atom Trap Trace Analysis (ATTA) method for the analysis of two long-lived rare krypton isotopes, ^81Kr (t_1/2=2.3 × 10^5 years, I.A. ˜ 10-13) and ^85Kr (t_1/2=10.8 years, I.A. ˜ 10-11). ^81Kr analyses can be used to determine the ages of old ice and groundwater in a range (5 × 10^4 - 2 × 10^6 years) beyond the reach of radio-carbon dating; Analyses of ^85Kr , a fission product of uranium and plutonium, can serve as a means to help verify compliance with the Nuclear Non-Proliferation Treaty. In ATTA, individual atoms of the desired isotope are selectively captured into a laser trap and detected by observing the fluorescence of trapped atoms. The first application of ATTA is dating the ancient groundwater of the Nubian Aquifer underneath the Western Desert of Egypt. This is one of the largest aquifers in the world. The residence time of its water are of great interest in fundamental geology as well as for utilitarian reasons. This work marks the beginning of a useful tool in Earth sciences. * This work is supported by the U.S. Department of Energy, Division of Nuclear Physics, under contract W-31-109-ENG-38.

  17. Ancient Egypt.

    ERIC Educational Resources Information Center

    Evers, Virginia

    This four-week fourth grade social studies unit dealing with religious dimensions in ancient Egyptian culture was developed by the Public Education Religion Studies Center at Wright State University. It seeks to help students understand ancient Egypt by looking at the people, the culture, and the people's world view. The unit begins with outlines…

  18. The Formation of the Patterns of Desert Shrub Communities on the Western Ordos Plateau, China: The Roles of Seed Dispersal and Sand Burial

    PubMed Central

    Wang, Yange; Yang, Xiaohui; Shi, Zhongjie

    2013-01-01

    The western Ordos Plateau is a key area of shrub diversity and a National Nature Reserve of endangered shrub species in north-west China. Desert expansion is becoming the most important threat to these endangered species. However, little is known about the effects of sand burial on the dynamics of the shrub community. This study aims to investigate how the shrubs as a community and as different individual shrubs respond to the disturbances caused by the desert expansion. The approach used by this study is to separate the seed-dispersal strategy from the sand-burial forces that are involved in structuring the shrub communities at different disturbance stages. Four communities for different disturbance stages were surveyed by using 50×50 m plots. The individual shrubs were classified into coloniser and successor groups at the seed-dispersal stage and strong and weak sand-burial tolerance groups at the sand-expansion stage. We employed spatial point pattern analysis with null models for each community to examine the seed-dispersal strategy and sand-burial forces affecting community distribution patterns. At the seed-dispersal stage, the interactions between the colonisers and the successors showed significant positive correlation at a scale of 0–1 m and significant negative correlation at a scale of 2 m; significant negative correlations between the groups with strong and weak sand-burial tolerance in the early stage of sand expansion at scales of 3–6 m, and significant positive correlation in the later stage of sand expansion at a scale of 13 m, were found. Seed-dispersal strategy is a reasonable mechanism to explain the shrub community pattern formation in the earlier stages, whereas sand burial is the primary reason for the disappearance of shrubs with weak sand-burial tolerance, this irreversible disturbance causes homogenisation of the community structure and produces aging populations of shrub species. This has an important influence on the succession direction of desert shrub communities. PMID:23922877

  19. Current status of phytoparasitic nematodes and their host plants in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Egypt many phytoparasitic nematodes constitute a major constraint to agricultural production, especially in sandy soil and reclaimed desert lands. Nematological surveys were conducted to determine the genera and species of phytoparasitic nematodes on associated host plants in Egypt. The results i...

  20. Morphology and development of pahoehoe flow-lobe tumuli and associated features from a monogenetic basaltic volcanic field, Bahariya Depression, Western Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Khalaf, Ezz El Din Abdel Hakim; Hammed, Mohamed Saleh

    2016-01-01

    The dimensions, landforms, and structural characteristics of pahoehoe flow-lobe tumuli from Bahariya Depression are collectively reported here for the first time. The flow-lobe tumuli documented here characterize hummocky flow surfaces. These tumuli are characterized by low, dome-like mounds, lava-inflation clefts, and squeeze ups. Flow-lobe tumuli are of various shapes and sizes, which are affected by the mechanism of inflation because they formed in response to the increase of pressure within the flow when the flow's crust becomes thicker. The tumuli often appear isolated or in small groups in the middle sectors of the lava flows, whereas in the distal sectors they form large concentration, suggesting the presence of complex lava tubes inside of the flow. Tumuli exhibited by El Bahariya lava flows are between 3.0 and 50 m in length and up to 5.0 m in height with lenticular geometry in aerial view. The flow emplacement of flow-lobe tumuli is controlled by variations in local characteristics such as nature of the substrate, flow orientation, slope, interferrence with other lobes, and rate of lava supply. Their presence generally towards the terminal ends of flow fields suggests that they seldom form over the clogged portions of distributary tubes or pathways. Thus, localized inflations that formed over blockages in major lava tubes result in formation of flow-lobe tumuli. The three-tiered (crust-core-basal zone) internal structure of the flow-lobe tumuli, resembling the typical distribution of vesicles in P-type lobes, confirms emplacement by the mechanism of inflation. All the available data show that the morphology and emplacement mechanism of the studied flow-lobe tumuli may be analogous to similar features preserved within topographically confined areas of the Hawaiian and Deccan hummocky lava flows. Considering the age of the studied volcanic fields (?22 Ma) it is most probable that the structures described here may be amongst the oldest recognized examples of lava inflation.

  1. Resilience to stress and disturbance, and resistance to Bromus tectorum l. invasion in cold desert shrublands of western North America

    USGS Publications Warehouse

    Chambers, Jeanne C.; Bradley, Bethany A.; Brown, Cynthia S.; D'Antonio, Carla; Germino, Matthew J.; Grace, James B.; Hardegree, Stuart P.; Miller, Richard F.; Pyke, David A.

    2013-01-01

    Alien grass invasions in arid and semi-arid ecosystems are resulting in grass–fire cycles and ecosystem-level transformations that severely diminish ecosystem services. Our capacity to address the rapid and complex changes occurring in these ecosystems can be enhanced by developing an understanding of the environmental factors and ecosystem attributes that determine resilience of native ecosystems to stress and disturbance, and resistance to invasion. Cold desert shrublands occur over strong environmental gradients and exhibit significant differences in resilience and resistance. They provide an excellent opportunity to increase our understanding of these concepts. Herein, we examine a series of linked questions about (a) ecosystem attributes that determine resilience and resistance along environmental gradients, (b) effects of disturbances like livestock grazing and altered fire regimes and of stressors like rapid climate change, rising CO2, and N deposition on resilience and resistance, and (c) interacting effects of resilience and resistance on ecosystems with different environmental conditions. We conclude by providing strategies for the use of resilience and resistance concepts in a management context. At ecological site scales, state and transition models are used to illustrate how differences in resilience and resistance influence potential alternative vegetation states, transitions among states, and thresholds. At landscape scales management strategies based on resilience and resistance—protection, prevention, restoration, and monitoring and adaptive management—are used to determine priority management areas and appropriate actions.

  2. Impact of consecutive extreme rainstorm events on particle transport: Case study in a Sonoran Desert range, western USA

    NASA Astrophysics Data System (ADS)

    Dorn, Ronald I.

    2015-12-01

    Quantifying erosion rates in different landscape settings provides insight into how landforms change under different climatic, tectonic and anthropogenic influences. Sediment traps designed to capture grus detached from granitic hill crests of an arid Sonoran Desert mountain range were placed prior to every precipitation event over a three-year period, just above rills that drain areas between 18 and 68 m2. The slopes are underlain by moderately to strongly weathered granitic rocks to a depth of about a meter. Within this 3-year window, a 1000-year precipitation event followed 27 days later by a 500-year event detached granitic grus in amounts far greater than previous storms, capturing between 22 × and 63 × the average amount transported in the previous 59 rain events - indicating the non-linear nature of the response of grus detachment to precipitation intensity. Considering every precipitation event over a 3-year period, no detachment occurred from events with less than 2 mm of total rainfall, and only minimal erosion occurred from rainfall events with totals between 2 and 10 mm with durations typically less than 30 min. Detachment increased greatly with rain intensities of 36 mm/h or more. Grus detachment from these arid crests increases with drainage area, a higher percentage of exposed soil, and steeper slopes. 87Sr/86Sr ratios reveal that suspended sediment transported from hill crest to trap derives from recycled dust and not the local granite bedrock.

  3. Movement of water through the thick unsaturated zone underlying Oro Grande and Sheep Creek Washes in the western Mojave Desert, USA

    USGS Publications Warehouse

    Izbicki, J.A.; Radyk, J.; Michel, R.L.

    2002-01-01

    Previous studies indicate that a small quantity of recharge occurs from infiltration of streamflow in intermittent streams in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. Chloride, tritium, and stable isotope data collected in the unsaturated zone between 1994 and 1998 from boreholes drilled in Oro Grande and Sheep Creek Washes indicate that infiltration of streamflow occurs to depths below the root zone, and presumably to the water table, along much of Oro Grande Wash and near the mountain front along Sheep Creek Wash. Differences in infiltration at sites along each wash are the result of hydrologic variables such as proximity to the mountain front, quantity of streamflow, and texture of the subsurface deposits. Differences in infiltration between the washes are the result of large-scale geomorphic processes. For example, Oro Grande wash is incised into the Victorville fan and infiltration has occurred at approximately the same location over recent geologic time. In contrast, Sheep Creek Wash overlies an active alluvial fan and the stream channel can move across the fan surface through time. Infiltration does not occur to depths below the root zone at control sites outside of the washes.

  4. Data from a thick unsaturated zone underlying Oro Grande and Sheep Creek washes in the western part of the Mojave Desert, near Victorville, San Bernardino County, California

    USGS Publications Warehouse

    Izbicki, John A.; Clark, Dennis A.; Pimental, Maria I.; Land, Michael; Radyk, John C.; Michel, Robert L.

    2000-01-01

    This report presents data on the physical properties of unsaturated alluvial deposits and on the chemical and isotopic composition of soil water and soil gas collected at 12 monitoring sites in the western part of the Mojave Desert, near Victorville, California. Sites were installed using the ODEX air-hammer method. Seven sites were located in the active channels of Oro Grande and Sheep Creek Washes. The remaining five sites were located away from the active washes. Most sites were drilled to a depth of about 100 feet below land surface; two sites were drilled to the water table almost 650 feet below land surface. Drilling procedures, lithologic and geophysical data, and site construction and instrumentation are described. Core material was analyzed for water content, bulk density, water potential, particle size, and water retention. The chemical composition of leachate from almost 1,000 subsamples of cores and cuttings was determined. Water extracted from selected subsamples of cores was analyzed for tritium and the stable isotopes of oxygen and hydrogen. Water from suction-cup lysimeters and soil-gas samples also were analyzed for chemical and isotopic composition. In addition, data on the chemical and isotopic composition of bulk precipitation from five sites and on ground water from two water-table wells are reported.

  5. Cultural Diversity or Cultural Imperialism: Liberal Education in Egypt.

    ERIC Educational Resources Information Center

    Blanks, David R.

    1998-01-01

    A faculty member's experience at the American University in Cairo (Egypt) reveals that pluralism and tolerance are western concepts, even within the college curriculum. National identity affords cultural stability: where the American melting-pot experience is reinforced by the notion of cultural diversity, the national identity of Egypt is…

  6. The 40Ar/39Ar thermochronology of the eastern Mojave Desert, California, and adjacent western Arizona with implications for the evolution of metamorphic core complexes

    NASA Astrophysics Data System (ADS)

    Foster, David A.; Harrison, T. Mark; Miller, Calvin F.; Howard, Keith A.

    1990-11-01

    Mesozoic thickening and Cenozoic extension resulted in the juxtaposition of upper and middle crustal rocks in the eastern Mojave Desert, southeastern California and western Arizona. The application of 40Ar/39Ar thermochronology to rocks in this region provides information about the timing and nature of thrusting, plutonism, metamorphism, denudation, and detachment faulting. The 40Ar/39Ar ages of 175 to 125 Ma from the Clipper, Piute, Turtle, Mohave, Bill Williams, and Hualapai Mountains are interpreted to be the result of a middle Mesozoic thermal event(s) caused by crustal thickening. The 40Ar/39Ar data from the Clipper and Piute Mountains suggest that this thermal event was followed by a period of cooling at rates of 1°-5°C/m.y. Orogenesis culminated during the Late Cretaceous when rocks exposed in the Old Woman-Piute, Chemehuevi, and Sacramento Mountains attained temperatures >500°C which reset the K-Ar systems of minerals from Proterozoic rocks. High-grade metamorphism in the Old Woman Mountains area was caused by the intrusion of the Old Woman-Piute batholith at 73±1 Ma. Cooling rates following batholith emplacement in the Old Woman Mountains were ˜100°C/m.y. between 73 and 70 Ma and 5°-10°C/m.y. from 70 to ˜30 Ma. Between 65 and 25 Ma the entire eastern Mojave Desert underwent a period of cooling at a rate of 2°-10°C/m.y. By 30 Ma, rocks exposed in the Old Woman-Piute, Marble, Ship, Clipper, and Turtle Mountains were below ˜100°C. The 40Ar/39Ar ages from the Sacramento Mountains suggest that mylonitization caused by the onset of regional extension occurred at 23±1 Ma. When extension started in the Chemehuevi Mountains, rocks exposed in the southwestern and northeastern portions of footwall to the Chemehuevi detachment fault were at ˜180°C and ˜350°C, respectively. This suggests that the exposed part of the Chemehuevi detachment fault initiated at a dip of 5°-30° or as a series of higher-angle faults that cut to a depth of 10-12 km and were later rotated to their present dip. Unroofing of the footwalls to detachment faults in the Sacramento and Chemehuevi Mountains resulted in average cooling rates of 10°-50°C/m.y. between 22 and 15 Ma.

  7. Management of Egypt's Surface and Groundwater Resources: Present and Future

    NASA Astrophysics Data System (ADS)

    Sultan, M.; Ahmed, M.; Yan, E.; Milewski, A.; Mohamed, L.; Farag, A. Z. A.

    2014-12-01

    The River Nile is the main source of fresh water in Egypt. Most of Egypt's River Nile water (>85%) originates as precipitation over the Ethiopian highlands and is channeled by the Blue Nile. The construction (years: 2011 to 2017) of the Renaissance Dam (reservoir capacity: 70 x 109m3) on the Blue Nile poses an extreme threat to Egypt's population. If the reservoir was to be filled in 7 years, Egypt will lose (during each of 7 years following dam completion) a minimum of 15 x 109m3 of its annual allocation (55 x 109m3) to reservoir filling (10 x 109m3), evaporation (3.5 x 109m3), and infiltration (1.5 x 109m3). Three solutions are proposed: Solution I takes advantage of the cyclicity of Nile floods and is based on findings from a calibrated (against temporal head data) unconfined 2-dimensional transient groundwater flow model for Lake Nasser and surroundings and a calibrated (against lake levels) surface water model. Models show with time: (1) losses to infiltration will decrease (1975-193: 58.4 109m3; 1993-2001: 43.6 x 109m3) due to silting of Lake bottom and encroachment of excess Lake Nasser water will increase (e.g., 1975-1993: none; 1993-2001: 17 x 109m3). We propose to develop sustainable agricultural in the Western Desert: (1) In high flood years, excess Lake Nasser water (e.g., 1993-2001: 17 x 109m3) is channeled across the plateau bounding (from west) the River Nile valley to artificially recharge the Nubian Sandstone Aquifer System (NSAS) that crops out west of the plateau and, (2) in low flood years, we extract the recharged groundwater. Solution II calls on mining the NSAS at reasonable rates. Using temporal (January 2003 - September 2012) Gravity Recovery and Climate Experiment (GRACE) data we estimate the annual depletion rates at 2 x 109m3 due to artificial extraction (1.5 x 109m3) and natural discharge (0.5 x 109m3). Assuming current GRACE depletion rates, the recoverable groundwater (5,180 x 109m3) will last for 2500 years; if we were to quadruple the artificial extraction rates (6 x 109m3), the reservoir will last for some 800 years. Solution III calls on the sustainable utilization of the NSAS groundwater in Sinai that receives an estimated minimum annual modern recharge of 13 x 106m3. Currently, these waters are lost as discharge in water bodies and/or diverted across political boundaries by major NE trending fault systems.

  8. Composition and antimicrobial activity of the essential oil of Heracleum thomsonii (Clarke) from the cold desert of the western Himalayas.

    PubMed

    Guleria, Shailja; Saini, Rikki; Jaitak, Vikas; Kaul, V K; Lal, Brij; Rahi, Praveen; Gulati, Arvind; Singh, Bikram

    2011-08-01

    Volatile oil composition of hydro-distilled (HD) and supercritical carbon dioxide (SC-CO(2)) essential oil of freshly collected aerial parts of Heracleum thomsonii (Umbeliferae) from the western Himalayas was studied by GC-FID and GC-MS. Results revealed qualitative and quantitative dissimilarity in the composition of hydro-distilled and SC-CO(2) extracted oils. Nineteen constituents, which accounted for 89.32% of total constituents in HD oil, represented by limonene (4.31%), (Z)-?-ocimene (3.69%), terpinolene (22.24%), neryl acetate (36.19%), nerol (9.51%) and p-cymene-8-ol (2.61%) were identified. In SC-CO(2) extracted oil, 24 constituents representing 89.95% of total constituents were identified. Terpinolene (5.08%), germacrene D (2.17%), neryl acetate (51.62%), nerol (9.78%), geranyl acetate (2.06%), ?-bisabolol (2.48%) and 1-nonadecanol (4.96%) were the dominating constituents. In vitro antimicrobial activity of hydro-distilled oil was conducted against microrobial strains including two Gram-positive (Staphylococcus aureus and Bacillus subtilis) and five Gram-negative (Burkholderia cepacia, Escherichia coli, Enterobacter cloacae, Klebseilla pneumoniae and Pseudomonas aeruginosa) bacteria as well as seven fungi (Candida albicans, Issatchenkia orientalis, Aspergillus flavus, Aspergillus niger, Aspergillus parasiticus, Aspergillus sydowii and Trichophyton rubrum) using broth microdilution method. The results of bioassay showed that the oil exhibited moderate to high antimicrobial activity against fungi C. albicans (MIC 625 µg?ml(-1)), A. parasiticus (MIC 312.5 µg?ml(-1)), A. sydowii (MIC 312.5 µg?ml(-1)), T. rubrum (MIC 625 µg?ml(-1)), Gram-positive bacteria B. subtilis (MIC 625?µg?ml(-1)) and Gram-negative bacteria P. aeruginosa (MIC 312.5 µg?ml(-1)). PMID:21854172

  9. Fairy, tadpole, and clam shrimps (Branchiopoda) in seasonally inundated clay pans in the western Mojave Desert and effect on primary producers

    PubMed Central

    2010-01-01

    Background Fairy shrimps (Anostraca), tadpole shrimps (Notostraca), clam shrimps (Spinicaudata), algae (primarily filamentous blue-green algae [cyanobacteria]), and suspended organic particulates are dominant food web components of the seasonally inundated pans and playas of the western Mojave Desert in California. We examined the extent to which these branchiopods controlled algal abundance and species composition in clay pans between Rosamond and Rogers Dry Lakes. We surveyed branchiopods during the wet season to estimate abundances and then conducted a laboratory microcosm experiment, in which dried sediment containing cysts and the overlying algal crust were inundated and cultured. Microcosm trials were run with and without shrimps; each type of trial was run for two lengths of time: 30 and 60 days. We estimated the effect of shrimps on algae by measuring chlorophyll content and the relative abundance of algal species. Results We found two species of fairy shrimps (Branchinecta mackini and B. gigas), one tadpole shrimp (Lepidurus lemmoni), and a clam shrimp (Cyzicus setosa) in our wet-season field survey. We collected Branchinecta lindahli in a pilot study, but not subsequently. The dominant taxa were C. setosa and B. mackini, but abundances and species composition varied greatly among playas. The same species found in field surveys also occurred in the microcosm experiment. There were no significant differences as a function of experimental treatments for either chlorophyll content or algal species composition (Microcoleus vaginatus dominated all treatments). Conclusions The results suggest that there was no direct effect of shrimps on algae. Although the pans harbored an apparently high abundance of branchiopods, these animals had little role in regulating primary producers in this environment. PMID:21143855

  10. Egypt's fundamentalists say condoms immoral.

    PubMed

    Soliman, S

    1995-06-01

    The first AIDS case in Egypt was reported almost 10 years ago, yet Egypt still does not have reliable statistics on the HIV/AIDS epidemic (officially, 513 HIV infections and 88 AIDS cases; more likely, 3000 and 10,000, respectively). HIV/AIDS bears a stigma. The government claims that every HIV-infected Egyptian acquired the infection through a blood transfusion while in the Gulf or through sexual intercourse in Europe. Cultural, social, and religious norms that discourage promiscuity may explain the low HIV/AIDS rate but these same taboos put women at risk by making it difficult for them to protect themselves. Islamic fundamentalist women reinforce the Islamic principle of forbidding sex education. They consider AIDS a plague of immoral Western society. They refuse to accept the fact that many men do not practice safer sex. These women consider condoms immoral. They think God will curse women who refuse to have sexual intercourse at their husbands' bidding. Many nongovernmental organizations consider an intensive education program as the only means to avert disaster. Egypt has yet to implement its model AIDS program. All hospitals in Cairo and some hospitals in rural areas have equipment to test for HIV. Surveillance systems have been limited to high risk groups. In Egypt, it is mandatory to test foreigners for HIV. Prisoners, prostitutes, homosexuals, and blood donors are tested randomly without their consent. Positive results are often reported to authorities before the persons learn their HIV status. A campaign for widespread sex education is the only action recommended so far. It includes a mass media component and community meetings and conferences. An Egyptian physician has found an anti-viral drug that stimulates the immune system, but his work does not receive much coverage outside Egypt. Egyptians need to tackle their cultural taboos about discussion of sex to curb the HIV/AIDS epidemic. PMID:12289036

  11. Foreign Deities in Egypt

    E-print Network

    Zivie-Coche, Christiane

    2011-01-01

    government and religion in ancient Egypt. The questionEgypt, Zivie-Coche, UEE 2011 te Velde, Herman 1967 Seth, god of confusion: A study of his role in Egyptian mythology and religion.Egypt is the topic of Schneider (2003, 2006). Issues of alterity in Egyptian religion

  12. Ancient Egypt

    NASA Astrophysics Data System (ADS)

    Swamy, Ashwin Balegar

    This thesis involves development of an interactive GIS (Geographic Information System) based application, which gives information about the ancient history of Egypt. The astonishing architecture, the strange burial rituals and their civilization were some of the intriguing questions that motivated me towards developing this application. The application is a historical timeline starting from 3100 BC, leading up to 664 BC, focusing on the evolution of the Egyptian dynasties. The tool holds information regarding some of the famous monuments which were constructed during that era and also about the civilizations that co-existed. It also provides details about the religions followed by their kings. It also includes the languages spoken during those periods. The tool is developed using JAVA, a programing language and MOJO (Map Objects Java Objects) a product of ESRI (Environmental Science Research Institute) to create map objects, to provide geographic information. JAVA Swing is used for designing the user interface. HTML (Hyper Text Markup Language) pages are created to provide the user with more information related to the historic period. CSS (Cascade Style Sheets) and JAVA Scripts are used with HTML5 to achieve creative display of content. The tool is kept simple and easy for the user to interact with. The tool also includes pictures and videos for the user to get a feel of the historic period. The application is built to motivate people to know more about one of the prominent and ancient civilization of the Mediterranean world.

  13. Whole-Genome Optical Mapping and Finished Genome Sequence of Sphingobacterium deserti sp. nov., a New Species Isolated from the Western Desert of China

    PubMed Central

    Molnár, István; Li, Xinna; Tang, Ran; Chen, Ming; Wang, Lin; Su, Shiyou; Zhang, Wei; Lin, Min

    2015-01-01

    A novel Gram-negative bacterium, designated ZWT, was isolated from a soil sample of the Western Desert of China, and its phenotypic properties and phylogenetic position were investigated using a polyphasic approach. Growth occurred on TGY medium at 5–42°C with an optimum of 30°C, and at pH 7.0–11.0 with an optimum of pH 9.0. The predominant cellular fatty acids were summed feature 3 (C16:1?7c/C16:1?6c or C16:1?6c/C16:1?7c) (39.22%), iso-C15:0 (27.91%), iso-C17:0 3OH (15.21%), C16:0 (4.98%), iso-C15:0 3OH (3.03%), C16:0 3OH (5.39%) and C14:0 (1.74%). The major polar lipid of strain ZWT is phosphatidylethanolamine. The only menaquinone observed was MK-7. The GC content of the DNA of strain ZWT is 44.9 mol%. rDNA phylogeny, genome relatedness and chemotaxonomic characteristics all indicate that strain ZWT represents a novel species of the genus Sphingobacterium. We propose the name S. deserti sp. nov., with ZWT (= KCTC 32092T = ACCC 05744T) as the type strain. Whole genome optical mapping and next-generation sequencing was used to derive a finished genome sequence for strain ZWT, consisting of a circular chromosome of 4,615,818 bp in size. The genome of strain ZWT features 3,391 protein-encoding and 48 tRNA-encoding genes. Comparison of the predicted proteome of ZWT with those of other sphingobacteria identified 925 species-unique proteins that may contribute to the adaptation of ZWT to its native, extremely arid and inhospitable environment. As the first finished genome sequence for any Sphingobacterium, our work will serve as a useful reference for subsequent sequencing and mapping efforts for additional strains and species within this genus. PMID:25830331

  14. Global observations and spectral characteristics of desert dust and

    E-print Network

    Graaf, Martin de

    Global observations and spectral characteristics of desert dust and biomass burning aerosols Martin characteristics of desert dust and biomass burning scenes · Conclusions and Outlook #12;where Rayleigh R340 Saudi-Arabian lowlands Kara-Bogaz Gol Lybian Desert SaharaWestern Sahara Bodèle Prospero et al, 2002

  15. Megaliths and Neolithic astronomy in southern Egypt

    NASA Astrophysics Data System (ADS)

    Malville, J. Mckim; Wendorf, Fred; Mazar, Ali A.; Schild, Romauld

    1998-04-01

    The Sahara west of the Nile in southern Egypt was hyperarid and unoccupied during most of the Late Pleistocene epoch. About 11,000 years ago the summer monsoons of central Africa moved into Egypt, and temporary lakes or playas were formed. The Nabta Playa depression, which is one of the largest in southern Egypt, is a kidney-shaped basin of roughly 10km by 7km in area. We report the discovery of megalithic alignments and stone circles next to locations of Middle and Late Neolithic communities at Nabta, which suggest the early development of a complex society. The southward shift of the monsoons in the Late Neolithic age rendered the area once again hyperarid and uninhabitable some 4,800 radiocarbon years before the present (years BP). This well-determined date establishes that the ceremonial complex of Nabta, which has alignments to cardinal and solstitial directions, was a very early megalithic expression of ideology and astronomy. Five megalithic alignments within the playa deposits radiate outwards from megalithic structures, which may have been funerary structures. The organization of the megaliths suggests a symbolic geometry that integrated death, water, and the Sun. An exodus from the Nubian Desert at ~4,800 years BP may have stimulated social differentiation and cultural complexity in predynastic Upper Egypt.

  16. Geochemical modeling of evaporation process in Lake Qarun, Egypt

    NASA Astrophysics Data System (ADS)

    Abdel Wahed, Mahmoud S. M.; Mohamed, Essam A.; El-Sayed, Mohamed I.; M'nif, Adel; Sillanpää, Mika

    2014-09-01

    Lake Qarun is an inland closed saline lake. It lies within the Fayoum Depression in the Western Desert of Egypt. Evaporation modeling has been carried out using PHREEQC to simulate the geochemical evolution of surface drainage waters inflow towards lake water. In the case of Lake Qarun, it is the first attempt to carry out such kind of modeling. Performance of this model helped to address the different sources of dissolved major ions to Lake Qarun and to identify the mechanisms control the lake's water chemistry. The model demonstrated that evaporation-crystallization process is the main mechanism controlling the evolution of lake water chemistry where major ions Na+, Mg2+, Cl- and SO42- have been built up in the lake by evaporation while Ca2+ and HCO3- are depleted by calcite precipitation. Moreover, the simulated model reproduced the real data observed in Lake Qarun except in the case of SO42- which is in real more enriched in the lake than the model output. The additional source of SO42- is reported to be from groundwater. The models result agreed well with the modified evolutionary Hardie and Eugster's scheme (1970) in which the final major composition of Lake Qarun water is Na-Mg-SO4-Cl type. In future, the monitoring of Lake Qarun chemistry with detection of any other sources of elements and/or local reactions inside the lake can be detected by performing the simulated evaporation model reported by the present study.

  17. Lake Nasser and Toshka Lakes, Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  18. Thar Desert

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This ASTER sub-scene covers an area of 12 x 15 km in NW India in the Thar Desert. The sand dunes of the Thar Desert constantly shift and take on new shapes. Located in northwestern India and eastern Pakistan, the desert is bounded on the south by a salt marsh known as the Rann of Kutch, and on the west by the Indus River plain. About 800 kilometers long and about 490 kilometers wide, the desert's terrain is mainly rolling sandhills with scattered growths of shrub and rock outcroppings. Only about 12 to 25 centimeters of rain fall on the desert each year, and temperatures rise as high as 52 degrees Celsius. Much of the population is pastoral, raising sheep for their wool. The image is located at 24.4 degrees north latitude and 69.3 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  19. Dust Plume off the Coast of Egypt

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Dwarfing the Nile, a river of dust flowed out of the deserts of northern Egypt on May 19, 2007. As the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite passed overhead at 12:05 p.m. local time in Cairo, the sensor captured this image of the dust spreading northward over the Mediterranean Sea from the sandy deserts that span the country. At the margins of the plume, ribbons and ripples of dust are translucent, allowing a glimpse of the desert and water beneath, but in the center, the cloud is opaque, revealing nothing of the surface below. The part of north-central Egypt hidden by the dust plume is the Qattara Depression, the country's lowest point. Dipping down to 133 meters below sea level (436 feet), the depression is home to sandy deserts and dry lake beds that occasionally flood. The sand and fine, lake bed sediments are easily lofted into the air by strong winds that scour the area in late winter and early spring. In the eastern (right-hand) part of the image, the Nile River is lined by narrow ribbons of dull green vegetation. The fan-shaped delta is dotted with tan-colored spots, marking the location of cities and towns. The Nile Valley and Delta make up only a small fraction of the country's total land area, yet they support almost the entire population. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides this image in additional resolutions. The Earth Observatory also provides a 250-meter-resolution KMZ file of this image for use with Google Earth.

  20. Nile behaviour and Upper Palaeolithic humans in Upper Egypt

    NASA Astrophysics Data System (ADS)

    Vermeersch, Pierre M.

    2014-05-01

    There is evidence of a decreasing human occupation of the Upper Egyptian Nile valley during the MIS 5 to MIS 3 period. Whereas very large extraction sites of the Middle Stone Age have been recorded, only very few sites of the Upper Palaeolithic have been found. The best explanation of this fact is that during the Late Middle Stone Age and the Upper Palaeolithc there was nearly no need for raw materials because there was only a very restricted population present in Upper Egypt. From about 22 ka BP an important population increase is registered by the presence of numerous Late Palaeolithic sites. During the whole LGM there is abundant presence of humans along the Nile Valley in Upper Egypt. This population was mainly living from fishing. There seems to be an abrupt end of the Palaeolithic occupation after 12.8 ka BP. Until now, no sites were found in the Valley until some rare Epipaleolithic sites occur about 8.0 ka BP. It will be suggested that these population changes are influenced by the river Nile behaviour. The best interpretation of the observations in the Upper Egyptian Nile Valley is the hypothesis that at the same time that Nile flow was reduced because of the dryness in its source area, the impact of aeolian activity was increased over Northeast Africa. The increased aeolian activity by northern winds in the Fayum and Wadi Ryan during the LGM resulted in the accumulation of aeolian sand in the valley. That aeolian sand was transported along the western Nile valley cliffs until it was accumulated when the Nile Valley change it S-N direction, such as at Nag'Hammadi. At other places sand was invading the Nile valley, directly from the Western Desert, creating a damming of the Nile at several places such as Armant and Aswan. As Nile flow was quite reduced, the Nile was unable to erode all the incoming sand and the Nile water with its important clay content was dammed. At several places large lakes were created in the Nile Valley. Those lakes were an ideal place for the settlement of the Late Palaeolithic fishers. There came an abrupt end to this situation when the Nile returned to its meandering regime at the end of the LGM. This situation created an catastrophic food crisis for the

  1. Napoleon in Egypt.

    ERIC Educational Resources Information Center

    Fagan, Brian

    1989-01-01

    Recounts the 1798 Egyptian campaign of Napoleon Bonaparte, whose Scientific and Artistic Commission documented and described the glories of ancient Egypt. The expedition was a disaster by military standards, but the cultural legacies included the Rosetta Stone, and a chronicle entitled "Description de L'Egypte," which did much to popularize…

  2. Ancient Egypt: History 380.

    ERIC Educational Resources Information Center

    Turk, Laraine D.

    "Ancient Egypt," an upper-division, non-required history course covering Egypt from pre-dynastic time through the Roman domination is described. General descriptive information is presented first, including the method of grading, expectation of student success rate, long-range course objectives, procedures for revising the course, major course…

  3. Desert Survivors!

    ERIC Educational Resources Information Center

    Horton, Jessica; Friedenstab, Steve

    2013-01-01

    This article describes a special third-grade classroom unit based on the reality show "Survivor." The goal of this engaging and interactive unit was to teach students about physical and behavioral adaptations that help animals survive in various desert biomes. The activity combines research, argument, and puppet play over one week of…

  4. Field and ASTER imagery data for the setting of gold mineralization in Western Allaqi-Heiani belt, Egypt: A case study from the Haimur deposit

    NASA Astrophysics Data System (ADS)

    Zoheir, Basem; Emam, Ashraf

    2014-11-01

    Although associated with carbonatized/listvenitized ophiolites and thrust structures, the morphology and internal structures of the auriferous quartz veins in the Haimur deposit suggest mineralization concurrent with NE-SW dextral brittle-ductile shear zones. The latter are attributed to intense transpression regime and are associated with (N)NE-trending tight to isoclinals folds that deform the early accretionary structures. Image processing techniques applicable to the Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) data are used for mapping structures and hydrothermal alteration associated with the Haimur deposit. The automated lineament extraction by LINE module on high resolution ASTER imagery provides efficient data for potential dilation loci. Emphasis is placed on reliability of mineral indices extracted from the ASTER band ratios for identification of possibly mineralized alteration zones associated with NE-trending shear zones. Field and remote sensing data, together with the structural fabrics along the lode-associated shear zones clearly constrain on the genetic relationship between the Haimur gold deposit and post-accretionary transpression/shearing. We conclude that hydrothermal alteration zones that are confined to tightly enfolded ophiolites and transpressive shear zones along the Western Allaqi-Heiani belt are most potential targets for new exploration plans.

  5. Enrichment in Egypt.

    ERIC Educational Resources Information Center

    Harrington, Jean S.

    1985-01-01

    The Cairo (Egypt) American College, offers a program for academically able elementary students based on a broad enrichment philosophy model and selective pullout classes. A resource teacher describes her experiences with the program and its students. (CL)

  6. The Cretaceous glauconitic sandstones of Abu Tartur, Egypt

    NASA Astrophysics Data System (ADS)

    Pestitschek, Brigitte; Gier, Susanne; Essa, Mahmoud; Kurzweil, Johannes

    2010-05-01

    The Abu Tartur mine is located in the Western Desert of Egypt, 50 km west of El Kharga City. Geologically, the Abu Tartur plateau is built by a sequence of Upper Cretaceous (Campanian - Maastrichtian) phosphorites, black shales and glauconitic sandstones. The phosphate deposits are of great economic importance and have been mined since their discovery in 1967. Outcrop sections were measured, sampled, sedimentologically characterized and described. One specific glaucony layer was investigated mineralogically and chemically in detail and compared to a subsurface sample from the mine. Two depositional regimes can be interpreted based on sedimentary architecture and structures: 1) a deeper-water hemipelagic environment, where phosphorites and organic carbon-rich shales were deposited and 2) a shallower, prograding higher energy shelf environment with glauconies. From a sequence stratigraphic perspective 1) was deposited during the transgressive systems tract and the early highstand while 2) was deposited during the remaining highstand and a lowstand prograding wedge (Glenn & Arthur, 1990). Petrographic and SEM investigations show that the glaucony grains are of authochtonous origin. XRF, EMPA and thin-section analyses show that the glaucony grains from the outcrop differ significantly in their chemical composition, morphology and color from the grains of the mine sample. The fresh glauconies are enriched in Fe2O3 and K2O compared to the surface samples. XRD analyses of the clay fraction of the six outcrop samples and the mine sample show that the grains consist of illite(glauconite)/smectite mixed-layers, with more illite layers (80 %) in the mine sample. The charge distribution diagram muscovite-pyrophyllite-celadonite shows a clear trend from smectitic glaucony to illitic glaucony, the mine sample plots exactly in the field for glauconites. All these features indicate that the surface samples are strongly altered by weathering and that glauconite progressively transforms into iron-rich illte/smectite mixed layers and then into smectites. For any chemical and mineralogical characterization of glauconites at surface, these weathering effects have to be taken into consideration. GLENN, C. R. & ARTHUR, M. A. (1990): Anatomy and origin of a Cretaceous phosphorites-greensand giant, Egypt. Sedimentology, 37, 123-154.

  7. Egypt's next steps Ahmed Zewail

    E-print Network

    Zewail, Ahmed

    1 Egypt's next steps Ahmed Zewail 3 Feb 2011 Mubarak must step down, a new constitution must change, writes Ahmed Zewail. CAIRO The revolt that has erupted across Egypt is in many ways historic that the transition to a new Egypt can take place in an orderly and peaceful manner. Dr. Ahmed Zewail was awarded

  8. Safsaf Oasis, Egypt

    NASA Technical Reports Server (NTRS)

    1998-01-01

    These images show two views of a region of south-central Egypt, each taken by a different type of spaceborne sensor. On the left is an optical image from the Landsat Thematic Mapper, and on the right is a radar image from the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR). This comparison shows that the visible and infrared wavelengths of Landsat are only sensitive to the materials on the surface, while the radar wavelengths of SIR-C/X-SAR can penetrate the thin sand cover in this arid region to reveal details hidden below the surface. Field studies in this area indicate that the L-band radar can penetrate as much as 2 meters (6.5 feet) of very dry sand to image buried rock structures. Ancient drainage channels, shown at the bottom of this image, are filled with sand more than 2 meters (6.5 feet) thick and therefore appear dark because the radar waves cannot penetrate them. Only the most recently active channels are visible in the Landsat scene. Some geologic structures at the surface are visible in both images. However, many buried features, such as rock fractures and the blue circular granite bodies in the upper center of the image on the right, are visible only to the radar. The Safsaf Oasis is located near the bright yellow feature in the lower left center of the Landsat image. Scientists are using the penetrating capabilities of radar imaging in desert areas to study structural geology, mineral exploration, ancient climates, water resources and archaeology. Each image is 30.8 kilometers by 25.6 kilometers (19.1 miles by 15.9 miles) and is centered at 22.7 degrees north latitude, 29.3 degrees east longitude. North is toward the upper right. In the Landsat image, the colors are assigned as follows: red is Band 7 (mid-infrared); green is Band 4 (near infrared); and blue is Band 1 (visible blue light). The colors assigned to the radar frequencies and polarizations are as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is X-band, vertically transmitted and received. The radar image was acquired by the Spaceborne Imaging Radar-C/ X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 16, 1994, on board the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Earth Science Enterprise. The Landsat Program is managed jointly by NASA, the National Oceanic and Atmospheric Administration and the United States Geological Survey.

    Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations, and data processing of X-SAR.

  9. Desert Test Site Uniformity Analysis

    NASA Technical Reports Server (NTRS)

    Kerola, Dana X.; Bruegge, Carol J.

    2009-01-01

    Desert test sites such as Railroad Valley (RRV) Nevada, Egypt-1, and Libya-4 are commonly targeted to assess the on-orbit radiometric performance of sensors. Railroad Valley is used for vicarious calibration experiments, where a field-team makes ground measurements to produce accurate estimates of top-of-atmosphere (TOA) radiances. The Sahara desert test sites are not instrumented, but provide a stable target that can be used for sensor cross-comparisons, or for stability monitoring of a single sensor. These sites are of interest to NASA's Atmospheric Carbon Observation from Space (ACOS) and JAXA's Greenhouse Gas Observation SATellite (GOSAT) programs. This study assesses the utility of these three test sites to the ACOS and GOSAT calibration teams. To simulate errors in sensor-measured radiance with pointing errors, simulated data have been created using MODIS Aqua data. MODIS data are further utilized to validate the campaign data acquired from June 22 through July 5, 2009. The first GOSAT vicarious calibration experiment was conducted during this timeframe.

  10. Saharan desert dust microphysical properties from PCA inversion of Raman lidar data over

    E-print Network

    Graaf, Martin de

    Saharan desert dust microphysical properties from PCA inversion of Raman lidar data over Western Europe M. de Graaf1, D.P. Donovan1, A. Apituley1,2, K.M. Wilson1,2 In May 2009 a Saharan desert dust desert dust was advected from the Sahara over Leipzig (Fig. 1). The Raman lidar measurements (Fig. 2

  11. Desert Dust Air Mass Mapping in the Western Sahara, using Particle Properties Derived from Space-based Multi-angle Imaging

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Fiebig, Marcus; Schladitz, Alexander; von Hoyningen-Huene, Wolfgang

    2008-01-01

    Coincident observations made over the Moroccan desert during the SAhara Mineral dUst experiMent (SAMUM) 2006 field campaign are used both to validate aerosol amount and type retrieved from Multi-angle Imaging SpectroRadiometer (MISR) observations, and to place the sub-orbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days for which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 to 0.1. This is about as well as can be expected given spatial sampling differences; the space-based observations capture AOT trends and variability over an extended region. The field data also validate MISR's ability to distinguish and to map aerosol air masses, from the combination of retrieved constraints on particle size, shape, and single-scattering albedo. For the three study days, the satellite observations (a) highlight regional gradients in the mix of dust and background spherical particles, (b) identify a dust plume most likely part of a density flow, and (c) show an air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometers away.

  12. Dwarfs in ancient Egypt.

    PubMed

    Kozma, Chahira

    2006-02-15

    Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities. PMID:16380966

  13. Nile Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The Nile Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population of 57 million. The capital city of Cairo is at the apex of the delta in the middle of the scene. Across the river from Cairo can be seen the three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  14. Nile River Delta, Egypt

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

  15. Data from a Thick Unsaturated Zone Underlying Two Artificial Recharge Sites along Oro Grande Wash in the Western Part of the Mojave Desert, near Victorville, San Bernardino County, California, 2001-2006

    USGS Publications Warehouse

    Clark, Dennis A.; Izbicki, John A.; Johnson, Russell D.; Land, Michael

    2009-01-01

    This report presents data on the physical and hydraulic properties of unsaturated alluvial deposits and on the chemical and isotopic composition of water collected at two recharge sites in the western part of the Mojave Desert, near Victorville, California, from 2001 to 2006. Unsaturated-zone monitoring sites were installed adjacent to the two recharge ponds using the ODEX air-hammer and air rotary method to depths of about 460 feet and 269 feet below land surface. Each of the two unsaturated-zone monitoring sites included a water-table well, matric-potential sensors, and suction-cup lysimeters installed in a single bore hole. Drilling procedures, lithologic and geophysical data, and site construction and instrumentation are described. Core material was analyzed for water content, bulk density, water potential, particle size, and water retention. The chemical composition of leachate from almost 400 samples of cores and cuttings was determined. Water from suction-cup lysimeters also was analyzed for chemical and isotopic composition. In addition, data on the chemical and isotopic composition of groundwater from the two water-table wells are reported along with chemical and isotopic composition of the surface water in the recharge ponds.

  16. Reflections about bizarre mummification practices on mummies at Egypt's Dakhleh oasis: a review.

    PubMed

    Aufderheide, Arthur C

    2009-12-01

    About 100 mummified human remains were excavated from the Dakhleh Oasis in Egypt's Western Desert. Of these, less than half were examined by dissection. These dated to the Late Ptolemaic and Roman Periods. Initially, a confusing pattern of mortuary mummification practices was encountered that was identified ultimately as a product of primarily initial spontaneous mummification by desiccation. This was followed by tomb robbing in antiquity with unwrapping; body disarticulation followed, in turn, by mummy body reconstruction with atypical use of resin applications. Some of the resin was shown to be contaminated by bitumen that was responsible for inappropriately old radiocarbon dates of mummy tissue samples. Chemical reconstruction of diet using stable isotope ratios of carbon and nitrogen characterized their diet to be primarily that of C3 plants, consistent with trading records excavated from that site. Analysis of the mummy coprolites also enabled the first finding of the intestinal parasite Enterobius vermicularis in either ancient or modern Egyptian human coprolites. The principal focus of this report is to demonstrate and verify the value of including visceral dissection as part of a mummy examination whenever possible. PMID:20440958

  17. SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN.

    USGS Publications Warehouse

    Breed, Carol S.; McCauley, John F.; Schaber, Gerald G.

    1984-01-01

    Shuttle Imaging Radar provides a pictorial framework to guide exploration for mineral resources (potential placers), groundwater sources, and prehistoric archaeological sites in the Western Desert of Egypt and Sudan. Documented penetration by the SIR-A signal of dry surficial sediment to depths of a meter or more revealed bedrock geologic features and networks of former stream valleys otherwise concealed beneath windblown sand, alluvium, and colluvial deposits. 'Radar units' mapped on SIR-A images according to relative brightness and degree of mottling correspond to subsurface geologic and topographic features identified in more than 50 test pits. Petrologic examination of pit samples confirms that a variety of depositional environments existed in this now hyper-arid region before it was mantled by windblown sand sheets and dunes. Wet sand was discovered in two buried valleys shown on the radar images and located in the field with the aid of co-registered maps and Landsat images, and a satellite navigation device. Buried valleys whose streams once traversed mineralized zones are potential sites of placers (gold, tin).

  18. Recent environmental change and prehistoric human activity in Egypt and Northern Sudan

    NASA Astrophysics Data System (ADS)

    Nicoll, Kathleen

    2004-03-01

    This paper reviews the various Late Quaternary records that are available from western Egypt and northern Sudan, which includes more than 500 published radiocarbon dates and various sedimentary archives from local landscape components, including palaeolakes, soils, drainages (wadis), and archaeological sites. This palaeoenvironmental compilation frames the spatial and temporal context of local cultural activities when the region was most hospitable ˜9000-6000 BP; at this time, monsoonal weather influenced the portion of the African continental interior, creating enough convective rainfall for occasional surface water storage. In this part of the modern Sahara, rapid hydroclimatic changes play a key role in geomorphic evolution and resource availability. As 'watering holes' formed and dried up in the Early to Middle Holocene, Neolithic people developed various subsistence strategies, including opportunistic hunting of small animals (e.g. gazelle and hare), and food-related (e.g. wild sorghum, millet, and legumes) activities: gathering, plant cultivation and livestock-rearing. During its wettest phases during the 'monsoonal maximum,' the area was drought-prone, sustaining a meager steppe-shrub desert flora. Further desertification and aeolian deflation during the Middle and Late Holocene fostered technological innovation, migration and settlement, as well as the further development of agrarian communities and complex culture.

  19. Desert Voices: Southwestern Children's Literature.

    ERIC Educational Resources Information Center

    Polette, Keith

    1997-01-01

    Examines three books with different ways of writing about the desert. Discusses: "Here Is the Southwestern Desert" by Madeline Dunphy, "The Desert Is My Mother" by Pat Mora, and "The Desert Mermaid" by Alberto Blanco. (PA)

  20. Ancient Egypt: Personal Perspectives.

    ERIC Educational Resources Information Center

    Wolinski, Arelene

    This teacher resource book provides information on ancient Egypt via short essays, photographs, maps, charts, and drawings. Egyptian social and religious life, including writing, art, architecture, and even the practice of mummification, is conveniently summarized for the teacher or other practitioner in a series of one to three page articles with…

  1. Egypt's National Education Debate.

    ERIC Educational Resources Information Center

    Cook, Bradley James

    2000-01-01

    Examines the vigorous dialectic occurring among intellectuals, religious leaders, and politicians trying to define the appropriate role of Islam in Egyptian education. Discusses the call for the Islamization of education in contemporary Egypt, aspects of Islamic law, the position of the state on religious education, and the influence of a small…

  2. Ancient Egypt, Sacred Science, and Transatlantic Romanticism

    E-print Network

    Redd, Marques Jerard

    2011-01-01

    Egypt in England and America: The Cultural Memorials of Religion,Egypt in England and America: The Cultural Memorials of Religion,Egypt, these writers attempted to create a consistent, coherent, and interrelated system, where art, science, philosophy, and religion

  3. The Regional Environmental Impacts of Atmospheric Aerosols over Egypt

    NASA Astrophysics Data System (ADS)

    Zakey, Ashraf; Ibrahim, Alaa

    2015-04-01

    Identifying the origin (natural versus anthropogenic) and the dynamics of aerosols over Egypt at varying temporal and spatial scales provide valuable knowledge on the regional climate impacts of aerosols and their ultimate connections to the Earth's regional climate system at the MENA region. At regional scale, Egypt is exposed to air pollution with levels exceeding typical air-quality standards. This is particularly true for the Nile Delta region, being at the crossroads of different aerosol species originating from local urban-industrial and biomass-burning activities, regional dust sources, and European pollution from the north. The Environmental Climate Model (EnvClimA) is used to investigate both of the biogenic and anthropogenic aerosols over Egypt. The dominant natural aerosols over Egypt are due to the sand and dust storms, which frequently occur during the transitional seasons (spring and autumn). In winter, the maximum frequency reaches 2 to 3 per day in the north, which decreases gradually southward with a frequency of 0.5-1 per day. Monitoring one of the most basic aerosol parameters, the aerosol optical depth (AOD), is a main experimental and modeling task in aerosol studies. We used the aerosol optical depth to quantify the amount and variability of aerosol loading in the atmospheric column over a certain areas. The aerosols optical depth from the model is higher in spring season due to the impacts of dust activity over Egypt as results of the westerly wind, which carries more dust particles from the Libyan Desert. The model result shows that the mass load of fine aerosols has a longer life-time than the coarse aerosols. In autumn season, the modelled aerosol optical depth tends to increase due to the biomass burning in the delta of Egypt. Natural aerosol from the model tends to scatter the solar radiation while most of the anthropogenic aerosols tend to absorb the longwave solar radiation. The overall results indicate that the AOD is lowest in winter due to airborne particles washed out by rain events. Conversely, the AOD increases in summer because particle accumulation is favored by the absence of precipitation during this season. Moreover, in summer, photochemical processes in the atmosphere lead to slight increases in the values of aerosol optical characteristics, despite lower wind speeds [hence less wind-blown dust] relative to other seasons. This study has been conducted under the PEER 2-239 research project titled "the Impact of Biogenic and Anthropogenic Atmospheric Aerosols to Climate in Egypt". Project website: CleanAirEgypt.org

  4. ECOLOGY OF DESERT SYSTEMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional wisdom considers deserts stark, harsh regions that support few living things. Most people also believe that water alone makes the desert bloom. Ecology of Desert Systems challenges these conventional views. This volume explores a broad range of topics of interest to ecosystem, popula...

  5. Hydrogeochemical analysis and evaluation of groundwater in the reclaimed small basin of Abu Mina, Egypt

    NASA Astrophysics Data System (ADS)

    Salem, Zenhom E.; Atwia, Mohamed G.; El-Horiny, Mohamed M.

    2015-09-01

    Agricultural reclamation activities during the last few decades in the Western Nile Delta have led to great changes in the groundwater levels and quality. In Egypt, changing the desert land into agricultural land has been done using transferred Nile water (through irrigation canal systems) or/and groundwater. This research investigates the hydrogeochemical changes accompanying the reclamation processes in the small basin of Abu Mina, which is part of the Western Nile Delta region. In summer 2008, 23 groundwater samples were collected and groundwater levels were measured in 40 observation wells. Comparing the groundwater data of the pre-reclamation (1974) and the post-reclamation (2008) periods, groundwater seems to have been subjected to many changes: rise in water level, modification of the flow system, improvement of water quality, and addition of new salts through dissolution processes. Generally, Abu Mina basin is subdivided into two areas, recharge and discharge. The dissolution and mixing were recognized in the recharge areas, while the groundwater of the discharge region carries the signature of the diluted pre-reclamation groundwater. The salts of soil and aquifer deposits play an important role in the salt content of the post and pre-reclamation groundwater. NaCl was the predominant water type in the pre-reclamation groundwater, while CaSO4, NaCl and MgSO4 are the common chemical facies in the post-reclamation groundwater. The post-reclamation groundwater mostly indicates mixing between the pre-reclamation groundwater and the infiltrated freshwater with addition of some ions due to interaction with soil and sediments.

  6. New Paleocene Sepiid Coleoids (Cephalopoda) from Egypt: Evolutionary Significance and Origin of the Sepiid ‘Rostrum’

    PubMed Central

    Koš?ák, Martin; Jagt, John W. M.; Speijer, Robert P.; Stassen, Peter; Steurbaut, Etienne

    2013-01-01

    New coleoid cephalopods, assignable to the order Sepiida, are recorded from the Selandian/Thanetian boundary interval (Middle to Upper Paleocene transition, c. 59.2 Ma) along the southeastern margin (Toshka Lakes) of the Western Desert in Egypt. The two genera recognised, Aegyptosaepia n. gen. and ?Anomalosaepia Weaver and Ciampaglio, are placed in the families Belosaepiidae and ?Anomalosaepiidae, respectively. They constitute the oldest record to date of sepiids with a ‘rostrum-like’ prong. In addition, a third, generically and specifically indeterminate coleoid is represented by a single rostrum-like find. The taxonomic assignment of the material is based on apical parts (as preserved), i.e., guard, apical prong (or ‘rostrum-like’ structure), phragmocone and (remains of) protoconch, plus shell mineralogy. We here confirm the shell of early sepiids to have been bimineralic, i.e., composed of both calcite and aragonite. Aegyptosaepia lugeri n. gen., n. sp. reveals some similarities to later species of Belosaepia, in particular the possession of a distinct prong. General features of the phragmocone and protoconch of the new form are similar to both Belocurta (Middle Danian [Lower Paleocene]) and Belosaepia (Eocene). However, breviconic coiling and the presence of a longer ventral conotheca indicate closer ties with late Maastrichtian–Middle Danian Ceratisepia. In this respect, Aegyptosaepia n. gen. constitutes a link between Ceratisepia and the Eocene Belosaepia. The occurrence of the new genus near the Selandian/Thanetian boundary suggests an earlier origin of belosaepiids, during the early to Middle Paleocene. These earliest known belosaepiids may have originated in the Tethyan Realm. From northeast Africa, they subsequently spread to western India, the Arabian Plate and, probably via the Mediterranean region, to Europe and North America. PMID:24348918

  7. Modern Egypt: A Development Perspective.

    ERIC Educational Resources Information Center

    Scott, Rosalind; And Others

    Egypt is a culture which combines the traditional with the modern. This text aims to foster an appreciation of Egypt as a changing culture facing the challenges of development. Topics included are: (1) Village Life; (2) Urban Life; (3) Nile; (4) Government; (5) Agriculture; (6) Economy; (7) Health/Games; (8) Education; (9) Religion; (10)…

  8. Mesozoic carbonate-siliciclastic platform to basin systems of a South Tethyan margin (Egypt, East Mediterranean)

    NASA Astrophysics Data System (ADS)

    Tassy, Aurélie; Crouzy, Emmanuel; Gorini, Christian; Rubino, Jean-Loup

    2015-04-01

    The Mesozoïc Egyptian margin is the south margin of a remnant of the Neo-Tethys Ocean, at the African northern plate boundary. East Mediterranean basin developed during the late Triassic-Early Jurassic rifting with a NW-SE opening direction (Frizon de Lamotte et al., 2011). During Mesozoïc, Egypt margin was a transform margin with a NW-SE orientation of transform faults. In the Eastern Mediterranean basin, Mesozoïc margins are characterized by mixed carbonate-siliciclastics platforms where subsidence and eustacy are the main parameters controlling the facies distribution and geometries of the platform-to-basin transition. Geometries and facies on the platform-slope-basin system, today well constrained on the Levant area, where still poorly known on the Egyptian margin. Geometries and stratigraphic architecture of the Egyptian margin are revealed, thanks to a regional seismic and well data-base provided by an industrial-academic group (GRI, Total). The objective is to understand the sismostratigraphic architecture of the platform-slope-basin system in a key area from Western Desert to Nile delta and Levant margin. Mapping of the top Jurassic and top Cretaceous show seismic geomorphology of the margin, with the cartography of the hinge line from Western Desert to Sinaï. During the Jurassic, carbonate platform show a prograding profile and a distally thickening of the external platform, non-abrupt slope profiles, and palaeovalleys incisions. Since the Cretaceous, the aggrading and retrograding mixed carbonate-siliciclastic platform show an alternation of steep NW-SE oblique segments and distally steepened segments. These structures of the platform edge are strongly controlled by the inherited tethyan transform directions. Along the hinge line, embayments are interpreted as megaslides. The basin infilling is characterised by an alternation of chaotic seismic facies and high amplitude reflectors onlaping the paleoslopes. MTC deposits can mobilize thick sedimentary series (up to 3500 m) as a mixed combination of debris flows, internal preserved blocks, and/or compressively-deformed distal allochthonous masses. Transported material have proceeded from the dismantling of the Mesozoic mixed carbonate-siliciclastic platform. They can spread down slope over areas as large as 70000 of km2. According to stratigraphic correlations with global sea-level positions, platform instability would have been triggered by the gravitational collapse of the carbonate-siliciclastic platform under its own weight after successive subaerial exposures which were able to generate karstification processes. Seismic interpretation is constrained by a detailed assessment of the Egyptian margin paleogeography supported by wells. This margin segment is briefly compared to the outcropping Apulian margin in Italy.

  9. [Sexuality in Ancient Egypt].

    PubMed

    Androutsos, G; Marketos, S

    1994-10-01

    The present article explores the sexuality in ancient Egypt. In particular in this article are presented the ways of concubinage (marriage, concubinage, adultery), the incest, loves of the pharaohs and of the common people, the freedom of choice in garments, the status of the hetairas and of the whores, the sexual perversions (male and female homosexuality, necrophilia, sodomism, bestiality, rape, masturbation, exhibitionism), the operations of the genitals (circumcision, excision, castration) and finally the level of knowledge in gynaecology, fertility, contraception and obstetrics that even today demands our admiration. PMID:7858632

  10. Reclaiming freshwater sustainability in the Cadillac Desert

    PubMed Central

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H. W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%. PMID:21149727

  11. Reclaiming freshwater sustainability in the Cadillac Desert

    USGS Publications Warehouse

    Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

    2010-01-01

    Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

  12. New insights into microbially induced sedimentary structures in alkaline hypersaline El Beida Lake, Wadi El Natrun, Egypt

    NASA Astrophysics Data System (ADS)

    Taher, Amany G.; Abdel-Motelib, Ali

    2015-10-01

    Microbially induced sedimentary structures (MISS) were studied in detail in the alkaline hypersaline El Beida Lake of Wadi El Natrun in the western desert sector of Egypt, based on field observations and sampling performed in 2013 and 2014. Geomorphologically, the lake can be subdivided into three zones, each with characteristic sedimentary and biosedimentary structures. The marginal elevated zone that borders the lake is characterized by thick blocky crusts devoid of microbial mats. The middle-lower supratidal zone has luxuriant microbial mats associated with knotty surfaces, mat cracks and wrinkle structures. A zone of ephemeral shallow pools and channels is characterized by reticulate surfaces, pinnacle mats, sieve-like surfaces, gas domes and mat chips. In the microbial mats, authigenic minerals include thenardite Na2SO4, trona Na3(CO3)(HCO3)•2H2O and halite NaCl. Scanning electron microscopy (SEM) analyses revealed that the minerals are closely associated with the MISS, suggesting some influence of microorganisms on mineral precipitation. Complex interactions between regional hydrological cycles and diagenetic processes imply low preservation potential. MISS signatures of such saline lakes can serve as key analogues for interpreting the geologic record.

  13. Calcareous benthonic foraminifera across the Cretaceous/Paleocene transition of Gebel Um El-Ghanayem, Kharga Oasis, Egypt

    NASA Astrophysics Data System (ADS)

    Orabi, Orabi H.; Khalil, Hamza M.

    2014-08-01

    The studies of benthic calcareous foraminifera of the Maastrichtian-early Paleocene Dakhla Formation in Gebel Um El-Ghanayem (Western Desert, Egypt), improve reconstruction of depositional environments of these successions. In total, 68 taxa of benthic foraminifera were identified in the studied succession. The late Maastrichtian assemblages (Zone CF3) are dominated by calcareous foraminifera with tapered tests, this tapered taxon Loxostomum applinae, Lox. tegulatum various dentalinid taxa, and Buliminella cushmani dominate in CF3 Biozone. We thus interpret these faunas as being dominated by infaunal morphogroups, suggesting a moderately eutrophic environment. Danian assemblages are characterized by abundant epifaunal trochospiral species, such as Cibicidoides abudurbensis, Cibicidoides farafraensis, and Gyroidinoides girardanus. The infaunal morphogroups make up 25-47% of fauna in the Danian, in contrast to 62-76% in the Upper Maastrichtian. This dominance of the Danian benthic foraminiferal assemblages by epifaunal or mixed epifaunal/infaunal morphogroups suggests that the food supply to the benthos was less abundant than in the latest Cretaceous. The Cretaceous/Paleocene boundary (K/Pg) is within the upper unit of the Lower Kharga Member and marked by a hiatus in at least the top of CF3 Zone of the Upper Maastrichtian to the Lower Paleocene (base Plc Zone).

  14. Paleocene stratigraphy in Egypt

    NASA Astrophysics Data System (ADS)

    Farouk, Sherif

    2016-01-01

    The Egyptian Paleocene is widely distributed with vertical and lateral facies changes geographically separated and subject to different tectonic and sedimentary regimes. Five coeval facies associations of the Paleocene outcrops are identified and named from south to north: Garra El-Arbain, Nile Valley, Farafra, Sinai, and Southern Galala. Ten Paleocene third-order depositional sequences (Ds Da1 to Ds Th9) are tentatively distinguished in Egypt. These are bounded at their base and top by ten sequence boundaries (Eg.Da-1, Eg.Da-2, Eg.Da-3, Eg.Da-4, Eg.Da-5, Eg.Da-6, Eg.Se-7, Eg.Th.-8, Eg.Th.-9, and Eg.Eo-10). The relative ages and correlation of the Paleocene depositional sequences are based on planktonic foraminiferal biostratigraphy. Comparison of identified Paleocene sequences in and outside Egypt are referred to eustatic sea-level changes and partly to regional tectonics events, which have caused hiatuses of variable durations and different configurations of Paleocene sedimentary regimes from place to place.

  15. Transect workshop held in Egypt

    NASA Astrophysics Data System (ADS)

    Barazangi, Muawia

    A workshop on the progress of the Global Geoscience Transects (GGT) project in the Middle East and Africa (see maps) was held January 15-17 in Cairo, Egypt. (Transect plans in the region have been described in Eos, 69, p. 124). It was jointly organized and funded by the Egyptian National Committee of Geodesy and Geophysics and the International Lithosphere Program coordinating Committee CC-7 of GGT. A. Ashour of Cairo University, Egypt, chaired the workshop; the general secretary was S. Riad of Assiut University, Egypt, who was responsible for most of the organization, scheduling and implementation of the workshop.

  16. New Lakes in the Egyptian Desert

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Four lakes formed recently in southern Egypt in an area that was previously desert. Fed by unusually high levels of rainfall and water overflowing from the Aswan High Dam on the Nile River, the first lake appeared in 1998. The Aswan's overflowing waters are channeled through an arroyo into a reservoir, as expected, but as the high rains have continued, so has the overflow. Consequently, the reservoir has grown in size and three more lakes have formed. Authorities in Egypt estimate that, together, the lakes now hold about 700 billion cubic feet of water--one quarter the Nile's total water supply. Scientist don't know whether or not the lakes will remain, or will dry up within a few years. In this true-color image acquired by the Moderate-resolution Imaging Spectroradiometer (MODIS), on October 10, 2000, the lakes are the areas of dark pixels located about 50 km west of Lake Nasser. Image by Robert Simmon Reto Stockli, and Brian Montgomery, NASA GSFC

  17. Desert Perchlorate Field Work

    USGS Multimedia Gallery

    USGS scientists dig soil pits in Nevada's Amargosa Desert to study the distribution of natural perchlorate and to determine the atmospheric-soil-plant interactions that affected perchlorate's cycling in a terrestrial ecosystem. Amargosa Desert, Nevada ~17 km south of Beatty; ~20 km east of D...

  18. Desert Storm environmental effects

    NASA Astrophysics Data System (ADS)

    Kimball, E. W.

    It is noted that after more than six months of operation of the Patriot launch station in the Saudi Arabian desert no problems that were attributed to high temperature occurred. The environmental anomalies that did occur were cosmetic in nature and related to dust and salt fog. It was concluded that the Desert Storm environmental effects were typical of worldwide hot, dry climates.

  19. Negev: Land, Water, and Life in a Desert Environment

    NASA Astrophysics Data System (ADS)

    Back, William

    In view of the continuing increased concern about the extreme fragility of deserts and desert margins, Negev provides a timely discussion of land-use practices compatible with the often conflicting goals of preservation and development. The success o f agricultural and hydrologic experiments in the Negev desert of Israel offers hope to the large percentage of the world's population that lives with an unacceptably low quality of life in desert margins. Deserts are the one remaining type of open space that, with proper use, has the potential for alleviating the misery often associated with expanding population.In addition to the science in the book, the author repeatedly reinforces the concept that “western civilization is inextricably bound to the Negev and its environs, from which it has drawn, via its desert-born religions—Judasium, Christianity, and Islam—many of the mores and concepts, and much of the imagery and love of the desert, including man's relation to nature and to ‘God’.” Deserts often are erroneously perceived to be areas of no water: In reality, these are areas in which a little rainfall occurs sporadically and unpredictably over time. This meager water supply can be meticulously garnered to produce nutritious crops and forage.

  20. Integrating Gene Transcription-Based Biomarkers to Understand Desert Tortoise and Ecosystem Health

    E-print Network

    Lewison, Rebecca

    Integrating Gene Transcription-Based Biomarkers to Understand Desert Tortoise and Ecosystem Health, Western Ecological Research Center, Nevada Field Stations, Henderson, NV Abstract: Tortoises and survival of tortoises is difficult to detect. As an addition to current diagnostic methods for desert

  1. Home Range, Reproduction, and Survival of the Desert Kit Fox, Southeastern, California 

    E-print Network

    Randel III, Charles J

    2015-07-17

    Kit foxes (Vulpes macrotis) are small, nocturnally active, arid-land foxes found in semi-arid and desert climates in western North American and northern Mexico. Two kit fox subspecies: the federally endangered and state ...

  2. Atmospheric Environment 40 (2006) 38813897 Field measurements of desert dust deposition in Libya

    E-print Network

    Clarke, Michèle

    2006-01-01

    and the Caribbean (Perry et al., 1997; Prospero, 1999; Prospero and Lamb, 2003; Holmes and Miller, 2004). Airbourne significant sources being the Libyan Desert; the playa lakes of western Tunisian and northern Algeria; Mali

  3. DISTRIBUTIONAL CHANGES AND POPULATION STATUS FOR AMPHIBIANS IN THE EASTERN MOJAVE DESERT

    EPA Science Inventory

    A number of amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert of western North America, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distributional changes for amphi...

  4. Study Abroad Egypt--2012 Student Handbook

    E-print Network

    of the course are: 1. To teach students about the history, art, and architecture of ancient Egypt within, and architecture of ancient Egypt and Nubia by visiting cities, pyramids, tombs, and temples built by Egyptians. We in understanding and contextualizing the lectures you have already heard. Ancient Egypt will come alive for you

  5. Mathematics in Ancient Egypt Philippe Cara

    E-print Network

    Einmahl, Uwe

    Mathematics in Ancient Egypt Philippe Cara Department of Mathematics http://www.vub.ac.be/DWIS BEST Summerschool "Pyramids in the Cosmos" VUB, 7th September 2001 #12;1 The use of Mathematics in Ancient Egypt · Partitioning of fertile grounds #12;1 The use of Mathematics in Ancient Egypt · Partitioning of fertile grounds

  6. Sonoran Desert: Fragile Land of Extremes

    USGS Publications Warehouse

    Produced and Directed by Wessells, Stephen

    2003-01-01

    'Sonoran Desert: Fragile Land of Extremes' shows how biologists with the U.S. Geological Survey work with other scientists in an effort to better understand native plants and animals such as desert tortoises, saguaro cacti, and Gila monsters. Much of the program was shot in and around Saguaro National Park near Tucson, Arizona. Genetic detective work, using DNA, focuses on understanding the lives of tortoises. Studies of saguaros over many decades clarify how these amazing plants reproduce and thrive in the desert. Threats from fire, diseases in tortoises, and a growing human population motivate the scientists. Their work to identify how these organisms live and survive is a crucial step for the sound management of biological resources on public lands. This 28-minute program, USGS Open-File Report 03-305, was shot entirely in high definition video and produced by the USGS Western Ecological Research Center and Southwest Biological Science Center; produced and directed by Stephen Wessells, Western Region Office of Communications.

  7. Alexandria (Al Iskandariya), Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This image of Alexandria was taken by astronauts on board the International Space Station in December 2000 using an Electronic Still Camera. A wider-angle view (STS088-739-90) taken from the Space Shuttle in December 1998 is available for context. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. Originally the town was built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos (see referenced website, below) to the mainland. Since then sedimentary deposits have widened the mole. Since 1905, when the 370,000 Alexandrians lived in an area of about 4 sq km between the two harbors, the city (population 4 million; see referenced website, below) has grown beyond its medieval walls and now occupies an area of about 300 sq km. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon. Reference Youssef Halim and Fatma Abou Shouk, 2000, Human impacts on Alexandria's marine environment: UNESCO, Coastal Regions and Small Islands Unit (CSI), Coastal Management Sourcebooks 2 (accessed December 20, 2000) Additional photographs taken by astronauts can be viewed at NASA-JSC's Gateway to Astronaut Photography of Earth. Image ISS001-ESC-5025 provided by the Earth Sciences and Image Analysis Laboratory, Johnson Space Center.

  8. Eyewitness introduction to Egypt: "The gift of the Nile".

    PubMed

    Brown, Geraldine

    2009-01-01

    Northeastern corner of Africa, lying at the crossroads between the two continents of Europe and Asia (in the Sinai Peninsula), while bordering Libya, Sudan, Israel and the Red Sea. Egypt is the most ancient tourist country in the world. Several health fact-finding missions in the last few years were made to this small country that is frequently defined by the Valley of the Nile. With the spreading deserts on either side, or a very rich heritage of ancient relics, these scenic vistas are without equal elsewhere in the world. Although there are significant cultural differences among the population, Egypt has a long history of ethnic and religious compassion. Among the many rarities, main tourist attractions include the three great Pyramids of Giza and the Sphinx, amazing ancient wonders of the world. These fact-finding missions included how health and medical care are defined, how people and culture are intertwined with its physical features, land use, and the economy and its resources. PMID:19927898

  9. The Desert Environment January 26, 1999 1 The Desert Environment

    E-print Network

    Reiss, Steven P.

    The Desert Environment January 26, 1999 1 The Desert Environment Revised Paper Steven P. Reiss1@cs.brown.edu Abstract The Desert software engineering environment is a suite of tools developed to enhance pro- grammer virtual files on demand to address specific tasks. All this is done in an open and extensible environment

  10. The application of petrophysics to resolve fluid flow units and reservoir quality in the Upper Cretaceous Formations: Abu Sennan oil field, Egypt

    NASA Astrophysics Data System (ADS)

    Lala, Amir Maher Sayed; El-sayed, Nahla Abd El-Aziz

    2015-02-01

    Petrophysical flow unit concept can be used to resolve some of the key challenges faced in the characterization of hydrocarbon reservoirs. The present study deals with petrophysical evaluation of some physical properties of the Upper Cretaceous rock samples obtained from the Abu-Roash and the Bahariya Formations at southwest of Sennan oil field in the Western Desert of Egypt. The aim of this study was achieved through carrying out some petrophysical measurements of porosity, bulk density, permeability, mean hydraulic radius (Rh), irreducible water saturation, and radius of pore throat at mercury saturation of 35% in order to determine reservoir characteristics. In this study, the relationships obtained between the measured petrophysical properties such as porosity, permeability and pore throat flow unit types were established for 53 sandstone core samples obtained from two different stratigraphic units. Flow zone indicator (FZI) has been calculated to quantify the flow character of the Abu-Roash and Bahariya reservoir rocks based on empirically derived equations of robust correlation coefficients. The correlations among porosity, permeability, bulk density, mean hydraulic radius and pore throat flow properties reflect the most important reservoir behavior characteristics. The calculated multiple regression models indicate close correlation among petrophysical properties and Rh and R35%. The obtained models are able to predict Rh and R35% by using porosity and permeability, to map reservoir performance and predict the location of stratigraphic traps.

  11. Analysis of groundwater flow in arid areas with limited hydrogeological data using the Grey Model: a case study of the Nubian Sandstone, Kharga Oasis, Egypt

    NASA Astrophysics Data System (ADS)

    Mahmod, Wael Elham; Watanabe, Kunio; Zahr-Eldeen, Ashraf A.

    2013-08-01

    Management of groundwater resources can be enhanced by using numerical models to improve development strategies. However, the lack of basic data often limits the implementation of these models. The Kharga Oasis in the western desert of Egypt is an arid area that mainly depends on groundwater from the Nubian Sandstone Aquifer System (NSAS), for which the hydrogeological data needed for groundwater simulation are lacking, thereby introducing a problem for model calibration and validation. The Grey Model (GM) was adopted to analyze groundwater flow. This model combines a finite element method (FEM) with a linear regression model to try to obtain the best-fit piezometric-level trends compared to observations. The GM simulation results clearly show that the future water table in the northeastern part of the study area will face a severe drawdown compared with that in the southwestern part and that the hydraulic head difference between these parts will reach 140 m by 2060. Given the uncertainty and limitation of available data, the GM produced more realistic results compared with those obtained from a FEM alone. The GM could be applied to other cases with similar data limitations.

  12. Team Egypt! Integrating the Disciplines.

    ERIC Educational Resources Information Center

    Greenwald, Amanda Welsh

    2000-01-01

    Describes a unit on Egypt used in an interdisciplinary curriculum that involves activities in social studies, art, science, language (Latin), and computers. Explains that each discipline is assessed separately in order to reward students' strengths. Highlights the benefits of interdisciplinary curricula. (CMK)

  13. The Geometry of Desert

    E-print Network

    Kagan, Shelly

    2005-01-01

    Kansas The Geometry of Desert Shelly Kagan Here are two widely accepted claims about (moral) desert. First, people differ from one another in terms of how deserving they are, and because of this, some deserve more than others. Second, other things being equal..., it is an intrinsically good thing for people to get what they deserve. These two claims-which I will pretty much take as given in this paper-seem simple and straightforward enough. Of course, they imme­ diately bring us face to face with some familiar (and perennially...

  14. Tectonic framework of northeast Egypt and its bearing on hydrocarbon exploration

    SciTech Connect

    Khalil, M.; Moustafa, A.R.

    1995-08-01

    Detailed structural study of northern and central Sinai, the northern Eastern Desert, and the northern Gulf of Suez clarified the tectonic framework of northeast Egypt. This framework is related to the movements between the African Plate and the Eurasian and Arabian Plates. Late Cretaceous folding and thrusting in response to oblique convergence between the African and Eurasian Plates formed NE-ENE oriented, doubly plunging, en echelon folds of the northern Egypt fold belt. This fold belt is well exposed in northern Sinai and a few other places but is concealed under younger sediments in the other parts of northern Egypt. Younger folding of local importance is related to dextral slip on the Themed Fault (Central Sinai) in post Middle Eocene-pre Miocene time. Early Miocene rifting of the Afro-Arabian Plate led to the opening of the Suez rift and deposition of significant syn-rift facies. Half grabens and tilted fault blocks dominate the rift. Slightly tilted fault blocks characterize the competent Middle Eocene limestones of the Eastern Desert south of the Cairo-Suez road but north of this road, Middle Eocene rocks are locally dragged on nearby E-W and NW-SE oriented faults forming fault-drag folds. Ductile Upper Eocene and Miocene rocks are also folded about gentle NW-SE oriented doubly plunging folds. The different stages of tectonic activity in northern Egypt contributed to the development of different types of structural traps as well as different source, reservoir, and cap rocks. The sedimentary history of the region indicates well developed marine sediments of Jurassic, Cretaceous, Eocene, and Miocene ages. Basin development in structurally low areas provided good sites for hydrocarbon generation and maturation.

  15. Palynology and Stratigraphy of the Nubian Sandstone in Libya and Comparison with Egypt

    NASA Astrophysics Data System (ADS)

    Tekbali, Ali; Hlal, Osama

    2013-04-01

    The so-called "Nubian Sandstone" outcrops along a wide area from Algeria to the Red Sea, forming two regressive phases. The lower phase is represented in Egypt by the Basal Clastic Unit, the Desert Rose Unit, the Abu Ballas Formation and the Matruh Shale. In Libya it is represented by the Mesak Sandstone, Sarir Sandstone, Cabao Sandstone and Kiklah Formation. In both countries, these successions are covered by a carbonate sequence, resulting from the Tethyan transgression during the Cenomanian. In Egypt however, the upper regressive phase is represented by the Taref Sandstone which was deposited during a brief period of active progradation, following the Tethyan incursion. This is not observed in Libya. Comparison of palynological studies in Libya with those documented by several authors in Egypt reveals that the "Nubian" facies in Libya were deposited before equivalent facies in Egypt. The Basal Clastic Unit, dated as Hautrauvian-Barremian, may be equivalent, at least to a part of the Neocomian Cabao Sandstone in NW Libya. Jarmah Member of the Mesak Formation in Libya was dated as Berriasian on the basis of Pilosisporites and Trilobosporites. This makes it older than any "Nubian" unit in Egypt. The Matruh Shale was assigned to the Aptian on the basis of Tricolpites, and the Abu Balls Formation 34 as Aptian-Albian on the basis of Tricolpites and Rousisporites radiatus. Whereas, there is no equivalent to the Aptian in NW Libya, the Aptian-Albian of Egypt is similar to Zone 1 of the Kiklah Formation and As Sarir Sandstone, which were dated as early Albian on the basis of Afropollis spp., and Perotriletes pannuceus, an Albian element not recorded in Egypt. The Plant Beds in southwestern Egypt were dated as Cenomanian on the basis of advanced angiosperm pollen. In Libya, equivalent bodies were considered Vraconian, representing the uppermost Albian, because it lacks Cenomanian pollen (e.g. Tricolpites mutabilis). Comparison of local sea-level changes with global sea-level curves is used to reconstruct paleogeography. Integration of palynology with geological data and tectonic implications indicates that, despite similarity in paleogeographic processes of the Nubian Sandstone, geological and structural settings remain different. The "Nubian Sandstone" provides a typical succession that can be studied in the light of sequence stratigraphy.

  16. Species Diversity of Seed-Eating Desert Rodents in Sand Dune Habitats Author(s): James H. Brown

    E-print Network

    Brown, James H.

    Species Diversity of Seed-Eating Desert Rodents in Sand Dune Habitats Author(s): James H. Brown DIVERSITY OF SEED-EATING DESERT RODENTS IN SAND DUNE HABITATS' JAMES H. BROWN Department of Biology of semistabilized,wind- drifted sand in eastern California, Nevada, and western Utah. These dunes were similar

  17. A study of Desert Dermatoses in the Thar Desert Region

    PubMed Central

    Chatterjee, Manas; Vasudevan, Biju

    2015-01-01

    Introduction: Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is therefore important to survival. This original article focuses on dermatoses occurring in a population in the Thar desert of India, predominantly located in Rajasthan. Materials and Methods: This is a descriptive study involving various dermatoses seen in patients residing in the Thar desert region over a duration of 3 years. Results: Infections were the most common condition seen among this population and among them fungal infections were the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis and skin tumors were found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. Conclusion: The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. The concept of desert dermatology needs to be understood in more details to provide better care to those suffering from desert dermatoses and this article is a step forward in this regard. PMID:25657392

  18. Aspects of conservation in the excavation site of the Athribis temple in Egypt

    NASA Astrophysics Data System (ADS)

    Leisen, Hans; von Plehwe-Leisen, Esther; Verbeek, Christina; Jürgens, Christine; Krause, Sabine

    2008-12-01

    The late Ptolemaic temple of Athribis in Upper Egypt is built of regional limestone and preciously decorated with reliefs, inscriptions, plaster and polychromy. It is collapsed and only partly preserved and it disposes of some still buried rooms. The temple is situated in a desert climate and highly contaminated with soluble salts. Based on mappings of materials and preservation conditions, on investigations into the materials used and the damaging factors the development of a conservation conception for the limestone remains has been started. Conservation materials have been selected or are specially developed. A test area for some tasks has been prepared and controlled after 1 year of exposure. The paper shows the status quo of the work of the stone conservation group in an archaeological site in desert climate.

  19. Hydrogeochemical evolution of inland lakes’ water: A study of major element geochemistry in the Wadi El Raiyan depression, Egypt

    PubMed Central

    Mohamed, Essam A.; El-Kammar, Ahmed M.; Yehia, Mohamed M.; Abu Salem, Hend S.

    2015-01-01

    Wadi El Raiyan is a great depression located southwest of Cairo in the Western Desert of Egypt. Lake Qarun, located north of the study area, is a closed basin with a high evaporation rate. The source of water in the lake is agricultural and municipal drainage from the El Faiyum province. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the Faiyum province and received water that exceeded the capacity of Lake Qarun. Two hydrogeological regimes have been established in the area: (i) higher cultivated land and (ii) lower Wadi El Raiyan depression lakes. The agricultural drainage water of the cultivated land has been collected in one main drain (El Wadi Drain) and directed toward the Wadi El Raiyan depression, forming two lakes at different elevations (upper and lower). In the summer of 2012, the major chemical components were studied using data from 36 stations distributed over both hydrogeological regimes in addition to one water sample collected from Bahr Youssef, the main source of freshwater for the Faiyum province. Chemical analyses were made collaboratively. The major ion geochemical evolution of the drainage water recharging the El Raiyan depression was examined. Geochemically, the Bahr Youssef sample is considered the starting point in the geochemical evolution of the studied surface water. In the cultivated area, major-ion chemistry is generally influenced by chemical weathering of rocks and minerals that are associated with anthropogenic inputs, as well as diffuse urban and/or agricultural drainage. In the depression lakes, the water chemistry generally exhibits an evaporation-dependent evolutionary trend that is further modified by cation exchange and precipitation of carbonate minerals. PMID:26644942

  20. Metal and fluid sources in a potential world-class gold deposit: El-Sid mine, Egypt

    NASA Astrophysics Data System (ADS)

    Helmy, Hassan; Zoheir, Basem

    2015-04-01

    Lode gold mineralization at the El-Sid mine area is associated with the ca. 600 Ma Fawakhir granite intrusion, which cuts the ~737 Ma ophiolite nappes in the Central Eastern Desert of Egypt. The mineralized quartz veins are hosted by ~E- and NE-trending fault/fracture sets cutting the western boundary of the intrusion and sheared ophiolites. The results of electron microprobe analyses of gold-associated hydrothermal sulfide and silicate minerals suggest that Au was mobilized alongside Ni, Co, Cr and As from the adjacent ophiolitic serpentinite. After granite emplacement, hydrothermal fluids interacted with the sheared serpentinite, leaching metals and re-depositing them in the faults/fractures and adjacent wall rock in a cyclic process. Low-salinity aqueous-carbonic fluids with significant quantities of volatile species (CO2, CH4, and N2 ± H2S) leached and transported Au from deep to shallow crustal levels. Carbon dioxide had a buffering effect on the Au-bearing hydrothermal solution, maintaining its pH within a narrow near-neutral range, where elevated gold concentration was transported by complexation with reduced magmatic sulfur in a reducing environment. Gold deposition along fault/fracture conduits in the Fawakhir granite and adjacent serpentinite resulted from interplay of pressure drop, fluctuations in oxygen and sulfur fugacities, and exsolution of the volatile phases. Infiltration of meteoric water may have contributed to the formation of the late stage gold-sulfide mineralization that formed at shallower levels during terrane uplift. Sulfidation of the Fe-rich magmatic minerals was, on the other hand, the overriding process in the wall rock as evidenced by abundant disseminated sulfides with gold inclusions. Considering the structural control by regional shear zones (fluid conduits) and the voluminous granitic and ophiolitic rocks (metal sources), a high tonnage gold deposit amenable to open pit mining at the El-Sid mine area is very likely.

  1. Hydrogeochemical evolution of inland lakes' water: A study of major element geochemistry in the Wadi El Raiyan depression, Egypt.

    PubMed

    Mohamed, Essam A; El-Kammar, Ahmed M; Yehia, Mohamed M; Abu Salem, Hend S

    2015-11-01

    Wadi El Raiyan is a great depression located southwest of Cairo in the Western Desert of Egypt. Lake Qarun, located north of the study area, is a closed basin with a high evaporation rate. The source of water in the lake is agricultural and municipal drainage from the El Faiyum province. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the Faiyum province and received water that exceeded the capacity of Lake Qarun. Two hydrogeological regimes have been established in the area: (i) higher cultivated land and (ii) lower Wadi El Raiyan depression lakes. The agricultural drainage water of the cultivated land has been collected in one main drain (El Wadi Drain) and directed toward the Wadi El Raiyan depression, forming two lakes at different elevations (upper and lower). In the summer of 2012, the major chemical components were studied using data from 36 stations distributed over both hydrogeological regimes in addition to one water sample collected from Bahr Youssef, the main source of freshwater for the Faiyum province. Chemical analyses were made collaboratively. The major ion geochemical evolution of the drainage water recharging the El Raiyan depression was examined. Geochemically, the Bahr Youssef sample is considered the starting point in the geochemical evolution of the studied surface water. In the cultivated area, major-ion chemistry is generally influenced by chemical weathering of rocks and minerals that are associated with anthropogenic inputs, as well as diffuse urban and/or agricultural drainage. In the depression lakes, the water chemistry generally exhibits an evaporation-dependent evolutionary trend that is further modified by cation exchange and precipitation of carbonate minerals. PMID:26644942

  2. Environmental Processes and Spectral Reflectance Characteristics Associated with Soil Erosion in Desert Fringe Regions

    NASA Technical Reports Server (NTRS)

    Jacobberger, P. A.

    1987-01-01

    Results of analysis of spectral variation of sand dunes in El Ghorabi, Bahariya, Egypt; Tombouctou/Azaouad, Mali; and Tsodilo Hills, western Botswana are presented. Seasonal variations in dune extent and location of dune crests and their relationship to such factors as wind and weather variations are emphasized.

  3. Regional geothermal exploration in Egypt

    NASA Technical Reports Server (NTRS)

    Morgan, P.; Boulos, F. K.; Swanberg, C. A.

    1983-01-01

    A study is presented of the evaluation of the potential geothermal resources of Egypt using a thermal gradient/heat flow technique and a groundwater temperature/chemistry technique. Existing oil well bottom-hole temperature data, as well as subsurface temperature measurements in existing boreholes, were employed for the thermal gradient/heat flow investigation before special thermal gradient holes were drilled. The geographic range of the direct subsurface thermal measurements was extended by employing groundwater temperature and chemistry data. Results show the presence of a regional thermal high along the eastern margin of Egypt with a local thermal anomaly in this zone. It is suggested that the sandstones of the Nubian Formation may be a suitable reservoir for geothermal fluids. These findings indicate that temperatures of 150 C or higher may be found in this reservoir in the Gulf of Suez and Red Sea coastal zones where it lies at a depth of 4 km and deeper.

  4. Snow, the Great River, and the Desert

    NASA Astrophysics Data System (ADS)

    Rango, A.

    2005-12-01

    While many major rivers around the world originate from alpine snowpacks in mountain regions, some experience the extreme contrast of flowing through harsh desert environments downriver. One such stream is the Rio Grande which rises in the San Juan and the Sangre de Christo mountains of southern Colorado and northern New Mexico. Eventually, the snow fed Rio Grande flows through North America's largest desert, the Chihuahuan Desert in New Mexico, Texas, and Mexico, and simultaneously becomes part of the border between the United States and Mexico. As is often true, urban areas develop along the river corridors rather than in more inaccessible mountain regions. This demographic preference tends to isolate the vast majority of population in the Rio Grande, who are dependent on water for their livelihoods, from the mountain snowpacks where the flow is generated. Ironically then, snow is seldom viewed as the source of the much needed water flowing through the desert by the majority of the basin's population. In arid regions of the western U.S., water demand far exceeds the water supply, and water use is apportioned under the doctrine of prior appropriation with the oldest right getting the first use of water. The increasing population in urban areas does not usually have a right to use the water flowing through the desert unless water rights have been purchased by municipalities from the major category of water user in these basins, namely, irrigated agriculture. In the entire Rio Grande basin, irrigation makes up 80% of the consumptive use of water. Additionally, basin compacts and international treaties apportion water between states and countries. Because these formal agreements were based on above average runoff years, there is little flexibility in changing the use of water, particularly in dry to normal runoff years. Most of the older water rights in the Rio Grande, especially the upper basin, are supplied by snowmelt. This leaves the lower basin to depend upon rainfall-produced runoff occurring mostly during the sporadic summer monsoon season. Water harvesting techniques which promote heterogeneous water accumulation or production can effectively make more water available in certain areas at the expense the expense of nearby areas. The use of water ponding dikes on arid rangeland can promote increased native vegetation productivity through increases in soil moisture. Stock tanks lined with impervious material are also used to collect whatever runoff that is generated for later use. Desert dwellers living along rivers must rely on conservation measures and ingenuity in order to come up with a very limited water resource to survive. This survival is continually in doubt because population(and consequently water demand) continues to grow in these arid regions while the water supply remains relatively constant.

  5. Epidemic of mesothelioma in Egypt.

    PubMed

    Gaafar, R M; Eldin, N H Aly

    2005-07-01

    Asbestos has been recognized in Egypt since a long time as ancient Egyptians were using it in mummification. Mesothelioma in Egypt is mainly attributed to environmental origin with a high incidence of women and young adults affected. The incidence of mesothelioma is rising in Egypt. Epidemiological data for 635 malignant mesothelioma (MM) patients over 4 years in the third Millennium were collected from the National Cancer Institute (NCI), Cairo University and Abbassia Chest hospital. This number is more than four times the number diagnosed in the previous 11 years at NCI. A clinicopathological study was done for 100 malignant pleural mesothelioma (MPM) patients and showed that asbestos exposure and SV40 positivity were evident in 67% and 60% of cases, respectively. The median survival was 14.3 months and the 1 and 2 year survival rates were 60% and 27%, respectively. Evaluation of p53 and pRb immunohistochemically showed that pRb alteration was related to poor survival. Other biological prognostic factors such as EGFR, HER-2, glutathione S transferase (GST) and MDR were evaluated in 50 cases. Overexpression of EGFR was correlated with lack of clinical benefit and poor survival. GST potentiated the effect of EGFR on survival. The use of EGFR inhibitors may have a role in the treatment of MM. Asbestos in Cairo is a silent killer and measures toward eliminating it entirely or at least strictly controlling human contact with this dangerous carcinogen have to be taken in order to combat the coming epidemic of mesothelioma in Egypt. PMID:15950794

  6. Cataract surgery in ancient Egypt.

    PubMed

    Blomstedt, Patric

    2014-03-01

    Ophthalmology was one of the most important specialties in Egyptian medicine, and more specialists are known in this field than in any other. This specialization seems, however, to have been of a purely noninvasive nature. Even though it has been claimed that cataract surgery was performed in pharaonic Egypt, careful analysis of the sources does not support the claim. No example of cataract surgery or of any other invasive ophthalmologic procedure can be found in the original sources. PMID:24485861

  7. Orthopedic surgery in ancient Egypt

    PubMed Central

    Blomstedt, Patric

    2014-01-01

    Background — Ancient Egypt might be considered the cradle of medicine. The modern literature is, however, sometimes rather too enthusiastic regarding the procedures that are attributed an Egyptian origin. I briefly present and analyze the claims regarding orthopedic surgery in Egypt, what was actually done by the Egyptians, and what may have been incorrectly ascribed to them. Methods — I reviewed the original sources and also the modern literature regarding surgery in ancient Egypt, concentrating especially on orthopedic surgery. Results — As is well known, both literary sources and the archaeological/osteological material bear witness to treatment of various fractures. The Egyptian painting, often claimed to depict the reduction of a dislocated shoulder according to Kocher’s method, is, however, open to interpretation. Therapeutic amputations are never depicted or mentioned in the literary sources, while the specimens suggested to demonstrate such amputations are not convincing. Interpretation — The ancient Egyptians certainly treated fractures of various kinds, and with varying degrees of success. Concerning the reductions of dislocated joints and therapeutic amputations, there is no clear evidence for the existence of such procedures. It would, however, be surprising if dislocations were not treated, even though they have not left traces in the surviving sources. Concerning amputations, the general level of Egyptian surgery makes it unlikely that limb amputations were done, even if they may possibly have been performed under extraordinary circumstances. PMID:25140982

  8. Astronomy Education Challenges in Egypt

    NASA Astrophysics Data System (ADS)

    El Fady Beshara Morcos, Abd

    2015-08-01

    One of the major challenges in Egypt is the quality of education. Egypt has made significant progress towards achieving the Education for All and the Millennium Development Goals (MDGs). Many associations and committees as education reform program and education support programs did high efforts in supporting scientific thinking through the scientific clubs. The current state of astronomical education in Egypt has been developed. Astronomy became a part in both science and geography courses of primary, preparatory and secondary stages. Nowadays the Egyptian National Committee for Astronomy, put on its shoulders the responsibility of revising of astronomy parts in the education courses, beside preparation of some training programs for teachers of different stages of educations, in collaboration with ministry of education. General lectures program has been prepared and started in public places , schools and universities. Many TV and Radio programs aiming to spread astronomical culture were presented. In the university stage new astronomy departments are established and astrophysics courses are imbedded in physics courses even in some private universities.

  9. Structural influence on the evolution of the pre-Eonile drainage system of southern Egypt: Insights from magnetotelluric and gravity data

    NASA Astrophysics Data System (ADS)

    Roden, Jeff; Abdelsalam, Mohamed G.; Atekwana, Estella; El-Qady, Gad; Tarabees, Elhamy Aly

    2011-12-01

    The Wadi Kubbaniya in the Western Desert of Egypt north of the City of Aswan has been interpreted as the downstream continuation of the Wadi Abu Subeira, comprising an ancient W- and NW-flowing river system originating from the Precambrian crystalline rocks of the Red Sea Hills which were uplifted during the Miocene in association with the opening of the Red Sea. This drainage system is thought to have been active before the onset of the N-flowing Egyptian Nile which started ˜6 Ma with the Eonile phase; an event that resulted in carving of ˜1000 km long canyon (the Eonile canyon) extending from the Mediterranean Sea in the north to Aswan in the south due to the Messinian Salinity Crisis. This study utilizes geophysical data to examine the role of regional tectonics and local structures in controlling the evolution of the pre-Eonile drainage system. Magnetotelluric (MT) and gravity surveys were conducted along two ˜5 km-long profiles across the NW-trending Wadi Kubbaniya. Two-dimensional (2D) inversion of MT data and gravity models indicate the Wadi Kubbaniya is filled with loosely-consolidated sandstone and conglomerate that extend to a depth of ˜150-200 m into Cretaceous sandstone formations which overlie Precambrian crystalline rocks. These results were evaluated in terms of two end-member models; an incision model in which the 150-200 m thick sedimentary rocks were considered as being deposited within an incised valley that was carved into bedrock, or a structural model in which the sedimentary rocks are considered as filling a NW-trending graben controlled by normal faults that deform the Cretaceous sandstone formations and the underlying Precambrian crystalline rocks. Geological observations as well as supporting seismic data favor the interpretation that the Wadi Kubbaniya is a NW-trending graben similar to other extensional structures found 400 km northwest along-strike of Wadi Kubbaniya. These structures are impressively parallel to the western shorelines of the Red Sea and the Gulf of Suez suggesting a regional tectonic link between them. Strain localization of these grabens (which are likely Miocene in age) might have been facilitated by inherited Precambrian and Jurassic - Early Cretaceous structures, such as the NW-trending Najd fault system, the most dominant regional structural grain in the Red Sea Hills of Egypt as well as the NW-trending grabens, such as the Kom Ombo graben located ˜25 km to the northeast of Wadi Kubbaniya.

  10. Deserts of China

    USGS Publications Warehouse

    Walker, Alta S.

    1982-01-01

    Improving arid land quality requires an understanding of the original state of the land and its relationship to wind, water, and plant regimes, as well as understanding of interactions within the present ecosystem.  Chinese scientists and local residents have made significant advances in improving arid environments in gobi and sandy deserts and in less arid sandy lands.  Wind patterns are being changed by planting forest belts to protect oases and sandy lands, and on a smaller scale by planting grasses and shrubs or constructing straw grids.  Research on reclamation of deserts is now focusing on how sand-fixing plants may be adapted to local environments, and how the resources of grazing land and water may be effectively exploited without being overused.

  11. Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health

    PubMed Central

    Köberl, Martina; Müller, Henry; Ramadan, Elshahat M.; Berg, Gabriele

    2011-01-01

    Background To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. Methodology/Principal Findings We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. Conclusions/Significance After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher diversity and a better ecosystem function for plant health but a loss of extremophilic bacteria. Interestingly, we detected that indigenous desert microorganisms promoted plant health in desert agro-ecosystems. PMID:21912695

  12. Egypt: Beyond Pharaohs, Feluccas and Fellahin.

    ERIC Educational Resources Information Center

    Holt, Evelyn R.

    In a random study of five middle school social studies textbooks available for adoption in the state of Indiana in 1984, great variation in the treatment of Egypt was noted. Coverage of contemporary history was incomplete in all cases. All texts dealt with Egypt's ancient history, but what was reported was questionable. Only one text addressed in…

  13. Women--Sex Objects in Ancient Egypt.

    ERIC Educational Resources Information Center

    Mutimer, Brian T. P.

    Although it has been said that the women in Ancient Egypt enjoyed a reasonable state of social and professional equality with men, this paper presents an alternate theory--that women were second-class citizens whose physical prowess was secondary to their role as sex objects. It appears that men and women in Ancient Egypt often participated in the…

  14. Sphinx and Great Pyramid of Giza, Egypt

    USGS Multimedia Gallery

    The Spinx and the Great Pyramid of Giza, Egypt are pictured here. USGS and University of Pennsylvania research shows that ancient pollen and charcoal preserved in deeply buried sediments in Egypt's Nile Delta document the region’s ancient droughts and fires, including a huge drought 4,200...

  15. Published: 3 January 2013 Egypt's New Year

    E-print Network

    Zewail, Ahmed

    1 Published: 3 January 2013 Egypt's New Year Resolution Op-Ed by Ahmed H. Zewail CAIRO -- Egypt -- for the return of normal life. Tyler Hicks/The New York Timess #12;2 One middle-class Egyptian Muslim, Ahmed

  16. Jeeps Penetrating a Hostile Desert

    ERIC Educational Resources Information Center

    Bailey, Herb

    2009-01-01

    Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

  17. Factors influencing the rates, processes and magnitude of accumulation of carbon in desert soils

    NASA Technical Reports Server (NTRS)

    Mcfadden, Leslie D.

    1994-01-01

    This report summarizes research funded through NASA's Soil Landscape Climate Program which includes studies of the systematics of carbon storage and flux in the terrestrial environment, specifically terrestrial soils. Efforts focussed on the nature of carbon behavior in arid environments, where the majority of the carbon is present as inorganic carbon stored as pedogenic carbonate in desert calcic soils. Studies were supported of soils in two areas of western North America's major deserts: the Mojave Desert and the Chihuahuan Desert. Part 1 of this report summarizes the results of research conducted in the area of the Providence Mountains, California in the eastern Mojave Desert. Part 2 of this report summarizes the results of research in the Sevilleta Wildlife Refuge in central New Mexico, one of the sites of the UMN Biology Department's Long Term Ecological Research.

  18. Workshop on Extraterrestrial Materials from Cold and Hot Deserts

    NASA Technical Reports Server (NTRS)

    Schultz, Ludolf (Editor); Franchi, Ian A. (Editor); Reid, Arch M. (Editor); Zolensky, Michael E. (Editor)

    1999-01-01

    Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalog of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modern falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering processes, (2) terrestrial ages, (3) investigations of "unusual" meteorites, and (4) collection and curation.

  19. Workshop on Extraterrestrial Materials from Cold and Hot Deserts

    NASA Technical Reports Server (NTRS)

    Schultz, Ludolf (Editor); Franchi, Ian A. (Editor); Reid, Arch M. (Editor); Zolensky, Michael E. (Editor)

    2000-01-01

    Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalogue of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modem falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering processes, (2) terrestrial ages, (3) investigations of "unusual" meteorites, and (4) collection and curation.

  20. Space Radar Image of Safsaf Oasis, Egypt

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This three-frequency space radar image of south-central Egypt demonstrates the unique capability of imaging radar to penetrate thin sand cover in arid regions to reveal hidden details below the surface. Nearly all of the structures seen in this image are invisible to the naked eye and to conventional optical satellite sensors. Features appear in various colors because the three separate radar wavelengths are able to penetrate the sand to different depths. Areas that appear red or orange are places that can be seen only by the longest wavelength, L-band, and they are the deepest of the buried structures. Field studies in this area indicate L-band can penetrate as much as 2 meters (6.5 feet) of very dry sand to image buried rock structures. Ancient drainage channels at the bottom of the image are filled with sand more than 2 meters (6.5 feet) thick and therefore appear dark because the radar waves cannot penetrate them. The fractured orange areas at the top of the image and the blue circular structures in the center of the image are granitic areas that may contain mineral ore deposits. Scientists are using the penetrating capabilities of radar imaging in desert areas in studies of structural geology, mineral exploration, ancient climates, water resources and archaeology. This image is 51.9 kilometers by 30.2 kilometers (32.2 miles by 18.7 miles) and is centered at 22.7 degrees north latitude, 29.3degrees east longitude. North is toward the upper right. The colors are assigned to different radar frequencies and polarizations as follows: red is L-band, horizontally transmitted and received; green is C-band, horizontally transmitted and received; and blue is X-band, vertically transmitted and received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 16, 1994, on board the space shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

  1. The Kamil Crater in Egypt.

    PubMed

    Folco, Luigi; Di Martino, Mario; El Barkooky, Ahmed; D'Orazio, Massimo; Lethy, Ahmed; Urbini, Stefano; Nicolosi, Iacopo; Hafez, Mahfooz; Cordier, Carole; van Ginneken, Matthias; Zeoli, Antonio; Radwan, Ali M; El Khrepy, Sami; El Gabry, Mohamed; Gomaa, Mahomoud; Barakat, Aly A; Serra, Romano; El Sharkawi, Mohamed

    2010-08-13

    We report on the detection in southern Egypt of an impact crater 45 meters in diameter with a pristine rayed structure. Such pristine structures are typically observed on atmosphereless rocky or icy planetary bodies in the solar system. This feature and the association with an iron meteorite impactor and shock metamorphism provides a unique picture of small-scale hypervelocity impacts on Earth's crust. Contrary to current geophysical models, ground data indicate that iron meteorites with masses of the order of tens of tons can penetrate the atmosphere without substantial fragmentation. PMID:20651117

  2. Space Radar Image of Giza Egypt - with enlargement

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the area west of the Nile River near Cairo, Egypt. The Nile River is the dark band along the right side of the image and it flows approximately due North from the bottom to the right. The boundary between dense urbanization and the desert can be clearly seen between the bright and dark areas in the center of the image. This boundary represents the approximate extent of yearly Nile flooding which played an important part in determining where people lived in ancient Egypt. This land usage pattern persists to this day. The pyramids at Giza appear as three bright triangles aligned with the image top just at the boundary of the urbanized area. They are also shown enlarged in the inset box in the top left of the image. The Great Pyramid of Khufu (Cheops in Greek) is the northern most of the three Giza pyramids. The side-looking radar illuminates the scene from the top, the two sides of the pyramids facing the radar reflect most of the energy back to the antenna and appear radar bright; the two sides away from the radar reflect less energy back and appear dark Two additional pyramids can be seen left of center in the lower portion of the image. The modern development in the desert on the left side of the image is the Sixth of October City, an area of factories and residences started by Anwar Sadat to relieve urban crowding. The image was taken on April 19, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered on latitude 29.72 degrees North latitude and 30.83 degrees East longitude. The area shown is approximately 20 kilometers by 30 kilometers. The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is C-band horizontally transmitted, horizontally received; blue is C-band horizontally transmitted, vertically received.

  3. Distribution and vegetation reconstruction of the deserts of northern China during the mid-Holocene

    NASA Astrophysics Data System (ADS)

    Li, Qin; Wu, Haibin; Guo, Zhengtang; Yu, Yanyan; Ge, Junyi; Wu, Jianyu; Zhao, Deai; Sun, Aizhi

    2014-07-01

    Desertification is potentially a serious threat to society, and therefore, it is critical to understand how deserts may respond to future climate change. The mid-Holocene (6 ± 0.5 14C ka) was warmer than present, and the distribution of deserts at this time may have implications for understanding their response to future warming. Here we reconstruct the distribution of deserts in northern China during the mid-Holocene by combining data on vegetation type and the sedimentary facies of aeolian deposits. The results demonstrate that during the mid-Holocene, the deserts retreated northwestward to the location of the modern 300 mm isohyet. Most of the Eastern Desert was stabilized with steppe or forest-steppe vegetation, whereas the Western Desert exhibited no significant change and remained mobile, occupied by desert vegetation. The deserts in northern China were greatly reduced during the mid-Holocene because of the enhancement of the East Asian summer monsoon in a warmer climate than today.

  4. Dental surgery in ancient Egypt.

    PubMed

    Blomstedt, Patric

    2013-01-01

    Many different surgical procedures have over the years been attributed to the ancient Egyptians. This is also true regarding the field of dental surgery. The existence of dentists in ancient Egypt is documented and several recipes exist concerning dental conditions. However, no indications of dental surgery are found in the medical papyri or in the visual arts. Regarding the osteological material/mummies, the possible indications of dental surgery are few and weak. There is not a single example of a clear tooth extraction, nor of a filling or of an artificial tooth. The suggested examples of evacuation of apical abscesses can be more readily explained as outflow sinuses. Regarding the suggested bridges, these are constituted of one find likely dating to the Old Kingdom, and one possibly, but perhaps more likely, dating to the Ptolemaic era. Both seem to be too weak to have served any possible practical purpose in a living patient, and the most likely explanation would be to consider them as a restoration performed during the mummification process. Thus, while a form of dentistry did certainly exist in ancient Egypt, there is today no evidence of dental surgery. PMID:24665522

  5. Supersymmetry without the Desert

    E-print Network

    Yasunori Nomura; David Poland

    2006-09-26

    Naturalness of electroweak symmetry breaking in weak scale supersymmetric theories may suggest the absence of the conventional supersymmetric desert. We present a simple, realistic framework for supersymmetry in which (most of) the virtues of the supersymmetric desert are naturally reproduced without having a large energy interval above the weak scale. The successful supersymmetric prediction for the low-energy gauge couplings is reproduced due to a gauged R symmetry present in the effective theory at the weak scale. The observable sector superpotential naturally takes the form of the next-to-minimal supersymmetric standard model, but without being subject to the Landau pole constraints up to the conventional unification scale. Supersymmetry breaking masses are generated by the F-term and D-term VEVs of singlet and U(1)_R gauge fields, as well as by anomaly mediation, at a scale not far above the weak scale. We study the resulting patten of supersymmetry breaking masses in detail, and find that it can be quite distinct. We construct classes of explicit models within this framework, based on higher dimensional unified theories with TeV-sized extra dimensions. A similar model based on a non-R symmetry is also presented. These models have a rich phenomenology at the TeV scale, and allow for detailed analyses of, e.g., electroweak symmetry breaking.

  6. Desert landscape irrigation

    SciTech Connect

    Quinones, R.

    1995-06-01

    Industrialization can take place in an arid environment if a long term, overall water management program is developed. The general rule to follow is that recharge must equal or exceed use. The main problem encountered in landscape projects is that everyone wants a lush jungle setting, tall shade trees, ferns, with a variety of floral arrangements mixed in. What we want, what we can afford, and what we get are not always the same. Vegetation that requires large quantities of water are not native to any desert. Surprisingly; there are various types of fruit trees, and vegetables that will thrive in the desert. Peaches, plums, nut trees, do well with drip irrigation as well as tomatoes. Shaded berry plans will also do well, the strawberry being one. In summary; if we match our landscape to our area, we can then design our irrigation system to maintain our landscape and grow a variety of vegetation in any arid or semiarid environment. The application of science and economics to landscaping has now come of age.

  7. Applications of remote sensing, GIS, and groundwater flow modeling in evaluating groundwater resources: Two case studies; East Nile Delta, Egypt and Gold Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Abdelaziz Ali Ismael, Abdulaziz Mohamed

    Quaternary aquifer, East Nile Delta, Egypt. Due to the progressive increase in the development of desert land in Egypt, the demand for efficient water resources management and accurate land cover change information is increasing. In this study, we introduce a methodology to map and monitor land cover change patterns related to agricultural development and urban expansion in the desert fringes of the Eastern Nile Delta region. Using a hybrid classification approach, we employ multitemporal Landsat TM/ETM+ images from 1984, 1990, and 2003 to produce three land cover/land use maps. Post-classification comparison of these maps was used to obtain "from-to" statistics and change detection maps. The change detection results show that agricultural development increased 14% through the study period. Land reclamation during 1990-2003 exceeded that during 1984-1990 by a factor of two, reflecting a systematic national plan for desert reclamation that went into effect. We find that the increase in urbanization (by ˜21,300 hectares) during 1990-2003 was predominantly due to encroachment into traditionally cultivated land at the fringes of urban centers. Our results accurately quantify the land cover changes and delineate their spatial patterns, demonstrating the utility of Landsat data in analyzing landscape dynamics over time. Such information is critical for making efficient and sustainable policies for resource management. A three dimensional GIS-based groundwater flow model was developed to delineate a safe future framework for groundwater development in the Quaternary aquifer north Ismaelia Canal, East Nile Delta where a progressive rise in head associated with agricultural development is reported. The calibrated transient model was used to predict the future head distribution after 20 years assuming the same landuse. Results of this run showed that the groundwater head continued to increase with maximum increase up to 2.0 m in the unconfined part of the aquifer which jeopardizes a considerable area of the agricultural land with soil salinity and water logging. Therefore, three strategies, each with three scenarios, extending between 2004 and 2024 were designed to involve different pumping stress and infiltration rates from irrigation return to control the rising water level and estimate the production potential of the aquifer during drought. Gold Valley, Death Valley, California, USA. This study evaluates the hydrogeology of Gold Valley as a typical example of intermountain basins of Death Valley area and develops a GIS-based model that reasonably estimates the precipitation infiltration rates from altitude and slope data of the catchment area. Water balance calculations of the hydrological parameters in Gold Valley, provided by Inyo County, California, indicated that the majority of recharge takes place at high altitude (>1100 m) during winter with a negligible effect of evaporation on the stable isotopic composition of groundwater. Furthermore, water balance calculations in Gold Valley were utilized in identifying the coefficients of a GIS-based model that subsequently was refined to the best fit with the calculations of the water budget. A resistivity survey conducted in Gold Valley showed that groundwater is collected in upstream compartmentalized reservoirs and suggests that groundwater flow mostly takes place through the fracture zone of the bedrock. This pattern explains the relationship between precipitational infiltration in the Gold Valley catchment area and the attachment spring flow in Willow Creek. The estimated water budget in Gold Valley and the geoelectric profiles provided from this study can be investigated into the Death Valley Regional Groundwater Flow model (DVRGWF). In addition, the GIS-based model can be efficiently applied in other intermountain basins in Death Valley or other areas of arid environment of the Western U.S. to estimate the local precipitational infiltration. Accurate estimates of flux, well defined flow systems, and locations of recharge/discharge in mountain ranges provide e

  8. Interdisciplinary Graduate Internship Opportunities Desert Archaeology, Inc.

    E-print Network

    Watkins, Joseph C.

    Interdisciplinary Graduate Internship Opportunities ARIZONA Desert Archaeology, Inc. Desert since 1982, serving a diverse set of clients--from government agencies to private firms. Desert, and of the highest professional quality. Desert Archaeology has deep roots in the southwestern United States

  9. Late Quaternary history of the Atacama Desert

    E-print Network

    #12;#12;#12;#12;#12;73 Late Quaternary history of the Atacama Desert Claudio Latorre, Julio L and Kate Rylander Of the major subtropical deserts found in the Southern Hemisphere, the Atacama Desert is the driest. Throughout the Quaternary, the most pervasive climatic influence on the desert has been

  10. Impact of highway geometry and posted speed on operating speed at multi-lane highways in Egypt

    PubMed Central

    Semeida, Ahmed M.

    2012-01-01

    The paper presents an analysis of roadway factors and posted speed limits that affect the operating speed at multi-lane highways in Egypt. Field data on multi-lane highways in Egypt are used in this investigation. The analysis considers two categories of highways. The first consists of two desert roads (Cairo–Alexandria and Cairo–Ismailia desert roads) and the second consists of two agricultural roads (Cairo–Alexandria and Tanta–Damietta agricultural roads). The paper includes three separate relevant analyses. The first analysis uses the regression models to investigate the relationships between operating speed (V85) as dependent variable, and roadway factors and posted speed as independent variables. The road factors are lane width, shoulder width, pavement width, median width, number of lanes in each direction, and existence of side access along each section. The second analysis uses the Artificial Neural Network (ANN) to explore the previous relationships while the third one examines the suitability of the posted speed limits on the roads under study. It is found that the ANN modeling gives the best model for predicting the operating speed and the most influential variables on V85 are the pavement width, followed by the median width and the existence of side access along section. It is also found that the posted speed limit has a very small effect on the operating speed due to the bad behavior of drivers in Egypt. These results are so important for controlling V85 on multi-lane rural highways in Egypt. PMID:25685460

  11. USGS Scientists in Wadi Degla, Northern Egypt

    USGS Multimedia Gallery

    USGS scientists looking at Eocene sandstones and limestones in Wadi Degla, northern Egypt. This area was studied to understand the Levant Basin Province, as both regions have similar rock formations....

  12. Developing a solar energy industry in Egypt

    E-print Network

    AbdelMessih, Sherife (Sherife Mohsen)

    2009-01-01

    This paper assesses Egypt's current energy infrastructure and its problems, the available solar energy resource, and the technologies required to harness this resource. After this assessment, an industry based on high ...

  13. Evolutionary hotspots in the Mojave Desert

    USGS Publications Warehouse

    Vandergast, Amy G.; Inman, Richard D.; Barr, Kelly R.; Nussear, Kenneth E.; Esque, Todd C.; Hathaway, Stacie A.; Wood, Dustin A.; Medica, Philip A.; Breinholt, Jesse W.; Stephen, Catherine L.; Gottscho, Andrew D.; Marks, Sharyn B.; Jennings, W. Bryan; Fisher, Robert N.

    2013-01-01

    Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted.

  14. Gujarat, Western India

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Extremely high sediment loads are delivered to the Arabian Sea along the coast of Pakistan (upper left) and western India. In the case of the Indus River (far upper left) this sedimentation, containing large quantities of desert sand, combines with wave action to create a large sand-bar like delta. In the arid environment, the delta lacks much vegetation, but contains numerous mangrove-lined channels. This true-color image from May 2001 shows the transition from India's arid northwest to the wetter regions farther south along the coast. The increase in vegetation along the coast is brought about by the moisture trapping effect of the Western Ghats Mountain Range that runs north-south along the coast. Heavy sediment is visible in the Gulf of Kachchh (north) and the Gulf of Khambhat(south), which surround the Gujarat Peninsula.

  15. Warming trends: Saharan desert warming

    NASA Astrophysics Data System (ADS)

    Lavaysse, Christophe

    2015-09-01

    A key element of the West African monsoon is changing faster than in the surrounding areas but the reason is unknown. Now research assesses the specific behaviour of the temperature over the Saharan desert.

  16. Tectonic architecture through Landsat-7 ETM+/SRTM DEM-derived lineaments and relationship to the hydrogeologic setting in Siwa region, NW Egypt

    NASA Astrophysics Data System (ADS)

    Masoud, Alaa; Koike, Katsuaki

    2006-08-01

    Fracture zones on the Earth's surface are important elements in the understanding of plate motion forces, the dynamics of the subsurface fluid flow, and earthquake distributions. However, good exposures of these features are always lacking in arid regions, characterized by flat topography and where sand dunes extensively cover the terrain. During field surveys these conditions, in many cases, hinder the proper characterization of such features. Therefore, an approach that identifies the regional fractures as lineaments on remotely-sensed images or shaded digital terrain models, with its large scale synoptic coverage, could be promising. In the present work, a segment tracing algorithm (STA), for lineament detection from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) imagery, and the data from the Shuttle Radar Topographic Mission (SRTM) 30 m digital elevation model (DEM), has been applied in the Siwa region, located in the northwest of the Western Desert of Egypt. The objectives are to analyze the spatial variation in orientation of the detected linear features and its relation to the hydrogeologic setting in the area and the underlying geology, and to evaluate the performance of the algorithm applied to the ETM+ and the DEM data. Detailed structural analysis and better understanding of the tectonic evolution of the area could provide useful tools for hydrologists for reliable groundwater management and development planning. The results obtained have been evaluated by the structural analysis of the area and field observations. Four major vertical fracture zones were detected corresponding to two conjugate sets of strike-slip faults that governed the surface, and subsurface environments of the lakes in the region, and these correlate well with the regional tectonics.

  17. Original sounding and drifting balloon-borne measurements in the western Mediterranean with the aerosol counter/sizer LOAC during summer ChArMEx campaigns, with a focus on desert dust events

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Dulac, François; Vignelles, Damien; Jeannot, Matthieu; Verdier, Nicolas; Chazette, Patrick; Crenn, Vincent; Sciare, Jean; Totems, Julien; Durand, Pierre; Barret, Brice; Jambert, Corinne; Mallet, Marc; Menut, Laurent; Mailler, Sylvain; Basart, Sara; Baldasano, José Maria

    2015-04-01

    LOAC (Light Optical Aerosol Counter) is a new small optical particle counter/sizer of ~250 grams designed to fly under all kinds of balloons. The measurements are conducted at two scattering angles (12° and 60°), allowing the determination of the aerosol particle concentrations in 19 size classes within a diameter range of ~0.2-100 µm and some identification of the nature of particles dominating different size classes. Following laboratory calibration, the sensor particularly discriminates wet or liquid particles, mineral dust, soot carbon particles and salts. Comparisons with other in situ sensors at the surface and with remote sensing measurements on the vertical were performed to give confidence in measurements. The instrument has been operated at the surface, under all kinds of balloons up to more than 35 km in altitude, including tethered, sounding, open stratospheric and new boundary-layer pressurized drifting balloons (BLPB) from CNES, and was tested on board a small UAV. Operations encompass a variety of environments including the Arctic (Reykjavik, Island, and Kiruna, Sweden), Brazil (Sao Paolo), the western Mediterranean Basin, southwestern France, peri-urban (Ile de France) and urban areas (Paris and Vienna). Presented results are focused on the LOAC balloon-borne measurements performed in the western Mediterranean basin during MISTRALS/ChArMEx campaigns (Mediterranean Integrated Studies aT Regional And Local Scales/the Chemistry-Aerosol Mediterranean Experiment; http://www.mistrals-hjome.org; http://charmex.lsce.ipsl.fr), with a focus on African dust events. Two test flights with a first version of LOAC under sounding balloons were first successfully performed in late June 2012 near Marseille during an intense dust event. In 2013, 19 LOAC flights have been performed under meteorological balloons and 12 under low altitude drifting balloons, most of them from Minorca Island (Spain) in June and early July and others from Levant Island (south of France) in late July and early August . A number of the 2013 flights were coupled with ozone concentration measurements (see presentation of Gheusi et al. in the same session). LOAC balloons were especially, but not only, dedicated to study the various Saharan dust events that occurred during the campaign. In particular, a series of flights were conducted every 12 hours during the 15-19 June dust event. Forest fire smoke from North America was also sampled in late June over Minorca, as well as anthropogenic polluted layers in various occasions. LOAC data (available from ChArMEx database http://mistrals.sedoo.fr/ChArMEx) are interpreted with the help of coincident lidar, sun photometer remote sensing measurements available in Menorca, and satellite products and air mass trajectories. The sounding flights allow us to determine the vertical extent of the various aerosol layers, and to follow the particle size distribution and the concentration evolution along the vertical. The low altitude drifting balloons, which stayed roughly at constant altitude between 350 and 3330 m up to more than 25 h, allow us to study the time-evolution of the aerosol concentrations in the same air mass. Under both balloon types, LOAC has detected larges particles up to ~30 µm in diameter. The flights drifting within dust layers indicate that there is a relatively stable particle size distribution during transport over the sea, with no clear sedimentation loss of large particles. Aerosol simulations with the CHIMERE and NMMB/§BSC chemistry-transport models are compared to LOAC measurements. Acknowledgements: LOAC was developed with support of the French ANR. Balloon operations were performed by CNES and special acknowledgements are addressed to Gilles Dupouy, Françoise Douchin and collaborators for field operations. Alexis Doerenbacher from Météo-France and Claude Basdevant from Ecole Polytechnique are also acknowledged for their helpful contribution in providing balloon-related forecasts, quicklooks and data (http://www.lmd.polytechnique.fr/BAMED/index.html). The LOAC balloon campaigns wer

  18. Egypt's population policies and family planning program: a critical examination 

    E-print Network

    Carr, Aline B.

    1996-01-01

    Egypt's national family planning program, in existence since 1965, has been fairly successful in increasing the use of family planning methods and lowering the population growth rate in Egypt. However, the fact that as few as 10 percent of women...

  19. Mate desertion in the snail kite

    USGS Publications Warehouse

    Beissinger, S.R.; Snyder, N.F.R.

    1988-01-01

    Mate desertion during the breeding cycle was documented at 28 of 36 (78%) snail kite, Rostrhamus sociabilis nests in Florida between 1979 and 1983. Offspring mortality occurred at only one deserted nest, however. Parents that were deserted by their mates continued to care for their young until independence (3?5 additional weeks) and provided snails at a rate similar to that of both parents combined before desertion. Males and females deserted with nearly equal frequency, except in 1982 when more females deserted. No desertion occurred during drought years, whereas desertion occurred at nearly every nest during favourable conditions. The occurrence of mate desertion was generally related to indirect measures of snail abundance: foraging range, snail delivery rates to the young and growth rates. Small broods were deserted more frequently by females than by males and tended to be deserted earlier than large ones. After desertion, deserters had the opportunity to re-mate and nest again since breeding seasons were commonly lengthy, but whether they did so was impossible to determine conclusively in most cases. The deserted bird sometimes incurred increased energetic costs and lost breeding opportunities during periods of monoparental care.

  20. Western Foot Patrol Western University

    E-print Network

    Lennard, William N.

    Western Foot Patrol Western University Room 57, University Community Centre London, Ontario N6A 3K7 August 2014 Get involved! Volunteer with Western Foot Patrol Welcome to Western! Thank you for your interest in volunteering for Western Foot Patrol (WFP)! WFP is a free service that promotes

  1. Opportunities for woody crop production using treated wastewater in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Nile River provides nearly 97% of Egypt's freshwater supply. Egypt's share of Nile waters is allocated according to international treaty obligations and is fixed at 55.5 billion cubic meters annually. As a result, Egypt will not be able to meet increasing water demand using freshwater from the N...

  2. Women's Status, Autonomy, and Fertility in Transitional Egypt

    E-print Network

    Samari, Goleen

    2015-01-01

    primarily in Upper Egypt. The religion of the women is notReligion and Nationalism: A Contrapuntal Reading of the History of Female Activism and Political Change in Egypt."religion may also affect women’s status and autonomy in Egypt.

  3. 77 FR 71777 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ... Trade Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 33439, June 6, 2012 to revise... Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 33439, June 6, 2012. Due to the.... Commercial Service Cairo, Egypt U.S. Commercial Service Washington, DC Dennis Simmons, Deputy...

  4. Trans-Pacific transport of Saharan dust to western North America: A case study

    E-print Network

    Lyatt Jaeglé

    about 1400 Tg/year (65% of the global emission) while the deserts of Asia (including the Gobi and Takla was simplified in this case by the distinct, and somewhat unusual, lack of dust activity over Eurasia (Gobi and Takla Makan deserts) at this time. Over western North America the dust layer, although subsiding close

  5. Desert and desertification in Iran

    NASA Astrophysics Data System (ADS)

    Bahrami, M.

    2009-04-01

    One of the greatest environmental concerns in Iran as in other arid and semiarid countries is the transformation of once productive, or marginally productive, land to deteriorated land and soil unable to support plants and animals. Because the land becomes barren and dry, the process is described as desertification, which occurs as a sequence of events. The area of deserts in Iran is about 340,000 Km2 (less than one fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40 % of which is active sand dunes. Most of features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases. The deserts of Iran are generally classified in the subtropical, warm, arid and semiarid group, but the effect and presence of some geographical and geoclimatical factors such as height, vicinity to Indian Ocean and so on do some changes in climatic conditions and geographical features causing some local and regional differences in them. Geographically, two groups of deserts have been known in Iran: (1) Coastal deserts which, like a ribbon with variable width, stretch from extreme southeast to extreme southwest, at the north parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. This causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering to that of physical. (2) internal deserts, which rest in central, eastern and southeastern plateau of the country and in independent and semi dependent depressions. This situation, which is due to the surrounding high mountains, blocks humidity entry and causes the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert pavement), Kalut (Yardang), Hoodoo and wind deposited features such as different kinds of sand dunes (Seif, Nebka, Rebdous, Barkhan, Ghourd, Erg) and Loess, most of which exhibit beautiful landscapes suitable for ecotourism and scientific tours. Salt deserts (Kavir or Playas), which rest in the lowest parts of internal depressions, are the most current features in Iran deserts. The most extensive and specific salt deserts are in the course of floods or at the end of them, which consist of fine grained sediments in the lowest parts of the depressions. Many factors have been participated in the formation of salt deserts in Iran, the most important of which, are morphotectonical (such as folding and faulting due to the last epirogenic and orogenic movements), climatical and hydrological (occurred in Quaternary), geological and pedological (such as the presence of Neogene evaporitic formations).

  6. Analysis of utilization of desert habitats with dynamic simulation

    USGS Publications Warehouse

    Williams, B.K.

    1986-01-01

    The effects of climate and herbivores on cool desert shrubs in north-western Utah were investigated with a dynamic simulation model. Cool desert shrublands are extensively managed as grazing lands, and are defoliated annually by domestic livestock. A primary production model was used to simulate harvest yields and shrub responses under a variety of climatic regimes and defoliation patterns. The model consists of six plant components, and it is based on equations of growth analysis. Plant responses were simulated under various combinations of 20 annual weather patterns and 14 defoliation strategies. Results of the simulations exhibit some unexpected linearities in model behavior, and emphasize the importance of both the pattern of climate and the level of plant vigor in determining optimal harvest strategies. Model behaviors are interpreted in terms of shrub morphology, physiology and ecology.

  7. Identification and interpretation of tectonic features from Skylab imagery. [Mojave Desert block of Texas, Arizona, and Chihuahua, Mexico

    NASA Technical Reports Server (NTRS)

    Abdel-Gawad, M. (principal investigator)

    1975-01-01

    The author has identified the following significant results. Two alternate models for the extension of the Texas zone through the Mojave Desert block have been developed: (1) along the Pisgah Line, and (2) along the eastern Transverse Ranges; this model suggests a counterclockwise rotation of the Mojave block. Analysis of S190B photographs of the western Mojave Desert provides strong evidence for the feasibility of identifying recent fault breaks.

  8. BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.

    EPA Science Inventory

    Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg?1 ...

  9. Advantages of endophyte infection for irrigated pastures of semiarid, cold-desert environments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little research has evaluated possible endophyte benefits to adaptation and production of grasses in the irrigated pastures of the semiarid, cold-desert environments of the western USA. Severe irrigation shortages are common; however, production demands are increasing, necessitating maximizing tall ...

  10. Biological soil crusts as an integral component of desert environments

    USGS Publications Warehouse

    Belnap, Jayne; Weber, Bettina

    2013-01-01

    The biology and ecology of biological soil crusts, a soil surface community of mosses, lichens, cyanobacteria, green algae, fungi, and bacteria, have only recently been a topic of research. Most efforts began in the western U.S. (Cameron, Harper, Rushforth, and St. Clair), Australia (Rogers), and Israel (Friedmann, Evenari, and Lange) in the late 1960s and 1970s (e.g., Friedmann et al. 1967; Evenari 1985reviewed in Harper and Marble 1988). However, these groups worked independently of each other and, in fact, were often not aware of each other’s work. In addition, biological soil crust communities were seen as more a novelty than a critical component of dryland ecosystems. Since then, researchers have investigated many different aspects of these communities and have shown that although small to microscopic, biological soil crusts are critical in many ecological processes of deserts. They often cover most of desert soil surfaces and substantially mediate inputs and outputs from desert soils (Belnap et al. 2003). They can be a large source of biodiversity for deserts, as they can contain more species than the surrounding vascular plant community (Rosentreter 1986). These communities are important in reducing soil erosion and increasing soil fertility through the capture of dust and the fixation of atmospheric nitrogen and carbon into forms available to other life forms (Elbert et al. 2012). Because of their many effects on soil characteristics, such as external and internal morphological characteristics, aggregate stability, soil moisture, and permeability, they also affect seed germination and establishment and local hydrological cycles. Covering up to 70% of the surface area in many arid and semi-arid regions around the world (Belnap and Lange 2003), biological soil crusts are a key component within desert environments.

  11. Women's position and family planning in Egypt.

    PubMed

    Govindasamy, P; Malhotra, A

    1996-01-01

    In this report, data from the 1988 Egypt Demographic and Health Survey are used to address some of the most frequently raised questions about the relationship between gender inequality and reproductive behavior. The findings from binomial and multinomial logit models show that while the relationship between women's position and fertility control in Egypt is complex, some clear, broad patterns exist that have important theoretical and policy implications. First, although women's status in Egypt is clearly multidimensional, the reproductive aspect of women's position has a strong connection with the nonreproductive dimensions. Second, the case of the continued use of education and employment as proxies of women's position, especially in relationship to fertility control, is considerably discredited by the results. Finally, the findings indicate that Egyptian culture supports gender equality in the form of interaction and negotiation rather than women's autonomy. PMID:8986031

  12. Geology and origin of Meatiq Dome, Egypt: A Precambrian metamorphic core complex?

    NASA Astrophysics Data System (ADS)

    Sturchio, Neil C.; Sultan, Mohamed; Batiza, Rodey

    1983-02-01

    Meatiq Dome, a metamorphic complex in the Precambrian basement of the Eastern Desert of Egypt, exhibits many of the essential features of Cordilleran metamorphic core complexes. It is an antiformal structure with low-dipping foliation and unidirectional mineral-slickenside lineation. The core consists of granite gneiss and is conformably overlain by a heterogeneous, isoclinally folded, mylonitic carapace. The carapace grades upward into a nonmylonitic cover of low-grade ophiolitic rocks. The mylonitic rocks are interpreted to have formed in a low-angle ductile shear zone during a compressional tectonic event accompanied by syntectonic intrusion of tonalite. Doming postdated mylonitization. The absence of a brittle detachment surface at Meatiq Dome is its primary distinction from the otherwise similar Cordilleran complexes.

  13. A comprehensive study of noble gases and nitrogen in "Hypatia", a diamond-rich pebble from SW Egypt

    NASA Astrophysics Data System (ADS)

    Avice, Guillaume; Meier, Matthias M. M.; Marty, Bernard; Wieler, Rainer; Kramers, Jan D.; Langenhorst, Falko; Cartigny, Pierre; Maden, Colin; Zimmermann, Laurent; Andreoli, Marco A. G.

    2015-12-01

    This is a follow-up study of a work by Kramers et al. (2013) on a very unusual diamond-rich rock fragment found in the area of south west Egypt in the south-western side of the Libyan Desert Glass strewn field. This pebble, called Hypatia, is composed of almost pure carbon. Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) results reveal that Hypatia is mainly made of defect-rich diamond containing lonsdaleite and multiple deformation bands. These characteristics are compatible with an impact origin on Earth and/or in space. We also analyzed concentrations and isotopic compositions of all five noble gases and nitrogen in several ?mg sized Hypatia samples. These data confirm the conclusion by Kramers et al. (2013) that Hypatia is extra-terrestrial. The sample is relatively rich in trapped noble gases with an isotopic composition being close to the Q component found in many types of meteorites. 40Ar/36Ar ratios in individual steps are as low as 0.4 ± 0.3. Cosmic-ray produced "cosmogenic" 21Ne is present in concentrations corresponding to a nominal cosmic-ray exposure (CRE) age of roughly 0.1 Myr if produced in a typical meter-sized meteoroid. Such an atypically low nominal CRE age suggests high shielding in a considerably larger body. In addition to the Xe-Q composition, an excess of radiogenic 129Xe (from the decay of short-lived radioactive 129I) is observed (129Xe /132Xe = 1.18 + / - 0.03). Two isotopically distinct N components are present, an isotopically heavy component (?15N ? + 20 ‰) released at low temperatures and a major isotopically light component (?15N ? - 110 ‰) at higher temperatures. This disequilibrium in N suggests that the diamonds in Hypatia were formed in space rather than upon impact on Earth (?N15atm = 0 ‰). All our data are broadly consistent with concentrations and isotopic compositions of noble gases in at least three different types of carbon-rich meteoritic materials: carbon-rich veins in ureilites, graphite in acapulcoites/lodranites and graphite nodules in iron meteorites. However, Hypatia does not seem to be directly related to any of these materials, but may have sampled a similar cosmochemical reservoir. Our study does not confirm the presence of exotic noble gases (e.g. G component) that led Kramers et al. (2013) to propose that Hypatia is a remnant of a comet nucleus that impacted the Earth.

  14. Desert Rock Coatings Ronald I. Dorn

    E-print Network

    Dorn, Ron

    Chapter 7 Desert Rock Coatings Ronald I. Dorn Introduction Desert landforms are characterized by an abundance of `bare' rock and mineral surfaces. Mountains host widespread exposures of bedrock. Gravel desert pave- ments cap alluvial terraces and fans. Even sand dunes are themselves composed of rock fragments

  15. Mesozoic evolution of the northeast African shelf margin, Libya and Egypt

    SciTech Connect

    Aadland, R.K.; Schamel, S.

    1988-08-01

    The present tectonic features of the northeast African shelf margin between the Nile delta and the Gulf of Sirte are products of (1) precursory late Paleozoic basement arches, (2) early Mesozoic rifting and plate separation, and (3) Late Cretaceous structural inversion. Isopach and structural maps, cross sections, and sediment accumulation (geohistory) curves constructed from 89 wells in the Western Desert and 27 wells in northeastern Libya depict the structural and stratigraphic development of the northeast African shelf margin.

  16. Instrumental neutron activation analysis of soil and sediment samples from Siwa Oasis, Egypt

    NASA Astrophysics Data System (ADS)

    Badawy, Wael M.; Ali, Khaled; El-Samman, Hussein M.; Frontasyeva, Marina V.; Gundorina, Svetlana F.; Duliu, Octavian G.

    2015-07-01

    Instrumental neutron activation analysis was used to study geochemical peculiarities of the Siwa Oasis in the Western Egyptian Desert. A total of 34 elements were determined in soil and sediment samples (Na, Mg, Al, Cl, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, As, Br, Rb, Sr, Zr, Sb, I, Cs, Ba, La, Ce, Nd, Eu, Tb, Dy, Tm, Yb, Hf, Ta, Th, and U). For data interpretation Cluster analysis was applied. Comparison with the available literature data was carried out.

  17. Quantifying dust emissions from desert landforms, eastern Mojave Desert, USA

    NASA Astrophysics Data System (ADS)

    Sweeney, Mark R.; McDonald, Eric V.; Etyemezian, Vicken

    2011-12-01

    The measurement of natural dust emissions from desert landforms is crucial in environmental hazard assessment and field checking the accuracy of global dust models. More than 500 individual dust measurements from eight common desert landforms in southern California were collected using the PI-SWERL (Portable In Situ Wind Erosion Lab). The largest emitters of dust are dry washes (13.787 to 0.007 mg m - 2 s - 1 ), dunes, playa margins, distal alluvial fans, and lacustrine beaches. Low emitters include salt-crusted playas (0.692 to 0.002 mg m - 2 s - 1 ), silt-clay-crusted playas, and desert pavements. High emissions are a function of saltating sand that bombards the surface, liberating dust-sized particles for entrainment. Low dust emissions are primarily a function of surface crusting, gravel armoring, and vegetation density. PI-SWERL measurements reveal that emission rates can vary by at least three orders of magnitude, reflecting local variability in soil texture and continuity of surface crusts. Shear-stress partitioning models can be applied to dust data measured by the PI-SWERL to account for large surface roughness features, such as vegetation. The results presented here give an approximation of the contributions to atmospheric dust loading by landforms in the Mojave Desert, and can potentially be used to improve atmospheric dust models.

  18. New leaf diseases of barley in Egypt.

    PubMed

    Mehiar, F F; El-Deen, E; Wasfy, H; El-Samra, I A

    1976-01-01

    Leaf diseases of barley were observed also in Egypt. From leaves of barley were isolated: Helminthosporium teres, H. gramineum, Stemphylium vesicarium, Alternaria triticina, Vlocladium chartarum, Acnemonium kiliense, Stemphylium spec. accompanied with the Pleospora stage. Inoculations on both attached and detached leaves showed that all the tested fungi were pathogenic, except Acremonium kiliense and Ulocladium chartarum. PMID:1037183

  19. Detection of Strawberry Viruses in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a USAID-MERC funded project, ‘Disease-indexing and mass propagation of superior strawberry cultivars’, an effort was made to evaluate the virus status of strawberries in Egypt. Diagnostic reverse transcription-polymerase chain reaction (RT-PCR) tests for Strawberry mottle, Strawberry cri...

  20. Earth's motions in pharaonic Egypt: Religious interpretations

    NASA Astrophysics Data System (ADS)

    Jambon, Emmanuel

    This paper will deal with the representations of the earth's movements in pharaonic Egypt. At first, testimonies of an ancient literary pattern, the "sky and earth" figure, will be observed, and then, the pictures where earth is represented "alone". We will explore the different ways the Egyptians depicted and interpreted this phenomena through various texts.

  1. Journey to Egypt: A Board Game

    ERIC Educational Resources Information Center

    Selvidge, Ellen

    2006-01-01

    This author describes how her elementary students first became interested in studying ancient Egypt. Her students' interest in the ancient Egyptian studies began when a student checked out a library book on Egyptology that contained colorful images and was soon swarmed by interested classmates. Many of her students began practicing writing…

  2. Women's "Justification" of Domestic Violence in Egypt

    ERIC Educational Resources Information Center

    Yount, Kathryn M.; Li, Li

    2009-01-01

    We explored the influences of women's social learning, marital resources and constraints, and exposure to norms about women's family roles on their views about wife hitting or beating among 5,450 participants in the 2005 Egypt Demographic and Health Survey. One half justified wife hitting or beating for some reason. Women from rural areas who were…

  3. Review of Parasitic Zoonoses in Egypt

    PubMed Central

    Youssef, Ahmed I.; Uga, Shoji

    2014-01-01

    This review presents a comprehensive picture of the zoonotic parasitic diseases in Egypt, with particular reference to their relative prevalence among humans, animal reservoirs of infection, and sources of human infection. A review of the available literature indicates that many parasitic zoonoses are endemic in Egypt. Intestinal infections of parasitic zoonoses are widespread and are the leading cause of diarrhea, particularly among children and residents of rural areas. Some parasitic zoonoses are confined to specific geographic areas in Egypt, such as cutaneous leishmaniasis and zoonotic babesiosis in the Sinai. Other areas have a past history of a certain parasitic zoonoses, such as visceral leishmaniasis in the El-Agamy area in Alexandria. As a result of the implementation of control programs, a marked decrease in the prevalence of other zoonoses, such as schistosomiasis and fascioliasis has been observed. Animal reservoirs of parasitic zoonoses have been identified in Egypt, especially in rodents, stray dogs and cats, as well as vectors, typically mosquitoes and ticks, which constitute potential risks for disease transmission. Prevention and control programs against sources and reservoirs of zoonoses should be planned by public health and veterinary officers based on reliable information from systematic surveillance. PMID:24808742

  4. Censorship and Security Agents Pervade Egypt's Universities

    ERIC Educational Resources Information Center

    Mills, Andrew

    2008-01-01

    This article offers a glimpse into one of the many ways in which the Egyptian government and the campus administrators it appoints are slowly and persistently squeezing the life out of universities in Cairo, Egypt. Classroom discussions are monitored, faculty appointments and academic research are scrutinized, and faculty participation in outside…

  5. Food insecurity and food deserts.

    PubMed

    Camp, Nadine L

    2015-08-15

    Food insecurity has been steadily increasing in the United States with prevalence at nearly 15% of all households. Nurse practitioners can assess for food insecurity and provide local resources for families living in neighborhoods without easy access to healthy foods, otherwise known as food deserts. PMID:26180911

  6. On a Crowded Desert Island.

    ERIC Educational Resources Information Center

    Rothstein, Samuel

    1989-01-01

    Suggests reference sources most appropriate for a desert island. In addition to "Robinson Crusoe" (Daniel Defoe) and a reference guide to the literature of travel, the list includes basic books on reference work, guides to reference sources, journals, an almanac, encyclopedias, a guide to English usage, and a book of quotations. (14 references)…

  7. Modeling Soil Moisture in the Mojave Desert

    USGS Publications Warehouse

    Miller, David M.; Hughson, Debra; Schmidt, Kevin M.

    2008-01-01

    The Mojave Desert is an arid region of southeastern California and parts of Nevada, Arizona, and Utah; the desert occupies more than 25,000 square miles (fig. 1). Ranging from below sea level to over 5,000 feet (1,524 m) in elevation, the Mojave Desert is considered a ?high desert.? On the west and southwest it is bounded by the Sierra Nevada, the San Gabriel, and the San Bernardino Mountains. These imposing mountains intercept moisture traveling inland from the Pacific Ocean, producing arid conditions characterized by extreme fluctuations in daily temperatures, strong seasonal winds, and an average annual precipitation of less than six inches. The Mojave Desert lies farther south and at a lower elevation than the cooler Great Basin Desert and grades southward into the even lower and hotter Sonoran Desert.

  8. Phylogeography of Beck's Desert Scorpion, Paruroctonus becki, reveals Pliocene diversification in the Eastern California Shear Zone and postglacial expansion in the Great Basin Desert.

    PubMed

    Graham, Matthew R; Jaeger, Jef R; Prendini, Lorenzo; Riddle, Brett R

    2013-12-01

    The distribution of Beck's Desert Scorpion, Paruroctonus becki (Gertsch and Allred, 1965), spans the 'warm' Mojave Desert and the western portion of the 'cold' Great Basin Desert. We used genetic analyses and species distribution modeling to test whether P. becki persisted in the Great Basin Desert during the Last Glacial Maximum (LGM), or colonized the area as glacial conditions retreated and the climate warmed. Phylogenetic and network analyses of mitochondrial cytochrome c oxidase 1 (cox1), 16S rDNA, and nuclear internal transcribed spacer (ITS-2) DNA sequences uncovered five geographically-structured groups in P. becki with varying degrees of statistical support. Molecular clock estimates and the geographical arrangement of three of the groups suggested that Pliocene geological events in the tectonically dynamic Eastern California Shear Zone may have driven diversification by vicariance. Diversification was estimated to have continued through the Pleistocene, during which a group endemic to the western Great Basin diverged from a related group in the eastern Mojave Desert and western Colorado Plateau. Demographic and network analyses suggested that P. becki underwent a recent expansion in the Great Basin. According to a landscape interpolation of genetic distances, this expansion appears to have occurred from the northwest, implying that P. becki may have persisted in part of the Great Basin during the LGM. This prediction is supported by species distribution models which suggest that climate was unsuitable throughout most of the Great Basin during the LGM, but that small patches of suitable climate may have remained in areas of the Lahontan Trough. PMID:23933071

  9. ESR signal intensity and crystallinity of quartz from Gobi and sandy deserts in East Asia and implication for tracing Asian dust provenance

    NASA Astrophysics Data System (ADS)

    Sun, Youbin; Chen, Hongyun; Tada, Ryuji; Weiss, Dominik; Lin, Min; Toyoda, Shin; Yan, Yan; Isozaki, Yuko

    2013-08-01

    Electron spin resonance (ESR) signal intensity and crystallinity index (CI) of fine- (<16 µm) and coarse-grained (>16 µm) quartz were measured in surface samples from the Taklimakan desert in western China, the Badain Juran, Tengger and Mu Us deserts in northern China, and the Gobi desert in southern Mongolia to evaluate whether these geophysical parameters can serve as reliable provenance tracers of Asian dust. The results indicate that spatial variability of both ESR signal intensity and CI is evident within the Taklimakan deserts and the Mongolian Gobi, but less significant in the three deserts of northern China. Coarse-grained quartz from the Mongolian Gobi and northern China deserts can be differentiated from the Taklimakan desert using the ESR signal intensity. Fine-grained quartz originating from three major Asian dust sources, i.e., the Gobi-sandy deserts in western China, northern China and southern Mongolia, can be distinguished effectively using the combination of ESR and CI signals. Our results suggest that ESR signal intensity and CI can discriminate the sources of fine-grained quartz better than coarse-grained quartz, providing an effective approach to trace the provenance of fine-grained dust deposition on the land and in the ocean.

  10. 78 FR 26682 - Culturally Significant Objects Imported for Exhibition Determinations: “Hall of Ancient Egypt

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-07

    ...Exhibition Determinations: ``Hall of Ancient Egypt'' AGENCY: Department of State...to the exhibition ``Hall of Ancient Egypt.'' The referenced notice is...in the exhibition ``Hall of Ancient Egypt,'' imported from abroad...

  11. The Ends of Islamic Fundamentalism: Hegemonic Discourse and the Islamic Question in Egypt

    E-print Network

    Campo, Juan E.

    1995-01-01

    as Egypt, Israel, and Algeria; the rediscovery of religionEgypt — they extend'across the civilized world, across all religions.religion versus secularism. For centuries, the Muslim population in Egypt

  12. Mortality, Recruitment and Change of Desert Tree Populations in a Hyper-Arid Environment

    PubMed Central

    Andersen, Gidske L.; Krzywinski, Knut

    2007-01-01

    Background Long-term vegetation changes in hyper-arid areas have long been neglected. Mortality, recruitment and change in populations of the ecologically and culturally important and drought persistent Acacia tortilis and Balanites aegyptiaca are therefore estimated in the Eastern Desert of Egypt, and are related to the primary agents of change, water conditions and human intervention. Methodology A change analysis using high-resolution Corona images (1965) in combination with field data (2003) is the basis for recruitment, mortality and change estimates. For assessing the influence of water conditions on patterns in recruitment and survival, different types of generalized linear models are tested. Conclusions The overall trend in population size in that part of the Eastern Desert studied here is negative. At some sites this negative trend is alarming, because the reduction in mature trees is substantial (>50%) at the same time as recruitment is nearly absent. At a few sites there is a positive trend and better recruitment. Frequent observations of sprouting in saplings indicate that this is an important mechanism to increase their persistence. It is the establishment itself that seems to be the main challenge in the recruitment process. There are indications that hydrological variables and surface water in particular can explain some of the observed pattern in mortality, but our results indicate that direct human intervention, i.e., charcoal production, is the main cause of tree mortality in the Eastern Desert. PMID:17299588

  13. Fluid inclusions in the mesozonal gold deposit at Atud mine, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Harraz, Hassan Z.

    2002-10-01

    Gold mineralization at the Atud mine occurs as fracture-filling auriferous quartz veins hosted in Neoproterozoic dioritic rocks and along their contact with metagabbro. Gold mineralization is associated with metasomatic alteration zones around shear zones and quartz-carbonate vein arrays. The mineralized veins consist of quartz, carbonate and albite gangue enclosing minor amounts of pyrrhotite, arsenopyrite, pyrite and sphalerite. Trace amounts of galena, chalcopyrite, magnetite and rutile are also present. Paragenetically, the mineralization is divided, with decreasing temperature, into three stages, namely: (1) Early (Au-poor, pyrrhotite-arsenopyrite-pyrite-quartz vein); (2) Main (Au-rich, sphalerite-arsenopyrite-pyrite-galena ± chalcopyrite-quartz vein); and (3) Late (quartz-carbonate-pyrite ± galena). Gold (15.6-36.2 at.% Ag) is present mainly as discrete grains of native gold (<5-20 ?m in diameter). Free gold appears mainly as inclusions in quartz and as microscopic inclusions (<5 ?m) in arsenopyrite and pyrite. Gold also occurs in fractures and grain boundaries of pyrite, arsenopyrite and base metal sulphides. These occurrences of gold indicate that several influxes of gold and/or stages of remobilization took place. Based on temperatures inferred from arsenopyrite compositions by electron microprobe, the estimated temperatures for Early and Main mineralized stages reach 340-430, and 273-368 °C, respectively. The sulphur activity (atm) of ore formation at the Atud deposit was estimated for each stage as 10 -6.5-10 -9.6, and 10 -8-10 -12.2, respectively. Fluid inclusions in quartz intimately associated with the mineralization are dominated by aqueous H 2O-CO 2 + NaCl types. In most cases, these fluid inclusions co-exist in individual samples and show various CO 2 phase volume proportions at 40 °C. Co-existing H 2O-rich liquid and CO 2-rich vapour fluid inclusions homogenized into liquid and carbonic vapour phases, respectively, over the same temperature range (270-490 °C). The petrographic observations and microthermometric data suggest that fluid inclusions in quartz intimately associated with the early and main mineralizing events were trapped during phase separation of an originally homogenous H 2O-CO 2 liquid, with low salinity (2.8-8.2 wt.% NaCl equiv.) and high density of 0.8-0.9 g/cc (corresponding to 15-76 mol% CO 2). These data are consistent with transportion of gold as a bisulphide complex. Gold deposition occurred over a temperature range of 270-430 °C and pressures of 160-272 MPa (˜6-11 km depths), likely due to decreases in sulphur activity (10 -6.5-10 -12.2) accompanying fluid unmixing. Gold deposition in the Atud diorites was related to fluid phase separation, sulphidization and carbonatization of host dioritic rocks during hydrothermal alteration and mineralization. The diorites are considered to have acted as preferential sites for fluid flow and ore precipitation due to their brittle nature during regional deformation.

  14. Paleoclimatic and Tectonic History of the Eastern Desert, Egypt and Surroundings

    NASA Technical Reports Server (NTRS)

    Arvidson, Raymond E.

    1997-01-01

    This report covers work for the Planetary Geology and Geophysics Program, which has focused on three areas: analysis of the tectonics and paleoclimatic conditions in north eastern Africa, analysis of surficial geology and damage associated with the 1993 Missouri River floods and rates of lava flow degradation at Lunar Crater volcanic field in Nevada. Work has resulted in several dozen abstracts, several dissertations and a number of papers.

  15. Geometry and texture of quartz veins in Wadi Atalla area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Akawy, Ahmed

    2007-02-01

    Several quartz vein sets with varying orientation, geometry and internal structure were recognized in the Atalla area. The veins were associated with the deformation phases affecting the area. En echelon and extensional veins are the main geometrical types. Syn-kinematic veins associated with the major northeast-over-southwest thrust faults were later boudinaged, folded and re-folded. En echelon veins, fibrous veins, and extensional veins are associated with the NNW-SSE faults. Other veins are associated with the NW-SE, N-S, NE-SW and E-W faults. Veins are concentrated at the intersection zones between faults. The internal structure of the veins comprises syntaxial, antitaxial, and composite types and reflects a change from a compressive stress regime to an extensional one. Chocolate-tablet structures and synchronous and co-genetic vein networks indicate later multi-directional extension of the area. Interaction between cracking and sealing of fractures is a common feature in the study area indicating that it was easy for the pore pressure to open pre-existing fractures instead of creating new ones. The reopening of pre-existing fractures rather than creating new ones is also indicated by the scattering of vein data around ?3. There is an alteration and change in characteristics of the wall rock due to increase in fluid flow rate. Fault-valving probably is also a cause of the complex geometry of some veins.

  16. Watering the Desert: Environment, Irrigation, and Society in the Premodern Fayyum, Egypt

    E-print Network

    Haug, Brendan James

    2012-01-01

    part of the canal system here. The Ptolemaic eastern desertwell-managed system. Yet even in the Ptolemaic period wheresystem and numerous new villages provided settlement and well-watered farmland for demobilized Ptolemaic

  17. Isotopic and hydrogeochemical evaluation of groundwater at Qusier-Safaga area, eastern desert, Egypt.

    PubMed

    Awad, M A; Hamza, M S; Atwa, S M; Sallouma, M K

    1996-06-01

    The groundwater resources of the El-Qusier-Safaga area on the Red Sea coastal zone have still to be utilised fully for social and economic development. In the present study, an inventory of recharge sources and quality of groundwater in different water bearing formations is made to assist in management of these vital resources. From a hydrochemical point of view, the origin of salinity in the five investigated aquifers are mainly dissolution of terrestrial minerals, leaching of soilsvia floods or ion exchanges processes. Stable isotope data clarify the interaction between different aquifers and indicate that the source of recharge is mainly meteoric water originating from palaeowater of the Pleistocene pluvial period, and from local precipitation as well as some marine water. Evaluation of the groundwater quality for domestic, irrigation and industrial purposes is discussed. PMID:24194374

  18. Distribution of desert varnish in Arizona

    NASA Technical Reports Server (NTRS)

    Elvidge, Christopher D.

    1989-01-01

    Desert varnish is the dark coat of clay and ferromanganese oxides developed on exposed rock surfaces in arid regions. It forms from the accretion of material from windblown dust. The distribution of desert varnish was mapped in Arizona. It was discovered that desert varnish could be mapped on a regional scale. Well developed desert varnish is common on stable rock surfaces in areas having alkaline soils and less than about 25 cm of annual precipitation. Rock surfaces in areas having more than 40 cm of annual precipitation are generally devoid of desert varnish. An experiment was conducted with varnished desert pavement stone. The stones were broken in half and half was set on a roof in central Illinois from April until October. Removed from the alkaline desert environment, it only took seven months for the varnish to develop an eroded appearance. This experiment graphically illustrates the dependency of desert varnish on alkalinity. In this context, the zones of eroded desert varnish in Arizona indicate that the area of active desert varnish formation has fluctuated, expanding in drier times and contracting/eroding in wetter times.

  19. Management of Disused Radioactive Sealed Sources in Egypt - 13512

    SciTech Connect

    Mohamed, Y.T.; Hasan, M.A.; Lasheen, Y.F.

    2013-07-01

    The future safe development of nuclear energy and progressive increasing use of sealed sources in medicine, research, industry and other fields in Egypt depends on the safe and secure management of disused radioactive sealed sources. In the past years have determined the necessity to formulate and apply the integrated management program for radioactive sealed sources to assure harmless and ecological rational management of disused sealed sources in Egypt. The waste management system in Egypt comprises operational and regulatory capabilities. Both of these activities are performed under legislations. The Hot Laboratories and Waste Management Center HLWMC, is considered as a centralized radioactive waste management facility in Egypt by law 7/2010. (authors)

  20. Unusual dominance by desert pupfish (Cyprinodon macularius) in experimental ponds within the Salton Sea Basin

    USGS Publications Warehouse

    Saiki, Michael K.; Martin, Barbara A.; Anderson, Thomas W.

    2011-01-01

    In October 2006, months after shallow experimental ponds in the Salton Sea Basin were filled with water from the Alamo River and Salton Sea, fish were observed in several ponds, although inlets had been screened to exclude fish. During October 2007November 2009, nine surveys were conducted using baited minnow traps to document species and relative abundance of fish. Surveys yielded 3,620 fish representing five species. Desert pupfish (Cyprinodon macularius), the only native species encountered, was the most numerous and comprised >93% of the catch. Nonnative species included western mosquitofish (Gambusia affinis, 4.1%), sailfin molly (Poecilia latipinna, 2.8%), and tilapia (a mixture of hybrid Mozambique tilapia Oreochromis mossambicus ?? O. urolepis and redbelly tilapia Tilapia zillii, <0.1%). Dominance by desert pupfish, which persisted over our 2 years of study, was unusual because surveys conducted in nearby agricultural drains yielded relatively few desert pupfish.

  1. Benchmarking performance: Environmental impact statements in Egypt

    SciTech Connect

    Badr, El-Sayed A.; Zahran, Ashraf A.; Cashmore, Matthew

    2011-04-15

    Environmental impact assessment (EIA) was formally introduced in Egypt in 1994. This short paper evaluates 'how well' the EIA process is working in practice in Egypt, by reviewing the quality of 45 environmental impact statements (EISs) produced between 2000 and 2007 for a variety of project types. The Lee and Colley review package was used to assess the quality of the selected EISs. About 69% of the EISs sampled were found to be of a satisfactory quality. An assessment of the performance of different elements of the EIA process indicates that descriptive tasks tend to be performed better than scientific tasks. The quality of core elements of EIA (e.g., impact prediction, significance evaluation, scoping and consideration of alternatives) appears to be particularly problematic. Variables that influence the quality of EISs are identified and a number of broad recommendations are made for improving the effectiveness of the EIA system.

  2. [Concepts of the heart in Ancient Egypt].

    PubMed

    Ziskind, Bernard; Halioua, Bruno

    2004-03-01

    The heart was regarded in Ancient Egypt as the organic motor of the body and also the seat of intelligence, an important religious and spiritual symbol. It was considered as one of the eight parts of human body. Counter to other organs it had to be kept carefully intact in the mummy to ensure its eternal life. In Ancient Egypt, the concept of heart included three constituents: heart-haty, heart-ib, and the spiritual seat of intelligence, emotion and memory. The hieroglyphs representing the heart early in the first dynasty were drawn with eight vessels attached to it. Egyptian doctors have elaborated an original conception of cardiovascular physiology which endured 30 centuries. PMID:15067585

  3. Influence of surface roughness of a desert

    NASA Technical Reports Server (NTRS)

    Sud, Y. C.; Smith, W. E.

    1984-01-01

    A numerical simulation study, using the current GLAS climate GCM, was carried out to examine the influence of low bulk aerodynamic drag parameter in the deserts. The results illustrate the importance of yet another feedback effect of a desert on itself, that is produced by the reduction in surface roughness height of land once the vegetation dies and desert forms. Apart from affecting the moisture convergence, low bulk transport coefficients of a desert lead to enhanced longwave cooling and sinking which together reduce precipitation by Charney's (1975) mechanism. Thus, this effect, together with albedo and soil moisture influence, perpetuate a desert condition through its geophysical feedback effect. The study further suggests that man made deserts is a viable hypothesis.

  4. Seismicity and kinematic evolution of middle Egypt

    NASA Astrophysics Data System (ADS)

    Badawy, A.; Abdel-Monem, S. M.; Sakr, K.; Ali, Sh. M.

    2006-08-01

    Based on historical and instrumental seismicity as well as recent GPS measurements, the seismicity and kinematic evaluation of middle Egypt is presented. Middle Egypt suffered in historical times by six major earthquakes and the Ramses II temple on the west bank of the Nile in Luxor, was almost destroyed by an ancient event. The temporal distribution of recent earthquakes (1900-1997) is highly scattered with only nine events recorded. Only after the installation of the modern Egyptian national seismograph network (ENSN) the seismic record of middle Egypt increased with a total of 280 earthquakes from 1998 to 2004. Focal mechanism solutions of the largest five events during the ENSN's operation period reveal reverse faulting mechanism with minor strike-slip component on the west bank of the Nile, while a normal faulting mechanism dominate in the eastern side. The orientations of both P- and T-axes are consistent with the Red Sea-Gulf of Suez stress field. Dynamic source parameters of these five events were derived from P-wave spectra as well. Three campaigns of GPS measurements were carried out for the middle Egypt network that established after the first instrumental earthquake on 14 December 1998 in this area. The velocity vectors for each epoch of observations were calculated and deformation analysis was performed. The horizontal velocity varies between 1 and 4 mm/year across the network. The deformation pattern suggests significant contraction across the southeastern sector of the study area while, the northwestern part is characterized by an extension strain rates. High shear strain is observed along the epicenteral area of the Mw = 4.0 June 2003 earthquake possibly reflecting the stress accumulation stage of a seismic cycle.

  5. Network topology of the desert rose

    NASA Astrophysics Data System (ADS)

    Hope, Sigmund; Kundu, Sumanta; Roy, Chandreyee; Manna, Subhrangshu; Hansen, Alex

    2015-09-01

    Desert roses are gypsum crystals that consist of intersecting disks. We determine their geometrical structure using computer assisted tomography. By mapping the geometrical structure onto a graph, the topology of the desert rose is analyzed and compared to a model based on diffusion limited aggregation. By comparing the topology, we find that the model gets a number of the features of the real desert rose right, whereas others do not fit so well.

  6. Water Resources Center, Desert Research Institute Annual Technical Report

    E-print Network

    Water Resources Center, Desert Research Institute Annual Technical Report FY 1998 Introduction Focus Category #3 Climatological Processes Lead Institution Desert Research Institute Principal Desert Research Institute 01 Victor R. Baker Professor University of Arizona 02 Stephen G. Wells

  7. 75 FR 57761 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ...that on September 10, 2010, Desert Southwest Power, LLC (Desert Southwest) filed responses...July 28, 2010 letter regarding Desert Southwest's petition for declaratory...502-8659. Comment Date: 5 p.m. Eastern Time on September 24,...

  8. 75 FR 61467 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ...that on September 24, 2010, Desert Southwest Power, LLC (Desert Southwest) supplemented the...July 28, 2010 letter regarding Desert Southwest's petition for declaratory...502-8659. Comment Date: 5 p.m. Eastern Time on October 4, 2010....

  9. NMSU courtesy photo Chihuahuan Desert Rangeland Research Center

    E-print Network

    Johnson, Eric E.

    NMSU courtesy photo Chihuahuan Desert Rangeland Research Center Our mission is to conduct. Chihuahuan Desert Rangeland Research Center (Knox Hall, Room 329) New Mexico State University MSC 3-I, P ofprecipitationisacriticalcomponentofsustainablegrazingin theChihuahuanDesert. · Identifiedthevalueofcontrollinghoneymesquiteaspart

  10. Alternate Energy from the Desert

    NASA Astrophysics Data System (ADS)

    Malek, E.

    2003-12-01

    Due to rapid growth of the world's population and more demands for energy, and due to limited amount of fossil fuels (which provide 95 % of the world's energy needs), harnessing of alternate energy sources such as solar and wind power should be considered. In addition to the mountain passes with usually high wind, vast and flat desert areas could be good candidates for harvesting both solar and wind power. We set up a weather station in the middle of a desert, approximately 65 km east-west by 130 km north-south, located at Dugway (40\\deg 08' N, 113\\deg 27' W, 1124 m above mean sea level) in northwestern Utah, USA, in 1999. This station measured the incoming (Rsi) and outgoing (Rso) solar or shortwave radiation using two CM21 Kipp & Zonen pyranometers (one inverted), the incoming (Rli or atmospheric) and outgoing (Rlo or terrestrial) longwave radiation, using two CG1 Kipp & Zonen pyrgeometers (one inverted), and the net (Rn) radiation using a Q*7 net radiometer (Radiation Energy Balance System, REBS). We also measured the 3-m wind speed (U3) and direction (R.M. Young wind monitor) and precipitation (Campbell Sci., Inc.) and some other weather parameters. The measurements were taken every two seconds, and averaged into 20-min, continuously, throughout the year. The two-year (January 2000 - December 2001) period comparisons of global or solar radiation and windiness with two other stations in central (Hunter) and northern (Logan) Utah, indicate higher average solar radiation [Rsi,Dugway = 601 MJ / (m2-month) vs. Rsi, Hunter = 5371 MJ /(m2-month) and Rsi, Logan = 516 MJ /(m2-month)] and much higher 10-m average wind (UDugway = 478 km/d vs. UHunter = 323 km/d and ULogan = 275 km/d) throughout the period over the desert. These data reveal the possibility of simultaneously harvesting these two sources of clean energies at this vast and uniform desert area. Keywords: Desert, energy, radiation balance, solar and wind energies, windiness.

  11. The age of the Taklimakan Desert.

    PubMed

    Sun, Jimin; Liu, Tungsheng

    2006-06-16

    The Taklimakan Desert is located in the foreland basin of the Tibetan Plateau. We report here the results of stratigraphic investigations of a 1626-meter-thick sequence with interbedded wind-blown silt from the southern marginal Taklimakan Desert. Because the studied section is located downwind of the desert, the eolian silt accumulation is closely linked to desert formation. Our new evidence indicates that shifting sand dunes prevailed in the Tarim Basin by at least 5.3 million years ago, as they do today. We attribute this event to late Cenozoic climatic deterioration, as well as to changes in atmospheric circulation induced by Tibetan Plateau uplift. PMID:16778048

  12. Characterization of the Sonoran desert as a radiometric calibration target for Earth observing sensors

    USGS Publications Warehouse

    Angal, Amit; Chander, Gyanesh; Xiong, Xiaoxiong; Choi, Tae-young; Wu, Aisheng

    2011-01-01

    To provide highly accurate quantitative measurements of the Earth's surface, a comprehensive calibration and validation of the satellite sensors is required. The NASA Moderate Resolution Imaging Spectroradiometer (MODIS) Characterization Support Team, in collaboration with United States Geological Survey, Earth Resources Observation and Science Center, has previously demonstrated the use of African desert sites to monitor the long-term calibration stability of Terra MODIS and Landsat 7 (L7) Enhanced Thematic Mapper plus (ETM+). The current study focuses on evaluating the suitability of the Sonoran Desert test site for post-launch long-term radiometric calibration as well as cross-calibration purposes. Due to the lack of historical and on-going in situ ground measurements, the Sonoran Desert is not usually used for absolute calibration. An in-depth evaluation (spatial, temporal, and spectral stability) of this site using well calibrated L7 ETM+ measurements and local climatology data has been performed. The Sonoran Desert site produced spatial variability of about 3 to 5% in the reflective solar regions, and the temporal variations of the site after correction for view-geometry impacts were generally around 3%. The results demonstrate that, barring the impacts due to occasional precipitation, the Sonoran Desert site can be effectively used for cross-calibration and long-term stability monitoring of satellite sensors, thus, providing a good test site in the western hemisphere.

  13. PHYLOGEOGRAPHY OF BUFO PUNCTATUS: LONG TERM EVOLUTION WITHIN THE WARM DESERTS OF NORTH AMERICA AND LATE QUATERNARY RANGE SHIFTING

    EPA Science Inventory

    Bufo punctatus, the red-spotted toad, is a widespread anuran of the warm-desert regions of western North America. This distribution makes this species ideal for evaluating biotic response to geotectonically and climatically mediated episodes of landscape transformation (e.g., ear...

  14. African Historical Religions: A Conceptual and Ethnical Foundation for "Western Religions."

    ERIC Educational Resources Information Center

    Alexander, E. Curtis

    This paper attempts to set the record straight with regard to the following assumptions: (1) the Africans of the antiquities of Ethiopia and Egypt were black people; and (2) the same black people developed the foundation that provides the basis for the so-called major Western religions of Judaism, Christianity, and Islam. There are two parts to…

  15. 77 FR 33439 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-06

    ...at the gateway of trade for Africa and the Middle East. It is...ports and airports in Egypt and Africa, own facilities in Europe and...Middle East and as far away as Russia. Historically traders, Kuwait's...Egypt and the largest city in Africa. A majority of the...

  16. 75 FR 58353 - Business Development Mission to Egypt and Morocco

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... port logistics, infrastructure projects, safety and security, and energy infrastructure. The mission... equipment for protecting Morocco's two vast coastlines and remote national borders. Energy Infrastructure Egypt Egypt is one of the largest electrical energy producing countries in the Middle East. Over...

  17. Resource Unit on Egypt for the Intermediate Grades.

    ERIC Educational Resources Information Center

    Husbands, Kenneth; Taylor, Bob

    Resources for teaching about modern and ancient Egypt are provided in this guide for intermediate grade social studies teachers. Material includes: a detailed outline for a unit on Egypt which contains a geographic overview followed by sections on the Nile River Valley, agriculture, the pharaohs, religion, architecture, science, hieroglyphics,…

  18. Integrate the Arts. The Art of Ancient Egypt.

    ERIC Educational Resources Information Center

    Parks, Mary

    1996-01-01

    Presents three art projects that can bring to life the study of ancient Egypt for elementary students. After researching Egypt's history and culture, students can create King Tut masks, make Cleopatra headdresses, and craft cartouche pendants. The article describes the materials needed and steps required to complete each project. (SM)

  19. 78 FR 14979 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ...U.S. and Foreign Commercial Service...regarding the Trade Mission to Egypt...2013. The effect of this notice...in the U.S. Trade Mission to Egypt...U.S. and Foreign Commercial Service...Authority For Investment and Free Zones...

  20. A SURVEY OF CYST NEMATODES (HETERODERA SPP.) IN NORTHERN EGYPT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information concerning the occurrence and distribution of cyst nematodes (Heterodera spp.) in Egypt is important to assess their potential to cause economic damage to crop plants. A nematode survey was conducted in Alexandria and El-Behera Governorates in northern Egypt to identify the species of cy...

  1. Separate but Equal: Segregated Religious Education in Egypt's Public Schools

    ERIC Educational Resources Information Center

    Isaac, John

    2012-01-01

    The Arab Spring exposed the hidden secrets of Egyptian society to the global community. In spite of the insatiable media attention paid to the Mubarak regime and the toll it took on the entire country, Egypt's education system received little attention. For decades, Egypt's public schools have forced students to attend segregated classes, based on…

  2. Power and Gender in Ancient Egypt: The Case of Hatshepsut

    ERIC Educational Resources Information Center

    Hilliard, Kristina; Wurtzel, Kate

    2009-01-01

    Hatshepsut (1479-1458 B.C.E) ruled New Kingdom Egypt for roughly 20 years as one of the few female pharaohs in the history of ancient Egypt. Her rule began when her husband died and her stepson was too young to be pharaoh. To legitimize her role as pharaoh, Hatshepsut began a significant building campaign by constructing numerous images, temples,…

  3. Tech Talk for Social Studies Teachers: Ancient Egypt.

    ERIC Educational Resources Information Center

    Pahl, Ronald H.

    1998-01-01

    Presents an annotated bibliography of 10 Web sites concerning ancient Egypt that have materials appropriate for social studies classes. Includes virtual tours of Egypt and specific temples, explorations of the pyramids, archaeological and geographic information, and information on the Egyptian "Book of the Dead." (MJP)

  4. 78 FR 14979 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... Trade Mission to Egypt April 14-16, 2013, published at 78 FR 7752, February 4, 2013. The effect of this... participation in the U.S. Trade Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 33439, June 6, 2012. In 77 FR 71777, December 4, 2012, the Department of Commerce announced that the...

  5. Published: 23 June 2011 Another Revolution Afoot in Egypt

    E-print Network

    Zewail, Ahmed

    way to cure fanaticism. Op-Ed by Ahmed H. Zewail Cairo -- Nearly 100 days after the revolution, Egypt journalist Emad Ahmed wrote in a recent essay on "Egypt's Bridges" to the future, the post. Vision of a new generation As Mr. Ahmed has written, two dominant visions have shaped the Egyptian

  6. Western Skink

    USGS Multimedia Gallery

    The Western skink (Plestiodon skiltonianus) is a relatively common and widespread lizard in Southern California. It is more secretive and prefers more grassy habitat than the Western fence lizard or the side-blotched lizard, yet USGS and National Park Service biologists are finding signs of genetic ...

  7. Rainfall Variability in Deserts and the Timing of Seed Release in Chorizanthe rigida, a Serotinous Winter Desert Annual

    E-print Network

    Martínez-Berdeja, Alejandra

    2014-01-01

    desert annual Abstract Timing of seed release is a criticaldeserts Abstract Serotiny and delayed seed dispersal areseed dispersal in North American deserts ………………………. ……4 Abstract……………………………………………………………………………………

  8. First Ladies' Symposium on Early Childhood in Egypt (Cairo, Egypt, May 21, 2001).

    ERIC Educational Resources Information Center

    O'Gara, Chloe

    This document is comprised of the papers presented at the First Ladies' Symposium on Early Childhood in Egypt in May 2001. Participating in the symposium were representatives from the World Bank, the Amsterdam Institute for International Development, the Children's Project, and the Academy for Educational Development. The symposium opened with an…

  9. Notes from the Great American Desert

    ERIC Educational Resources Information Center

    Grady, Marilyn L.; LaCost, Barbara Y.

    2005-01-01

    In the good old days, the state that is Nebraska was identified as part of the Great American Desert. In many ways, in climate and terrain, it still bears a resemblance to a desert. As a frontier or a land of pioneers, it deserves recognition. Invisibility may be one of the greatest challenges women face. One of the great flaws in the writing of…

  10. On carbon sequestration in desert ecosystems

    USGS Publications Warehouse

    Schlesinger, W.H.; Belnap, J.; Marion, G.

    2009-01-01

    Recent reports of net ecosysytem production >100 g C m-2 yr-1 in deserts are incompatible with existing measurements of net primary production and carbon pools in deserts. The comparisions suggest that gas exchange measurements should be used with caution and better validation if they are expected to indicate the magnitude of carbon sink in these ecosysytems. ?? 2009 Blackwell Publishing.

  11. ECOLOGY OF DESERT SYSTEMS BOOK REVIEW

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 12 chapters of Whitford's book, Ecology of Desert Systems, summarize the comprehensive experiences and knowledge of a scientist with an extensive research background on a wide variety of physical and biological aspects of desert ecology. The author illustrates facts and concepts presented in th...

  12. Magnetic Analysis Techniques Applied to Desert Varnish

    NASA Technical Reports Server (NTRS)

    Schmidgall, E. R.; Moskowitz, B. M.; Dahlberg, E. D.; Kuhlman, K. R.

    2003-01-01

    Desert varnish is a black or reddish coating commonly found on rock samples from arid regions. Typically, the coating is very thin, less than half a millimeter thick. Previous research has shown that the primary components of desert varnish are silicon oxide clay minerals (60%), manganese and iron oxides (20-30%), and trace amounts of other compounds [1]. Desert varnish is thought to originate when windborne particles containing iron and manganese oxides are deposited onto rock surfaces where manganese oxidizing bacteria concentrate the manganese and form the varnish [4,5]. If desert varnish is indeed biogenic, then the presence of desert varnish on rock surfaces could serve as a biomarker, indicating the presence of microorganisms. This idea has considerable appeal, especially for Martian exploration [6]. Magnetic analysis techniques have not been extensively applied to desert varnish. The only previous magnetic study reported that based on room temperature demagnetization experiments, there were noticeable differences in magnetic properties between a sample of desert varnish and the substrate sandstone [7]. Based upon the results of the demagnetization experiments, the authors concluded that the primary magnetic component of desert varnish was either magnetite (Fe3O4) or maghemite ( Fe2O3).

  13. Spectral action and big desert

    E-print Network

    Marc Knecht; Thomas Schucker

    2006-05-15

    The values of the Higgs mass are obtained for two possibilities of extending the standard model in a way compatible with the existence of a noncommutative structure at high energies. We assume the existence of a big desert between the low energy electroweak scale and the high energy scale $\\Lambda = 1.1\\times 10^{17}$ GeV, where noncommutative features become relevant. We conclude that it is extremely difficult to depart from the Higgs mass value $ m_H= 175.1^{+5.8}_{-9.8}$ GeV obtained from noncommutative geometry for the standard model with three generations only.

  14. Indirect determination of broadband turbidity coefficients over Egypt

    NASA Astrophysics Data System (ADS)

    El-Metwally, Mossad

    2013-01-01

    Long-term data from diffuse and global irradiances were used to calculate direct beam irradiance which was used to determine three atmospheric turbidity coefficients (Linke T L , Ångström ? and Unsworth-Monteith ? a ) at seven sites in Egypt in the period from 1981 to 2000. Seven study sites (Barrani, Matruh, Arish, Cairo, Asyut, Aswan and Kharga) have been divided into three categories: Mediterranean climate (MC), desert Nile climate (DNC) and urban climate (UC, Cairo). The indirect method (i.e., global irradiance minus diffuse irradiance) used here allows to estimate the turbidity coefficients with an RMSE% ?20 % (for ?, ? a and T L ) and ~30 % (for ?) if compared with those estimated by direct beam irradiance and sunphotometeric data, respectively. Monthly averages of T L , ? and ? a show seasonal variations with mainly maxima in spring at all stations, due to Khamsin depressions coming from Sahara. Secondary maxima is observed in summer and autumn at DNC and MC (Barrani and Arish) stations in summer due to dust haze which prevails during that season and at UC (Cairo) in autumn, due to the northern extension of the Sudan monsoon trough, which is accompanied by small-scale depressions with dust particles. The mean annual values of ?, ? a , and T L (0.216, 0.314, and 4.6, respectively) are larger in Cairo than at MC stations (0.146, 0.216, and 3.8, respectively) and DNC stations (0.153, 0.227, and 3.8, respectively). Both El-Chichon and Mt. Pinatubo eruptions were examined for all records data at MC, UC and DNC stations. The overburden caused by Mt. Pinatubo's eruption was larger than El-Chichon's eruption and overburden for ?, and T L at DNC stations (0.06, and 0.58 units, respectively) was more pronounced than that at MC (0.02, and 0.26, respectively) and UC (0.05 and 0.52 units, respectively) stations. The annual variations in wind speed and turbidity parameters show high values for both low and high wind speed at all stations. The wind directions have a clear effect on atmospheric turbidity, and consequently, largest turbidities occur when the wind carries aerosols from the main particle sources, such as industrial particle sources around Cairo or to some extent from the Sahara surrounding all study stations.

  15. Women in Egypt: new roles and realities.

    PubMed

    Lesch, A M; Sullivan, E L

    1986-01-01

    This is an extensive background presentation on the recent changes in Egyptian society, followed by results of a survey of attitudes toward family planning and the role of women. There have been remarkable social changes in Egypt recently, accompanied by rapid growth of the densely packed population. Virtually all of Egypt's 50 million people live on the banks of the Nile, 12 million of them in Cairo. Family planning has been government policy since 1981; the IUD and the pill are commonly used; but sterilization and abortion are illegal except for certain medical indications. Family subsidies and many public services have been eliminated, and even the lower classes are feeling the pinch of high cost of living, to the extent of desiring to balance their family size with their income. The survey was conducted by 35 students of the American University in Cairo, targeting middle and upper class adults, middle and upper class students, and lower class workers and domestics. The subjects were selected to be known to the interviewers to increase reliability of the data. This design created bias in the results, a preponderance of urban, student, single, childless and upper class subjects relative to the general population. The most common trend in the survey results was a conservatism among men, the lower class or less educated, or the rural lower classes. For example most women wanted 2 children, while those with traditional views valued male children and questioned the rights of women to be educated, to work outside the home, and to use contraception. The survey found that few people knew much about Egypt's Personal Status Law of 1979, which specifies women's rights regarding divorce, alimony, child support, and male polygamy. Women faced with divorce, however, rapidly learn their rights. This study revealed a consensus toward egalitarian values, along with distinct discord between the classes and sexes, and conflict between modern development and traditional roles for women. PMID:12315070

  16. Elsheimer, Galileo, and The Flight into Egypt

    NASA Astrophysics Data System (ADS)

    Howard, D.; Longair, M. S.

    2011-06-01

    Elsheimer's The Flight into Egypt is famous as the first apparently naturalistic rendering of the night sky. It was painted at almost exactly the same date as the invention of the telescope and predated Galileo's discoveries described in his Sidereus Nuncius of 1610. This paper, a follow-up to that of Howard (1992), discusses the history of the discovery of the telescope through this period and assesses how realistically Elsheimer depicted the sky. It is argued that the sky was not one that Elsheimer could ever have seen and that the painting is more a religious iconographic text than an accurate representation of the sky.

  17. Diversity and Community Composition of Vertebrates in Desert River Habitats.

    PubMed

    Free, C L; Baxter, G S; Dickman, C R; Lisle, A; Leung, L K-P

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  18. Diversity and Community Composition of Vertebrates in Desert River Habitats

    PubMed Central

    Free, C. L.; Baxter, G. S.; Dickman, C. R.; Lisle, A.; Leung, L. K.-P.

    2015-01-01

    Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

  19. 75 FR 57761 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ... Energy Regulatory Commission Desert Southwest Power, LLC; Notice of Filing September 14, 2010. Take notice that on September 10, 2010, Desert Southwest Power, LLC (Desert Southwest) filed responses to the... Commission's July 28, 2010 letter regarding Desert Southwest's petition for declaratory order...

  20. Global observations of desert dust and biomass burning aerosols

    E-print Network

    Graaf, Martin de

    Global observations of desert dust and biomass burning aerosols Martin de Graaf KNMI #12 and desert dust observations from GOME and SCIAMACHY · Conclusions and Outlook #12; · Absorbing Aerosol + desert dust ocean scene spectrum ocean desert dust #12;Clear sky ocean scene spectrum + Rayleigh Ocean

  1. Thermal and water relations of desert beetles

    NASA Astrophysics Data System (ADS)

    Cloudsley-Thompson, J.

    2001-11-01

    The physical problems that living organisms have to contend with in hot deserts are primarily extremes of temperature, low humidity, shortage or absence of free water, and the environmental factors that accentuate these - such as strong winds, sand-storms, lack of shade, rocky and impenetrable soils. Climatic factors are particularly important to smaller animals such as arthropods on account of their relatively enormous surface to volume ratios. Nevertheless, beetles (especially Tenebrionidae and, to a lesser extent, Chrysomelidae) are among the most successful animals of the desert, and are often the only ones to be seen abroad during the day. Similar physical problems are experienced by insects in all terrestrial biomes, but they are much enhanced in the desert. Although climatic extremes are often avoided by burrowing habits coupled with circadian and seasonal activity rhythms, as well as reproductive phenology, several species of desert beetle are nevertheless able to withstand thermal extremes that would rapidly cause the death of most other arthropods including insects. The reactions of desert beetles to heat are largely behavioural whilst their responses to water shortage are primarily physiological. The effects of coloration are not discussed. In addition to markedly low rates of transpiration, desert beetles can also withstand a considerable reduction in the water content of their tissues. The study of desert beetles is important because it illustrates many of the solutions evolved by arthropods to the problems engendered, in an extreme form, by life in all terrestrial environments.

  2. Geol. Mag. 149 (5), 2012, pp. 783797. c Cambridge University Press 2011 783 doi:10.1017/S0016756811000975

    E-print Network

    Stern, Robert J.

    Gneiss Dome, as well as several other plutons in the Eastern Desert, indicating an important magmatic the mantle around 810 Ma. Keywords: Eastern Desert, gneiss dome, geochronology, geochemistry. 1. Introduction the Eastern Desert of Egypt, now constituting the western part of the ANS, has been the origin of the lower

  3. Satellite Observations of Desert Dust-induced Himalayan Snow Darkening

    NASA Technical Reports Server (NTRS)

    Gautam, Ritesh; Hsu, N. Christina; Lau, William K.-M.; Yasunari, Teppei J.

    2013-01-01

    The optically thick aerosol layer along the southern edge of the Himalaya has been subject of several recent investigations relating to its radiative impacts on the South Asian summer monsoon and regional climate forcing. Prior to the onset of summer monsoon, mineral dust from southwest Asian deserts is transported over the Himalayan foothills on an annual basis. Episodic dust plumes are also advected over the Himalaya, visible as dust-laden snow surface in satellite imagery, particularly in western Himalaya. We examined spectral surface reflectance retrieved from spaceborne MODIS observations that show characteristic reduction in the visible wavelengths (0.47 nm) over western Himalaya, associated with dust-induced solar absorption. Case studies as well as seasonal variations of reflectance indicate a significant gradient across the visible (0.47 nm) to near-infrared (0.86 nm) spectrum (VIS-NIR), during premonsoon period. Enhanced absorption at shorter visible wavelengths and the resulting VIS-NIR gradient is consistent with model calculations of snow reflectance with dust impurity. While the role of black carbon in snow cannot be ruled out, our satellite-based analysis suggests the observed spectral reflectance gradient dominated by dust-induced solar absorption during premonsoon season. From an observational viewpoint, this study underscores the importance of mineral dust deposition toward darkening of the western Himalayan snow cover, with potential implications to accelerated seasonal snowmelt and regional snow albedo feedbacks.

  4. Transnasal excerebration surgery in ancient Egypt.

    PubMed

    Fanous, Andrew A; Couldwell, William T

    2012-04-01

    Ancient Egyptians were pioneers in many fields, including medicine and surgery. Our modern knowledge of anatomy, pathology, and surgical techniques stems from discoveries and observations made by Egyptian physicians and embalmers. In the realm of neurosurgery, ancient Egyptians were the first to elucidate cerebral and cranial anatomy, the first to describe evidence for the role of the spinal cord in the transmission of information from the brain to the extremities, and the first to invent surgical techniques such as trepanning and stitching. In addition, the transnasal approach to skull base and intracranial structures was first devised by Egyptian embalmers to excerebrate the cranial vault during mummification. In this historical vignette, the authors examine paleoradiological and other evidence from ancient Egyptian skulls and mummies of all periods, from the Old Kingdom to Greco-Roman Egypt, to shed light on the development of transnasal surgery in this ancient civilization. The authors confirm earlier observations concerning the laterality of this technique, suggesting that ancient Egyptian excerebration techniques penetrated the skull base mostly on the left side. They also suggest that the original technique used to access the skull base in ancient Egypt was a transethmoidal one, which later evolved to follow a transsphenoidal route similar to the one used today to gain access to pituitary lesions. PMID:22224784

  5. Ophthalmic medicolegal cases in Upper Egypt

    PubMed Central

    Wasfy, Ismail A; Wasfy, Ehab IA; Aly, Tarek A; Abd-Elsayed, Alaa A

    2009-01-01

    Purpose To describe the pattern of ophthalmic medicolegal cases with emphasis on cases of assault, and to acquaint ophthalmologists with rules pertaining to expert testimony and medical reports. Methods A retrospective study was carried out to review files of 247 medicolegal cases from Upper Egypt seen by the senior author in 8 years. These were classified categorically and were analyzed from various characteristics and aspects. The scheme for examination of subjects and for formulating the medicolegal report is described. Results The different categories were assault in 224 cases (90.5%), military recruitment evasion in 8 cases (3.25%), occupational disability claims in 8 cases (3.25%) and medical malpractice in 7 cases (3%). Thirty two cases (13%) presented with alleged functional visual loss, of them 25 cases (10%) were malingering. Traumatic lens subluxation or dislocation was seen in 37 (13.5%) cases and phthisis and atrophia bulbi was the presenting sign in 55 (22.3%) cases. Twenty percent of assault cases were females. There were no differences in incidence between the provinces in Upper Egypt. Assault tools inflicted injuries are described, as well as the outcome of these cases. Claims against military recruits could not be substantiated. Occupational claims for damages were false. Alleged medical negligence cases were rejected based on accepted standards of care and not on unexpected complications. Conclusion Medical reports have to be structured, detailed, accurate and unbiased. Data in this work are useful for statistical and planning purposes in the medicolegal domain. PMID:19121208

  6. The nature of plague in late eighteenth-century Egypt.

    PubMed

    Mikhail, Alan

    2008-01-01

    This article uses an examination of the 1791 plague in Egypt to explore the relationships among disease, famine, flood, drought, and death in late eighteenth-century Egypt. It analyzes how plague functioned as part of a regular biophysical pathology of the environment in which the disease came and went as one iteration in a cycle that included famine, wind, flood, drought, price inflation, and revolt. Using the works of Egyptian chroniclers, archival materials, secondary studies, and traveler accounts, this article integrates plague into the study of the Egyptian environment by showing how it was a regular and expected part of life in Egypt. PMID:18622069

  7. Group Psychotherapy in Egypt: Past, Present, and Future.

    PubMed

    Rakhawy, Mona; Taha, Mohamed; Sabry, Noha

    2015-10-01

    Egypt has a central position in Africa and the Middle East. Events in the last few years have brought Egypt to the forefront of the world's interest in politics, sociology, and group psychology. This paper explores the evolution, development, and current status of group psychotherapy and group processes in Egypt. Starting from times of old in Pharaonic, Islamic, and Christian cultures, the paper discusses the theoretical orientation of contemporary group psychotherapy in the country, its status in the health care system, its training and research opportunities, and its current and future challenges. PMID:26401802

  8. Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates

    USGS Publications Warehouse

    Esque, T.C.; Schwalbe, C.R.; DeFalco, L.A.; Duncan, R.B.; Hughes, T.J.

    2003-01-01

    We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation cover. A range of 0 to 7 tortoises was encountered during surveys, and live tortoises were found on all transects. In addition to desert tortoises, only small (<1 kg) mammals and reptiles (11 taxa) were found dead on the study areas. We hypothesize that indirect effects of fire on desert habitats might result in changes in the composition of diets and loss of vegetation cover, resulting in an increase in predation and loss of protection from temperature extremes. These changes in habitat also might cause changes in vertebrate communities in burned areas.

  9. Desert Dust and Monsoon Rain

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kim, Kyu-Myong

    2014-01-01

    For centuries, inhabitants of the Indian subcontinent have know that heavy dust events brought on by strong winds occur frequently in the pre-monsoon season, before the onset of heavy rain. Yet scientists have never seriously considered the possibility that natural dust can affect monsoon rainfall. Up to now, most studies of the impacts of aerosols on Indian monsoon rainfall have focused on anthropogenic aerosols in the context of climate change. However, a few recent studies have show that aerosols from antropogenic and natural sources over the Indian subcontinent may affect the transition from break to active monsoon phases on short timescales of days to weeks. Writing in Nature Geoscience, Vinoj and colleagues describe how they have shown that desert dust aerosols over the Arabian Sea and West Asia can strenghten the summer monsoon over the Indial subcontinent in a matter of days.

  10. Hidden carbon sink beneath desert

    NASA Astrophysics Data System (ADS)

    Li, Yan; Wang, Yu-Gang; Houghton, R. A.; Tang, Li-Song

    2015-07-01

    For decades, global carbon budget accounting has identified a "missing" or "residual" terrestrial sink; i.e., carbon dioxide (CO2) released by anthropogenic activities does not match changes observed in the atmosphere and ocean. We discovered a potentially large carbon sink in the most unlikely place on earth, irrigated saline/alkaline arid land. When cultivating and irrigating arid/saline lands in arid zones, salts are leached downward. Simultaneously, dissolved inorganic carbon is washed down into the huge saline aquifers underneath vast deserts, forming a large carbon sink or pool. This finding points to a direct, rapid link between the biological and geochemical carbon cycles in arid lands which may alter the overall spatial pattern of the global carbon budget.

  11. Chronology of rock falls and slides in a desert mountain range: Case study from the Sonoran Desert in south-central Arizona

    E-print Network

    Dorn, Ron

    Chronology of rock falls and slides in a desert mountain range: Case study from the Sonoran Desert Keywords: Desert Medieval Warm Period Physical weathering Rock fall Rock slides In order to respond the slopes of desert mountain ranges, a case study in the Sonoran Desert reveals new insight into the desert

  12. Impact of the Desert dust on the summer monsoon system over Southwestern North America

    NASA Astrophysics Data System (ADS)

    Zhao, C.; Liu, X.; Leung, L. R.

    2012-04-01

    The radiative forcing of dust emitted from the Southwest United States (US) deserts and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for 15 years (1995-2009). During the monsoon season, dust has a cooling effect (-0.90 W m-2) at the surface, a warming effect (0.40 W m-2) in the atmosphere, and a negative top-of-the-atmosphere (TOA) forcing (-0.50 W m-2) over the deserts on 24-h average. Most of the dust emitted from the deserts concentrates below 800 hPa and accumulates over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day-1 over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August) show that dust heating of the lower atmosphere over the deserts strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to ~40 % over the eastern slope of the Mountains (Arizona-New~Mexico-Texas regions). This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the mega-drought conditions projected for the future.

  13. Impact of the Desert Dust on the Summer Monsoon System over Southwestern North America

    SciTech Connect

    Zhao, Chun; Liu, Xiaohong; Leung, Lai-Yung R.

    2012-04-24

    The radiative forcing of dust emitted from the Southwest United States (US) deserts and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for 15 years (1995-2009). During the monsoon season, dust has a cooling effect (-0.90 W m{sup -2}) at the surface, a warming effect (0.40 W m{sup -2}) in the atmosphere, and a negative top-of-the-atmosphere (TOA) forcing (-0.50 W m{sup -2}) over the deserts on 24-h average. Most of the dust emitted from the deserts concentrates below 800 hPa and accumulates over the western slope of the Rocky Mountains and Mexican Plateau. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.5 K day{sup -1} over the western slope of the Mountains. Model sensitivity simulations with and without dust for 15 summers (June-July-August) show that dust heating of the lower atmosphere over the deserts strengthens the low-level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in an eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. These monsoonal circulation changes lead to a statistically significant increase of precipitation by up to {approx}40% over the eastern slope of the Mountains (Arizona-New Mexico-Texas regions). This study highlights the interaction between dust and the NAM system and motivates further investigation of possible dust feedback on monsoon precipitation under climate change and the megadrought conditions projected for the future.

  14. Desert Dust Satellite Retrieval Intercomparison

    NASA Technical Reports Server (NTRS)

    Carboni, E.; Thomas, G. E.; Sayer, A. M.; Siddans, R.; Poulsen, C. A.; Grainger, R. G.; Ahn, C.; Antoine, D.; Bevan, S.; Braak, R.; Brindley, H.; DeSouza-Mchado, S.; Deuze, J. L.; Diner, D.; Ducos, F.; Grey, W.; Hsu, C.; Kalashnikova, O. V.; Kahn, R.; North, P. R. J.; Salustro, C.; Smith, A.; Tanre, D.; Torres, O.; Veihelmann, B.

    2012-01-01

    This work provides a comparison of satellite retrievals of Saharan desert dust aerosol optical depth (AOD) during a strong dust event through March 2006. In this event, a large dust plume was transported over desert, vegetated, and ocean surfaces. The aim is to identify and understand the differences between current algorithms, and hence improve future retrieval algorithms. The satellite instruments considered are AATSR, AIRS, MERIS, MISR, MODIS, OMI, POLDER, and SEVIRI. An interesting aspect is that the different algorithms make use of different instrument characteristics to obtain retrievals over bright surfaces. These include multi-angle approaches (MISR, AATSR), polarisation measurements (POLDER), single-view approaches using solar wavelengths (OMI, MODIS), and the thermal infrared spectral region (SEVIRI, AIRS). Differences between instruments, together with the comparison of different retrieval algorithms applied to measurements from the same instrument, provide a unique insight into the performance and characteristics of the various techniques employed. As well as the intercomparison between different satellite products, the AODs have also been compared to co-located AERONET data. Despite the fact that the agreement between satellite and AERONET AODs is reasonably good for all of the datasets, there are significant differences between them when compared to each other, especially over land. These differences are partially due to differences in the algorithms, such as as20 sumptions about aerosol model and surface properties. However, in this comparison of spatially and temporally averaged data, at least as significant as these differences are sampling issues related to the actual footprint of each instrument on the heterogeneous aerosol field, cloud identification and the quality control flags of each dataset.

  15. doi: 10.1130/G31068.1 2010;38;723-726Geology

    E-print Network

    Peters, Shanan E.

    ://www.geosociety.org/pubs/copyrt.htm#gsaclick official positions of the Society. citizenship, gender, religion, or political viewpoint. Opinions Al-Hitan in the Western Desert of Egypt (Fig. 1). Incised valley fills are formed by fluvial erosion

  16. Elite Theban Women of the Eighth-Sixth Centuries BCE in Egypt: Identity, Status and Mortuary Practice

    E-print Network

    Li, Jean

    2010-01-01

    in Roman Egypt: art, identity and funerary religion. Oxford:as religion, arts and literature, and the economy of Egypt.Egypt: Tradition, Innovation and Women .. 8 Introduction Historical Overview .. 9 Tradition and innovation: kingship, religion,

  17. Microbial ecology of hot desert edaphic systems.

    PubMed

    Makhalanyane, Thulani P; Valverde, Angel; Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Cowan, Don A

    2015-03-01

    A significant proportion of the Earth's surface is desert or in the process of desertification. The extreme environmental conditions that characterize these areas result in a surface that is essentially barren, with a limited range of higher plants and animals. Microbial communities are probably the dominant drivers of these systems, mediating key ecosystem processes. In this review, we examine the microbial communities of hot desert terrestrial biotopes (including soils, cryptic and refuge niches and plant-root-associated microbes) and the processes that govern their assembly. We also assess the possible effects of global climate change on hot desert microbial communities and the resulting feedback mechanisms. We conclude by discussing current gaps in our understanding of the microbiology of hot deserts and suggest fruitful avenues for future research. PMID:25725013

  18. Behind desert storm; The new military paradigm

    SciTech Connect

    Klare, M.T. )

    1991-05-01

    The author discusses US foreign policy in light of Operation Desert Storm. Near-future military technology is discussed, including: strategic weapons, advanced missile systems, and satellite defense communication systems.

  19. Basal Anthropoids from Egypt and the Antiquity of Africa's Higher

    E-print Network

    Licciardi, Joseph M.

    Basal Anthropoids from Egypt and the Antiquity of Africa's Higher Primate Radiation Erik R, into a morphologically and behaviorally diverse parapithecoid clade of great antiquity. The early or early middle Eocene

  20. Female circumcision is curbed in Egypt.

    PubMed

    Wiens, J

    1996-08-01

    In the wake of the death of an 11-year-old girl the Egyptian government has banned any government-affiliated medical staff from performing female circumcision. Egyptian health policy has shifted from trying to control the practice by keeping it under government supervision towards condemnation. In October 1995 the health minister banned female circumcision from being carried out in state hospitals, a direct reversal of a 1994 decree that asked state hospitals to set aside one day a week for performing the procedure. The further restriction follows an incident in July 1996 when an 11-year-old girl bled to death in the rural area of Mansoora after being circumcised by a barber. Female genital mutilation in Egypt changed from an accepted custom to a political hot topic after the news network CNN in September 1994 featured the circumcision of a 9-year-old girl from Cairo. The footage embarrassed Egyptians and fueled an outcry by women's groups and nongovernmental organizations. Statistics compiled in 1994 by Egypt's former ministry of population estimated that between 70% and 90% of Egyptian women were circumcised. But a more recent survey puts the figure even higher, with 97% of women in both rural and urban areas having been circumcised. Circumcisions range from clitoridectomies to almost total removal of the outside genitalia. The practice seems to be rooted in both African tradition and Islamic beliefs, although many Islamic countries do not practice female circumcision. The main motivation seems to be in controlling women's sexual urges, and the belief that circumcision makes a woman more feminine. A university professor of gynecology teaches his medical students that circumcision is healthier for the woman. Most circumcisions in Egypt are performed by barbers or midwives, despite a sporadically enforced law forbidding the operation by anyone but a trained medical staff member. There is a high rate of complications, with some operations leading to infertility. Groups like the Population Council hope that further education and public debate will help to stop the practice. PMID:8704530

  1. Linking Populus euphratica Hydraulic Redistribution to Diversity Assembly in the Arid Desert Zone of Xinjiang, China

    PubMed Central

    Yang, Xiao-Dong; Zhang, Xue-Ni; Lv, Guang-Hui; Ali, Arshad

    2014-01-01

    The hydraulic redistribution (HR) of deep-rooted plants significantly improves the survival of shallow-rooted shrubs and herbs in arid deserts, which subsequently maintain species diversity. This study was conducted in the Ebinur desert located in the western margin of the Gurbantonggut Desert. Isotope tracing, community investigation and comparison analysis were employed to validate the HR of Populus euphratica and to explore its effects on species richness and abundance. The results showed that, P. euphratica has HR. Shrubs and herbs that grew under the P. euphratica canopy (under community: UC) showed better growth than the ones growing outside (Outside community: OC), exhibiting significantly higher species richness and abundance in UC than OC (p<0.05) along the plant growing season. Species richness and abundance were significantly logarithmically correlated with the P. euphratica crown area in UC (R2?=?0.51 and 0.84, p<0.001). In conclusion, P. euphratica HR significantly ameliorates the water conditions of the shallow soil, which then influences the diversity assembly in arid desert communities. PMID:25275494

  2. Regional and Seasonal Diet of the Western Burrowing Owl in South-Central Nevada

    SciTech Connect

    Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier

    2009-04-01

    We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats (Dipodomys spp.) and pocket mice (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.

  3. Orbital migration and the brown dwarf desert

    E-print Network

    Philip J. Armitage; Ian A. Bonnell

    2002-10-08

    The orbital elements of extreme mass ratio binaries will be modified by interactions with surrounding circumstellar disks. For brown dwarf companions to Solar-type stars the resulting orbital migration is sufficient to drive short period systems to merger, creating a brown dwarf desert at small separations. We highlight the similarities and the differences between the migration of brown dwarfs and massive extrasolar planets, and discuss how observations can test a migration model for the brown dwarf desert.

  4. Nile River, Lake Nasser, Aswan High Dam, Egypt, Africa

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Lake Nasser, (24.0N, 33.0E) at the Aswan High Dam on the Nile River, in Egypt is the world's second largest artificial lake, extending 500 km, in length and about 5000 sq. km. in area. The lake has a storage capacity sufficient to irrigate farms in Egypt and Sudan year round allowing up to three harvests per year. Other benefits include year round river navagation, hydroelectric power, more fish harvests, reduced flooding and more industrial employment. opportunites.

  5. Vascular medicine and surgery in ancient Egypt.

    PubMed

    Barr, Justin

    2014-07-01

    Lauded alike by ancient civilizations and modern society, pharaonic Egyptian medicine remains an object of fascination today. This article discusses its surprisingly sophisticated understanding of a cardiovascular system. The term "cardiovascular system," however, carries assumptions and meanings to a modern audience, especially readers of this journal, which simply do not apply when considering ancient conceptions of the heart and vessels. For lack of better language, this article will use "cardiovascular" and similar terms while recognizing the anachronistic inaccuracy. After briefly summarizing ancient Egyptian medicine generally, it will review the anatomy, pathology, and treatment of the vasculature. The practice of mummification in ancient Egypt provides a unique opportunity for paleopathology, and the conclusion will explore evidence of arterial disease from a modern scientific perspective. PMID:24970660

  6. The management of confidentiality in Egypt.

    PubMed

    Ghali, A Y; Lindenthal, J J; Thomas, C S

    1991-01-01

    Patient confidentiality is an important issue for treating clinician regardless of the cultural background. Though cultural and religious issues may have an impact on the confidentiality standards. This article discusses the confidentiality standards in Egypt citing the laws and ethical codes governing them. This is followed by a research study in which a questionnaire containing ten vignettes representing different common themes confronted by the practicing clinician was completed by forty-one Egyptian psychiatrists. They checked off categories representing alternatives they might choose dealing with the themes. Each respondent received a score. The scores were compared with those of American and Israeli psychiatrists who participated in a similar study. There were no statistically significant differences though Egyptian and Israeli psychiatrists appear to be somewhat more inclined to break confidentiality. However, significant differences were found to exist for some of the vignettes between the three groups. PMID:1822573

  7. Geodiversity assessment of the Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Torab, Magdy; Farghaly, Enas

    2015-04-01

    The Sinai Peninsula is a triangular plateau lies in NE corner of Egypt, its head in the south at Ras Mohammed and its other sides between the Gulf of Aqaba and Gulf of Suez and the triangle base on the Mediterranean Sea. Sinai Peninsula is the most attractive region from the geological, geomorphological and environmental stand points of view because it displays a variety of simple and complex structural and landforms, (Abu Al-Izz,1971). In general, Sinai Peninsula reflects all geologic column of Egypt. Geomorphologically, Sinai Peninsula comprises many geomorphologic units such as mountains blocks, cliffs, isolated hills, wadies, hogbacks, questas, sand ridges, muddy and marshy lands, lakes and shorelines. This paper aims to define and measure geodiversity assessment index of the Sinai Peninsula as the quantitative variety of geological, topographical, geomorphological, hydrological and soil features. Some geodiversity indices maps for the above features produced for Sinai Peninsula were based on the methodology presented by (Pereira et al, 2012), it depends upon calculate of some geodiversity elements for overlay grid of the study area, which divided topographic, geological maps of the Sinai Peninsula with scale 1:500000 and satellite image (landsat 8, 27th October 2014, 12 bands, 30m). It divided into 743 squares (10x10 km), and some partial geodiversity indices such as geological, topographical, geomorphological, hydrological and soil indices were calculated by counting the number of each element inside each square, then the overall geodiversity index map produced by calculate the total number of all indices inside each square, the geodiversity index map were classified into some gradual categories by using isolines: very low, low, medium, high and very high.

  8. Opportunities for woody crop production using treated wastewater in Egypt. II. Irrigation strategies.

    PubMed

    Evett, Steven R; Zalesny, Ronald S; Kandil, Nabil F; Stanturf, John A; Soriano, Chris

    2011-01-01

    An Egyptian national program targets annual reuse of 2.4 billion m3 of treated wastewater (TWW) to irrigate 84,000 ha of manmade forests in areas close to treatment plants and in the desert. To evaluate the feasibility of such afforestation efforts, we describe information about TWW irrigation strategies based on (1) water use of different tree species, (2) weather conditions in different climate zones of Egypt, (3) soil types and available irrigation systems, and (4) the requirement to avoid deep percolation losses that could lead to groundwater contamination. We conclude that drip irrigation systems are preferred, that they should in most cases use multiple emitters per tree in order to increase wetted area and decrease depth of water penetration, that deep rooting should be encouraged, and that in most situations irrigation system automation is desirable to achieve several small irrigations per day in order to avoid deep percolation losses. We describe directed research necessary to fill knowledge gaps about depth of rooting of different species in sandy Egyptian soils and environments, tree crop coefficients needed for rational irrigation scheduling, and depth of water penetration under different irrigation system designs. A companion paper addresses recommendations for afforestation strategies (see Zalesny et al. 2011, this issue). PMID:22046755

  9. A genetic assessment of the recovery units for the mojave population of the desert tortoise, Gopherus agassizii

    USGS Publications Warehouse

    Murphy, R.W.; Berry, K.H.; Edwards, T.; McLuckie, A.M.

    2007-01-01

    In the 1994 Recovery Plan for the Mojave population of the desert tortoise, Gopherus agassizii, the US Fish and Wildlife Service established 6 recovery units by using the best available data on habitat use, behavior, morphology, and genetics. To further assess the validity of the recovery units, we analyzed genetic data by using mitochondrial deoxyribonucleic acid (mtDNA) sequences and nuclear DNA microsatellites. In total, 125 desert tortoises were sampled for mtDNA and 628 for microsatellites from 31 study sites, representing all recovery units and desert regions throughout the Mojave Desert in California and Utah, and the Colorado Desert of California. The mtDNA revealed a great divergence between the Mojave populations west of the Colorado River and those occurring east of the river in the Sonoran Desert of Arizona. Some divergence also occurred between northern and southern populations within the Mojave population. The microsatellites indicated a low frequency of private alleles and a significant correlation between genetic and geographic distance among 31 sample sites, which was consistent with an isolation-by-distance population structure. Regional genetic differentiation was complementary to the recovery units in the Recovery Plan. Most allelic frequencies in the recovery units differed. An assignment test correctly placed most individuals to their recovery unit of origin. Of the 6 recovery units, the Northeastern and the Upper Virgin River units showed the greatest differentiation; these units may have been relatively more isolated than other areas and should be managed accordingly. The Western Mojave Recovery Unit, by using the new genetic data, was redefined along regional boundaries into the Western Mojave, Central Mojave, and Southern Mojave recovery units. Large-scale translocations of tortoises and habitat disturbance throughout the 20th century may have contributed to the observed patterns of regional similarity. ?? 2007 Chelonian Research Foundation.

  10. Internal and External Adaptation in Army Families: Lessons from Operations Desert Shield and Desert Storm

    ERIC Educational Resources Information Center

    Pittman, Joe F.; Kerpelman, Jennifer L.; McFadyen, Jennifer M.

    2004-01-01

    This study examined 1,064 Army families reunited after a member's deployment for Operation Desert Shield and Operation Desert Storm. Postdeployment outcomes were conceptualized in terms of the "fit" between the family and the demands of Army life, especially the stress of deployment. A structural model was used to test the hypothesized effects of…

  11. Book review of "Life Strategies of Succulents in Deserts with Special Reference to the Namib Desert"

    E-print Network

    Martin, Craig E.

    1993-01-01

    : http://www.botany.org/plantsciencebulletin/psb-1993-39-1.php Key words: Book review Text of the article: Life Strategies of Succulents in Deserts with Special Reference to the Namib Desert . D.J. von Willem, B.M. Eller, M.J.A. Werger, E...

  12. HIGH FOLIAR NITROGEN IN DESERT SHRUBS: AN IMPORTANT ECOSYSTEM TRAIT OR DEFECTIVE DESERT DOCTRINE?

    EPA Science Inventory

    Nitrogen concentrations in green and senesced leaves of perennial desert shrubs were compiled from a worldwide literature search to test the validity of the doctrine that desert shrubs produce foliage and leaf litter much richer in nitrogen than that in the foliage of plants from...

  13. Paradoxical anaerobism in desert pupfish.

    PubMed

    Heuton, Matt; Ayala, Luis; Burg, Chris; Dayton, Kyle; McKenna, Ken; Morante, Aldo; Puentedura, Georgina; Urbina, Natasha; Hillyard, Stanley; Steinberg, Spencer; van Breukelen, Frank

    2015-12-01

    In order to estimate metabolic demands of desert pupfish for conservation purposes, we measured oxygen consumption in fish acclimated to the ecologically relevant temperatures of 28 or 33°C. For these experiments, we used fish derived from a refuge population of Devils Hole pupfish (Cyprinodon diabolis). Measurement of routine oxygen consumption (V?O2,routine) revealed some 33°C-acclimated fish (10% of 295 assayed fish) periodically exhibited periods of no measurable oxygen consumption despite available ambient oxygen tensions that were above the critical PO2 . We call this phenomenon paradoxical anaerobism. The longest observed continuous bout with no oxygen consumption was 149?min, although typical bouts were much shorter. Fish maintained normal posture and ventilation rate (>230 ventilations per minute) during paradoxical anaerobism. Fish rarely demonstrated a compensatory increase in oxygen use following a period of paradoxical anaerobism. In contrast, only one out of 262 sampled fish acclimated at 28°C spontaneously demonstrated paradoxical anaerobism. Muscle lactate concentration was not elevated during periods of paradoxical anaerobism. However, the amount of ethanol released by the 33°C-acclimated fish was 7.3 times greater than that released by the 28°C acclimation group, suggesting ethanol may be used as an alternative end product of anaerobic metabolism. Exposure to exogenous ethanol, in concentrations as low as 0.1%, produced periods of paradoxical anaerobism even in 28°C-acclimated fish. PMID:26632453

  14. Observation of local cloud and moisture feedbacks over high ocean and desert surface temperatures

    NASA Technical Reports Server (NTRS)

    Chahine, Moustafa T.

    1995-01-01

    New data on clouds and moisture, made possible by reanalysis of weather satellite observations, show that the atmosphere reacts to warm clusters of very high sea surface temperatures in the western Pacific Ocean with increased moisture, cloudiness, and convection, suggesting a negative feedback limiting the sea surface temperature rise. The reverse was observed over dry and hot deserts where both moisture and cloudiness decrease, suggesting a positive feedback perpetuating existing desert conditions. In addition, the observations show a common critical surface temperature for both oceans and land; the distribution of atmospheric moisture is observed to reach a maximum value when the daily surface temperatures approach 304 +/- 1 K. These observations reveal complex dynamic-radiative interactions where multiple processes act simultaneously at the surface as well as in the atmosphere to regulate the feedback processes.

  15. Scaling properties of rainfall and desert dust in the Canary Islands

    NASA Astrophysics Data System (ADS)

    Peñate, I.; Martín-González, J. M.; Rodríguez, G.; Cianca, A.

    2013-12-01

    Precipitation and desert dust event occurrence time series measured in the Canary Islands region are examined with the primary intention of exploring their scaling characteristics as well as their spatial variability in terms of the island's topography and geographical orientation. In particular, the desert dust intrusion regime in the islands is studied in terms of its relationship with visibility. Analysis of dust and rainfall events over the archipelago exhibits distributions in time that obey power laws. Results show that the rain process presents a high clustering and irregular pattern on short timescales and a more scattered structure for long ones. In contrast, dustiness presents a more uniform and dense structure and, consequently, a more persistent behaviour on short timescales. It was observed that the fractal dimension of rainfall events shows an important spatial variability, which increases with altitude, as well as towards northern latitudes and western longitudes.

  16. 78 FR 45285 - Culturally Significant Objects Imported for Exhibition Determinations: “Egypt's Mysterious Book...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Egypt's Mysterious Book of the..., 2003), I hereby determine that the objects to be included in the exhibition ``Egypt's Mysterious...

  17. 78 FR 20372 - Culturally Significant Objects Imported for Exhibition Determinations: “Hall of Ancient Egypt

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-04

    ... From the Federal Register Online via the Government Printing Office ] DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Hall of Ancient Egypt'' SUMMARY... objects to be included in the exhibition ``Hall of Ancient Egypt,'' imported from abroad for...

  18. 78 FR 20372 - Culturally Significant Objects Imported for Exhibition Determinations: “Hall of Ancient Egypt

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-04

    ...Imported for Exhibition Determinations: ``Hall of Ancient Egypt'' SUMMARY: Notice is hereby given of the following...objects to be included in the exhibition ``Hall of Ancient Egypt,'' imported from abroad for temporary...

  19. 76 FR 73759 - Culturally Significant Objects Imported for Exhibition Determinations: “Ancient Egypt-Art and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-29

    ...Objects Imported for Exhibition Determinations: ``Ancient Egypt--Art and Magic: Treasures From the Foundation Gandur...that the objects to be included in the exhibition ``Ancient Egypt--Art and Magic: Treasures from the Foundation...

  20. 78 FR 45285 - Culturally Significant Objects Imported for Exhibition Determinations: “Egypt's Mysterious Book...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-26

    ...Imported for Exhibition Determinations: ``Egypt's Mysterious Book of the Faiyum'' SUMMARY: Notice is hereby given of the following...objects to be included in the exhibition ``Egypt's Mysterious Book of the Faiyum,'' imported from abroad for temporary...

  1. Assessment and management of water resources in Egypt to face drought and water scarcity

    NASA Astrophysics Data System (ADS)

    Wolters, Wouter; El Guindy, Samia; Salah El Deen, Magdy; Roest, Koen; Smit, Robert; Froebrich, Jochen

    2013-04-01

    Egypt is one of the countries hardest hit by global and climate change. Challenges include population growth; increased demands for food, water, and energy; as well as changing land use patterns and urbanization. Egypt's part of the Mediterranean is characterized by a very complex hydrological system, as it lacks rainfall (Cairo average 30 mm/year) and it is completely dependent on the Nile river flow. The growth of the Egyptian population and its economy in the near future leads to an increase in the demand for water and the overall water allocation priority basically is: first drinking water, then industry, and whatever is remaining will be available for agriculture and nature. Because the agricultural sector uses more than 80 per cent of available water, the main option available to reduce water scarcity in the priority sectors of the economy is to allocate less to the agriculture sector. Scientifically based advances in facing future drought and water scarcity through innovations increasing yields and food security by measures leading to "more crop per drop" are required. New and modern large- and medium-scale agriculture is being developed in desert areas with participation of the private sector for investments. To prepare the farming community and others elsewhere, for the future situation of water shortages, a paradigm shift is needed. New farming systems under tight water supply conditions are in development to prepare for a future with less water. Egyptian farming systems need a major transition to prevent further marginalization of agriculture, which would also have a major impact on food security. Central to this transition should be the increase of value generated per volume available water, also referred to as "more crop per drop" or "more cash per splash". There is room for the urgently required improvement: the present return on water in agriculture in Egypt is about US 0.25 /m3, where values of over US 1 /m3 are "easily" reached elsewhere. Moreover, innovations on resource efficiency enabling use of rest and by-products of one agricultural activity as an input for another one will be profitable for the food producers and will also be better for the environment. The creative design process to reach the required technological and policy innovations contributes to the developed adaptation strategy to face drought and water scarcity. Results will incorporate some previously un-thought of options. The issues of water scarcity and drought have consequences and implications that can no longer be adequately addressed by any one of the Ministries alone. Many other government departments and agencies must be involved and decisions will have to be made at the highest political level. All policies in Egypt must be conscious of the limitations in water availability, and water policies need to address technological developments as well as the full range of other issues, including: macro-economic factors, economic issues that influence farm-level decisions, development of human capital, governance, and financial risk management.

  2. Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larea tridentata

    USGS Publications Warehouse

    Hunter, Kimberly L.; Betancourt, Julio L.; Riddle, Brett R.; Van Devender, Thomas R.; Cole, K.L.; Spaulding, W.G.

    2001-01-01

    1. A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26a??10 14C kyr bp or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ~4.0 14C kyr bp. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr bp. Hexaploids appeared by 8.5 14C kyr bp in the lower Colorado River Basin, reaching their northernmost limits (~37A?N) in the Mohave Desert between 5.6 and 3.9 14C kyr bp. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture.

  3. Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larrea tridentata

    USGS Publications Warehouse

    Hunter, K.L.; Betancourt, J.L.; Riddle, B.R.; Van Devender, T. R.; Cole, K.L.; Geoffrey, Spaulding W.

    2000-01-01

    1 A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26-10 14C kyr BP or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ???4.0 14C kyr BP. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr BP. Hexaploids appeared by 8.5 14C kyr BP in the lower Colorado River Basin, reaching their northernmost limits (???37??N) in the Mohave Desert between 5.6 and 3.9 14C kyr BP. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture. ?? 2001 Blackwell Science Ltd.

  4. Views of Ancient Egypt. Teacher's Guide. School Arts: Looking/Learning.

    ERIC Educational Resources Information Center

    Downs, Linda; Brenner, Carla

    This teaching guide discusses ancient Egyptian culture, the lithographs made by Napoleon's scientists in 1798-99 to study and record every aspect of Egypt, the world's subsequent fascination with Egypt, ancient Egyptian architecture, Egyptian writing, and archeologists' illustrations of Egypt. The guide suggests activities for elementary school,…

  5. Opportunities for woody crop production using treated wastewater in Egypt, I. Afforestation strategies.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Nile River provides nearly 97% of Egypt's freshwater supply. Egypt's share of Nile waters is allocated according to international treaty obligations and is fixed at 55.5 billion cubic meters annually. As a result, Egypt will not be able to meet increasing water demand using freshwater from the ...

  6. Fulbright-Hays Summer Seminars Abroad Program 1989. Egypt: Transition to the Modern World.

    ERIC Educational Resources Information Center

    Office of International Education (ED), Washington, DC.

    This document consists of four papers on various aspects of development in Egypt prepared by participants in the Fulbright-Hays Seminars Abroad Program in Egypt in 1989. Four of the papers are descriptive, one is a lesson plan. The papers included are: (1) "Egypt: Transition to Modern Times" (Katherine Jensen) focuses on the role of women in…

  7. Published: 3 November 2014 Don't Cut Aid to Egypt: The Hopeful Case for

    E-print Network

    Zewail, Ahmed

    Fattah Sisi, center, has taken serious steps toward reforming the ailing Egyptian economy. (Pablo years the Middle East has witnessed peace between Israel and Egypt. Today, the U.S. needs Egypt's partnership more than ever. In addition to the peace treaty between Egypt and Israel, which is crucial to U

  8. 78 FR 23208 - Importation of Fresh Oranges and Tangerines From Egypt Into the United States

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ...APHIS-2012-0053] Importation of Fresh Oranges and Tangerines From Egypt Into the United...have prepared a pest list associated with oranges and tangerines from Egypt that identifies...determine the risk posed by peach fruit fly in oranges and tangerines from Egypt. Based on...

  9. Modelling the Landmark Navigation Behavior of the Desert Ant Cataglyphis

    E-print Network

    Moeller, Ralf

    Modelling the Landmark Navigation Behavior of the Desert Ant Cataglyphis Technical Report Ralf M of the desert ant Cataglyphis in asymmetrical landmark configurations. Whereas according to the snapshot model

  10. Thyroid function in the desert tortoise, Gopherus agassizii 

    E-print Network

    Kohel, Kathryn Anne

    1994-01-01

    To characterize seasonal changes in thyroid function in a terrestrial reptile, thyroid hormones were measured over a period of two years in desert tortoises, Gopherus agassizii, maintained at the Desert Tortoise Conservation Center in Las Vegas, NV...

  11. Economic analysis of critical habitat designation for the desert tortoise (Mojave population)

    USGS Publications Warehouse

    Schamberger, Mel; MacGillvray, Timothy J.; Draper, Dirk D.

    1993-01-01

    The U.S. Fish and Wildlife Service emergency 1isted the Mojave population of the desert tortoise as endangered on August 4, 1989. The Mojave population formally was listed as threatened on April 2, 1990. The Endangered Species Act of 1973, as amended, requires that the economic benefits and costs and other relevant effects of critical habitat designation be considered. The Secretary of the Interior may exclude from designation areas where the costs of designation are greater than the benefits, unless the exclusion would result in extinction of the species. Desert tortoises are threatened by an accumulation of human-and disease-related mortality accompanied by habitat destruction, degradation, and fragmentation. Many desert tortoises are illegally collected for pets, food, and commercial trade. Others are accidentally struck and killed by vehicles on roads and highways or are killed by gunshot or vehicles traveling off-highway. Raven predation on hatchling desert tortoises has increased as raven populations in the desert have risen. An upper respiratory tract disease is suspected to be a major cause of mortality in the western Mojave Desert. This presumably incurable affliction presumably is thought to be spread through the release of infected tortoises into the desert. The Service has proposed designating critical habitat in nine counties within four states. The 12 critical habitat units encompass 6.4 million acres of land, more than 80% federally owned. This region is economically and demographically diverse. Most of the land is sparsely settled and characterized as a hot desert ecosystem. Major industries in the region include entertainment and lodging (primarily in Las Vegas), property development to accommodate the rapid population growth, and services. Millions of rural acres in the region are leased by the federal government for livestock grazing and used for mining. Overall economic benefits to the affected states derived from cattle and sheep grazing in the hot desert areas are minimal and, according to a recent U.S. General Accounting Office study (1991), local economies do not depend on the grazing of public lands for economic survival. The economic analysis describes the economy in 1990, prior to designation, and estimates the effects of designation. The report estimates those incremental effects attributable to critical habitat designation. Impacts attributable to listing the species were not considered in this analysis. Although critical habitat units have been designated in nine counties, two counties are omitted from the economic analysis because of the small proportion of critical habitat acreage they include. Three key activities (cattle grazing, mineral extraction, and off-road vehicle use) were studied in detail. Even if livestock grazing and commercial off-road racing events were eliminated in the proposed critical habitat units, the potential incremental regional economic impacts would be extremely small. The findings in the report do not include the assumption that mining would be eliminated from critical habitat units, but rather that consultation may result in added mitigation and/or relocation of features. Studies show that society will realize benefits from preservation of species and ecosystems. Survey-based studies confirm that benefits exist and are substantial in size, although these benefits often are not measured in traditional economic markets. The total benefit to society of desert tortoise preservation includes several components. Biodiversity in the Mojave and Colorado Deserts will be improved, some recreation values may increase, and gains in intrinsic value will be realized. Critical habitat designation should result in the loss of fewer than 425 total jobs in the seven counties. These include 340 direct ranching jobs and 85 indirect jobs in other industries. This estimated employment loss will not be permanent for most laborers, it is anticipated that over 85% will be reemployed within two years. The economic consequences of designating critical habitat includes reduced ranch profit

  12. Introduction and domestication of woody plants for sustainable agriculture in desert areas

    NASA Astrophysics Data System (ADS)

    Shelef, Oren; Soloway, Elaine; Rachmilevitch, Shimon

    2014-05-01

    High radiation in hot deserts results in high salinity, especially in irrigated fields. Whenever not treated properly, this salinization may harm crops and eventually bring to soil destruction, field abandonment, or literally desertification. Furthermore, the range of crops that can be grown commercially in hot deserts is limited (Nerd et al. 1990). With the globalization of the last century, Introduction of exotic species for commercial use became more accessible. However, these attempts may involve extreme land changes including establishment of potential invasive species. Therefore domestication of native species should be preferred rather than introduction of exotics. In the last six years we did first steps of domesticating several native species, searching for commercial potential (pharmaceutics, food, biomass for energy and desalination of constructed wetlands). We studied aspects of desert plant physiology in drought and saline conditions. We wish to share the knowledge we gained regarding the physiology and commercial potential of the following desert plant species: 1) Bassia indica is an annual halophyte. We proposed to use it for salt phytoremediation in constructed wetlands for wastewater treatment and as feed for livestock; 2) Commiphora gileadensis is considered as the balm tree of Judea, praised for its use as holy oil and in perfumes but also considered as a cure for many diseases. C. gileadensis today grows naturally in southwest Arabia and Somaliland. We found anti-proliferative and apoptotic effect of C. gileadensis extracts on several human cancer cells. Ben Gurion University of the Negev has patented these findings. 3) Artemisia sieberi and A. judaica are both known for various therapeutic traits. While studying effects of irrigation intensity on these traits, some allopathic characters were discovered. 4) Fichus palmate disappeared from Israel, but remind in neighbouring Jordan and Egypt. This tree may serve as a robust stand for fig plantation in arid conditions. 5) Balanites aegyptiaca is potentially a good biomass crop and good feed for grazers as goats. We illuminated differences related to drought tolerance between two distinct ecotypes. Attempts to develope sustainable agriculture based on local species will save resources (water, fertilizers, insecticides and herbicides), keep endangered plant species and enhance vegetation reestablishment.

  13. Concentration, size-distribution and deposition of mineral aerosol over Chinese desert regions

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao Y.; Arimoto, R.; Zhu, G. H.; Chen, T.; Zhang, G. Y.

    1998-09-01

    The mass-particle size distributions (MSDs) of 9 elements in ground-based aerosol samples from dust storm (DS) and non-dust storm (N-DS) periods were determined for 12 sites in 9 major desert regions in northern China. The masses of the 9 elements (Al, Fe, K, Mg, Mn, Sc, Si, Sr and Ti) in the atmosphere were dominated by local mineral dust that averaged 270?g m-3, and the MSDs for the elements were approximately log-normal. On the basis of Al data, the<10?m particles account for ~84% of the total dust mass over the deserts. Model-calculated ("100-step" method) dry deposition velocities (Vd) for the 9 dust-derived elements during N-DS periods ranged from 4.4 to 6.8cms-1, with a median value of 5.6cms-1. On the basis of a statistical relationship between D99% (the dust particle diameter corresponding to the uppermost 1% of the cumulative mass distribution) and Vd, one can also predict dry velocities, especially when D99% ranges from 30 to 70?m. This provides a simple way to reconstruct Vd for dust deposits (like aeolian loess sediments in the Loess Plateau). The estimated daily dry deposition fluxes were higher during DS vs. N-DS periods, but in most cases, the monthly averaged fluxes were mainly attributable to N-DS dust. Two regions with high dust loading and fluxes are identified: the "Western High-Dust Desert" and the "Northern High-Dust Desert", with Taklimakan Desert and Badain Juran Desert as their respective centers. These are energetic regions in which desert-air is actively exchanged, and these apparently are the major source areas for Asian dust.

  14. Geophysical Investigations of the Smoke Creek Desert and their Geologic Implications, Northwest Nevada and Northeast California

    USGS Publications Warehouse

    Ponce, David A.; Glen, Jonathan M.G.; Tilden, Janet E.

    2006-01-01

    The Smoke Creek Desert is a large basin about 100 km (60 mi) north of Reno near the California-Nevada border, situated along the northernmost parts of the Walker Lane Belt, a physiographic region defined by diverse topographic expression consisting of northweststriking topographic features and strike-slip faulting. Because geologic and geophysical framework studies play an important role in understanding the hydrogeology of the Smoke Creek Desert, a geophysical effort was undertaken to help determine basin geometry, infer structural features, and estimate depth to basement. In the northernmost parts of the Smoke Creek Desert basin, along Squaw Creek Valley, geophysical data indicate that the basin is shallow and that granitic rocks are buried at shallow depths throughout the valley. These granitic rocks are faulted and fractured and presumably permeable, and thus may influence ground-water resources in this area. The Smoke Creek Desert basin itself is composed of three large oval sub-basins, all of which reach depths to basement of up to about 2 km (1.2 mi). In the central and southern parts of the Smoke Creek Desert basin, magnetic anomalies form three separate and narrow EW-striking features. These features consist of high-amplitude short-wavelength magnetic anomalies and probably reflect Tertiary basalt buried at shallow depth. In the central part of the Smoke Creek Desert basin a prominent EW-striking gravity and magnetic prominence extends from the western margin of the basin to the central part of the basin. Along this ridge, probably composed of Tertiary basalt, overlying unconsolidated basin-fill deposits are relatively thin (< 400 m). The central part of the Smoke Creek Desert basin is also characterized by the Mid-valley fault, a continuous geologic and geophysical feature striking NS and at least 18-km long, possibly connecting with faults mapped in the Terraced Hills and continuing southward to Pyramid Lake. The Mid-valley fault may represent a lateral (east-west) barrier to ground-water flow. In addition, the Mid-valley fault may also be a conduit for along-strike (north-south) ground-water flow, channeling flow to the southernmost parts of the basin and the discharge areas north of Sand Pass.

  15. An analysis of Saharan desert dust over Mediterranean Basin

    NASA Astrophysics Data System (ADS)

    Guarnieri, F.; Calastrini, F.; Busillo, C.; Pasqui, M.; Capecchi, V.

    2012-04-01

    The suspended particulate matter may modify the air quality with consequences on human health, affecting visibility limiting visual range, governing the extinction of radiation above the sea in clear sky conditions and acting as cloud condensation and ice nuclei during cloudy atmospheres. All year long, massive airborne plumes of desert dust from the Sahara and surrounding regions are exported to the tropical Atlantic Ocean and the Mediterranean Sea. Even though the North Atlantic Oscillation controlled inter-annual variations over Mediterranean Basin, the majority of dust intrusions on these areas are usually associated with the passage of either a cold or a warm low-pressure system. Dust transport begins over the Eastern Basin toward the end of the winter and early spring and spreads over the Western Basin in summer. To describe the dust phenomenon, a comprehensive methodology has been applied to the case study of June 2006, when significant dust outbreaks occurred. On the selected periods, a numerical model-chain is applied to reconstruct the evolution of the Saharan desert dust. In this way, it was possible to reconstruct the dust spatial distributions, with a good description of the vertical concentration profile. Simulation results are compared with a global model (GOCART) and satellite images showing a good agreement on the localization of the zones affected by dust intrusions. Furthermore, the hourly simulation results are compared with some available data from AERONET network. During the case study, the major dust concentration was transported above the boundary layer, while the dust deposition at ground level is lower, with a large intra-daily variation, due to HPBL dynamic.

  16. Controls on sediment production in two U.S. deserts

    NASA Astrophysics Data System (ADS)

    Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

    2014-09-01

    Much of the world’s airborne sediment originates from dryland regions. Soil surface disturbances in these regions are ever-increasing due to human activities such as energy and mineral exploration and development, recreation, suburbanization, livestock grazing and cropping. Sediment production can have significant impacts to human health with particles potentially carrying viruses such as Valley Fever or causing asthma or other respiratory diseases. Dust storms can cause decreased visibility at the ground level, resulting in highway accidents, and reduced visual quality in park and wildland airsheds. Sediment production and deposition is also detrimental to ecosystem health, as production reduces soil fertility at its source and can bury plants and other organisms where it is deposited. Therefore, it is important to understand how we can predict what areas are prone to producing sediment emissions both before and after soil surface disturbance. We visited 87 sites in two deserts of the western U.S. that represented a range of soil texture and surface cover types. We used a portable wind tunnel to estimate the threshold friction velocity (TFV) required to initiate sediment transport and the amount of sediment produced by the tunnel at a set wind speed. Wind tunnel runs were done before and after soil surface disturbance with a four-wheel drive vehicle. Results show that most undisturbed desert soils are very stable, especially if covered by rocks or well-developed biological soil crusts, which make them virtually wind-erosion proof. Particles at disturbed sites, in contrast, moved at relatively low wind speeds and produced high amounts of sediment. Silt was an important predictor of TFV and sediment production across all sites, whereas the influence of rock cover and biological soil crusts was site-dependent. Understanding the vulnerability of a site after disturbance is important information for land managers as they plan land use activities and attempt to mitigate the harmful effects that sediment production can have on both human and ecosystem health.

  17. Controls on sediment production in two U.S. deserts

    USGS Publications Warehouse

    Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

    2014-01-01

    Much of the world’s airborne sediment originates from dryland regions. Soil surface disturbances in these regions are ever-increasing due to human activities such as energy and mineral exploration and development, recreation, suburbanization, livestock grazing and cropping. Sediment production can have significant impacts to human health with particles potentially carrying viruses such as Valley Fever or causing asthma or other respiratory diseases. Dust storms can cause decreased visibility at the ground level, resulting in highway accidents, and reduced visual quality in park and wildland airsheds. Sediment production and deposition is also detrimental to ecosystem health, as production reduces soil fertility at its source and can bury plants and other organisms where it is deposited. Therefore, it is important to understand how we can predict what areas are prone to producing sediment emissions both before and after soil surface disturbance. We visited 87 sites in two deserts of the western U.S. that represented a range of soil texture and surface cover types. We used a portable wind tunnel to estimate the threshold friction velocity (TFV) required to initiate sediment transport and the amount of sediment produced by the tunnel at a set wind speed. Wind tunnel runs were done before and after soil surface disturbance with a four-wheel drive vehicle. Results show that most undisturbed desert soils are very stable, especially if covered by rocks or well-developed biological soil crusts, which make them virtually wind-erosion proof. Particles at disturbed sites, in contrast, moved at relatively low wind speeds and produced high amounts of sediment. Silt was an important predictor of TFV and sediment production across all sites, whereas the influence of rock cover and biological soil crusts was site-dependent. Understanding the vulnerability of a site after disturbance is important information for land managers as they plan land use activities and attempt to mitigate the harmful effects that sediment production can have on both human and ecosystem health.

  18. Nitrogen fixers in the rhizosphere of certain desert plants.

    PubMed

    Hamdi, Y; Yousef, A N

    1979-01-01

    Six species of common desert range plants; Achillea sp., Aristida plumosa, Artemisia herba-alba, Haloxylon articulatum, and Heliotropium ramosissimum were colleted from Western Desert in Iraq. Counts of Azotobacter spp. and total bacteria were estimated in both rhizosphere and non-rhizosphere soils. Biomass and total nitrogen content of the plants were determined. The R/N ratio (ratio between rhizosphere to non-rhizosphere) for Azotobacter sp. ranged between 1 to 19.5 with an average of 4.96. The number of Azotobacter in the rhizosphere ranged between 6.8 X 10(3) to 47 X 10(3) cells/g, while in the non-rhizosphere it ranged from 2 X 10(3) to 21 X 10(3). Aristida plumosa harboured the highest number, i.e., 47 X 10(3) cells/g, while Artemisia herba-alba showed the least, i.e., 6.8 X 10(3) cells/g. Total counts of bacteria in the rhizosphere ranged between 17.2 X 10(6) and 97 X 10(6) cells/g, that of the non-rhizosphere between 1.5 X 10(6) and 18 X 10(6) cells/g. The R/N ratio ranged between 2.03 X 22.5 with an average of 7.28. An appreciable gain of dry weight and total nitrogen was observed. Between 13 and 152 g with an average of 78.9 g dry weight and between 347 and 6684.0 mg with an average of 2452.0 mg nitrogen per plant were found. The possible contribution of Azotobacter to the nitrogen economy of the plants is discussed and further suggested. PMID:473956

  19. Comment on "A Reservoir of Nitrate Beneath Desert Soils"

    E-print Network

    Jackson, Robert B.

    Comment on "A Reservoir of Nitrate Beneath Desert Soils" Walvoord et al. (1) reported a large nitrate pool located deep ( 1 m) beneath desert soils. Two aspects of this work were particularly vary greatly over short temporal and spatial scales. We re- cently investigated 16 desert soil profiles

  20. Desert dust suppressing precipitation: A possible desertification feedback loop

    E-print Network

    Daniel, Rosenfeld

    Desert dust suppressing precipitation: A possible desertification feedback loop Daniel Rosenfeld (received for review October 11, 2000) The effect of desert dust on cloud properties and precipitation has desert dust contain small droplets and produce little precipitation by drop coalescence. Measurement

  1. Do Desert Ants Use Partial Image Matching for Landmark Navigation?

    E-print Network

    Moeller, Ralf

    Do Desert Ants Use Partial Image Matching for Landmark Navigation? Ralf Moller1;2 , Dimitrios University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland Desert ants (genus Cataglyphis) have of Experimental Biology, 199:129{140, 1996. 3] R. Wehner and F. Raber. Visual spatial memory in desert ants

  2. Ephemeral lakes and desert dust sources Natalie M. Mahowald,1

    E-print Network

    Mahowald, Natalie

    Ephemeral lakes and desert dust sources Natalie M. Mahowald,1 Robert G. Bryant,2 John del Corral,1 of inundation, desert dust loadings are reduced. There is some indication that after flooded areas have dried in modulating desert dust sources is unclear, in addition, problems with interpreting the TOMS AI make

  3. Anthropocene changes in desert area: Sensitivity to climate model predictions

    E-print Network

    Mahowald, Natalie

    Anthropocene changes in desert area: Sensitivity to climate model predictions Natalie M. Mahowald1] Changes in desert area due to humans have important implications from a local, regional to global level. Here I focus on the latter in order to better understand estimated changes in desert dust aerosols

  4. Probabilistic Terrain Analysis For High-Speed Desert Driving

    E-print Network

    Thrun, Sebastian

    Probabilistic Terrain Analysis For High-Speed Desert Driving Sebastian Thrun, Mike Montemerlo unrehearsed desert terrain at speeds in excess of 30mph, and without any human intervention. Stanley, our robotic vehicle described in this article, successfully tra- versed 131.6 miles of unpaved desert terrain

  5. An Economic View of Food Deserts in the United States

    ERIC Educational Resources Information Center

    Bitler, Marianne; Haider, Steven J.

    2011-01-01

    Considerable policy and academic attention has been focused on the topic of food deserts. We consider this topic from an economic perspective. First, we consider how the components of a standard economic analysis apply to the study of food deserts. Second, using this economic lens, we revisit the empirical literature on food deserts to assess the…

  6. EVALUATION OF MOISTURE FLUX FROM CHLORIDE DATA IN DESERT SOILS*

    E-print Network

    Scanlon, Bridget R.

    EVALUATION OF MOISTURE FLUX FROM CHLORIDE DATA IN DESERT SOILS* Bridget R. Scanlon Bureau chloride data in desert soils. J. Hydrol., 128: 137-156. Chloride-concentration data from 10 soil profiles in a 40 km2 area of the Chihuahuan Desert of Texas were used to assess chloride mass balance methods

  7. Critical Zones in Desert Fog: Aids to Multiscale Navigation

    E-print Network

    Furnas, George W.

    Critical Zones in Desert Fog: Aids to Multiscale Navigation Susanne Jul Computer Science +1 734-763-0076 furnas@umich.edu ABSTRACT In this paper, we introduce the problem of "desert fog desert fog in multiscale electronic worlds. Prototypes of these aids have been implemented

  8. Effects of a Highway on Mojave Desert Rodent Populations

    E-print Network

    Saltzman, Wendy

    Effects of a Highway on Mojave Desert Rodent Populations THEODORE GARLAND, JR.' and W. GLEN BRADLEY desert Larrea-Ambrosia- Yucca community in southern Nevada. During 12,000 trap nights, 612 rodents is available concerning the effects of roads on desert rodents. Effects of roads on small mammals may

  9. Learning Desert Geomorphology Virtually versus in the Field

    E-print Network

    Dorn, Ron

    Learning Desert Geomorphology Virtually versus in the Field RICHARD J. STUMPF II, JOHN DOUGLASS introductory physical geography college students who learned desert geomorphology only virtually, in the field was statistically indistinguishable from real field trips in establishing basic knowledge about desert geomorphology

  10. Software Visualization in the Desert Environment Steven P. Reiss

    E-print Network

    Reiss, Steven P.

    Software Visualization in the Desert Environment Steven P. Reiss Department of Computer Science Box for which they were developed. Our work on software visualization in the Desert environment is aimed to apply. The programming environment Desert provides the benefits of data integration without the costs

  11. 75 FR 19246 - Safety Zone; Desert Storm, Lake Havasu, AZ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ...USCG-2009-0809] RIN 1625-AA00 Safety Zone; Desert Storm, Lake Havasu, AZ AGENCY: Coast...Havasu City, Arizona in support of the Desert Storm Exhibition Run. This temporary...Purpose The Lake Racer LLC is sponsoring the Desert Storm Charity Poker Run and...

  12. Synaptic Thermoprotection in a Desert-Dwelling Drosophila Species

    E-print Network

    Robertson, Meldrum

    Synaptic Thermoprotection in a Desert-Dwelling Drosophila Species Amy E.M. Newman,* Chengfeng Xiao compared synaptic thermosensitivity between D. mela- nogaster and a desert species, D. arizonae. Synaptic with extreme temperatures, hot deserts for example, are especially interesting because in the face of high

  13. 75 FR 61467 - Desert Southwest Power, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-05

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Desert Southwest Power, LLC; Notice of Filing September 27, 2010. Take notice that on September 24, 2010, Desert Southwest Power, LLC (Desert Southwest) supplemented...

  14. SUNLIGHT TRANSMISSION THROUGH DESERT DUST AND MARINE AEROSOLS: DIFFUSE LIGHT

    E-print Network

    SUNLIGHT TRANSMISSION THROUGH DESERT DUST AND MARINE AEROSOLS: DIFFUSE LIGHT CORRECTIONS TO SUN transmission through desert dust and marine aerosols: Diffuse light corrections to Sun photometry 2004; published 27 April 2004. [1] Desert dust and marine aerosols are receiving increased scientific

  15. TECHNICAL NOTE STR/microsatellite primers for the desert tortoise,

    E-print Network

    Murphy, Bob

    TECHNICAL NOTE STR/microsatellite primers for the desert tortoise, Gopherus agassizii, and its: 25 November 2010 Ó Springer Science+Business Media B.V. 2010 Abstract The desert tortoise, Gopherus Mexican and United States state laws. We identified nine dinucleotide STR loci in the desert tortoise

  16. Research Article Desert Tortoise Use of Burned Habitat in the

    E-print Network

    Lewison, Rebecca

    Research Article Desert Tortoise Use of Burned Habitat in the Eastern Mojave Desert K. KRISTINA tortoise (Gopherus agassizii) in southern Nevada during 2005. The proliferation of non-native annual the conversion of tortoise habitat across the Mojave Desert. Immediate changes to vegetation are expected

  17. Health effects of particulate air pollution and airborne desert dust

    NASA Astrophysics Data System (ADS)

    Lelieveld, J.; Pozzer, A.; Giannadaki, D.; Fnais, M.

    2013-12-01

    Air pollution by fine particulate matter (PM2.5) has increased strongly with industrialization and urbanization. In the past decades this increase has taken place at a particularly high pace in South and East Asia. We estimate the premature mortality and the years of human life lost (YLL) caused by anthropogenic PM2.5 and airborne desert dust (DU2.5) on regional and national scales (Giannadaki et al., 2013; Lelieveld et al., 2013). This is based on high-resolution global model calculations that resolve urban and industrial regions in relatively great detail. We apply an epidemiological health impact function and find that especially in large countries with extensive suburban and rural populations, air pollution-induced mortality rates have been underestimated given that previous studies largely focused on the urban environment. We calculate a global premature mortality by anthropogenic aerosols of 2.2 million/year (YLL ? 16 million/year) due to lung cancer and cardiopulmonary disease. High mortality rates by PM2.5 are found in China, India, Bangladesh, Pakistan and Indonesia. Desert dust DU2.5 aerosols add about 0.4 million/year (YLL ? 3.6 million/year). Particularly significant mortality rates by DU2.5 occur in Pakistan, China and India. The estimated global mean per capita mortality caused by airborne particulates is about 0.1%/year (about two thirds of that caused by tobacco smoking). We show that the highest premature mortality rates are found in the Southeast Asia and Western Pacific regions (about 25% and 46% of the global rate, respectively) where more than a dozen of the most highly polluted megacities are located. References: Giannadaki, D., A. Pozzer, and J. Lelieveld, Modeled global effects of airborne desert dust on air quality and premature mortality, Atmos. Chem. Phys. Discuss. (submitted), 2013. Lelieveld, J., C. Barlas, D. Giannadaki, and A. Pozzer, Model calculated global, regional and megacity premature mortality due to air pollution by ozone and fine particulate matter, Atmos. Chem. Phys., 13, 7023-7037, 2013.

  18. Global perspectives--the Middle East: Egypt.

    PubMed

    Aidaros, H

    2005-08-01

    The Middle East region is characterised by the grouping of 20 countries with similar cultural traditions and religious concepts. The majority of the population of this region follows the religion of Islam, which considers all animals as important as humans, and others follow Christianity and Judaism. The majority of people dealing with animals have their own religious concepts, but most countries have no clear enforced official animal welfare regulations. Animal welfare activities in the Middle East region, as in Egypt for example, are carried out by various individuals, non-governmental organisations and the official Veterinary Services. The slaughter of animals for human consumption is in accordance with Islamic rites, which is the least painful method for the animals. Extensive production systems are the predominant systems in the region, and it is not common for animals in the region to suffer stress during production processes or slaughter. Although some success has been achieved in the area of animal welfare, as seen in improvements in health care, the development of modern abattoirs with proper facilities, and the establishment of policies for combating stray dogs, there are still major constraints to the implementation of effective animal welfare measures, including those for wildlife. These constraints include the lack of finances and the absence of effective legislative measures to prevent the trapping and/or hunting of wild animals for pleasure or illegal trade. PMID:16358510

  19. Seismic hazard assessments at Islamic Cairo, Egypt

    NASA Astrophysics Data System (ADS)

    Khalil, A. E.; Deif, A.; Abdel Hafiez, H. E.

    2015-12-01

    Islamic Cairo is one of the important Islamic monumental complexes in Egypt, near the center of present-day metropolitan Cairo. The age of these buildings is up to one thousand years. Unfortunately, many of the buildings are suffering from huge mishandling that may lead to mass damage. Many buildings and masjids were partially and totally collapsed because of 12th October 1992 Cairo earthquake that took place at some 25 km from the study area with a magnitude Mw = 5.8. Henceforth, potential damage assessments there are compulsory. The deterministic and probabilistic techniques were used to predict the expected future large earthquakes' strong-motion characteristics in the study area. The current study started with compiling the available studies concerned with the distribution of the seismogenic sources and earthquake catalogs. The deterministic method is used to provide a description of the largest earthquake effect on the area of interest, while the probabilistic method, on the other hand, is used to define the uniform hazard curves at three time periods 475, 950, 2475 years. Both deterministic and probabilistic results were obtained for bedrock conditions and the resulted hazard levels were deaggregated to identify the contribution of each seismic source to the total hazard. Moreover, the results obtained show that the expected seismic activities combined with the present situation of the buildings pose high alert to rescue both the cultural heritage and expected human losses.

  20. Implications of terrain movements in Egypt

    NASA Astrophysics Data System (ADS)

    Nassar, Mohamed M.

    1988-10-01

    The purpose of this paper is to study the causes of localized terrain movements in Egypt. The motivation behind this research has been the vast progress in constructing huge engineering structures (dams, bridge,, tall buildings, etc.) as well as extending the urban activities in many new cities. These must be properly studied to ensure their safety versus their cost and other economic factors. In addition, the recent tendency is towards building nuclear power stations whose locations must be carefully investigated against the hazard and danger of inevitable atomic leakage, especially in the case of seismically active regions. Also the discovery of new oil wells and mines and the effects of future depletion require considerable attention from qualified investigators. The relative tectonic movements of North Africa and Southern Europe, the seismic activities around the Alexandria region, the presence of faults related to the region of the High Dam and its reservoir in Aswan, the erosion of the banks of the River Nile and its islands as well as coastal lines along the Mediterranean and the Red Sea, and the deformation and damage to large buildings in the Cairo area are examined here as a few examples of the implications of the earth's deformations within Egyptian territory. Strong recommendations are made concerning the necessity of studying and monitoring the terrain movements in the areas where new cities, large engineering constructions and power plants are planned to be erected.

  1. A Reservoir of Nitrate Beneath Desert Soils

    USGS Publications Warehouse

    Walvoord, M.A.; Phillips, F.M.; Stonestrom, D.A.; Evans, R.D.; Hartsough, P.C.; Newman, B.D.; Striegl, R.G.

    2003-01-01

    A large reservoir of bioavailable nitrogen (upto ???104 kilograms of nitrogen per hectare, as nitrate) has been previously overlooked in studies of global nitrogen distribution. The reservoir has been accumulating in subsoil zones of and regions throughout the Holocene. Consideration of the subsoil reservoir raises estimates of vadose-zone nitrogen inventories by 14 to 71% for warm deserts and arid shrublands worldwide and by 3 to 16% globally. Subsoil nitrate accumulation indicates long-term leaching from desert soils, impelling further evaluation of nutrient dynamics in xeric ecosystems. Evidence that subsoil accumulations are readily mobilized raises concern about groundwater contamination after land-use or climate change.

  2. The impact of Great Basin Desert on summer monsoon precipitation over Southwest North America: the role of mineral dust

    NASA Astrophysics Data System (ADS)

    Zhao, C.; Liu, X.; Leung, L.

    2011-12-01

    The radiative forcing of dust emitted from the Great Basin Desert and its impact on monsoon circulation and precipitation over the North America monsoon (NAM) region are simulated using a coupled meteorology and aerosol/chemistry model (WRF-Chem) for multiple years. During the monsoon season, dust has a cooling effect (-0.90 W m-2) at the surface, a warming effect (0.35 W m-2) in the atmosphere, and a top-of-the-atmosphere (TOA) forcing (-0.50 W m-2) over the Great Basin Desert region on 24-hour average. Most of dust emitted from the desert concentrates below 800 hPa and stacks over the western slope of the Rocky Mountains and the Sierra Madre Occidental. The absorption of shortwave radiation by dust heats the lower atmosphere by up to 0.3 K/day over the western slope of the Mountains. The model sensitivity simulations show that the dust heating of lower atmosphere strengthens the low level southerly moisture fluxes on both sides of the Sierra Madre Occidental. It also results in the eastward migration of NAM-driven moisture convergence over the western slope of the Mountains. This migration leads to a statistically significant increase of precipitation by up to ~40% over the eastern slope of the Mountains. This study highlights the interaction between dust and NAM system, which deserves further investigation under future climate conditions to include the climate change feedbacks.

  3. Trophic relationships of small nonnative fishes in a natural creek and several agricultural drains flowing into the salton sea, and their potential, effects on the endangered desert pupfish

    USGS Publications Warehouse

    Martin, B.A.; Saiki, M.K.

    2009-01-01

    This study was conducted to characterize trophic relationships of small nonnative fishes and to determine if predation by these fishes contributes to the decline of desert pupfish (Cyprinodon macularius), an endangered cyprinodont on the verge of extinction. We sampled 403 hybrid Mozambique tilapias (Oreochromis mossambica by O. urolepis), 107 redbelly tilapias (Tilapia zillii), 32 longjaw mudsuckers (Gillkhthys mirabilis), 182 western mosquitofish (Gambusia affinis), 222 sailfin mollies (Poecilia latipinna), 63 shortfin mollies (Poecilia mexicana), and 235 porthole livebearers (Poecilurpsis gracilis) from a natural creek and four agricultural drains during September 1999- December 2001. Evidence of piscivory was in gastrointestinal contents of 14 hybrid Mozambique tilapias, 3 redbelly tilapias, 10 longjaw mudsuckers, 8 western mosquitofish, 2 sailfin mollies, and 8 porthole livebearers. Although digestion often was too advanced for identification of fishes consumed by nonnative fishes, remains of desert pupfish were in gastrointestinal contents of a longjaw mudsucker. Our findings, along with Field evidence from other studies that inverse relationships exist between abundances of desert pupfish and nonnative species, are consistent with the hypothesis that predation by nonnative species is contributing to decline of desert pupfish. We suspect that competitive interactions with nonnative fishes might also adversely affect abundance of desert pupfish.

  4. Television minidramas: social marketing and evaluation in Egypt.

    PubMed

    Lane, S D

    1997-06-01

    Television has been extensively used to communicate health messages for over a decade in Egypt. Viewers of the evening soap operas have been seeing six commercials for family planning, oral rehydration solution (ORS), and immunizations. People of all social classes can sing the jingles of the most popular ads. The producers of these health spots use increasingly sophisticated story lines, settings, and characters representing rural peasants, played by popular and well-liked actors. Evaluation of the content and impact of these messages has lagged behind the creative sophistication of their production. This article reviews the context and content of televised health messages in Egypt during the 1980s, critically assesses the evaluation of mass media health education, and suggests strategies for more effective evaluation. The author worked for some years with a private donor agency that funded the production of a number of televised health commercials in Egypt. PMID:9186959

  5. 76 FR 66354 - DesertXpress Enterprises, LLC and DesertXpress HSR Corporation-Construction and Operation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ...Transportation Board [Docket No. FD 35544] DesertXpress Enterprises, LLC and DesertXpress HSR Corporation-- Construction and...approval requirements of 49 U.S.C. 10901 for DesertXpress Enterprises, LLC and its subsidiary (DXE) to build and operate a...

  6. Postpartum beliefs and practices among non-Western cultures.

    PubMed

    Kim-Godwin, Yeoun Soo

    2003-01-01

    Postpartum health beliefs and practices among non-Western cultures are each distinct, but have many similarities. Two common belief systems surround 1) the importance of hot and cold, and 2) the necessity of confinement during a specific period of time after giving birth. This article describes common postpartum health beliefs among women in Guatemala, China, Jordan, Lebanon, Egypt, Palestine, India, and Mexico, and offers an exemplar from the author's experiences as a Korean woman giving birth in the United States. Cultural competence in the provision of postpartum care is essential for nurses in the healthcare world of the 21st century. PMID:12629311

  7. Distribution, habitat and habits of the desert tortoise (Gopherus agassizii) in the eastern Mojave Desert

    SciTech Connect

    Esque, T.C.; Bury, R.B. ); Medica, P.A. )

    1990-01-01

    The desert tortoise is widely distributed across most of southern Nevada below 1500 meters elevation and then ranges northeast into the Arizona Strip and southwestern Utah. There are several large populations, but also many isolated groups of desert tortoises due to the rugged topography and, possibly, unsuitable soils. We suggest that the greatest threats to tortoises in the eastern Mojave Desert are with peripheral populations. Tortoises in the eastern Mojave Desert occupy a wide variety of habitats from flats and bajadas in lower elevation to rocky slopes bordering on blackbrush and juniper woodland. In winter they use shallow burrows near Las Vegas but frequent deep caves in the northeast edge of their range. Tortoises in all areas may occur in steep, rocky habitats. Climatic extremes are frequent in this region and rainfall can be spotty due to several major mountain ranges that cause rain shadows. Forage is highly variable and this species can be an opportunistic herbivore. 11 refs., 13 figs.

  8. Post-Revolution Egypt: The Roy Adaptation Model in Community.

    PubMed

    Buckner, Britton S; Buckner, Ellen B

    2015-10-01

    The 2011 Arab Spring swept across the Middle East creating profound instability in Egypt, a country already challenged with poverty and internal pressures. To respond to this crisis, Catholic Relief Services led a community-based program called "Egypt Works" that included community improvement projects and psychosocial support. Following implementation, program outcomes were analyzed using the middle-range theory of adaptation to situational life events, based on the Roy adaptation model. The comprehensive, community-based approach facilitated adaptation, serving as a model for applying theory in post-crisis environments. PMID:26396214

  9. A note on a new study of intelligence in Egypt.

    PubMed

    Bakhiet, Salaheldin Farah Attallah; Lynn, Richard

    2014-12-01

    Three studies of intelligence in Egypt published between 1957 and 1989 and based on small samples gave British IQs between 77 and 83. The present paper reports the results of a recent study based on a much larger sample in order to examine how far the results of the older studies can be replicated. The Coloured Progressive Matrices was standardized in Egypt in 2011-2013 on a sample of 11,284 children aged 5.6 to 10.5 years. The sample obtained a British IQ of 84.2 and provides a satisfactory replication of the earlier studies. PMID:25386704

  10. Comparative study of volatile oil content and antimicrobial activity of pecan cultivars growing in Egypt.

    PubMed

    El Hawary, Seham S; Zaghloul, Soumaya S; El Halawany, Ali M; El Bishbishy, Mahitab H

    2013-11-01

    The volatile oils obtained from the leaves of four pecan cultivars growing in Egypt were evaluated for their chemical composition and antimicrobial activity. The selected cultivars (cv.) were Carya illinoinensis (Wangneh.) K. Koch. cv. Wichita, C. illinoinensis cv. Western Schley, C. illinoinensis cv. Cherokee, and C. illinoinensis cv. Sioux. The gas chromatography-mass spectrometry analyses revealed that the volatile oils from samples of the different cultivars differ in composition and percentage of their components. ?-Curcumene was found as the major constituent of the cv. Wichita oil, whereas germacrene D was the major component of cv. Sioux, cv. Cherokee, and cv. Western Schley. The antimicrobial activity was assayed using the Kirby-Bauer Method by measuring the zone of inhibition of growth. All volatile oils displayed an antimicrobial activity against the tested bacterial strains. On the other hand, only the volatile oil of cv. Wichita showed an antifungal effect on Aspergillus flavus. This work has identified candidates of volatile oils for future in vivo studies to develop antibiotic substitutes for the diminution of human and animal pathogenic bacteria. Nevertheless, the variations of the volatile oil components and antimicrobial potencies of the different studied cultivars, necessitate identifying the cultivars used in future studies. PMID:24180553

  11. Desert Research and Technology Studies 2008 Report

    NASA Technical Reports Server (NTRS)

    Romig, Barbara; Kosmo, Joseph; Gernhardt, Michael; Abercromby, Andrew

    2009-01-01

    During the last two weeks of October 2008, the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) Advanced Extravehicular Activity (AEVA) team led the field test portion of the 2008 Desert Research and Technology Studies (D-RATS) near Flagstaff, AZ. The Desert RATS field test activity is the year-long culmination of various individual science and advanced engineering discipline areas technology and operations development efforts into a coordinated field test demonstration under representative (analog) planetary surface terrain conditions. The 2008 Desert RATS was the eleventh RATS field test and was the most focused and successful test to date with participants from six NASA field centers, three research organizations, one university, and one other government agency. The main test objective was to collect Unpressurized Rover (UPR) and Lunar Electric Rover (LER) engineering performance and human factors metrics while under extended periods of representative mission-based scenario test operations involving long drive distances, night-time driving, Extravehicular Activity (EVA) operations, and overnight campover periods. The test was extremely successful with all teams meeting the primary test objective. This paper summarizes Desert RATS 2008 test hardware, detailed test objectives, test operations, and test results.

  12. Extrafloral nectar fuels ant life in deserts

    PubMed Central

    Aranda-Rickert, Adriana; Diez, Patricia; Marazzi, Brigitte

    2014-01-01

    Interactions mediated by extrafloral nectary (EFN)-bearing plants that reward ants with a sweet liquid secretion are well documented in temperate and tropical habitats. However, their distribution and abundance in deserts are poorly known. In this study, we test the predictions that biotic interactions between EFN plants and ants are abundant and common also in arid communities and that EFNs are only functional when new vegetative and reproductive structures are developing. In a seasonal desert of northwestern Argentina, we surveyed the richness and phenology of EFN plants and their associated ants and examined the patterns in ant–plant interaction networks. We found that 25 ant species and 11 EFN-bearing plant species were linked together through 96 pairs of associations. Plants bearing EFNs were abundant, representing ca. 19 % of the species encountered in transects and 24 % of the plant cover. Most ant species sampled (ca. 77 %) fed on EF nectar. Interactions showed a marked seasonal pattern: EFN secretion was directly related to plant phenology and correlated with the time of highest ant ground activity. Our results reveal that EFN-mediated interactions are ecologically relevant components of deserts, and that EFN-bearing plants are crucial for the survival of desert ant communities. PMID:25381258

  13. Unmasking Nebraska's "Desert in Disguise" David Loope

    E-print Network

    Loope, David B.

    Hills Loess Hills You are here #12;4 #12;about 2 miles dunes in this image are up to 300 feet high #12;Navajo Sandstone, southern Utah #12;Crossbedding exposed during construction of Calamus Dam near Burwell To be back-filled #12;32 Why burrow in desert sand? #12;Large tetrapod burrows from the Middle Triassic

  14. Desert pavement study at Amboy, California

    NASA Technical Reports Server (NTRS)

    Williams, S.; Greeley, R.

    1984-01-01

    Desert pavement is a general term describing a surface that typically consists of a thin layer of cm-sized rock fragments set on top of a layer of finer material in which no fragments are found. An understanding of desert pavement is important to planetary geology because they may play a major role in the formation and visibility of various aeolian features such as wind streaks, which are important on Mars and may be important on Venus. A field study was conducted in Amboy, California to determine the formation mechanism of desert pavements. The probable sequence of events for the formation and evolution of a typical desert pavement surface, based on this experiment and the work of others, is as follows. Starting with a layer of surface material consisting of both fine particles and rock fragments, aeolian deflation will rapidly erode the surface until an armored lag is developed, after which aeolian processes become less important. The concentration of fragments then slowly increases as new fragments are brought to the surface from the subsurface and as fragments move downslope by sheet wash. Sheet wash would be responsible for removing very fine particles from the surface and for moving the fragments relative to one another, forming interlocks.

  15. Microflora in soils of desert regions

    NASA Technical Reports Server (NTRS)

    Cameron, R. E.

    1970-01-01

    Desert soil samples, collected using aseptic techniques, are low in organic matter and cation exchange capacity. Aerobic and microaerophilic bacteria are most abundant, next are algae and molds. Chemical and physical properties are determined by standard procedures, including the Kjeldahl method and the use of Munsell soil color charts.

  16. Creosote Bush Shrubland in the Sonoran Desert

    USGS Multimedia Gallery

    Creosote bush shrublands are one of the driest Sonoran Desert plant communities; the creosote bush and white ratany are the dominant plants; a USGS study showed that their coverage is likely to decrease with forecasted climate change because of less winter precipitation and more ...

  17. Reproductive lsolation in Sonoran Desert Drosophila

    E-print Network

    Markow, Therese

    Reproductive lsolation in Sonoran Desert Drosophila Testing the Limits of the Rules Therese Ann of Drosophila (Coyne and Orr 1989a; Charlesworth et al. 1987). In a second contribution and its recent update (Coyne and Orr 1989b, 1997), theDrosophila literature again is surveyed exhaustively, providing the basis

  18. An Ecosystem Services Framework for Desert Landscapes

    EPA Science Inventory

    Governments, tribal leaders and citizens of the deserts in North America are facing unprecedented pressures from population growth and climate change. The dominant environmental and economic issue is to ensure that people have access to clean water and sanitation while vital ecos...

  19. Antioxidant Activity of Sonoran Desert Bee Pollen

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bee products have been consumed by mankind since antiquity and their health benefits are becoming more apparent. Bee pollen (pollen collected by honey bees) was collected in the high intensity ultraviolet (UV) Sonoran desert and was analyzed by the anti-2,2-diphenyl-1-picryhydrazyl (DPPH) assay and...

  20. The Desert Tortoise: A Delicate Balance

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This award winning program looks at the efforts to preserve the desert tortoise in and around the Edwards Air Force Base, CA area. It also explains what people should do if they come in contact with a tortoise. This video was produced in cooperation with Edwards Air Force Base.

  1. Gopherus agassizii (desert tortoise). Burrow collapse

    USGS Publications Warehouse

    Loughran, Caleb L.; Ennen, Joshua; Lovich, Jeffrey E.

    2011-01-01

    In the deserts of the southwestern U.S., burrows are utilized by the Desert Tortoise to escape environmental extremes (reviewed by Ernst and Lovich 2009. Turtles of the United States and Canada. 2nd ed. Johns Hopkins Univ. Press, Baltimore, Maryland. 827 pp.). However, the potential for mortality through burrow collapse and entrapment is poorly documented. Nicholson and Humphreys (1981. Proceedings of the Desert Tortoise Council, pp. 163?194) suggested that collapse due to livestock trampling may cause mortality. In addition, Lovich et al. (2011. Chelon. Cons. Biol. 10[1]:124–129) documented a Desert Tortoise that used a steel culvert as a burrow surrogate. The culvert filled completely with sediment following a significant rain event, entombing the animal and ultimately resulting in its death. We note that this mortality was associated with an anthropogenic structure; because tortoises are prodigious diggers, one might hypothesize that they have the ability to dig out of collapsed natural burrows in most situations. Circumstances described here presented us with an opportunity to test this hypothesis.

  2. Reclaiming freshwater sustainability in the Cadillac Desert

    E-print Network

    Sinha, Tushar

    the plow." Early stewards of freshwater resources--like John Wesley Powell-- warned that the American WestReclaiming freshwater sustainability in the Cadillac Desert John L. Saboa,1 , Tushar Sinhaa,2 , Laura C. Bowlingb , Gerrit H. W. Schoupsc , Wesley W. Wallenderd,e , Michael E. Campanaf , Keith A

  3. Endolithic microbial life in hot and cold deserts

    NASA Technical Reports Server (NTRS)

    Friedmann, E. I.

    1980-01-01

    Endolithic microorganisms (those living inside rocks) occur in hot and cold deserts and exist under extreme environmental conditions. These conditions are discussed on a comparative basis. Quantitative estimates of biomass are comparable in hot and cold deserts. Despite the obvious differences between the hot and cold desert environment, survival strategies show some common features. These endolithic organisms are able to 'switch' rapidly their metabolic activities on and off in response to changes in the environment. Conditions in hot deserts impose a more severe environmental stress on the organisms than in the cold Antarctic desert. This is reflected in the composition of the microbial flora which in hot desert rocks consist entirely of prokaryotic microorganisms, while under cold desert conditions eukaryotes predominate.

  4. [Light and blindness in ancient Egypt].

    PubMed

    Maria Rosso, Ana

    2010-01-01

    In Ancient Egypt, light and fire, which were closely related to the Sun God Ra, were the sources of life and well-being, while the dark meant danger and death. Similar to death, darkness drops on human beings in deep sleep and they enter a space inhabited by shadows. Dreams were believed to reveal an unknown world, to give the sleeper a glimpse into the future. Vision attracts distant objects and their light, on the other hand, can hurt the eyes like a burning flame. Eyes were the most important organ in Egyptian thought, as they allowed perception of the real world. Their importance has been immortalised in the myth of the Eye of Horus that explains the role of either eye. One represents the moonlight, which disperses the darkness of the night, and the other represents the sunshine, which creates life, and both could also represents the power of human intellect. Blindness, in turn, congenital or disease-related, was considered a divine punishment. A man, thus handicapped, would sink in a state of uncertainty and darkness. To protect the eyes from blindness, people used drops and ointments, which were believed to chase away all kinds of insects and demons that threatened with a variety of eye infections. Egyptian eye doctors or physicians, carried a special kit that contained green chrysocolla and a black kohl makeup, highly appreciated as prophylaxis because they personified Osiris' humours or body fluids. These products were offered to Gods to restore the brightness of divine glance and incite sun and moon to spread their beneficial light. PMID:21192112

  5. Grain-size study of aeolian sediments found east of Kumtagh Desert

    NASA Astrophysics Data System (ADS)

    Liu, Benli; Qu, Jianjun; Ning, Duihu; Gao, Yanhong; Zu, Ruiping; An, Zhishan

    2014-06-01

    A grain-size study was conducted on the surface sediments found east of Kumtagh Desert and its connected geomorphic units, such as the wadi, wetland, oasis, and alluvial fan. The frequency, cumulative curves, and scatter diagrams of four grain-size parameters, namely, the mean grain size, sorting, skewness, and kurtosis, were plotted to study the grain-size characteristics of each sediment. Multiple discriminant analyses were applied to distinguish the deposition environments. Results indicated large diversities in the sediments from different environments. The aeolian sediments from the sandy desert and the gobi land show uniform characteristics or homogeneous changes. The sand resources from the eastern part of the desert can be considered as the alluvial deposits from the southern Altyn Tagh Mountain carried by several erosion gullies. Meanwhile, the western Mingsha Megadune inherited sediments from the nearby Danghe River. The discriminant functions proposed by Sahu can distinguish the deposition process. However, these functions lose their accuracy when applied to heavily eroded aeolian and gobi sediments.

  6. Estimating wildfire risk on a Mojave Desert landscape using remote sensing and field sampling

    USGS Publications Warehouse

    Van Linn, Peter F., III; Nussear, Kenneth E.; Esque, Todd C.; DeFalco, Lesley A.; Inman, Richard D.; Abella, Scott R.

    2013-01-01

    Predicting wildfires that affect broad landscapes is important for allocating suppression resources and guiding land management. Wildfire prediction in the south-western United States is of specific concern because of the increasing prevalence and severe effects of fire on desert shrublands and the current lack of accurate fire prediction tools. We developed a fire risk model to predict fire occurrence in a north-eastern Mojave Desert landscape. First we developed a spatial model using remote sensing data to predict fuel loads based on field estimates of fuels. We then modelled fire risk (interactions of fuel characteristics and environmental conditions conducive to wildfire) using satellite imagery, our model of fuel loads, and spatial data on ignition potential (lightning strikes and distance to roads), topography (elevation and aspect) and climate (maximum and minimum temperatures). The risk model was developed during a fire year at our study landscape and validated at a nearby landscape; model performance was accurate and similar at both sites. This study demonstrates that remote sensing techniques used in combination with field surveys can accurately predict wildfire risk in the Mojave Desert and may be applicable to other arid and semiarid lands where wildfires are prevalent.

  7. The displaced eugeoclinal rocks in the El Paso Mountains and northern Mojave Desert: A Triassic sliver

    SciTech Connect

    Miller, J.S.; Glazner, A.F. . Dept. of Geology); Walker, J.D.; Martin, M.W. . Dept. of Geology)

    1993-04-01

    Many workers have drawn attention to the displaced eugeoclinal rocks in the northern Mojave Desert and El Paso Mountains and their importance in models for the development of an active continental margin in the western Cordillera. Existing models can generally for either strike-slip juxtaposition or thrust emplacement. New field data, U-Pb zircon geochronology, and isotopic data for metasedimentary rocks and plutons in the northern Mojave Desert and El Paso Mountains shed light on the timing and mechanism of emplacement of the eugeoclinal allocthon. The observations and data above indicate that Early Triassic plutons in the northern Mojave Desert came through oceanic lithosphere but later Jurassic plutons intercepted continental lithosphere. The authors suggest a model where eugeoclinal rocks were deposited on oceanic crust which was initially brought southward along a strike-slip fault and later thrust eastward over the cratonal assemblage. Permian thrusting is incompatible with their data and observations. Intrusion of lower Triassic strata by Early Triassic plutons in the Lane Mountain area permits some Early Triassic thrusting but the oceanic affinity of the plutons implies that thrusting did not involve continental lithosphere.

  8. Combating desertification: building on traditional knowledge systems of the Thar Desert communities.

    PubMed

    Gaur, Mahesh K; Gaur, Hemlata

    2004-12-01

    The Thar Desert of western India is known for its rich and ancient culture system and traditions. The communities have long been part of the Thar Desert ecosystem and have evolved specific strategies to live in harmony with its hostile environment. This culture has provided several miracle plants of immense food and medicinal value to modern civilisation. The ancient rural livelihood knowledge system reflects time-tested techno-scientific knowledge with a proven track record of sustainability, especially during natural hazards like drought and famines. In addition, several of the traditional skills of local communities in arts and crafts, music and instruments have made modern man aware of the art and techniques of sustainably utilising local biological resources and preserving their biodiversity along with using waste products of the forests, without harming the desert ecosystem. Traditional cultural and socio-religious values are fast dwindling under the impact of materialistic approach, industrialisation and development. This paper endeavours to illustrate the need to assist and propagate indigenous rural livelihood systems rather than mindlessly replace or abandon them as a result of state bureaucracies. PMID:15641373

  9. Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert

    PubMed Central

    Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

    2013-01-01

    Abstract The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mice are ecological specialists found within the Great Basin Desert and are potentially ideal organisms for assessing ecosystem health and inferring the biogeographic history of this vulnerable region. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of kangaroo mice and to evaluate gene flow, demographic trends, and genetic integrity. Results confirm that there are at least three genetically distinct units within M. megacephalus and two such units within M. pallidus. The three units of M. megacephalus appear to have different demographic histories, with effectively no gene flow among them since their divergence. Similarly, the two units of M. pallidus also appear to have experienced different demographic histories, with effectively no gene exchange. Contemporary effective population sizes of all groups within Microdipodops appear to be low (<500), suggesting that each genetic lineage may have difficulty coping with changing environmental pressures and hence may be at risk of extirpation. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem. The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of the dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mouse, and to evaluate gene flow, demographic trends, and genetic integrity. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem (photo credit J. C. Hafner). PMID:24567823

  10. Avian Influenza Vaccination of Poultry and Passive Case Reporting, Egypt

    PubMed Central

    Grosbois, Vladimir; Jobre, Yilma; Saad, Ahmed; El Nabi, Amira Abd; Galal, Shereen; Kalifa, Mohamed; El Kader, Soheir Abd; Dauphin, Gwenaëlle; Roger, François; Lubroth, Juan; Peyre, Marisa

    2012-01-01

    We investigated the influence of a mass poultry vaccination campaign on passive surveillance of highly pathogenic avian influenza subtype (H5N1) outbreaks among poultry in Egypt. Passive reporting dropped during the campaign, although probability of infection remained unchanged. Future poultry vaccination campaigns should consider this negative impact on reporting for adapting surveillance strategies. PMID:23171740

  11. Islamic Law and Legal Education in Modern Egypt

    ERIC Educational Resources Information Center

    Nakissa, Aria Daniel

    2012-01-01

    This dissertation examines the transmission of Islamic legal knowledge in modern Egypt. It is based on two years of ethnographic fieldwork in Cairo among formally trained Islamic scholars. With governmental permission, I was able to attend classes at both al-Azhar's Faculty of Shari'ah and Cairo University's Dar al-'Ulum. I…

  12. Scribing Work Songs at an Archeological Dig in Egypt

    ERIC Educational Resources Information Center

    Poppe, Donna

    2011-01-01

    This article reports research conducted in the northeastern corner of Egypt's Nile Delta during an excavation at the Mendes archeological dig site in July-August, 2007. Donald Redford, Professor at Pennsylvania State University, accepted the author as the only nonarcheologist that year. In addition to duties of measuring, registering, and storing…

  13. 77 FR 71777 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-04

    ...the U.S. Trade Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 33439, June 6, 2012. Due to the Thanksgiving holidays and disruptions related to Hurricane Sandy, it has been determined that additional time is needed to allow...

  14. We must unleash the power of Egypt's youth

    E-print Network

    Zewail, Ahmed

    in the global economy. One of the forces that will drive progress in Egypt is an appreciation of the value. There is a strange mix of excitement and trepidation in the air, but underlying it all is the prospect of real, no slogans saying `War with Israel'. #12;2 for reform is education. The country will never compete in global

  15. Design a Book: A Quest in Ancient Egypt

    ERIC Educational Resources Information Center

    Cooper, David

    2005-01-01

    This article describes a classroom project that combines creative writing, basic book design, and social studies content. During this project, the authors' seventh grade students research a variety of ancient Egyptian archaeological sites while reviewing course material from a unit of study on ancient Egypt, practice project management skills…

  16. The Great Pyramid Builders: An Integrated Theme on Ancient Egypt

    ERIC Educational Resources Information Center

    Stone, Brian

    2008-01-01

    This article describes a themed classroom project designed to teach about the culture and civilization of ancient Egypt. In preparing the project, it is noted that teachers should remember that different learning styles, including activities that provide meaningful experiences, are appropriate in accommodating the various ways children learn.…

  17. Using Social Studies Themes to Investigate Modern Egypt

    ERIC Educational Resources Information Center

    Hubbard, Janie

    2010-01-01

    Many elementary teachers explore the marvels of ancient Egypt with their students, as evidenced by the numerous available websites on this topic for teaching elementary history. The drama and mystery of ancient civilizations with treasures such as mummies, King Tut, and the Giza Pyramids are intriguing to children, yet there is another layer of…

  18. [Egypt: Selected Readings, Egyptian Mummies, and the Egyptian Pyramid.

    ERIC Educational Resources Information Center

    National Museum of Natural History, Washington, DC.

    This resource packet presents information and resources on ancient Egypt. The bibliography includes readings divided into five sections: (1) "General Information" (46 items); (2) "Religion" (8 items); (3) "Art" (8 items); (4) "Hieroglyphics" (6 items); and (5) selections "For Young Readers" (11 items). The packet also includes readings on…

  19. MULTIPLE WATER REUSE IN POULTRY PROCESSING: CASE STUDY IN EGYPT

    EPA Science Inventory

    An industrial-scale multiple water reuse system was under investigation for a period of four years at a modern poultry processing plant in Alexandria, Egypt. The system involved: chlorination of cooling water from the compressor; reuse of this water in the chiller; successive tra...

  20. 78 FR 7752 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... Trade Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 71777, December 4, 2012, to... FR 33439, June 6, 2012. In 77 FR 71777, December 4, 2012, the Department of Commerce announced that... responses. Accordingly, opportunities exist for U.S firms providing short-range radar systems,...

  1. African Refugees in Egypt: Trauma, Loss, and Cultural Adjustment

    ERIC Educational Resources Information Center

    Henry, Hani M.

    2012-01-01

    This study examined the influence of pre-immigration trauma on the acculturation process of refugees, as reflected in the manifestations of their continuing bonds with native cultures. Six African refugees who sought refuge in Egypt because of wars and political persecution were interviewed about the circumstances of their departure from their…

  2. Tackling Poverty-Migration Linkages: Evidence from Ghana and Egypt

    ERIC Educational Resources Information Center

    Sabates-Wheeler, Rachel; Sabates, Ricardo; Castaldo, Adriana

    2008-01-01

    Are migrants able to use the migration experience to their benefit, that is to improve their livelihoods, and is this result nuanced by whether migrants are poor or non-poor? This paper explores these questions quantitatively using data on migrants and non-migrants from Ghana and Egypt. It describes the main challenges in the empirical literature…

  3. Pharaonic Egypt and the origins of plague Eva Panagiotakopulu

    E-print Network

    Panagiotakopulu, Eva

    ORIGINAL ARTICLE Pharaonic Egypt and the origins of plague Eva Panagiotakopulu The origins as sufficiently detailed to enable the identification of bubonic plague, at least in Constantinople (for popular@sheffield.ac.uk ABSTRACT Aim This paper examines the possibility that bubonic plague was a disease endemic in the wild

  4. The Birth of a Refugee English Program, Cairo, Egypt.

    ERIC Educational Resources Information Center

    Isteero, Jean W.

    1988-01-01

    Describes the inception and development of an Ethiopian refugee English program in Cairo, Egypt. The following topics are addressed: (1) background; (2) teachers; (3) program; (4) classes; (5) materials; (6) content; and (7) day-to-day administration. An essay on "refugeehood" by a program participant is included. (BJV)

  5. Molecular Detection of Some Strawberry Viruses in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strawberry plants exhibiting distinct virus-like symptoms (stunting, mottling, yellowing, vein clearing, vein necrosis and vein banding) were collected from strawberry production fields and nurseries in Qalubia Governorate, Egypt (about 20 km north of Cairo). Plants of 'Festival' and 'Sweet Charlie'...

  6. Information Access in a Developing Country: Special Libraries in Egypt.

    ERIC Educational Resources Information Center

    Dimitroff, Alexandra

    1993-01-01

    Describes two special libraries in Cairo (Egypt) to illustrate how librarians provide information in specialized environments while coping with the economic constraints of a developing country. Topics discussed include document delivery, access to information, the need for a national information policy, and international cooperation with…

  7. Arab Spring Impact on Executive Education in Egypt

    ERIC Educational Resources Information Center

    Wafa, Dina

    2015-01-01

    Purpose: The purpose of this paper is to study the impact of the Arab Spring on public administration programs in Egypt, with a special focus on executive education programs. Design/Methodology/Approach: The study draws on stakeholder analysis, and uses both primary and secondary data. Findings: The author describes the impact of the Arab Spring…

  8. 78 FR 7752 - Trade Mission to Egypt and Kuwait

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... Trade Mission to Egypt and Kuwait March 10-14, 2013, published at 77 FR 71777, December 4, 2012, to... FR 33439, June 6, 2012. In 77 FR 71777, December 4, 2012, the Department of Commerce announced that.... Opportunities exist for U.S. providers of gas turbines, steam turbines, hydro and wind turbines, blades,...

  9. Wintertime in the Western U.S.

    NASA Technical Reports Server (NTRS)

    2002-01-01

    On Thursday (Feb. 14, 2002), the cloud cover that often overshadows the western United States this time of year broke to provide those at the Olympic Games with a beautiful day. The nearly cloud-free day was captured by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. A thick layer of snow blankets northernmost Nevada, northern Utah, most of Idaho and western Wyoming. The snow surrounds and highlights Utah's Great Salt Lake. Just south of the lake, clouds can be seen hovering over southern Utah. (In general, clouds appear streaky and uneven on a satellite image, and snow cover appears solid with definable borders.) North of the Great Salt Lake, one can clearly discern the light gray Northern Rocky Mountains cutting through Idaho and up into Canada. Moving southwest, the spine-like Sierra Nevada mountains separate the greenery of Southern California from the brown deserts of Arizona and Nevada. For an interesting contrast, compare this MODIS image to the MISR mosaic image of the Western United States during the summer (See Western United States Beyond the Four Corners). To access this image at a resolution of 500 meters per pixel, click on the image above. To access a full-resolution image at 250 meters per pixel, visit the MODIS Rapidfire Image Gallery. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  10. Geometeorological data collected by the USGS Desert Winds Project at Desert Wells, Sonoran Desert, central-west Arizona, 1981 - 1996

    USGS Publications Warehouse

    Helm, Paula J.; Breed, Carol S.; Tigges, Richard; Creighton, Shawn

    1998-01-01

    The data in this report were obtained by instruments deployed on a GOES-satellite data collection station operated by the U.S. Geological Survey Desert Winds Project at Desert Wells (latitude 33° 42' 08" N, longitude 113° 48' 40" W), La Paz County, west-central Arizona. The elevation is 344 m (1,130 ft). From January 9, 1981 through May 31, 1995 the station recorded eight parameters: wind direction, wind speed, peak gust, air temperature, precipitation, humidity, barometric pressure, and soil temperature. On June 1, 1995, the station was upgraded by adding a SENSIT sand-flux sensor, which records grain impacts concurrently with wind speed and wind direction measurements. Included with the data is descriptive text on the geology, soils, climate, vegetation, and land use at the site, as well as text on data format, date retrieval software and instructions, and metadata

  11. Climatic, eustatic, and tectonic controls on Quaternary deposits and landforms, Red Sea coast, Egypt

    SciTech Connect

    Arvidson, R.; Becker, R.; Shanabrook, A.; Luo, W.; Sultan, M.; Sturchio, N.; Lotfy, Z.; Mahmood, A.M.; El Alfy, Z.

    1994-06-10

    The degree to which local climatic variations, eustatic sea level fluctuations, and tectonic uplift have influenced the development of Quaternary marine and fluvial landforms and deposits along the Red Sea coast, Eastern Desert, Egypt was investigated using a combination of remote sensing and field data, age determinations of corals, and numerical simulations. False color composites generated from Landsat Thematic Mapper and SPOT image data, digital elevation models derived from stereophotogrammetric analysis of SPOT data, and field observations document that a {approximately}10-km-wide swath inland from the coast is covered in many places with coalescing alluvial fans of Quaternary age. Wadis cutting through the fans exhibit several pairs of fluvial terraces, and wadi walls expose alluvium interbedded with coralline limestone deposits. Further, three distinct coral terraces are evident along the coastline. Climatic, eustatic, and tectonic uplift controls on the overall system were simulated using a cellular automata algorithm with the following characteristics: (1) uplift as a function of position and time, as defined by the elevations and ages of corals; (2) climatic variations driven by insolation changes associated with Milankovitch cycles; (3) sea level fluctuations based on U/Th ages of coral terraces and eustatic data; and (4) parameterized fluvial erosion and deposition. Results imply that the fans and coralline limestones were generated in a setting in which the tectonic uplift rate decreased over the Quaternary to negligible values at present. During lowstands, wadis cut into sedimentary deposits; coupled with continuing uplift, fans were dissected, leaving remnant surfaces, and wadi-related terraces were generated by down cutting. Only landforms from the past three to four eustatic sea level cycles (i.e., {approximately} 300 to 400 kyr) are likely to have survived erosion and deposition associated with fluvial processes. 33 refs., 18 figs., 2 tabs.

  12. Banded iron-formations of late Proterozoic age in the central eastern desert, Egypt: geology and tectonic setting.

    USGS Publications Warehouse

    Sims, P.K.; James, H.L.

    1984-01-01

    Iron-formation occurs as stratigraphic units within a layered andesite-basalt sequence. The sequence is metamorphosed to greenschist facies, intruded by syntectonic granodiorite and post-tectonic granite, and complexly deformed and grossly fragmented; the rocks are allochthonous along thrust faults. The iron deposits are chemical precipitates, accumulated during lulls in volcanism, apparently in an intraoceanic island-arc environment. The deposits are of the Algoma type of iron-formation.-G.J.N.

  13. Radioelement distributions in the Proterozoic granites and associated pegmatites of Gabal El Fereyid area, Southeastern Desert, Egypt.

    PubMed

    Abd El-Naby, H H; Saleh, G M

    2003-10-01

    Lithologically, the rock types in the Gabal El Fereyid area are dominantly granites with minor amounts of pegmatites. The granites range in composition from tonalite to granite-adamallite with minor acidic dikes, quartz and pegmatite veins. The granite-adamallite is peraluminous and formed as a result of partial melting of amphibole-bearing rocks at depths of approximately 24-30 km and at temperatures of 800-950 degrees C. Among the different rock types, the muscovite-rich pegmatites had the highest U and Th contents (66 and 38 ppm on average, respectively). The high level of radioactivity in pegmatites is attributed to the presence of the radioactive minerals thorianite, uranophane and allanite as confirmed by XRD analysis. Binary relations of Zr/U, Zr/Th, Ce/U and Ce/Th against either U or Th in the granite-adamellite exhibit significant negative correlations indicating that both elements are not preferentially hosted in the accessory minerals phases such as zircon and monazite, but could be associated with major forming minerals such as biotite, muscovite, plagioclase and quartz, or U is situated within labile sites within granite. The uranium and thorium enrichment in the pegmatites is a two-stage process. The primary stage is magmatic whereas the secondary enrichment is from hydrothermal concentration. The magmatic U and Th are indicated by the presence of thorianite and allanite, whereas evidence of hydrothermal mineralization is the alteration of rock-forming minerals such as feldspar and the formation of secondary minerals such as uranophane and pyrite. PMID:14522238

  14. Phanerozoic tectonothermal history of the ArabianNubian shield in the Eastern Desert of Egypt: evidence from fission track

    E-print Network

    Fritz, Harald

    : evidence from fission track and paleostress data Ana-Voica Bojar *, Harald Fritz, Sabine Kargl, Wolfgang-Pan-African evolution of the Arabian­Nubian Shield, macro-scale tectonic studies, paleostress and fission track data, zircon and sphene fission track analyses from the Neoproterozoic basement indicate two major episodes

  15. Mapping of groundwater prospective zones using remote sensing and GIS techniques: A case study from the Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Abdalla, Fathy

    2012-07-01

    With the increasing demands for water due to increasing population, urbanization and agricultural expansion, groundwater resources are gaining much attention, particularly in arid and semi-arid regions. This study is based on determining the most important contributing parameters that indicate the groundwater potential such as slope, stream networks, lineaments, lithology and topography. Thematic map of each parameter was produced using the Geographic Information Systems (GIS) and remote sensing data (RS) techniques. These input layers were combined using the Raster Calculate Module of GIS to produce the final groundwater prospective zones of the investigated area. The final output map shows different zones of groundwater prospective potential, viz., very good (12.79%), good (26.95%), moderate (33.05%) and low (27.21%). The Wadi fillings and the Quaternary deposits, in addition to the fractured Precambrian basement rocks were identified as very good to good prospecting zones. Moreover, the thick fluvial deposits of old drainage which received much surface water in the past pluvial periods still store the “fossil” groundwater. Areas of steeply sloping hilly terrains of limestone and younger hard rocks were recognized to have moderate to low groundwater potentiality. Based on the chemical analysis, the groundwater in the study area is mostly not suitable for drinking purposes but it can be used for irrigation under special conditions. The overall results demonstrate that the use of remote sensing and GIS techniques provide powerful tools for groundwater development and the design of a suitable exploration plan.

  16. Dust storm over the Black Rock Desert: Larger-scale dynamic signatures

    NASA Astrophysics Data System (ADS)

    Lewis, John M.; Kaplan, Michael L.; Vellore, Ramesh; Rabin, Robert M.; Hallett, John; Cohn, Stephen A.

    2011-03-01

    A dust storm that originated over the Black Rock Desert (BRD) of northwestern Nevada is investigated. Our primary goal is to more clearly understand the sequence of dynamical processes that generate surface winds responsible for entraining dust from this desert. In addition to reliance on conventional surface and upper-air observations, we make use of reanalysis data sets (NCAR/NCEP and NARR)—blends of primitive equation model forecasts and observations. From these data sets, we obtain the evolution of vertical motion patterns and ageostrophic motions associated with the event. In contrast to earlier studies that have emphasized the importance of indirect transverse circulations about an upper-level jet streak, our results indicate that in this case the transition from an indirect to a direct circulation pattern across the exit region of upper-level jet streak is central to creation of low-level winds that ablate dust from the desert. It is further argued that the transition of vertical circulation patterns is in response to adjustments to geostrophic imbalance—an adjustment time scale of 6-9 h. Although unproven, we suggest that antecedent rainfall over the alkali desert 2 weeks prior to the event was instrumental in lowering the bulk density of sediments and thereby improved the chances for dust ablation by the atmospheric disturbance. We comprehensively compare/contrast our results with those of earlier investigators, and we present an alternative view of key dynamical signatures in atmospheric flow that portend the likelihood of dust storms over the western United States.

  17. Colonial legacy, women's rights and gender-educational inequality in the Arab World with particular reference to Egypt and Tunisia

    NASA Astrophysics Data System (ADS)

    Megahed, Nagwa; Lack, Stephen

    2011-08-01

    One aspect of the call for democracy in the recent Arab region uprisings is the issue of women's rights and gender equality. Three cultural and ideological forces have continued to shape the gender discourse in Arab Muslim-majority societies. They are: "Islamic" teaching and local traditions concerning women's roles in a given society; Western, European colonial perception of women's rights; and finally national gender-related policy reforms. This paper examines the past and present status of women and gender-educational inequality in the Arab world with particular reference to Egypt and Tunisia, prior to and post colonialism. Special attention is given to colonial legacy and its influence on gender and education; to current gender practices in the social sphere with a focus on women's modesty ( hijab); to international policies and national responses with regard to women's rights and finally to female participation in pre-university and higher education. These issues incorporate a discussion of cultural and religious constraints. The paper demonstrates similarities and differences between Egypt's and Tunisia's reform policies towards gender parity. It highlights the confrontation of conservative versus liberal ideologies that occurred in each country with the implementation of its gender-related reform policy.

  18. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  19. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  20. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Desert-land entryman may proceed... (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project § 2524.6 Desert-land... that a desert-land entryman who owns a water right and reclaims the land embraced in his entry...

  1. Simplifying Data Integration: The Design of the Desert Software Development Environment

    E-print Network

    Reiss, Steven P.

    Simplifying Data Integration: The Design of the Desert Software Development Environment Steven P the Desert environment. The Desert environment has been cre- ated to demonstrate that the facilities with Desert, attempts to explore different inte- grating frameworks for these tools. In the Desert environ

  2. Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: Resistance in different U.S. deserts

    USGS Publications Warehouse

    Belnap, J.

    2002-01-01

    Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the western U.S. (Great Basin, Colorado Plateau, Sonoran, Chihuahuan, and Mojave deserts). Results show that pre-disturbance cover of soil lichens is significantly correlated with the silt content of soils, and negatively correlated with sand and clay. While disturbance appeared to reduce NA at all sites, differences were statistically significant at only 12 of the 26 sites. Cool desert sites showed a greater decline than hot desert sites, which may indicate non-heterocystic cyanobacterial species are more susceptible to disturbance than non-heterocystic species. Sandy soils showed greater reduction of NA as sand content increased, while fine-textured soils showed a greater decline as sand content increased. At all sites, higher NA before the disturbance resulted in less impact to NA post-disturbance. These results may be useful in predicting the impacts of off-road vehicles in different regions and different soils. ?? 2002 Published by Elsevier Science Ltd.

  3. Environmental processes and spectral reflectance characteristics associated with soil erosion in desert fringe regions

    NASA Technical Reports Server (NTRS)

    Jacobberger, P. A.

    1986-01-01

    Two Thematic Mapper (TM) scenes were acquired. A scene was acquired for the Bahariya, Egypt field area, and one was acquired covering the Okavango Delta site. Investigations at the northwest Botswana study sites have concentrated upon a system of large linear (alab) dunes possessing an average wavelength of 2 kilometers and an east-west orientation. These dunes exist to the north and west of the Okavango Swamp, the pseudodeltaic end-sink of the internal Okavango-Cubango-Cuito drainage network. One archival scene and two TM acquisitions are on order, but at present no TM data were acquired for the Tombouctou/Azaouad Dunes, Mali. The three areas taken together comprise an environmental series ranging from hyperarid to semi-arid, with desertization processes operational or incipient in each. The long range goal is to predict normal seasonal variations, so that aperiodic spectral changes resulting from soil erosion, vegetation damage, and associated surface processes would be distinguishable as departures from the norm.

  4. An Experience Guide: Egypt and Israel 2000. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Egypt and Israel).

    ERIC Educational Resources Information Center

    Feijoo, Laura

    This "experience guide," developed by a teacher who traveled in the region, aims to provide information on the culture, history, society, geography, and political aspects of Egypt and Israel. Intended for teachers, the guide can enhance lessons in world history. Each segment summarizes a topic and provides questions designed to encourage research,…

  5. A Tour of Modern and Historic Egypt and Israel. Fulbright-Hays Summer Seminars Abroad Program, 2000 (Egypt and Israel).

    ERIC Educational Resources Information Center

    Holdren, Greg

    This curriculum unit supplement for middle school and secondary teachers helps students in grades 5-12 explore Egypt and Israel, in both ancient and modern contexts. The unit supplement begins with student objectives, such as practicing map and research skills and reviewing summary information concerning historic and current interests. It provides…

  6. High performance robotic traverse of desert terrain.

    SciTech Connect

    Whittaker, William

    2004-09-01

    This report presents tentative innovations to enable unmanned vehicle guidance for a class of off-road traverse at sustained speeds greater than 30 miles per hour. Analyses and field trials suggest that even greater navigation speeds might be achieved. The performance calls for innovation in mapping, perception, planning and inertial-referenced stabilization of components, hosted aboard capable locomotion. The innovations are motivated by the challenge of autonomous ground vehicle traverse of 250 miles of desert terrain in less than 10 hours, averaging 30 miles per hour. GPS coverage is assumed to be available with localized blackouts. Terrain and vegetation are assumed to be akin to that of the Mojave Desert. This terrain is interlaced with networks of unimproved roads and trails, which are a key to achieving the high performance mapping, planning and navigation that is presented here.

  7. Use Of Principal Components Analysis For Studying Deep Aquifers With Scarce Data-Application To The Nubian Sandstone Aquifer, Egypt And Israel

    NASA Astrophysics Data System (ADS)

    Melloul, A. J.

    1995-02-01

    A methodology was developed and applied to the Nubian Sandstone aquifer beneath the Sinai Peninsula (in Egypt) and the Negev Desert (in Israel) to improve understanding of the hydrology of a deep aquifer with scarce data. Principal Components Analysis (PCA) is a statistical technique that was used to combine various multidisciplinary data in order to identify chemical and physical groups, which were used to define groundwater flow paths. The findings of this study are in accord with the generally accepted hydrogeological conceptual model of the aquifer. However, through this study, new insights were obtained by the use of PCA method concerning: 1) the description of a complex flow system by grouping various qualitative and quantitative parameters; 2) the delineation of optimal operational zones for aquifer exploitation; and 3) the definition and characterization of six main groundwater flow paths from their outcrops in the southern part of the Sinai to its discharge zones in the Arava River Valley and Dead Sea area in the Negev desert. These flow paths are defined by their water categories, which are unified expressions of such properties as salinity, origin, and age of groundwater. This methodology is useful for analysing aquifer with scarce data and may also be helpful for studying other deep groundwater basins.

  8. Desert wetlands in the geologic record

    NASA Astrophysics Data System (ADS)

    Pigati, Jeffrey S.; Rech, Jason A.; Quade, Jay; Bright, Jordon

    2014-05-01

    Desert wetlands support flora and fauna in a variety of hydrologic settings, including seeps, springs, marshes, wet meadows, ponds, and spring pools. Over time, eolian, alluvial, and fluvial sediments become trapped in these settings by a combination of wet ground conditions and dense plant cover. The result is a unique combination of clastic sediments, chemical precipitates, and organic matter that is preserved in the geologic record as ground-water discharge (GWD) deposits. GWD deposits contain information on the timing and magnitude of past changes in water-table levels and, therefore, are a potential source of paleohydrologic and paleoclimatic information. In addition, they can be important archeological and paleontological archives because desert wetlands provide reliable sources of fresh water, and thus act as focal points for human and faunal activities, in some of the world's harshest and driest lands. Here, we review some of the physical, sedimentological, and geochemical characteristics common to GWD deposits, and provide a contextual framework that researchers can use to identify and interpret geologic deposits associated with desert wetlands. We discuss several lines of evidence used to differentiate GWD deposits from lake deposits (they are commonly confused), and examine how various types of microbiota and depositional facies aid in reconstructing past environmental and hydrologic conditions. We also review how late Quaternary GWD deposits are dated, as well as methods used to investigate desert wetlands deeper in geologic time. We end by evaluating the strengths and limitations of hydrologic and climatic records derived from GWD deposits, and suggest several avenues of potential future research to further develop and utilize these unique and complex systems.

  9. Water capture by a desert beetle

    NASA Astrophysics Data System (ADS)

    Parker, Andrew R.; Lawrence, Chris R.

    2001-11-01

    Some beetles in the Namib Desert collect drinking water from fog-laden wind on their backs. We show here that these large droplets form by virtue of the insect's bumpy surface, which consists of alternating hydrophobic, wax-coated and hydrophilic, non-waxy regions. The design of this fog-collecting structure can be reproduced cheaply on a commercial scale and may find application in water-trapping tent and building coverings, for example, or in water condensers and engines.

  10. Consumption of atmospheric methane by desert soils

    USGS Publications Warehouse

    Striegl, R.G.; McConnaughey, T.A.; Thorstenson, D.C.; Weeks, E.P.; Woodward, J.C.

    1992-01-01

    ATMOSPHERIC concentrations of methane, a greenhouse gas, are increasing at a rate of about 1% yr-1 (refs 1-4). Oxidation by methylotrophic bacteria in soil is the largest terrestrial sink for atmospheric CH4, and is estimated to consume about 30?? 1012 g CH4 yr-1 (refs 4-6). Spatial and temporal variability in the rate of soil CH4 consumption are incompletely understood6-19, as are the apparent inhibitory12,13,18 or enhancing20 effects of changes in land use. Dry deserts, which constitute 20% of total land surface, are not currently included in global soil uptake estimates. Here we describe measurements of the rate of uptake of atmospheric CH4 by undisturbed desert soils. We observed rates as great as 4.38 mg CH4 m-2 day-1; 50% of the measured rates were between 0.24 and 0.92 mg CH4 m2 d-1. Uptake of CH4 by desert soil is enhanced by rainfall after an initial soil-drainage period - opposite to the response of temperate forest soils12. Methane is consumed to a depth of about 2 m, allowing for deep removal of atmospheric CH4 if near-surface conditions are unfavourable for consumption. On the basis of an annual average CH4 consumption rate of 0.66 mg CH4 m-2 d-1, we estimate that the global CH4 sink term needs to be increased by about 7 ?? 1012 g yr-1 to account for the contribution of desert soils.

  11. Desert wetlands in the geologic record

    USGS Publications Warehouse

    Pigati, Jeff S.; Rech, Jason A.; Quade, Jay; Bright, Jordon

    2014-01-01

    Desert wetlands support flora and fauna in a variety of hydrologic settings, including seeps, springs, marshes, wet meadows, ponds, and spring pools. Over time, eolian, alluvial, and fluvial sediments become trapped in these settings by a combination of wet ground conditions and dense plant cover. The result is a unique combination of clastic sediments, chemical precipitates, and organic matter that is preserved in the geologic record as ground-water discharge (GWD) deposits. GWD deposits contain information on the timing and magnitude of past changes in water-table levels and, therefore, are a potential source of paleohydrologic and paleoclimatic information. In addition, they can be important archeological and paleontological archives because desert wetlands provide reliable sources of fresh water, and thus act as focal points for human and faunal activities, in some of the world's harshest and driest lands. Here, we review some of the physical, sedimentological, and geochemical characteristics common to GWD deposits, and provide a contextual framework that researchers can use to identify and interpret geologic deposits associated with desert wetlands. We discuss several lines of evidence used to differentiate GWD deposits from lake deposits (they are commonly confused), and examine how various types of microbiota and depositional facies aid in reconstructing past environmental and hydrologic conditions. We also review how late Quaternary GWD deposits are dated, as well as methods used to investigate desert wetlands deeper in geologic time. We end by evaluating the strengths and limitations of hydrologic and climatic records derived from GWD deposits, and suggest several avenues of potential future research to further develop and utilize these unique and complex systems.

  12. Adsorption of dyes on Sahara desert sand.

    PubMed

    Varlikli, Canan; Bekiari, Vlasoula; Kus, Mahmut; Boduroglu, Numan; Oner, Ilker; Lianos, Panagiotis; Lyberatos, Gerasimos; Icli, Siddik

    2009-10-15

    Sahara desert sand (SaDeS) was employed as a mineral sorbent for retaining organic dyes from aqueous solutions. Natural sand has demonstrated a strong affinity for organic dyes but significantly lost its adsorption capacity when it was washed with water. Therefore, characterization of both natural and water washed sand was performed by XRD, BET, SEM and FTIR techniques. It was found that water-soluble kyanite, which is detected in natural sand, is the dominant factor affecting adsorbance of cationic dyes. The sand adsorbs over 75% of cationic dyes but less than 21% for anionic ones. Among the dyes studied, Methylene Blue (MB) demonstrated the strongest affinity for Sahara desert sand (Q(e)=11.98 mg/g, for initial dye solution concentration 3.5 x 10(-5)mol/L). The effects of initial dye concentration, the amount of the adsorbent, the temperature and the pH of the solution on adsorption capacity were tested by using Methylene Blue as model dye. Pseudo-first-order, pseudo-second-order and intraparticle diffusion models were applied. It was concluded that adsorption of Methylene Blue on Sahara desert sand followed pseudo-second order kinetics. Gibbs free energy, enthalpy change and entropy change were calculated and found -6411 J/mol, -30360 J/mol and -76.58 J/mol K, respectively. These values indicate that the adsorption is an exothermic process and has a spontaneous nature at low temperatures. PMID:19515485

  13. Cryptic Neogene vicariance and Quaternary dispersal of the red-spotted toad (Bufo punctatus): insights on the evolution of North American warm desert biotas.

    PubMed

    Jaeger, Jef R; Riddle, Brett R; Bradford, David F

    2005-09-01

    We define the geographical distributions of mitochondrial DNA (mtDNA) lineages embedded within a broadly distributed, arid-dwelling toad, Bufo punctatus. These patterns were evaluated as they relate to hypothesized vicariant events leading to the formation of desert biotas within western North America. We assessed mtDNA sequence variation among 191 samples from 82 sites located throughout much of the species' range. Parsimony-based haplotype networks of major identified lineages were used in nested clade analysis (NCA) to further elucidate and evaluate shallow phylogeographic patterns potentially associated with Quaternary (Pleistocene-Holocene) vicariance and dispersal. Phylogenetic analyses provided strong support for three monophyletic lineages (clades) within B. punctatus. The geographical distributions of the clades showed little overlap and corresponded to the general boundaries of the Peninsular Desert, and two continental desert regions, Eastern (Chihuahuan Desert-Colorado Plateau) and Western (Mojave-Sonoran deserts), geographically separated along the Rocky Mountains and Sierra Madre Occidental. The observed divergence levels and congruence with postulated events in earth history implicate a late Neogene (latest Miocene-early Pliocene) time frame for separation of the major mtDNA lineages. Evaluation of nucleotide and haplotype diversity and interpretations from NCA reveal that populations on the Colorado Plateau resulted from a recent, likely post-Pleistocene, range expansion from the Chihuahuan Desert. Dispersal across historical barriers separating major continental clades appear to be recent, resulting in secondary contacts in at least two areas. Given the observed contact between major clades, we speculated as to why the observed deep phylogeographic structure has not been eroded during the multiple previous interglacials of the Pleistocene. PMID:16101772

  14. An experimental analysis of granivory in desert ecosystems

    SciTech Connect

    Davidson, D.W.

    1988-01-01

    In our studies of desert granivore ecology, we have outlined the network of interaction pathways linking granivore and resource species in a Chihuahuan Desert Ecosystem. Here, a major fraction of the primary productivity takes the form of the seeds of annual plants. These seeds support two major resident taxa of desert granivores, ants and rodents. Population responses to removal of various taxa of granivores or seasonal classes of resource species are described.

  15. 75 FR 55603 - Meeting of the California Desert District Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-13

    ...AL 0000] Meeting of the California Desert District Advisory Council SUMMARY: Notice...92-463 and 94-579, that the California Desert District Advisory Council to the Bureau...html. SUPPLEMENTARY INFORMATION: All Desert District Advisory Council meetings...

  16. 43 CFR 2524.1 - Conditions excusing entrymen from compliance with the desert-land laws.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Conditions excusing entrymen from compliance with the desert-land laws. 2524.1 Section 2524.1 Public...THE INTERIOR LAND RESOURCE MANAGEMENT (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project...

  17. 40 CFR 81.167 - Southeast Desert Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Southeast Desert Intrastate Air Quality Control Region...Control Regions § 81.167 Southeast Desert Intrastate Air Quality Control Region. The Southeast Desert Intrastate Air Quality Control...

  18. 43 CFR 2524.6 - Desert-land entryman may proceed independently of Government irrigation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2 2012-10-01 2012-10-01 false Desert-land entryman may proceed independently of Government...THE INTERIOR LAND RESOURCE MANAGEMENT (2000) DESERT-LAND ENTRIES Desert-Land Entries Within a Reclamation Project...

  19. 40 CFR 81.167 - Southeast Desert Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Southeast Desert Intrastate Air Quality Control Region...Control Regions § 81.167 Southeast Desert Intrastate Air Quality Control Region. The Southeast Desert Intrastate Air Quality Control...

  20. 40 CFR 81.167 - Southeast Desert Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Southeast Desert Intrastate Air Quality Control Region...Control Regions § 81.167 Southeast Desert Intrastate Air Quality Control Region. The Southeast Desert Intrastate Air Quality Control...