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1

Groundwater sapping processes, Western Desert, Egypt.  

SciTech Connect

Depressions of the Western Desert of Egypt (specifically, Kharga, Farafra, and Kurkur regions) are mainly occupied by shales that are impermeable, but easily erodible by rainfall and runoff, whereas the surrounding plateaus are composed of limestones that are permeable and more resistant to fluvial erosion under semiarid to arid conditions. Scallop-shaped escarpment edges and stubby-looking channels that cut into the plateau units are suggestive of slumping of limestones by ground-water sapping at the limestone-shale interfaces, removal of slump blocks by weathering and fluvial erosion, and consequent scarp retreat. Spring-derived tufa deposits found near the limestone escarpments provide additional evidence for possible ground-water sapping during previous wet periods. A computer simulation model was developed to quantify the ground-water sapping processes, using a cellular automata algorithm with coupled surface runoff and ground-water flow for a permeable, resistant layer over an impermeable, friable unit. Erosion, deposition, slumping, and generation of spring-derived tufas were parametrically modeled. Simulations using geologically reasonable parameters demonstrate that relatively rapid erosion of the shales by surface runoff, ground-water sapping, and slumping of the limestones, and detailed control by hydraulic conductivity inhomogeneities associated with structures explain the depressions, escarpments, and associated landforms and deposits. Using episodic wet pulses, keyed by {delta}{sup 18}O deep-sea core record, the model produced tufa ages that are statistically consistent with the observed U/Th tufa ages. This result supports the hypothesis that northeastern African wet periods occurred during interglacial maxima. The {delta}{sup 18}O-forced model also replicates the decrease in fluvial and sapping activity over the past million years, as northeastern Africa became hyperarid. The model thus provides a promising predictive tool for studying long-term landform evolution that involves surface and subsurface processes and climatic change.

Luo, W.; Arvidson, R.E.; Sultan, M.; Becker, R.; Crombie, M.K.; Sturchio, N.; El Alfy, Z.; Environmental Research; Washington Univ.; Egyptian Geological Survey and Mining Authority

1997-01-01

2

New age constraints on the Middle Stone Age occupations of Kharga Oasis, Western Desert, Egypt  

Microsoft Academic Search

Spring-deposited carbonate rocks, or tufas, exposed along the flanks of the Libyan Plateau near Kharga Oasis, Western Desert, Egypt, can provide a directly datable stratigraphic context for Middle Stone Age\\/Middle Paleolithic (MSA\\/MP) archaeological material, if such material can be found in situ within tufa strata. Two such localities (Mata'na Site G and Bulaq Wadi 3 Locus 1) described by Caton-Thompson

Jennifer R. Smith; Alicia L. Hawkins; Yemane Asmerom; Victor Polyak; Robert Giegengack

2007-01-01

3

SPECTRAL ANALYSIS OF ASTER, HYPERION, AND QUICKBIRD DATA FOR GEOMORPHOLOGICAL AND GEOLOGICAL RESEARCH IN EGYPT (DAKHLA OASIS, WESTERN DESERT)  

Microsoft Academic Search

This paper presents an evaluation, to which degree geological and geomorphological information can be obtained from modern remote sensing systems like the multispectral ASTER or the hyperspectral Hyperion sensor for a hyperarid desert region like the Dakhla Oasis (Western Desert, Egypt). To account for the enhanced information content these sensors provide, hyperspectral analysis methods, incorporating for example Minimum Noise Fraction-Transformation

G. Waldhoff; O. Bubenzer; A. Bolten; W. Koppe; G. Bareth

4

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

SciTech Connect

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.

Taha, M.A. (Conoco, Cairo (Egypt))

1988-08-01

5

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

Microsoft Academic Search

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

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

2001-01-01

6

A socio-ecological investigation of options to manage groundwater degradation in the Western Desert, Egypt.  

PubMed

Under increasing water scarcity, collective groundwater management is a global concern. This article presents an interdisciplinary analysis of this challenge drawing on a survey including 50 large and small farms and gardens in a village in an agricultural land reclamation area on the edge of the Western Desert of Egypt. Findings revealed that smallholders rely on a practice of shallow groundwater use, through which drainage water from adjacent irrigation areas is effectively recycled within the surface aquifer. Expanding agroindustrial activities in the surrounding area are socio-economically important, but by mining non-renewable water in the surrounding area, they set in motion a degradation process with social and ecological consequences for all users in the multi-layered aquifer system. Based on the findings of our investigation, we identify opportunities for local authorities to more systematically connect available environmental information sources and common pool resource management precedents, to counterbalance the degradation threat. PMID:22569842

King, Caroline; Salem, Boshra

2012-07-01

7

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

NASA Astrophysics Data System (ADS)

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.

Khalaf, S.; Gad, M. I.

2014-10-01

8

Refraction statics and seismic imaging: 2-D versus 3-D solutions in the Western Desert of Egypt  

SciTech Connect

Careful review of old geophysical and geological data from the Western Desert of Egypt led to the decision of shooting a 3-D seismic survey targeted to solve some of the encountered geophysical problems such as difficulty of tracing the very thin pay zone, identifying the stratigraphic plays and the main two problems of the seismic method in the Western Desert which are statics and poor imaging. In a case history form illustrated by examples, the result of the 3-D solutions will be shown. Furthermore, an analytical approach will be undertaken to clarify and highlight the sources of those geophysical problems and how the 3-D solution helped in resolving them.

El-Emam, A. [General Petroleum Co., Cairo (Egypt); Nessim, M. [Western Geophysical Co., Cairo (Egypt)

1994-12-31

9

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

10

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

NASA Astrophysics Data System (ADS)

The concentrations of 238U, 234U, 232Th and 228Th 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, 238U and 232Th, as well as the daughter isotopes, 234U, 230Th and 228Th, is systematic within and between the two oases. From the unusually consistent distribution of the 234U /238U 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 234U /238U 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 230Th and 228Th in the water samples supports this interpretation.

Dabous, Adel A.

1994-11-01

11

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

12

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

SciTech Connect

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.

Dabous, A.A. [Ain Shams Univ., Cairo (Egypt)] [Ain Shams Univ., Cairo (Egypt)

1994-11-01

13

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

NASA Astrophysics Data System (ADS)

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.

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

2010-09-01

14

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

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

15

SAR Remote Sensing of Buried Faults: Implications for Groundwater Exploration in the Western Desert of Egypt  

NASA Astrophysics Data System (ADS)

The hydrological setting of a desert plain area located in Egypt, west of Aswan city, is still not well understood, and thus, its groundwater potential remains largely unknown. Images from the ALOS/PALSAR L-band sensor have been used to detect and delineate the subsurface structures in this area. Linear, elliptical and circular polarization transformations were applied to the ALOS/PALSAR full polarimetric data by changing the orientation angle (?°) and elliptical angle (?°). The circular polarization (? = 0° and ? = 45°) proved to be the best transformation for revealing buried faults in various strike directions, which have not been reported in the last version of the official geologic map of this area. Such derived circular polarization images were further enhanced by applying the Optimal Polarization Contrast Enhancement method. The moisture content ( ? S ) of the study sites was generally low, with an average of roughly 0.01%. The average Root Mean Square Height (hRMS) of the surface roughness was also low with 0.01 cm across all sites. The relative dielectric constant (? r ) of the sand in the study area produced a very low value of 3.04. The effects of ? S , ? r and hRMS on the radar backscattered signals turned out to be very low, thus providing, optimal conditions for L-band to penetrate relatively deeply. Moreover, 21 GPR profiles were acquired using 270 MHz shielded antennas to validate the radar remote sensing results. These GPR profiles reveal obvious offsets in the subsurface stratigraphy suggesting that such highly fractured zones are possibly favorable zones for groundwater accumulation.

Gaber, Ahmed; Koch, Magaly; Helmi Griesh, M.; Sato, Motoyuki

2011-12-01

16

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

17

Characteristics of NORM in the oil industry from eastern and western deserts of Egypt.  

PubMed

Naturally occurring radionuclides (NORs) from the 232Th- and 238U-series, which are omnipresent in the earth's crust, can be concentrated by technical activities, particularly those involving natural resources. Although, a great deal of work has been done in the field of radiation protection and remedial action on uranium and other mines, recent concern has been devoted to the hazard arising from naturally occurring radioactive materials (NORM) in oil and gas facilities. NORM wastes associated with oil and gas operations from scale deposits, separated sludge and water at different oil fields in the eastern and western deserts were investigated. Concentrations of the uranium, thorium, and potassium (40K) series have been determined from high-resolution gamma-ray spectrometry. Total uranium content of samples was determined using laser fluorimetry. The levels of radioactivity were mainly due to enhanced levels of dissolved radium ions. Only minute quantities of uranium and thorium were present. The disequilibrium factor for 238U/226Ra has been determined. PMID:11339530

Shawky, S; Amer, H; Nada, A A; El-Maksoud, T M; Ibrahiem, N M

2001-07-01

18

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

NASA Astrophysics Data System (ADS)

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.

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

2006-07-01

19

Calcretes and palustrine carbonates in the Oligo-Miocene clastic-carbonate unit of the Farafra Oasis, Western Desert, Egypt: Their origin and paleoenvironmental significance  

NASA Astrophysics Data System (ADS)

The origin and paleoenvironmental significance of the calcretes and palustrine carbonates in the Oligo-Miocene clastic-carbonate unit that outcrops at the eastern sector of the Farafra Depression (Western Desert, Egypt) have been discussed based on field and petrographic investigations. The calcretes-palustrine carbonates assemblage occurs above a siliciclastic/distal alluvial-floodplain facies. The calcretes represent the transition from the underlying siliciclastic/distal alluvial-floodplain facies to the overlying palustrine carbonates. The calcrete-host rocks are muddy sandstones and sandy mudrocks. This study reveals the occurrence of groundwater calcretes with an upward gradational maturity pattern, ranging from incipient to nodular and to massive calcretes. The calcretes micromorphological analysis suggests that they were originated in vadose and phreatic diagenetic environments by groundwater through evaporation, degassing with no biological activity. The palustrine carbonates are also recognized above the calcrete horizons. They occur in the form of micritic limestones displaying different features that indicate their modifications during pedogenesis and subaerial exposure. These features include clotted-peloidal texture, fenestral fabric, mottling, pseudo-brecciation, desiccation cracks, pseudomicrokarst, root traces and silicification of the lime mud. The calcretes-palustrine carbonates assemblage records a progressive decrease in the terrigenous supply and a continuous rise of the groundwater table associated with local subsidence in a semi-arid to sub-humid climate. A model is suggested for the development of calcretes and palustrine carbonates in the study area.

Wanas, H. A.; Soliman, H. E.

2014-07-01

20

Jurassic-Cretaceous palynomorphs, palynofacies, and petroleum potential of the Sharib-1X and Ghoroud-1X wells, north Western Desert, Egypt  

NASA Astrophysics Data System (ADS)

Palynomorph and palynofacies analyses have been performed on 93 cutting samples from the Jurassic Masajid Formation and Cretaceous Alam El Bueib, Alamein, Dahab, Kharita, and Bahariya formations in the Sharib-1X and Ghoroud-1X wells, north Western Desert, Egypt. Two palynological biozones are proposed for the studied interval of the Sharib-1X well: the Systematophora penicillata-Escharisphaeridia pocockii Assemblage Zone (Middle to Late Jurassic) and the Cretacaeiporites densimurus-Elateroplicites africaensis-Reyrea polymorpha Assemblage Zone (mid-Cretaceous: late Albian to early Cenomanian). Spore coloration and visual kerogen analysis are used to assess the thermal maturation and source rock potential. Mature oil prone to overmature gas prone source rocks occur in the studied interval of the Sharib-1X well, whereas highly mature to overmature gas prone source rocks occur in the studied interval of the Ghoroud-1X well. Palynofacies and palynomorph assemblages in both wells reflect shallow marine conditions throughout the Jurassic and the late Albian and early Cenomanian. During these times, warm and dry climatic conditions prevailed. The Cretaceous palynomorph assemblages of the Sharib-IX well correlate with the Albian-Cenomanian Elaterates Province of Herngreen et al. (1996).

Zobaa, Mohamed K.; El Beialy, Salah Y.; El-Sheikh, Hassan A.; El Beshtawy, Mohamed K.

2013-02-01

21

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)

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.

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

2014-05-01

22

Substance geology of the western desert in Egypt and Sudan revealed by Shuttle Imaging Radar (SIR-A)  

NASA Technical Reports Server (NTRS)

A correlation of known archaeologic sites with the mapped locations of the streamcourses is expected and may lead to new interpretations of early human history in the Sahara. The valley networks, faults, and other subjacent bedrock features mapped on the SIR-A images are promising areas for ground water and mineral exploration. Additionally, the analogies between the interplay of wind and running water in the geologic history of the Sahara and of Mars are strengthened by the SIR-A discoveries of relict drainage systems beneath the eolian veneer of Egypt and Sudan.

Breed, C. S.; Schaber, G. G.; Mccauley, J. F.; Grolier, M. J.; Haynes, C. V.; Elachi, C.; Blom, R.; Issawi, B.; Mchugh, W. P.

1983-01-01

23

The uppermost deposits of the stratigraphic succession of the Farafra Depression (Western Desert, Egypt): Evolution to a Post-Eocene continental event  

NASA Astrophysics Data System (ADS)

This paper gives insight into continental sedimentary deposits that occur at the uppermost part of the stratigraphic succession present in the north-eastern sector of the Farafra Depression (Western Desert, Egypt). Using space imagery to complete the field work, the geology of the area has been mapped and the presence of a N-S oriented fault system is documented. The analysis of the morphotectonic features related to this fault system allows reconstructing the structural and sedimentological evolution of the area. The study indicates that the continental deposits were accumulated in alluvial systems that unconformably overlie shale and evaporitic rocks attributable to the Paleocene-Eocene Esna Formation. The deposits of the Esna Formation show soft-sediment deformation features, which include slump associated to dish and pillar sedimentary structures and provide evidence of syndepositional tectonic activity during the sedimentation of this unit. The outcrops are preserved in two areas on separated fault-bounded blocks. Proximal alluvial fan facies crop out in a dowthrown block close to the depression boundary. The proximal facies are made up mostly by polymictic conglomerates which occasionally contain boulders. The conglomerate clasts are mainly quartz, carbonate, anhydrite satin spar vein, mudrock, ironstone and nummulite fossils. The mid-fan facies consist of trough cross-bedded, rippled and cross-laminated quartzarenites with reworked glauconite grains and carbonate rock fragments, interpreted as deposited by distributary streams. The distal alluvial fan deposits consist of sandy marls that evolve toward the top of the sections into root-bioturbated lacustrine limestone beds that are locally silicified. The limestones are biomicrites containing characea, ostracods and gastropods with fenestral porosity. A number of features, including clast provenance (mainly from marine Paleocene and Eocene rocks), the observed fractural pattern (N-S direction related to the opening of the Red Sea), and the sedimentary relationships, suggests that the continental deposits were accumulated during the Oligocene-Miocene interval.

Sanz-Montero, M. E.; Wanas, H.; Muñoz-García, M. B.; González-Acebrón, L.; López, M. V.

2013-11-01

24

Paleozoic and Mesozoic stratigraphy and oil potential of Western Desert  

Microsoft Academic Search

The depocenter of the Paleozoic basin in western Egypt lies in the northwestern part of the Western Desert. The depositional axis of the basin, where thicknesses in excess of 2800 m (9200 ft) have been recorded, has a northwesterly trend to the vicinity of the Siwa Oasis. A less well-defined shallower basin with a northerly trend lies to the southwest.

N. A. Khalil; D. Young; A. E. M. Nairn

1983-01-01

25

Characteristics and genesis of shear zone-related gold mineralization in Egypt: A case study from the Um El Tuyor mine, south Eastern Desert  

Microsoft Academic Search

Although gold production from orogenic deposits in the Arabian–Nubian Shield is currently relatively minor, extensive alluvial and lode fields were exploited by the ancient Egyptians along the western side of the Red Sea in Upper Egypt and northern Sudan. In the Eastern Desert of Egypt, numerous but small gold deposits are generally related to auriferous quartz veins commonly associated with

Basem A. Zoheir

2008-01-01

26

Hydrologic and climatic implications of stable isotope and minor element analyses of authigenic calcite silts and gastropod shells from a mid-Pleistocene pluvial lake, Western Desert, Egypt  

NASA Astrophysics Data System (ADS)

Authigenic calcite silts at Wadi Midauwara in Kharga Oasis, Egypt, indicate the prolonged presence of surface water during the Marine Isotope Stage 5e pluvial phase recognized across North Africa. Exposed over an area of ˜ 4.25 km 2, these silts record the ponding of water derived from springs along the Libyan Plateau escarpment and from surface drainage. The ? 18O values of these lacustrine carbonates (- 11.3‰ to - 8.0‰ PDB), are too high to reflect equilibrium precipitation with Nubian aquifer water or water of an exclusively Atlantic origin. Mg/Ca and Sr/Ca of the silts have a modest negative covariance with silt ? 18O values, suggesting that the water may have experienced the shortest residence time in local aquifers when the water ? 18O values were highest. Furthermore, intra-shell ? 18O, Sr/Ca, and Ba/Ca analyses of the freshwater gastropod Melanoides tuberculata are consistent with a perennially fresh water source, suggesting that strong evaporative effects expected in a monsoonal climate did not occur, or that dry season spring flow was of sufficient magnitude to mute the effects of evaporation. The input of a second, isotopically heavier water source to aquifers, possibly Indian Ocean monsoonal rain, could explain the observed trends in ? 18O and minor element ratios.

Kieniewicz, Johanna M.; Smith, Jennifer R.

2007-11-01

27

The Lower Paleozoic rock units in Egypt: An overview  

Microsoft Academic Search

Lower Paleozoic rocks are exposed in various regions of Egypt (south central Sinai, north Eastern Desert and southwest Western Desert), in addition to occurring in the subsurface such as north Western Desert and the Gulf of Suez. The Lower Paleozoic rocks in Egypt include surface and subsurface rock units of formational status. The surface rock units are the Taba, Araba

H. A. Wanas

2011-01-01

28

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

NASA Astrophysics Data System (ADS)

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.

Brookes, Ian A.

2001-08-01

29

Carrion insects of the Egyptian western desert.  

PubMed

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

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

1991-09-01

30

Remobilization of gold from a chalcopyrite-pyrite mineralization Hamash gold mine, Southeastern Desert, Egypt  

Microsoft Academic Search

Pyrite, chalcopyrite, and gold occur in quartz veins in granitic rocks and as scattered and disseminated impregnations in shear zones of the highly altered metavolcanics in the Hamash area, Southeastern Desert, Egypt. The minerals are associated in part with pyrrhotite, digenite, tetrahedrite, chalcocite, bornite, and covellite. Pyrite occurs in two forms: (1) idio- to hypidiomorphic coarse crystals with inclusions of

M. Ezzeldin Hilmy; A. Osman

1989-01-01

31

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

Microsoft Academic Search

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

Basem A. Zoheir; Ahmed Akawy

2010-01-01

32

Uranium\\/Thorium isotope evidence for ground-water history in the Eastern Desert of Egypt  

Microsoft Academic Search

The ground-water in the surficial aquifer of the central Eastern Desert of Egypt has a relatively long residence time and is essentially in chemical equilibrium with its host rocks. The content of major elements and uranium suggest that granites have been the principal sources of dissolved ions even where sedimentary rocks are present. A leaching study of uranium and thorium

Adel A. Dabous; J. K. Osmond; Yehia H. Dawood

2002-01-01

33

77 FR 26950 - Designation of Areas for Air Quality Planning Purposes; California; Western Mojave Desert Ozone...  

Federal Register 2010, 2011, 2012, 2013

...Quality Planning Purposes; California; Western Mojave Desert Ozone Nonattainment Area...State of California to reclassify the Western Mojave Desert ozone nonattainment area...California located within the boundaries of the Western Mojave Desert area in the same...

2012-05-08

34

Listvenite–lode association at the Barramiya gold mine, Eastern Desert, Egypt  

Microsoft Academic Search

Several occurrences of gold-bearing quartz veins are situated along the east–northeast-trending Barramiya–Um Salatit ophiolitic belt in the central Eastern Desert of Egypt. In the Barramiya mine, gold mineralization within carbonaceous, listvenized serpentinite and adjacent to post-tectonic granite stocks points toward a significant role of listvenitization in the ore genesis. The mineralization is related to quartz and quartz–carbonate lodes in silicified\\/carbonatized

Basem Zoheir; Bernd Lehmann

2011-01-01

35

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

E-print Network

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... the light colour not absorb the solar radiation. The figure also show that the inside surface of the first layer of the wall before insulation layer decreased by about 3oC from the exposed surface and with 6 hours time lag. Also the outside surface...

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

2010-01-01

36

Leaf anatomy and its relation to the ecophysiology of some non-succulent desert plants from Egypt  

Microsoft Academic Search

A quantitative study of leaf anatomy of 20 species of some non-succulent perennial desert plants belonging to 12 families of the Dicotyledoneae is provided. The species were collected from natural desert habitats belonging to three phytogeographical regions of Egypt. Features representing xeromorphy include small leaf or leaflet area (18 species), pubescent surfaces (16 species), amphistomaticy, iso-bilateral leaf construction and multilayered

Gamal M Fahmy

1997-01-01

37

Remote sensing observations of sand movement in the Bahariya Depression, Western Egypt  

NASA Technical Reports Server (NTRS)

Aerial photographs taken in the 1940's have been used in combination with recent Landsat MSS and TM data to study dune movement in the Western Desert of Egypt. The El-Ghorabi dunes track northwest to southeast along the eastern edge of the Bahariya Depression. These dunes are of complex longitudinal form with well-defined, lag-covered interdune corridors. Studies using both aerial coverage and multitemporal MSS and TM image data reveal little or no net southward extension or movement of the seifs, although field measurements and remote sensing data indicate small-scale lateral migration of dune crests and interdune corridors through time. The primary process of sand transport for these dunes seems to be in response to seasonal shifts in dominant wind direction, as reflected in the development and rapid response of sand shadows leeward of the main dune masses.

Maxwell, Ted A.; Jacobberger, Patricia A.

1987-01-01

38

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

PubMed Central

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

Gomaa, Nasr H.

2012-01-01

39

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

40

PLEISTOCENE BIRD FAUNA FROM BIR TARFAWI (EGYPTIAN WESTERN DESERT)  

Microsoft Academic Search

Boche?ski, Z. 1991. Pleistocene bird fauna from Bir Tarfawi (Egyptian Western Desert). Ostrich 62: 29–34.At Bir Tarfawi, an archaeological site in the Egyptian Sahara dated to about 135000 years (before present), 202 bone fragments were identified as belonging to 24 bird species or genera. Most of the material is apparently from owl pellets. The birds represent aquatic and terrestrial forms

Zygmunt Boche?ski

1991-01-01

41

Extensional collapse along the Sevier Desert reflection, northern Sevier Desert basin, western United States  

NASA Astrophysics Data System (ADS)

Newly released and previously published seismic reflection data from the northern Sevier Desert basin provide a complete seismic transect between the tilted western margin of the basin and the eastern breakaway zone. When tied to well and surface age data, the transect delineates a continuum of extensional fault and basin fill geometries that developed between late Oligocene and Pleistocene time across the basin. A minimum of 18 km of top-to-the-west normal displacement is estimated across the Sevier Desert from only the most conspicuous growth geometries and offsets across listric normal faults that sole downward into the Sevier Desert reflection (SDR). The SDR clearly marks a normal fault zone beneath the entire basin, where stratal truncations are imaged for 50% of the 39 km length of the reflection east of the Cricket Mountains block. Restoration of extensional displacement along this entire 39 km fault length is necessary to reconstruct the pre-Oligocene configuration and erosion level of Sevier thrust sheets across the Sevier Desert area. The SDR normal fault zone underlies the former topographic crest of the Sevier orogenic belt, where it accommodated extensional collapse after cessation of regional contractile tectonism.

Coogan, James C.; Decelles, Peter G.

1996-10-01

42

Thrusting and transpressional shearing in the Pan-African nappe southwest El-Sibai core complex, Central Eastern Desert, Egypt  

Microsoft Academic Search

The Wadi El-Shush area in the Central Eastern Desert (CED) of Egypt is occupied by the Sibai core complex and its surrounding Pan-African nappe complex. The sequence of metamorphic and structural events in the Sibai core complex and the enveloping Pan-African nappe can be summarized as follows: (1) high temperature metamorphism associated with partial melting of amphibolites and development of

Mohamed A. Abd El-Wahed

2008-01-01

43

Calcareous nannofossil biostratigraphy and paleoecology of the Cretaceous–Tertiary transition in the central eastern desert of Egypt  

Microsoft Academic Search

The Gebel Qreiya and nearby Wadi Hamama sections of the central Eastern Desert are among the most complete K\\/T boundary sequences known from Egypt. The two sections were analyzed spanning an interval from l.83 Myr below to about 3 Myr above the K\\/T boundary. A 1-cm-thick red clay layer at the K\\/T boundary at Gebel Qreiya contains an Ir anomaly

Abdel Aziz A. M. Tantawy

2003-01-01

44

Kinematic analysis of the Migif area in the Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

The use of porphyroclasts rotating in a flowing matrix to estimate mean kinematic vorticity number (Wm) is important for quantifying the relative contributions of pure and simple shear in penetratively deformed rocks. The kinematic vorticity number determined for high temperature mylonitic gneisses in the Migif area in the Eastern Desert of Egypt range from ?0.6 to 0.9. The results from vorticity and strain analyses indicate that deformation in the area deviated from simple shear. It is concluded that nappe stacking occurred early during the thrusting event, probably by brittle imbrications, and that ductile strain was superimposed on the nappe structure at high-pressure as shown by a penetrative subhorizontal foliation is developed subparallel to the tectonic contacts with the under- and overlying nappes. The accumulation of ductile strain during underplating was not by simple shear but involved a component of vertical shortening, which caused the subhorizontal foliation in the Migif area. In most cases, this foliation was formed during thrusting of the nappes onto each other, suggesting that nappe stacking was associated with vertical shortening.

Kassem, Osama M. K.

2014-11-01

45

Petrogenesis of selected A-type granitic intrusions from Central Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

The Pan-African orogeny in the Arabian-Nubian Shield was terminated by intrusion of A-type granites (~ 595 Ma; Greenberg, 1981) and its volcanic equivalents. Subsequent to the intrusions of these granitic bodies the shield was exhumed. Eroded A-type granite pebbles were found in the molasse sediments that were deposited in intermountain basins. Therefore the A-type granites provide information about the last stage of the Pan-African geochemical system. Preliminary whole-rock geochemical data of three granitic intrusions (Kadabora, Um Naggat and El shiekh Salem) from the Central Eastern Desert of Egypt; indicate that all of them are peraluminous and with A-type characteristics. These intrusions show low CaO content (average 0.43 %wt), high FeOT/MgO ratio (10.46-121.88), high Na2O+K2O (average 8.04 %wt), marked enrichment of high field strength elements (Y, Nb and Ga except Zr), depletion in MgO (0.01-0.11 %wt) and with low concentration of Sr and Ba. The studied granitoids were emplaced in within plate tectonic regime. References: Greenberg, J.K. (1981): Characteristic and origin of Egyptian younger granites. Bull. Geol. Soc. Am. Part 1, v.92: 224-232.

Hassan, Tharwat; Asran, Asran; Amron, Taha; Hauzenberger, Christoph

2014-05-01

46

Paleozoic cratonal/miogeoclinal stratigraphy in the western Mojave Desert  

SciTech Connect

Detailed mapping of metasedimentary rocks by many workers in the western Mojave Desert, California, has revealed Paleozoic lithologies of cratonal/miogeoclinal affinity. These exposures are metamorphosed, highly strained, and dismembered, and sit as roof pendants to Mesozoic and Tertiary intrusive rocks. In most outcrops no diagnosis fossils are preserved. Age correlation of these units is based, therefore, solely on similarities to lithologic packages outside the region. Despite the complex tectonic history this area has suffered since the late Paleozoic paleogeographic elements trend southwest into the region from where they are last clearly defined near the California-Nevada border. Dolomitic and calcitic marbles, quartzites, and biotite schists make up a major part of the stratigraphy in many areas. The stratigraphy and lithology of these units strongly suggest that they are correlative with late Precambrian-Cambrian units in the Death Valley region. Possible Ordovician and Devonian marbles also are present within some sections; at least one locality contains stromatoporoids of probable Devonian age. Calcite marbles tentatively correlated with lithologically similar Permian units in the Death Valley area are also represented and appear to be depositionally overlain by Mesozoic( ) shallow-marine and are-derived clastic rocks. Although the western Mojave Desert region has experienced compressional, transcurrent, and extensional deformation since late Paleozoic, our current understanding and restoration of this deformation history does not significantly alter the general southwest Paleozoic paleogeographic trends known to exist farther east.

Martin, M.W.; Walker, J.D. (Univ. of Kansas, Lawrence (United States))

1991-02-01

47

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

NASA Astrophysics Data System (ADS)

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.

Zoheir, Basem; Weihed, Pär

2014-11-01

48

Oppositely dipping thrusts and transpressional imbricate zone in the Central Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

This paper documents the 40-60 km wide ENE-WSW trending Mubarak-Barramiya shear belt (MBSB) in the Central Eastern Desert of Egypt by examining its structural styles, kinematics and geometry. Our study revealed the existence of prevalent dextral and minor sinistral conjugate shear zones. The MBSB is metamorphic belt (greenschist-amphibolite) characterized by at least three post-collisional (740-540 Ma) ductile Neoproterozoic deformation events (D1, D2 and D3) followed by a brittle neotectonic deformation (D4). D1 event produced early top-to-the-northwest thrust displacements due to NW-SE shortening. D2 produced discrete zones of NNW-trending upright folds and culminated in initiation of major NW-trending sinistral shear zones of the Najd Fault System (NFS, at c. 640-540 Ma ago) as well as steeply dipping S2 foliation, and shallowly plunging L2 lineation. NW-to NNW-trending F2 folds are open to steep and vary in plunge from horizontal to vertical. D2 deformational fabrics are strongly overprinted by D3 penetrative structures. D3 is characterized by a penetrative S3 foliation, steeply SE- to NW-plunging and shallowly NE-plunging stretching lineations (L3), asymmetric and sheath folds (F3) consistent with dextral sense of movement exhibited by delta- and sigma-type porphyroclast systems and asymmetric boudinage fabrics. D2-D3 represent a non-coaxial progressive event formed in a dextral NE- over NW-sinistral shear zone during a partitioned transpression in response to E-W-directed compression during oblique convergence between East and West Gondwana developed due to closure of the Mozambique Ocean and amalgamation of the Arabian-Nubian Shield in Cryogenian-early Ediacaran time.

Abd El-Wahed, Mohamed A.

2014-12-01

49

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

Microsoft Academic Search

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

Matthew L. Brooks

1999-01-01

50

Pd-BISMUTHOTELLURIDES and Other Tellurides from Some Cu-Ni-PGE Deposits, Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

Pd-bismuthotellurides and other tellurides are described from three Cu-Ni-PGE deposits in the Eastern Desert, Egypt: Abu Swayl, Genina Gharbia, Gabbro Akarem. The deposits are hosted in Late Precambrian mafic-ultramafic rocks and have different geologic histories. The Abu Swayel deposit occurs in conformable, lens-like mafic-ultramafic rocks in metasediments. Mineralization and host rocks are metamorphosed (amphibolite facies; 550-650ºC, 4-5 kbar) and syn-metamorphically sheared. Metamorphism and associated fluid regimes resulted in remobilization and transport of Cu-sulfides and PGE, and development of hydrosilicates. Michenerite, merenskyite, Pd-Bi-melonite, (NiPdBi)Te2, melonite, hessite, altaite and joséite-B occur as inclusions in mobilized sulfides and along cracks in garnet and plagioclase. The Genina Gharbia and Gabbro Akarem deposits are hosted in concentrically zoned, Alaskan-type, complexes; neither is metamorphosed. At Genina Gharbia, ore forms either disseminations in peridotite or massive patches in hornblende-pyroxenite in the vicinity of metasediments. Important petrographic features are a dominance of hornblende, biotite and chlorapatite and alteration of plagioclase to epidote. Disseminated and network sulfide ores are dominated by po, pn, cp and minor py; accessories are cobaltite, molybdenite and valleriite. Sulfide textures and host rock petrography suggest a prolonged late-magmatic hydrothermal event. Michenerite, merenskyite, Pd-Bi-melonite, altaite, hessite, tsumoite and native-Te are mainly present at sulfide-silicate contacts. The Gabbro Akarem deposit is hosted in dunite pipes where net-textured and massive sulfides are associated with spinel and Cr-magnetite. Michenerite, merenskyite, Pd-Bi-melonite and hessite occur mainly as inclusions in sulfides. Typical magmatic textures indicate the limited role of late- and post-magmatic hydrothermal processes. Different geological history of the different deposits enables examination of the role played by late-magmatic and post-magmatic metamorphic fluids in the diversity of tellurides. High Te-activities, indicated by various tellurides at Abu Swayel and Genina Gharbia, relate to participation of solutions generated during metamorphism and late-magmatic hydrothermal activity respectively. The limited role of hydrothermal fluids in the Gabbro Akarem deposit is responsible for low Te activity. It is suggested that hydrothermal fluids introduced by late- and post-magmatic processes largely control Te-activity in Cu-Ni-PGE deposits in mafic-ultramafic rocks. Involvement of a sedimentary component either early, during magma contamination or later, during metamorphism, significantly increases Te-activity.

Helmy, H. M.

2003-04-01

51

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

E-print Network

The El Mayah molasse basin in the Eastern Desert of Egypt A. Shalaby a,b,*, K. Stu¨we a,*, H. Fritz Mayah basin is one of several Pan-African, sedimentary basins that formed across several hundreds clasts indicates that this part of the basin formed mostly after intrusion of what is known

Fritz, Harald

52

Spectral properties of carbonatized ultramafic mantle xenoliths and their host olivine basalts, Jabal Al Maqtal basin, South Eastern Desert, Egypt, using ASD FieldSpec spectroradiometer  

Microsoft Academic Search

Understanding the spectral properties of the carbonatized ultramafic mantle xenoliths and their host olivine basalts exposed at Jabal Al Maqtal strike-slip basin, south Eastern Desert, Egypt using portable ASD FieldSpec is the main task of this article. Field data revealed the presence of ultramafic mantle xenoliths at different stratigraphic levels within Jurassic olivine basalts. Ultramafic mantle xenoliths are recorded within

Ahmed A. Madani

2011-01-01

53

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

E-print Network

climatic condition of very hot and dry region in Egypt (Toshky region). The external climatic conditions and the temperature distribution inside the roof construction and the indoor air temperature were measured. The results of this study recognized...

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

2010-01-01

54

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

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF ENERGY Western Area Power Administration Desert Southwest Customer Service Region--Western Area Lower Colorado Balancing Authority...Rate Order No. WAPA-151 AGENCY: Western Area Power Administration, DOE....

2011-09-27

55

Origin of tourmaline in the metamorphosed Sikait pelitic belt, south Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

A Neoproterozoic metapelitic schist belt at the Sikait area of the south Eastern Desert is a favourable environment for localisation of tourmaline mineralisation in the Pan-African Belt in Egypt. Local concentrations of tourmaline in the Sikait area are closely associated with stratiform metapelitic schists. They are confined to the Nugrus shear zone, along which various leucocratic rocks (leucogranite, pegmatite, aplite) are syntectonically emplaced with various stages of hydrothermal quartz veins. Tourmaline occurs either as disseminated isolated clusters of crystals or as discontinuous tourmalinite bands within the metapelitic rocks, pegmatites and quartz veins. Four types of tourmaline-rich rocks were distinguished: (i) fine-grained tourmaline-rich rocks, which are associated with the biotite schist along contacts with gneissose granites (TR1); (ii) tourmaline-rich rocks, associated with the metapelitic and amphibolitic closely to Nugrus thrust zones (TR2); (iii) tourmaline-rich rocks, associated with the pelitic hornfels at the contact between metapelitic schist and leucogranite (TR3); and (iv) tourmaline-rich rocks and quartz veins, associated with chlorite-graphite schist in contact aureoles with leucogranite and pegmatite veins (TR4). Microprobe analyses revealed that tourmalines are Al saturated for the given Fe/Mg alkali-deficient group tourmaline with minor X-site vacancy and substitution of Ca for Na. Tourmalines belong to the schorl-dravite solid solution series and have a wide compositional range, from nearly end member dravite for TR3 tourmalines to schorl for TR4 tourmalines; TR1 and TR2 tourmalines have intermediate compositions. The Fe/(Fe + Mg) varies between 0.02 and 0.89. Variation in composition of Al-rich tourmalines is essentially caused by variations in Mg, Fe, Na, Ca and Ti. The whole rock chemical analyses of tourmaline-rich rocks closely resemble the trends observed for metapelitic schist and leucocratic rock and reflect mixing between phyllosilicate-rich and quartz-rich end members, which indicates that tourmaline-rich rocks do not contain a significant detrital component. Chondrite-normalised patterns of rare earth elements (REE) in tourmaline-rich rocks and quartz-rich tourmalines are similar to those of the surrounding unaltered metapelitic schists and leucocratic rocks, respectively. Minor depletions of LREE and local negative Ce anomalies characterise the chondrite-normalised REE pattern of TR1 tourmaline-rich rocks, suggesting its formation in the presence of seawater-derived fluids. However, TR4 types are characterised by low content ?REE, such as that of leucocratic rocks. Thus, the geochemical data imply relative immobility of Al, Ti, Cr and HREE during hydrothermal alteration and later metamorphism. The different tourmaline varieties and their respective compositions are interpreted in terms of multistage evolution. Formation of the TR1 tourmaline-rich rocks probably was the net result of several processes, including direct precipitation from B-rich hydrothermal fluids or colloids, early diagenetic reactions of biotite-pelitic sediments with these fluids and subsequent recrystallisation during late regional deformation and metamorphism to give TR2 tourmaline-rich rocks. The TR3 tourmaline-rich rocks mainly developed by the thermal metamorphic recrystallisation of TR1. Tourmaline-rich rocks and veins adjacent to leucogranite and pegmatite veins (TR4) are the result of B-metasomatism; the primary B having been recycled from tourmalinites during regional metamorphism and magmatism.

Harraz, H. Z.; El-Sharkawy, M. F.

2001-08-01

56

Mineralogical and structural characterization of alteration zones detected by orbital remote sensing at Shalatein District, SE Desert, Egypt  

NASA Astrophysics Data System (ADS)

In the Shalatein district, Eastern Desert of Egypt, Landsat Thematic Mapper (TM) data and fieldwork were combined with mineralogical and geochemical investigations in order to detect and characterize alteration zones within Pan-African rocks. The processing of Landsat TM data using ratioing (bands 5/7, 4/5, 3/1 in red, green, blue) showed two different types of alteration zones (type 1 and 2). Type 1 is close to the ophiolitic ultramafic rocks at Wadi Hodein and Wadi Beida areas, whereby type 2 is located within island-arc related metavolcanic rocks at Wadi Beida and Gabal El Qurun areas. Both of these alteration types are concordant with the main NW-SE structural trend. Mineralogical studies indicate that the type 1 alteration consists mainly of calcite, ankerite, magnesite, dolomite and quartz. Chromian spinel, pyrite, and Ni-bearing sulphides (gersdorffite, pentlandite and polydymite) are the main ore minerals within this type. Type 2 alteration is strongly potassium-enriched and pyrophyllite, kaolinite, illite, gypsum and quartz occur. The brecciated quartz-veins, which are associated with these alteration zones, consist of quartz, Fe-hydroxides, hematite and native gold. The gold content reaches up to 5 g/t in the alteration zone, while it extends up to 50 g/t in the quartz veins. This study presents a mineralogical characterization of such alteration zones and demonstrates the utility of orbital remote sensing for finding unknown alteration zones in the Eastern Desert of Egypt and other arid areas with similar host rock lithologies.

Ramadan, Talaat M.; Kontny, Agnes

2004-09-01

57

Soil–vegetation relationships in a coastal desert plain of southern Sinai, Egypt  

Microsoft Academic Search

The present study provides an analysis of soil, vegetation types as well as structure and species distribution in 19 sites in El-Qaa plain along the Gulf of Suez (south Sinai, Egypt), and focuses on the environmental factors that control the species distribution. A total of 203 species belonging to 39 families of the vascular plants are recorded. Asteraceae, Fabaceae, Chenopodiaceae

Monier M. Abd El-Ghani; Wafaa M Amer

2003-01-01

58

Habitat Invasibility and Dominance by Alien Annual Plants in the Western Mojave Desert  

Microsoft Academic Search

Patterns of habitat invasibility and alien dominance, respectively measured as species richness and biomass of alien annual\\u000a plants, were evaluated in association with four habitat factors at the Desert Tortoise Research Natural Area (DTNA) in the\\u000a western Mojave Desert, USA. Habitat factors varied in levels of disturbance outside (high) and inside (low) the DTNA, and\\u000a in levels of soil nutrients

Matthew L. Brooks

1999-01-01

59

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

Microsoft Academic Search

The Betam gold deposit, located in the southern Eastern Desert of Egypt, is related to a series of milky quartz veins along\\u000a a NNW-trending shear zone, cutting through pelitic metasedimentary rocks and small masses of pink granite. This shear zone,\\u000a along with a system of discrete shear and fault zones, was developed late in the deformation history of the area.

Basem A. Zoheir

2008-01-01

60

Petrology and Geochemistry of ultramafic rocks from Wadi Alam, South Eastern Desert of Egypt: evidences for two Neoproterozoic mantle reservoirs?  

NASA Astrophysics Data System (ADS)

Ultramafic rocks of the Neoproterozoic age are common in the Eastern Desert of Egypt. These rocks are commonly considered as a part of the widely distributed dismembered ophiolite sequence. The studied ultramafic rocks from Wadi Alam are classified into two main domains: mantle slices and non-slice ultramafics with intrusive nature. The non-slice ultramafics are observed within the mantle slices. Petrological and geochemical studies of the Neoproterozoic ultramafic rocks from wadi Alam in the South Eastern Desert of Egypt provided new evidences for possibility of two Neoproterozoic mantle reservoirs. The serpentinized ultramafic mantle slices have harzburgite composition. They underwent melting with 23.4 to 24% melt extraction. Following the melting, rocks suffered cryptic mantle metasomatism, including chemical enrichment of the incompatible elements (LILEs, HFSEs and LREE) relative to the primitive mantle compositions. Metasomatism in the mantle reservoir of the studied rocks took place mostly by hydrous fluids or silicate melts, which were derived from subducting oceanic lithosphere. The non-slice ultramafics are classified as cumulates and their compositions range from the dunite, lherzolite to harzburgite. They initially were formed from MORB or Mg-rich tholeiitic melts. Their clinopyroxenes record formation temperature of 700 to 1192 ° C and pressure of 10 to 12 kbar (i.e. 30-40 km depth). The enrichment characteristics of these rocks in the incompatible elements may reflect a metasomatized mantle source. The metasomatic signs of the proposed mantle source are related to melts derived from a subducting oceanic slab. Based on the Cr# and Mg# of the unaltered spinel cores, the serpentinized mantle slices formed in oceanic mantle wedge in the fore-arc setting. On the other hand, formation of the non-slice ultramafics (melts-derived rocks) occurred in a nascent fore-arc setting, subsequent to the formation of the mantle slice peridotites. It is assumed that the mantle slice peridotites were the source for the parental melts of the non-slice ultramafics, where the melting occurred due to spreading in the MOR-arc transition setting. Also, the difference in the degree of serpentinization for the mantle slices with signs of higher degrees of metamorphism in one hand and the non-slice ultramafic bodies refers to different serpentinization events among these rocks.

Gamal El Dien, Hamed; Hamdy, Mohamed; Salam Abu El-Ela, Abdel; Hassan, Adel

2014-05-01

61

Natural radionuclide concentrations in granite rocks in Aswan and Central-Southern Eastern Desert, Egypt and their radiological implications.  

PubMed

Different types of granites, used extensively in local construction, were collected from five localities in Egypt, namely: Abu Ziran (Central Eastern Desert), Gabal El Maesala (Aswan) and three areas from Wadi Allaqi, (Gabal Abu Marw, Gabal Haumor and Gabal um Shalman), in the South Eastern Desert. Granite samples were studied radiologically, petrographically and geochemically. The contents of natural radionuclides ((226)Ra, (232)Th and (40)K) were measured in investigated samples by using gamma spectrometry [NaI (Tl) 3'×3']. The activity concentrations of (226)Ra, (232)Th and (40)K in the selected granite samples ranged from 9±0.5 to 111±7, 8±1 to 75±4 and 100±6 to 790±40 Bq kg(-1), respectively. The external hazard index (H(ex)), absorbed dose and annual effective dose rate were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. The calculated radium equivalents were lower than the values recommended for construction materials (370 Bq kg(-1)). The excess lifetime cancer risks were also calculated. Petrographically, the granites studied are varied in the form of potash-feldspar, quartz, plagioclase, mica and hornblende. The accessory minerals are zircon, apatite and allanite. Geochemically, the chemical composition of the granite is studied especially for major oxides. They are characterized to have SiO(2), K(2)O, Na(2)O and Al(2)O(3) with depletion in CaO, MgO, TiO(2) and P(2)O(5). PMID:22147926

Issa, Shams A M; Uosif, M A M; Abd el-Salam, L M

2012-07-01

62

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

USGS Publications Warehouse

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.

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

1994-01-01

63

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

SciTech Connect

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.

Martin, M.W.; Walker, J.D. (Univ. of Kansas, Lawrence (United States))

1992-08-01

64

Nutritional Parameters and Chronic Energy Deficiency in Older Adults of Desert Areas of Western Rajasthan, India  

Microsoft Academic Search

Nutritional status was assessed in 212 older individuals (?60 years of age) in a cross - sectional study carried out in desert areas of western Rajasthan during 2003. Heights and weights were recorded and a family diet survey (one-day, 24-hour recall) was carried out in 200 households (HHs) from 20 villages. Body Mass Index (BMI) was used to classify nutritional

N. Arlappa; K. Mallikarjuna Rao; K. Venkaiah; G. N. V. Brahmam; K. Vijayaraghavan

2009-01-01

65

Magmatic and solid state structures of the Abu Ziran pluton: Deciphering transition from thrusting to extension in the Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

The 606 Ma old Abu Ziran granite of the Eastern Desert of Egypt intruded the southern margin of the Meatiq dome in a sinistral shear extensional setting. Its emplacement was enabled by a system of NW-trending sinistral shears, related Riedel shears and N-S extensional shear zones and faults. Magmatic flow was east-directed and controlled by Riedel shears that progressively rotated to an orientation favourable for extension. Strain markers that document magmatic flow show eastward decreasing strain together with strain increase from pluton centre to margins. This is explained by Newtonian flow between non-parallel plates and differences in flow velocities across the pluton. Solid state fabrics including shear fabrics, orientation of late magmatic dykes and quartz tension gashes, together with quartz C-axes distributions, document southward extensional shear within the solidified pluton and adjacent host rocks. Extensional shear is correlated with exhumation of the Meatiq dome coeval and soon after pluton solidification (585 Ma). Pressure temperature evolutionary paths, derived from fluid inclusions, show a clockwise path with exhumation by isothermal decompression in the Meatiq dome. By contrast, the overlying volcanosedimentary nappes experienced an anti-clockwise path released by temperature rise due to pluton emplacement followed by isobaric cooling. Quartz fabrics indicate high-temperature coaxial N-S flow in the northern Meatiq dome and lower-temperature, non-coaxial southward flow within the overlaying superficial nappe. This is explained by the exhumation process itself that progressively localised into simple shear domains when rocks approached higher crustal levels. Late extension at ca. 580 Ma was pure shear dominated and resulted in reversal of shear, now dextral, in the western Meatiq shear zone.

Fritz, Harald; Loizenbauer, Jürgen; Wallbrecher, Eckart

2014-11-01

66

Statistical evaluation of airborne gamma ray spectrometric data from the Magal Gebriel area, south Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

The interpretation of airborne gamma ray spectrometric data from the Magal Gebriel area, Eastern Desert, Egypt, has shown that a statistical treatment of these data in terms of individual geologic units is useful in detecting surface uranium mineralization. This is achieved through outlining the probable boundaries of potential uraniferous provinces. The locations and magnitudes of deviations in units equal to the standard deviation from the mean for e U, {e U}/{e Th} and {e U}/{K} are shown on a uranium anomaly map. This map shows two significant groupings of elevated eU values that coincide with elevated {e U}/{e Th} and {e U}/{K} values, associated with granitic rocks. This is in agreement with a recent geological study carried out on the Magal Gebriel area, which has reported the presence of secondary uranium minerals, namely B-uranophane, in these two parts. From the present study, the granitic bodies are considered to be the most promising for uranium prospecting in the area. The potential for significant uranium mineralization is still a matter of speculation. Uranium, thorium and potassium associations in these granitic bodies were studied applying correlation diagrams, indicating that uranium anomalies have the same pattern and are spatially related to both thorium and potassium anomalies, which suggests that there has been no uranium mobilization in these anomalous granites.

Abd El Nabi, Sami Hamed

1995-10-01

67

Application of ground geophysical data to the uranium occurrences of El-Erediya area, Central Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

Ground geophysical surveys were conducted in l-Erediya prospect area, located in the Central Eastern Desert, Egypt. These surveys include ground magnetic and spectrometric. The integration of the results obtained from the magnetic data, aided by geological information, led to the construction of basement tectonic map for the area under consideration. Gamma-ray spectrometric data revealed that the jasperoid veins, faults zones and fracture zones in the El-Erediya area are reflected by the highest spectrometric concentration, whereas granites are reflected by the highest radioactivity rock unit in the area; the amphibolites show up with the lowest radiometric level. The qualitative and quantitaive analysis of the observed magnetic anomalies in relation to the main structural and lithologic manifestations reveals that the average depth to the causative magnetic bodies lies within the basement complex, at two disturbing interfaces 80 and 250 m. From the application of the autocovariance function to the different magnetic and spectrometric data of the studied area, one can state that: there might by radioelement mineralization (U) controlled by WNW structural and having a deep seated fault system; there might be radioelement mineralization (K, eTh) controlled by NW structural and having a deep seated fault system; the EW near surface structure is of shallow origin.

Rabie, Said I.; Abdelhadi, Hassan M.; Ali, Ali S.

1997-02-01

68

Trypanosoma mega (Kinetoplastida) from Bufo viridis in Siwah Oasis, Egypt.  

PubMed

A large pleomorphic trypanosome, identified as Trypanosoma mega, is described from the toad Bufo viridis collected from Siwah Oasis at the Western Desert of Egypt. The prevalence of the trypanosome is 83.3%. Three trypanosome forms are described, small, intermediate and large stumpy form. Observations were also made on the lysed (diffused) trypanosomes. This is the first record of T. mega from B. viridis in Egypt which represents a new host and new geographical location. The measurements of the present trypanosome are given and compared with related forms previously described from Egypt. PMID:9097527

Ashour, A A; Gaafar, N A

1997-04-01

69

Community Conversations for Sustainability in the Desert: Leonora, Western Australia  

Microsoft Academic Search

The concept of sustainability calls for a holistic perspective where the prospects for future generations are not compromised by decisions made today. This paper provides an exploration of the Western Australian town of Leonora whose existence is based on mining, pastoralism, services to the region and tourism. The longest surviving residents with roots in Leonora country are the Aboriginal people

Dora Marinova; Silvia Lozeva; Kurt Seemann

2010-01-01

70

U-Pb TIMS age constraints on the evolution of the Neoproterozoic Meatiq Gneiss Dome, Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

Ages are used to constrain the temporal evolution of the Meatiq Gneiss Dome, Eastern Desert, Egypt, by dating (ID-TIMS) pre-, syn-, and post-tectonic igneous rocks in and around the dome. The Um Ba’anib Orthogneiss, comprising the deepest exposed structural levels of the dome, has a crystallization age of 630.8 ± 2 Ma. The overlying mylonites are interpreted to be a thrust sheet/complex (Abu Fannani Thrust Sheet) of highly mylonitized metasediments (?), migmatitic amphibolites, and orthogneisses with large and small tectonic lenses of less-deformed intrusives. Two syn-tectonic diorite lenses in this complex have crystallization ages of 609.0 ± 1.0 and 605.8 ± 0.9 Ma, respectively. The syn-tectonic Abu Ziran diorite, cutting across the tectonic contact between mylonite gneisses of the Abu Fannani Thrust Sheet and a structurally overlying thrust sheet of eugeoclinal rocks (“Pan-African nappe”), has a magmatic emplacement age of 606.4 ± 1.0 Ma. Zircons from a gabbro (Fawakhir ophiolite) within the eugeoclinal thrust sheet yielded a crystallization age of 736.5 ± 1.2 Ma. The post-tectonic Fawakhir monzodiorite intrudes the ophiolitic rocks and has an emplacement age of 597.8 ± 2.9 Ma. Two other post-tectonic granites, the Arieki granite that intrudes the foliated Um Ba’anib Orthogneiss, and the Um Had granite that cuts the deformed Hammamat sediments, have emplacement ages of 590 ± 3.1 and 596.3 ± 1.7 Ma, respectively. We consider formation of the Meatiq Gneiss Dome to be a young structural feature (<631 Ma), and our preferred tectonic interpretation is that it formed as a result of NE-SW shortening contemporaneous with folding of the nearby Hammamat sediments around 605-600 Ma, during oblique collision of East and West Gondwana.

Andresen, Arild; El-Rus, Mohamed Ali Abu; Myhre, Per Inge; Boghdady, Gamal Y.; Corfu, Fernando

2009-04-01

71

Late Neoproterozoic Nuqara Dokhan Volcanics, Central Eastern Desert, Egypt: Geochemistery and petrogenesis  

NASA Astrophysics Data System (ADS)

The Nuqara volcanic is one of the northernmost outcrops of the Arabian-Nubian Shield Dokhan volcanics. The origin and tectonic setting of the late Neoproterozoic Dokhan volcanics (ca. 610-560 Ma) in the Egyptian Eastern Desert is highly debated. The debate concerns the tectonic setting where they formed during transition between convergent to extensional regime or after the East- and the West-Gondwana collision (~600Ma). In order to solve this problem, lavas from Nuqara area were studied geologically and geochemically. Nuqara Dokhan volcanics comprises two main rock suites: (a) an intermediate volcanic suite, consisting of basaltic andesite, andesite and their associated pyroclastics rocks; and (b) a felsic volcanic suite composed of dacite, rhyolite and ignimbrites. The two suites display well-defined major and trace element trends and continuum in composition with wide ranges in SiO2 (52-75.73%), CaO (9.19-0.22%), MgO (5.29-0.05%), Sr (1367-7.4 ppm), Zr (688.5-172.7 ppm), Cr (207-0.4 ppm), and Ni (94.3-0.2 ppm). The Nuqara Dokhan volcanics are characterized by strong enrichment in LILE relative to HFSE and affiliated to the calc-alkaline subducted - related magmatism. Geochemical Modeling displays that the evolution of these rocks was governed by fractional crystallization of plagioclase, amphiboles, pyroxene, magnetite and apatite in the intermediate varieties and plagioclase, amphibole, magnetite, apatite and zircon in the felsic varieties. The obtained mineral chemistry of these volcanics reveals: (a) Plagioclase range in composition from An55 to An40 in basaltic andesite and from An39 to An24 in andesite. (b) Alkali feldspars have sanidine composition. (c) Clinopyroxenes have augite composition. The low Al2O3 contents (1.94-5.588 wt %) indicate that clinopyroxene crystallized at low - pressure conditions. (d) Amphiboles have magnesio- hornblende composition.

Hassan, Tharwat; Asran, Asran; Amron, Taha; Natflos, Theo

2014-05-01

72

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

NASA Astrophysics Data System (ADS)

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.

Khalaf, Ezz El Din Abdel Hakim

73

Geochemistry of the Banded Iron Formations and their Host Rocks in the Eastern Desert of Egypt BACKUS, Ethan L.1, GAGNON, Kelli E.1, EL-SHAZLY, Aley K.1, and KHALIL, Khalil Isaac2  

E-print Network

. The presence of abundant andraditic garnets and epidote suggests that the deposits underwent calcium (Posters) Paper # 92-54 Abstract Thirteen deposits of banded iron formations occur in an area extending over 30,000 km2 in the central Eastern Desert of Egypt. The deposits most resemble Algoma-type iron

El-Shazly, Aley

74

Integrating geologic and satellite imagery data for high-resolution mapping and gold exploration targets in the South Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

The granitoid-greenstone belts of the Arabian-Nubian Shield are well-endowed with lode gold and massive sulfide ores. Although generally characterized by excellent outcrops and arid desert realm, poor accessibility and lack of finance have been always retardant to detailed geologic mapping of vast areas of the shield. Lack of comprehensive geological information and maps at appropriate scales would definitely hinder serious exploration programs. In this study, band ratioing, principal component analysis (PCA), false-color composition (FCC), and frequency filtering (FFT-RWT) of ASTER and ETM+ data have substantially improved visual interpretation for detailed mapping of the Gebel Egat area in South Eastern Desert of Egypt. By compiling field, petrographic and spectral data, controls on gold mineralization have been assessed in terms of association of gold lodes with particular lithological units and structures. Contacts between foliated island arc metavolcanics and ophiolites or diorite are likely to be favorable loci for auriferous quartz veins, especially where the NW-SE foliation is deflected into steeply dipping NNW-trending shear planes. High-resolution mapping of the greenstone belt, structures and alteration zones associated with gold lodes in the study area suggests that dilatation by foliation deflection was related to emplacement of the Egat granitic intrusion, attendant with a sinistral transpression regime (i.e., ˜640-550 Ma?). Gold mineralization associated with granitoid intrusions in transpression-induced pull-apart structures elsewhere in the Eastern Desert (e.g., Fawakhir, Sukari and Hangaliya mines) emphasize the reliability of this setting as a model for gold exploration targets in greenstone terrains of Egypt, and may be elsewhere in the Arabian-Nubian Shield.

Zoheir, Basem; Emam, Ashraf

2012-05-01

75

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

NASA Astrophysics Data System (ADS)

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.

Frihy, Omran E.

2009-09-01

76

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

NASA Astrophysics Data System (ADS)

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.

Brooks, Matthew L.

1995-01-01

77

Magnetic fabrics and Pan-African structural evolution in the Najd Fault corridor in the Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

In order to assess the Pan-African structural evolution from early orogenic fabrics through Najd wrenching to the latest orogenic collapse/extension, the authors used field work, aided by aerial photographs and satellite images. This work is complemented by the study of the anisotropy of the magnetic susceptibility (AMS, or magnetic fabric). The Pan-African rock associations of the Um Gheig-Kadabora area can be divided into a lower tier composed mainly of amphibolite-migmatite and granitoid gneisses, and an upper tier of ophiolitic rocks, metavolcanics and their related volcaniclastics, and molasse-type Hammamat sediments. Both these units are intruded by late orogenic granitoid plutons and dykes. The lower tier is exposed in a domal structure in the El Sibai area, the upper tier forms a series of weakly to highly deformed thrust units, called Pan-African Nappes here, which are dissected by high strain shear zones. According to their age, these rock units are divided here into early and late-orogenic. The early orogenic rock association is characterized by medium-high metamorphic grades. The late orogenic rock association is characterized by low metamorphic grade. The rocks in the upper tier form a series of low angle thrust sheets, which are bounded by NW-striking high angle shear zones related to the Najd Fault System. The early orogenic rocks show a polyphase structural evolution with early folds, thrusts, and strike-slip shear zones. The late orogenic rocks show a relatively weaker deformation. The latest intrusives studied here are the dykes dissecting the late orogenic Kadabora granite. In the present work magnetic fabric data document the deformational features in detail and assess the role of the Najd Fault System in the deformational evolution. A strong variation in volume susceptibility of various rocks, due to their variations in mineral composition, is observed. Lower values are in the range of 10-6 SI units for late-orogenic alkaline granite and the dykes dissecting it, the highest susceptibilities exceed 7 × 10-2 SI units in magnetite-bearing serpentinite. Early orogenic rocks are characterized by relatively high anisotropies (P? up to 1.7) and are deformed in numerous shear zones. Most of these shear zones can be related to the Najd Fault System. In contrast, late orogenic sediments and intrusives show mostly low anisotropies. However, magnetic lineations are still distinctly oriented parallel with the Najd Fault trend. The very latest Pan-African intrusives, the broadly N-S trending dykes crosscutting the Kadabora pluton, imply c. E-W directed extension. Such an extension is consistent with the magnetic fabric in some of the dykes. Therefore, the Kadabora dykes mark the end of Najd wrenching and a late stage of extension in this part of the Eastern Desert of Egypt. The other dykes display mostly primary fabrics, related to magma flow during their intrusion and are thus post-deformational with regard to the Pan-African orogeny.

Abdeen, Mamdouh M.; Greiling, Reinhard O.; Sadek, Mohamed F.; Hamad, Sayed S.

2014-11-01

78

Human Impact On Landscape And The Revenue In Wadi El Rayan Western Desert Egypt  

NASA Astrophysics Data System (ADS)

Wadi El-Rayan depression occupy about 1800 Km2, it lies in 170 km southwest Cairo. Two lakes in El-Rayan depression initiated since 1973 in a big project when people inundate with excess agricultural sewage water. This article aim to estimate the landscape's response and it's revenue to human's intervention. Two new geomorphological maps, before and after the lakes prepared in the field to understand the landscape changes and its characteristics. Water fluctuation in El Rayan Lakes required multitemporal Landsat image. Geomorphological landforms disappeared and others initiated and neo-ecosystem had been generated. Active elongated sand dune fields covered by water and the dune pattern changed from straight-linear pattern to braided pattern and sand sheets delineating that linear dunes lost activity. Hence avoid and avert dune‘s hazards on the agriculture west of Nile Valley. Landforms and geologic heritage demonstrated that there is an old lake under El Rayan depression. The artificial lakes lead to rise the water table which may abut attempts to utilize from the underground water my stored and water from artificial lakes may infiltrate and contaminate this water. The water volume changed in the southern lake from 501,2 km³ at 1984 to 1097,4 km³ at 1999.

Asayed El Gammal, El

2010-05-01

79

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

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

80

Luminescence dating of Holocene playa sediments of the Egyptian Plateau Western Desert, Egypt  

NASA Astrophysics Data System (ADS)

This study is part of a multidisciplinary project dealing with the investigation of geoarchaeological sites on the Egyptian Plateau. With the aim of reconstructing the palaeoecological background, providing age assessment which put the various results in an age frame that is of special interest. Here, results of one particular section have been selected because of a discrepancy in age determination based on different approaches. Radiocarbon ages were inconsistent with the age range provided by the archaeological context in this area. The underestimation observed is inferred to be caused by poor 14C-sample quality. An attempt to overcome this problem was the determination of the depositional ages of the non-organic sediments by using optically stimulated luminescence (OSL). Equivalent doses of four sediment samples were estimated from OSL measurements carried out on sand-sized quartz grains using the single-aliquot regenerative-dose (SAR) protocol. Dose rates were calculated from neutron activation analysis results. From the OSL ages obtained, we conclude that the sediment sequence exposing an alternation of lacustrine and eolian layers was deposited in a short period of time during the mid-Holocene (mean of OSL ages ˜7.8 ka). Compared to the 14C ages, the luminescence ages fit better into the archaeological context confirmed by surface dating.

Bubenzer, O.; Hilgers, A.

2003-05-01

81

MATURITY-DEPENDENT GEOCHEMICAL MARKERS OF CRUDE PETROLEUMS FROM EGYPT  

Microsoft Academic Search

Maturity-dependent trends of a number of biomarker and nonbiomarker geochemical parameters were examined in crude oils from the Western Desert and the Gulf of Suez, Egypt. Molecular maturity assessments showed that all oils are at an advanced level of thermal maturity, and many ratios, such as CPI, hopane\\/hopane + moretane, C31 22S\\/22S + 22R hopanes and C29 ???-20S\\/20S + 20R

M. Sh El-Gayar; A. E. Abdelfattah; A. O. Barakat

2002-01-01

82

RETRACTED: Geology and petrogenesis of Neoproterozoic migmatitic rock association, Hafafit Region, Eastern Desert, Egypt: Implications for syntectonic anatectic migmatites  

NASA Astrophysics Data System (ADS)

This article has been retracted at the request of the Editor-in-Chief and Author. Please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy). Reason: This article was essentially a duplication of a paper that had already appeared in Egypt. J. Geol., 52 (2008) 25-54. The author would like to apologize for a misunderstanding on his part that led him to believe that the publication of the paper in a local journal and Lithos, without prior agreement with both journals and clear notification, did not represent duplicate publication.

El Bahariya, Gaafar

2009-12-01

83

Ground-Water Recharge from Small Intermittent Streams in the Western Mojave Desert, California  

USGS Publications Warehouse

Population growth has impacted ground-water resources in the western Mojave Desert, where declining water levels suggest that recharge rates have not kept pace with withdrawals. Recharge from the Mojave River, the largest hydrographic feature in the study area, is relatively well characterized. In contrast, recharge from numerous smaller streams that convey runoff from the bounding mountains is poorly characterized. The current study examined four representative streams to assess recharge from these intermittent sources. Hydraulic, thermal, geomorphic, chemical, and isotopic data were used to study recharge processes, from streamflow generation and infiltration to percolation through the unsaturated zone. Ground-water movement away from recharge areas was also assessed. Infiltration in amounts sufficient to have a measurable effect on subsurface temperature profiles did not occur in every year in instrumented study reaches. In addition to streamflow availability, results showed the importance of sediment texture in controlling infiltration and eventual recharge. Infiltration amounts of about 0.7 meters per year were an approximate threshold for the occurrence of ground-water recharge. Estimated travel times through the thick unsaturated zones underlying channels reached several hundred years. Recharging fluxes were influenced by stratigraphic complexity and depositional dynamics. Because of channel meandering, not all water that penetrates beneath the root zone can be assumed to become recharge on active alluvial fans. Away from study washes, elevated chloride concentrations and highly negative water potentials beneath the root zone indicated negligible recharge from direct infiltration of precipitation under current climatic conditions. In upstream portions of washes, generally low subsurface chloride concentrations and near-zero water potentials indicated downward movement of water toward the water table, driven primarily by gravity. Recharging conditions did not extend to the distal ends of all washes. Where urbanization had concentrated spatially distributed runoff into a small number of fixed channels, enhanced infiltration induced recharging conditions, mobilizing accumulated chloride. Estimated amounts of ground-water recharge from the studied reaches were small. Extrapolating on the basis of drainage areas, the estimated aggregate recharge from small intermittent streams is minor compared to recharge from the Mojave River. Recharge is largely controlled by streamflow availability, which primarily reflects precipitation patterns. Precipitation in the Mojave Desert is strongly controlled by topography. Cool moist air masses from the Pacific Ocean are mostly blocked from entering the desert by the high mountains bordering its southern edge. Storms do, however, readily enter the region through Cajon Pass. These storms generate flow in the Mojave River that often reaches Afton Canyon, more than 150 kilometers downstream. The isotopic composition of ground water reflects the localization of recharge beneath the Mojave River. Similar processes occur near San Gorgonio Pass, 75 kilometers southeast from Cajon Pass along the bounding San Andreas Fault.

Izbicki, John A.; Johnson, Russell U.; Kulongoski, Justin; Predmore, Steven

2007-01-01

84

Stable-isotope stratigraphy of the Cenomanian-Turonian (Upper Cretaceous) boundary event (CTBE) in Wadi Qena, Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

A high-resolution ?13C isotope record from Cenomanian-Turonian boundary interval of shallow marine successions in Egypt is presented. The ?13C curves show the typical features of the globally documented Cenomanian-Turonian positive excursion, including three of the main positive isotope peaks defining the Cenomanian-Turonian Boundary Event (CTBE). Based on high-resolution ammonite biostratigraphy, the CTBE started in the study area above the Late Cenomanian Neolobites vibrayeanus Zone within the Galala Formation, directly above the global sequence boundary Cenomanian 5 (SB Ce 5). A stratigraphic gap at that level cuts out the lower a-peak of the CTBE. The Cenomanian-Turonian boundary is located within the upper part of the positive excursion between carbon excursion peaks c and d, coinciding with the boundary between the Late Cenomanian Vascoceras cauvini and the Early Turonian Vascoceratid zones. The CTBE ended up-section of peak d, at the base of the Choffaticeras spp. Zone. The amplitude of the positive ?13C excursion in Egypt is very high (reaching 6.5‰ vs. V-PDB) and largely matches curves of European standard sections and others localities from different basins. Furthermore, the Lower Turonian Holywell Isotope Event, an important marker within the lowermost Turonian, has tentatively been recognized. The positive carbon stable isotope curves presented herein represent the outreach of the oceanic anoxic event (OAE) 2 in shallow-water nearshore sequences.

Nagm, Emad; El-Qot, Gamal; Wilmsen, Markus

2014-12-01

85

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

PubMed

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

Shahin, Hassan Abd El-Razek Aly

2014-01-01

86

Carbonate-orthopyroxenite lenses from the Neoproterozoic Gerf ophiolite, South Eastern Desert, Egypt: The first record in the Arabian Nubian Shield ophiolites  

NASA Astrophysics Data System (ADS)

Carbonate-orthopyroxenites (classic sagvandites) are reported in the Gerf ophiolite, South Eastern Desert, Egypt: the first finding from the Arabian Nubian Shield (ANS) ophiolites. They form massive lenses at the southern tip of the Gerf ophiolite, along the contact between the Shinai granite and Gerf serpentinized peridotites. The lenses show structural concordance with the neighboring country rocks and the granite contact. They consist mainly of metamorphic orthopyroxene + magnesite, among other metamorphic, relict primary and retrograde secondary minerals. Based only on chemistry, two types of carbonate-orthopyroxenites can be recognized, Types I (higher-Mg) and II (lower-Mg and higher-Fe). Field constraints, petrography and mineral chemistry indicate a metamorphic origin for the Gerf carbonate-orthopyroxenites. The euhedral form of relict primary chromian spinels combined with their high Cr#/low-TiO 2 character, and absence of clinopyroxene suggest that the protolith for the Gerf carbonate-orthopyroxenites is a highly depleted mantle peridotite derived from a sub-arc setting. Contact metamorphism accompanied by CO 2-metasomatism resulted in formation of the Gerf carbonate-orthopyroxenites during intrusion of the Shinai granite. The source of CO 2-rich fluids is most likely the neighboring impure carbonate layers. Correlation of the carbonate-orthopyroxenite mineral assemblages with experimental data for the system MgO-SiO 2-H 2O-CO 2 suggests metamorphic/metasomatic conditions of 520-560 °C, Pfluid = 2 kbar and extremely high X values (0.87-1).

Gahlan, Hisham A.; Arai, Shoji

2009-01-01

87

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

PubMed

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

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

2011-11-01

88

The distribution of radioelements in El Gluf biotite granite, north Eastern Desert, Egypt: a guide to the recognition of anomalously radioactive zones  

NASA Astrophysics Data System (ADS)

El-Gluf area is located in the north Eastern Desert of Egypt. It is underlain mainly by Precambrian basement rocks and Phanerozoic sediments. It has been systematically surveyed using high-sensitivity airborne gamma-ray spectrometric and magnetic methods. To identify and outline significant radiometric zones of anomalously high uranium and thorium concentrations in El Gluf biotite granite. These zones could be favourable for potential economic radioactive and/or metallic mineralization. This study could serve as a model for investigating the relationship between the geological structure and radioactive mineralization. Statistical analysis of the gamma-ray spectrometric data were carried out to delineate anomalies. A two-dimensional trend analysis of faults as tracedfrom the geological map, the radiometric gradients, magnetic lineations and the courses of wadis (valleys) were carried out to delineate major and minor trends in the area. Seven spectrometric anomalies (two pure uranium, two pure thorium, and three mixed) could be related to the prevailing faulting directions: N-S, N-W and NE. The NW and NE fault trends proved to have a significant impact on the localization of radiometric anomalies, which may point to potential and structurally controlled uranium and thorium mineralizations whose structures are considered to have acted as channel ways for the mineralized solutions.

Ammar, A. A.; Elkattan, E. M.; Elsadek, M. A.

1993-05-01

89

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

USGS Publications Warehouse

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.

Brooks, M.

1999-01-01

90

Late Pan-African granite emplacement during regional deformation, evidence from magnetic fabric and structural studies in the Hammamat-Atalla area, Central Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

Field investigations, microstructural observations, and magnetic fabric analyses revealed a polyphase, late Pan-African deformational evolution in the Um Sheqila-Um Had (595 Ma) composite pluton and in the Hammamat and Atalla areas of the Central Eastern Desert of Egypt in Ediacaran times. Major stages are early shortening (NNW-SSE), subsequent strike-slip (NW-SE shear zones), and late shortening (NW-SE). Strain studies on pebbles and xenoliths together with AMS data show a predominance of shallow, NW-SE trending X axes or magnetic lineations, associated with steep, NW-SE striking magnetic foliations. Magnetic fabrics and microstructures indicate a tectonic fabric in the Um Sheqila-Um Had granitoid plutons, which is dominated by steep NW-SE striking foliations and shallow NW-SE trending lineations, similar to those in the high-angle Atalla Shear Zone. There is a change of lineation directions from ESE-WNW at Um Sheqila (oldest) to NW-SE to Um Had II (youngest). This pattern may indicate an influence of strike-slip and is also consistent with NE-SW compression. This holds also true for the asymmetry of the contact aureole, which is extended towards NW, parallel with the trend of the magnetic lineation. The character and orientation of the deformation pattern in the Um Sheqila-Um Had plutons and the Atalla Shear Zone is thus similar to the pattern of the late shortening phase. The intrusion of the Um Sheqila-Um Had granitoid rocks, therefore, took place before the late shortening stage, but postdates early deformation, which, according to published data, was associated with lithospheric thinning in the Central Eastern Desert. Therefore, these Pan-African plutons do not represent the earliest post-deformational intrusions but a late stage of syn-deformational magmatic activity. At a regional scale, this deformation with steep foliations and shallow lineations may also be related with lateral escape tectonics. The pluton emplacement, the importance of transcurrent shear zones, and the low lithospheric thickness in the area are not consistent with tectonic elements at the Pan-African orogenic margin but imply a more internal position for the Wadi Hammamat area.

Greiling, R. O.; de Wall, H.; Sadek, M. F.; Dietl, C.

2014-11-01

91

Macroeconometric comparative analysis of the effects of Eastern European and Western technologies on less developed countries: the case of Egypt  

SciTech Connect

The primary objective of this study was to compare the effects of different technologies on the economic growth of the less developed countries (LDCs) of the Middle East. The primary question the study sought to answer was: how does the impact of Western, capital-intensive technology on the economic growth of LDCs compare to that of Eastern European, labor intensive technology. In addition, four subsidiary questions were posed, dealing with the policies, mechanisms, and institutions involved in the transfer of technology and the volume, trends, and patterns of technology transfer from the different suppliers. The study used the production function approach to develop econometric models that helped quantify the impact of the different technologies embodied in capital. To construct such models, capital was disaggregated into three factors: Eastern European, Western, and domestic. Then, using these econometric models, data for the period 1952-1980 were collected for the industrial sector of Egypt, and regression analyses, linear and nonlinear, were conducted. Results are presented briefly. It was also revealed that the contribution of total factor productivity to growth in Egyptian industry is small relative to the contribution of physical inputs.

Karake, Z.A.

1987-01-01

92

Origin of wehrlite cumulates in the Moho transition zone of the Neoproterozoic Ras Salatit ophiolite, Central Eastern Desert, Egypt: crustal wehrlites with typical mantle characteristics  

NASA Astrophysics Data System (ADS)

Ultramafic cumulates, mainly crustal true wehrlites, were discovered and described in the mantle-crust transition zone (MTZ) and the extremely lower layered gabbro sequence of the Ras Salatit ophiolite, Central Eastern Desert, Egypt. They form either boudinaged lensoidal tabular bodies or interdigitated layers often concordant with the planolinear fabrics of the Ras Salatit ophiolite rocks. The contact between wehrlites and the host MTZ dunite or layered gabbro is razor sharp, lobate and/or sinuous, without chilled margins or any visible deformations. The Ras Salatit wehrlites are orthopyroxene-free and composed mainly of olivine and clinopyroxene. They are texturally equilibrated and show a characteristic poikilitic texture. Crystallization order of the Ras Salatit wehrlites is olivine/spinel followed by clinopyroxene with the absence of plagioclase. Olivine and clinopyroxene of the Ras Salatit wehrlites are compositionally uniform and conspicuously high in Mg#, mostly around 0.93 and 0.92, respectively. Moreover, the clinopyroxene shows low Ti and Al contents coupled with marked depletion in LILE. The calculated melt in equilibrium with clinopyroxene from the Ras Salatit wehrlites is largely similar to lavas from the Izu-Bonin forearc. Given the above characteristics, the Ras Salatit wehrlites were produced by crystal accumulation from a hydrous depleted basaltic/tholeiitic melt corresponding to temperatures between 1,000 and 1,100°C at the oceanic crustal pressure (~2 kbar). The involved hydrous tholeiitic melt has been probably formed by fluid-assisted partial melting of a refractory mantle source (similar to the underlying harzburgites) in a somewhat shallow sub-arc environment.

Gahlan, Hisham A.; Arai, Shoji; Abu El-Ela, Fawzy F.; Tamura, Akihiro

2012-02-01

93

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

NASA Astrophysics Data System (ADS)

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.

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

2006-12-01

94

Effects of Protective Fencing on Birds, Lizards, and Black-Tailed Hares in the Western Mojave Desert.  

PubMed

/ 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. KEY WORDS: Birds; Fenced protection; Lepus californicus, Lizards; Mojave Desert; Off-highway vehicles; Protected area management; Sheep grazing PMID:9950700

BROOKS

1999-04-01

95

Post-fire plant recovery in the Mojave and Sonoran Deserts of western  

Microsoft Academic Search

Increasing wildfire activity is one of the most pressing management concerns in arid lands of the American West. To examine post-fire recovery of perennial vegetation in the Mojave and Sonoran Deserts, I analyzed data systematically synthesized from the literature. Post-fire sprouting by desert perennials is generally limited but varies among species. For example, only 3-37% of Larrea tridentata sprouted compared

S. R. Abell

96

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

USGS Publications Warehouse

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.

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

2004-01-01

97

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

USGS Publications Warehouse

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.

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

2008-01-01

98

Structural controls on Neoproterozoic mineralization in the South Eastern Desert, Egypt: an integrated field, Landsat TM, and SIR-C/X SAR approach  

NASA Astrophysics Data System (ADS)

The Arabian-Nubian Shield represents a complex amalgam of arcs and microcontinents assembled during Neoproterozoic closure of the Mozambique Ocean. The 750-720 Ma Allaqi suture is an arc/arc collision zone, formed when the Gerf terrane in the north overrode the circa 830-720 Ma Gabgaba terrane in the south, prior to closure of the Mozambique Ocean. Neoproterozoic rocks include ophiolitic ultramafic-mafic rocks, metasediments, intermediate metavolcanic rocks, intrusive gabbro-diorite rocks, granodiorites, biotite granites, and leucocratic granites. High-pressure/low-temperature metamorphism has been documented in rocks of the suture zone. Mineral deposits include nickel-copper-platinum and podiform chromite in ultramafic rocks, marble, gold-bearing quartz-veins in D 2 and D 3 shear zones, and radioactive mineralization associated with late leucocratic granitic rocks. Integrated field mapping and remote sensing techniques are used to distinguish and map the relationships between rock units, structures, and alteration zones associated with mineral deposits along the Allaqi suture of Egypt's SE Desert. Landsat TM images processed using a band ratioing technique show different rock types remarkably well, and are able to distinguish between alteration zones associated with ultramafic rocks (listwaenites) and those associated with leucocratic granitic rocks (greisenization, silicification and albitization). Black and white L-band SIR-C/X SAR images outline foliations, faults and folds that control mineralization at several deposits in the area, whereas color composite multiband Chh-Lhh-Lhv SIR-C/X SAR images reveal some elliptical granitic bodies that host radioactive mineralization. E-trending, tight to isoclinal, gently dipping folds, thrust faults and subvertical shear zones related to the Allaqi suture are overprinted by N-oriented structures related to the Wadi Ungate shear zone, formed during collision of east and west Gondwana during closure of the Mozambique Ocean. The location of the Wadi Ungate shear zone in the Wadi Shellman area was previously unknown due to burial of basement rocks beneath thin dry sands. A new structural map was prepared using Landsat TM ratio images and SIR-C/X SAR imagery. SIR-C/X SAR data conveys considerably more information about rocks and structures beneath the thin sand cover than discernible from aerial photographs or Landsat TM images.

Kusky, Timothy M.; Ramadan, Talaat M.

2002-07-01

99

Utilization of airborne gamma ray spectrometric data for geological mapping, radioactive mineral exploration and environmental monitoring of southeastern Aswan city, South Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

The present work utilizes airborne gamma ray spectrometric data in a trial to refine surface geology of igneous, metamorphic and sedimentary rocks, detect any radioactive mineralization and monitor environment at southeastern Aswan city, South Eastern Desert, Egypt. This area is mainly covered with igneous rocks (younger granites, older granites, metasediments, metavolcanics, metagabbro, Tertiary basalt and ring complex), metamorphic rocks as well as sedimentary rocks (Um Barmil Formation, Timsah Formation, Abu Aggag Formation and wadi sediments). Airborne gamma ray spectrometry can be very helpful in mapping surface geology. This provides estimates of the apparent surface concentrations of the most common naturally occurring radioactive elements, such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh). This is based on the assumption that, the absolute and relative concentrations of these radioelements vary measurably and significantly with lithology. The composite image technique is used to display simultaneously three parameters of the three radioelement concentrations and their three binary ratios on one image. The technique offers much in terms of lithological discrimination, based on colour differences and showed efficiency in defining areas, where different lithofacies occur within areas mapped as one continuous lithology. The integration between surface geological information and geophysical data led to detailing the surface geology and the contacts between different rock units. Significant locations or favourable areas for uranium exploration are defined, where the measurements exceed (X + 2S), taking X as the arithmetic mean of eU, eU/eTh and eU/K measurements and S as the standard deviation corresponding to each variables. The study area shows the presence of four relatively high uraniferous zones. These zones cannot be ignored and need further ground follow-up. In addition, the trend analysis based on the three radioelement maps and the published geological map shows that, most of the well-developed structural lineaments have NW, NE and ENE trends. Moreover, the average radiation dose rates in the study area, which range from 0.57 to 1.3 mSv yr-1 average, are calculated from the exposure rate for each rock unit. The dose rate levels still remain in the safe side to individuals and less than the maximum permissible from the natural gamma radiation sources, except younger granites and ring complex.

Youssef, Mohamed A. S.; Elkhodary, Shadia T.

2013-12-01

100

Aeolian and fluvial evidence of changing climate and wind patterns during the past 100 ka in the western Simpson Desert, Australia  

Microsoft Academic Search

Sediments near Finke in central Australia provide evidence of late Quaternary evolution and the interaction of aeolian and fluvial systems in response to changing climate in the western Simpson Desert. Thermoluminescence (TL) dating is used to develop a chronology of aeolian and alluvial activity and to identify differences in sand provenance. Quaternary alluviation in the Finke valley at this location

G. C. Nanson; X. Y. Chen; D. M. Price

1995-01-01

101

Multi-element association analysis of stream sediment geochemistry data for predicting gold deposits in Barramiya gold mine, Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

The use of traditional statistical methods can provide suitable indicators of geochemical element dispersion, and aids in targeting potential areas for mineral exploration. Analyzes of stream sediments from an ophiolite suite of ophiolitic mélange matrix and metasediments belt are used for regional geochemical prospecting of gold in the Barramiya mining district, Eastern Desert, Egypt. The principal rocks exposed in the study area are Late-Proterozoic volcano-sedimentary sequences intruded by serpentinite, small bodies of Older and Younger Granitoids, all injected by dykes of various compositions. Gold production derived mainly from shear zone with Au-bearing quartz veins hosted by ultramafic schists and serpentinites at fault intersections or along the basal décollement of the major thrusts, especially where granitoid massifs and stocks are common. Orebodies are mainly sulfide-bearing quartz and quartz-carbonate lodes associated with graphite-schist, listvenite and marble exposures, showing signs of structural control expressed in preferable orientation and consistent meso- and microfabrics. The area has two known gold deposits where several chromite mines are present. Auriferous veins are confined along E and ENE fracture systems and zones in a passive tectonic contact between the serpentinites and the metasediments. Results of 425 stream sediment samples from an area of ˜73 km2 analyzed for 13 trace elements are presented using simple statistical and R-mode factor methods. The overall sample density achieved by the survey is ˜6 samples/km2. Significant variations in background metal contents are recorded near the known mineralized sites. Preliminary visual interpretation of individual spatial distribution patterns of Ag, As, Au, Cu, Mo, Pb, and W show clear-cut relationships with known gold mineralization in the study area. Geochemical patterns of these elements delineate drainage basins with anomalous concentration of elements genetically related to gold mineralization. Gold in analyzed samples ranges from <0.02 to 3.51 ppm with average 0.21 ppm. Most of the high element concentrations in stream sediments are found in the graphite-schist and serpentinized marble rocks. Application of R-mode factor analysis indicates significant components of the sample composition. These reflect lithological, environmental and mineralization controls. Preparation of factor score map for the association Ag-Au-As-Cu-Zn-Pb-Mo-W enables a more precise delineation of zones of known gold mineralization as well as areas that may contain (on geological grounds) primary gold mineralization. The exploration significance of some anomalies has not been established, but a number of these anomalies may be related to undiscovered mineralization while others may be of no economic significance. Groundwater pH influences the hydromorphic dispersion patterns of Ag, As, and Au in different ways and this requires consideration during data interpretation.

Harraz, Hassan Z.; Hamdy, Mohamed M.; El-Mamoney, Mohamed H.

2012-06-01

102

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

PubMed

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

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

2010-11-01

103

Optical characteristics of biomass burning and desert dust over the Western Mediterranean during summer: a case study  

NASA Astrophysics Data System (ADS)

The present contribution reports on the aerosol vertical distributions in Barcelona (Spain) which were obtained when very high aerosol concentrations were observed on summer 2012. An EARLINET lidar system and AERONET sunphotometer located in Barcelona performed intensive measurements in the framework of the ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network) project. The data that were collected allow the characterization of the optical properties of the aerosols in this region, benefiting from the synergy of various remote sensing instruments. Due to its location in the Mediterranean basin, Barcelona metropolitan area is influenced by two major aerosol source regions: Europe and the Western Mediterranean Basin, as a major source of anthropogenic pollutants, and North Africa, as a principal source of natural dust. As a result, the composition of atmospheric aerosols in Barcelona station is a mixing of aerosols. During the period between 1 - 2 July, AOD reached high values (~ 0.5). In addition to anthropogenic local contributions, other aerosols long-range transported were also detected. Between 1 - 3 July, strong forest fires occurred in Alicante where advected to Barcelona area. On the other hand, between 28th June and 1st July, the northeastern Iberian Peninsula was affected by the intrusion of Saharan dust. The presence of Saharan dust was successfully forecasted by the BSC-DREAM8b dust regional model. MODIS and AERONET data, as well as air-mass backward trajectories confirmed the existence of biomass burning and desert dust in the case examined. Desert dust was detected between 2 and 4 km (above sea level, a.s.l) with maximum dust concentrations at ~ 4 km a.s.l on 1st June. On the other hand, favourable meteorological conditions made possible that biomass burning from Alicante was southern advected to Barcelona during the study period.

Basart, Sara; Sicart, Michaël; María Baldasano, José; Lane, Diego; Comerón, Adolfo

2013-04-01

104

Isolation and characterization of osmotolerant bacteria from thar desert of western Rajasthan (India).  

PubMed

The Thar Desert harsher environment harbors a limited diversity of life forms due to extreme conditions like low moisture of sandy soils and high soil temperature. In the present study, osmotolerant bacteria from the Thar soils were isolated and characterized. Bacteria were isolated from 20 soil samples (100 g), collected from sand dunes, suspended in water and absolute alcohol. A total of 11 biochemical and morphological tests were carried out for generic identification of bacteria. Osmotic tolerance capacity of isolates was examined on glycerol, NaCI and alcohol; and sequencing of 16S rRNA gene was also performed for bacterial identification. 16S to 23S rRNA internal transcribed spacer analysis (RISA) was done for phylogenetic analysis of isolates. The soil suspended in water contained 2.5 x 10(6) bacteria/g of soil while alcohol suspended soil had 4.4 x 10(4) bacteria/g. The 24 bacterial isolates were found tolerant to 26% glycerol, 14% NaCI and 10% of alcohol, and 22 out of 24 isolates were found Gram positive. The results showed that 45.83% and 41.67% bacteria belong to Bacillus spp. and Corynebacterium spp., respectively, while Acinetobacter spp., Aeromonas spp. and Staphylococcus spp. were in equal proportion (4.16% each). Six isolates were selected for 16S rRNA gene sequencing and five were found 95% similar with Bacillus licheniformis whereas one isolate was identified as B. subtilis. All the isolates showed good growth up to 50 degrees C with gradual reduction on subsequent increment of temperature. Out of 24 isolates, six could survive at 65 degrees C while one isolate could grow at 63 degrees C. Growth kinetic studies revealed that the reduction in generation time in solute(s) and temperature stress was more as compared to generation time in plain medium. This study suggests that virgin sand dunes may be a rich source of bacteria, tolerant to osmotrophic solutes, and can be examined for plant growth promotion activity in agriculture. Moreover, study might help to resolve the tactic adopted by microbes to defeat desiccation induced by various types of solutes. PMID:24432519

Sharma, Ramavtar; Manda, Rajni; Gupta, Shikha; Kumar, Sushil; Kumar, Vinod

2013-12-01

105

Water movement through a thick unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California, USA  

NASA Astrophysics Data System (ADS)

Previous studies indicated that small amounts of recharge occur as infiltration of intermittent streamflow in washes in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. These washes flow only a few days each year after large storms. To reach the water table, water must pass through an unsaturated zone that is more than 130 m thick. Results of this study, done in 1994-1998, show that infiltration to depths below the root zone did not occur at control sites away from the wash. At these sites, volumetric water contents were as low as 0.01 and water potentials (measured as the combination of solute and matric potentials using a water activity meter) were as negative as -14,000 kPa. Water-vapor movement was controlled by highly negative solute potentials associated with the accumulation of soluble salts in the unsaturated zone. Highly negative matric potentials above and below the zone of maximum solute accumulation result from movement of water vapor toward the highly negative solute potentials at that depth. The ?18O and ?D (delta oxygen-18 and delta deuterium) isotopic composition of water in coarse-grained deposits plots along a Rayleigh distillation line consistent with removal of water in coarse-grained layers by vapor transport. Beneath Oro Grande Wash, water moved to depths below the root zone and, presumably, to the water table about 130 m below land surface. Underneath Oro Grande Wash, volumetric water contents were as high as 0.27 and water potentials (measured as matric potential using tensiometers) were between -1.8 and -50 kPa. On the basis of tritium data, water requires at least 180-260 years to infiltrate to the water table. Clay layers impede the downward movement of water. Seasonal changes in water vapor composition underneath the wash are consistent with the rapid infiltration of a small quantity of water to great depths and subsequent equilibration of vapor with water in the surrounding material. It may be possible to supplement natural recharge from the wash with imported water. Recharge to the wash may be advantageous because the unsaturated zone is not as dry as most areas in the desert and concentrations of soluble salts are generally lower underneath the wash.

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

2000-12-01

106

The meaning of desert color in earth orbital photographs  

NASA Technical Reports Server (NTRS)

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.

El-Baz, F.

1978-01-01

107

Desert test site uniformity analysis  

Microsoft Academic Search

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

Dana X. Kerola; Carol J. Bruegge

2009-01-01

108

Effects of Protective Fencing on Birds, Lizards, and Black-Tailed Hares in the Western Mojave Desert  

Microsoft Academic Search

Effects of protective fencing on birds, lizards, black-tailed hares (Lepus californicus), perennial plant cover, and structural diversity of perennial plants were evalu- ated from spring 1994 through winter 1995 at the Desert Tor- toise 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

MATTHEW BROOKS

1999-01-01

109

U.S. in the World: Arizona/Egypt  

NSDL National Science Digital Library

Residents of Arizona and Egypt face a daily challenge: living in increasing numbers and concentrations in desert ecosystems. Read about how both face surprisingly similar conflicts and issues over water, land and industry.

Bureau, Population R.

110

Evidence for population fragmentation within a subterranean aquatic habitat in the Western Australian desert  

PubMed Central

The evolution of subterranean animals following multiple colonisation events from the surface has been well documented, but few studies have investigated the potential for species diversification within cavernicolous habitats. Isolated calcrete (carbonate) aquifers in central Western Australia have been shown to contain diverse assemblages of aquatic subterranean invertebrate species (stygofauna) and to offer a unique model system for exploring the mechanisms of speciation in subterranean ecosystems. In this paper, we investigated the hypothesis that microallopatric speciation processes (fragmentation and isolation by distance (IBD)) occur within calcretes using a comparative phylogeographic study of three stygobiontic diving beetle species, one amphipod species and a lineage of isopods. Specimens were sequenced for the mitochondrial cytochrome c oxidase 1 gene from three main sites: Quandong Well, Shady Well (SW) and Mt. Windarra (MW), spanning a 15?km region of the Laverton Downs Calcrete. Phylogenetic and haplotype network analyses revealed that each species possessed a single divergent clade of haplotypes that were present only at the southern MW site, despite the existence of other haplotypes at MW that were shared with SW. IBD between MW and SW was evident, but the common phylogeographic pattern most likely resulted from fragmentation, possibly by a salt lake adjacent to MW. These findings suggest that microallopatric speciation within calcretes may be a significant diversifying force, although the proportion of stygofauna species that may have resulted from in situ speciation in this system remains to be determined. PMID:21343944

Guzik, M T; Cooper, S J B; Humphreys, W F; Ong, S; Kawakami, T; Austin, A D

2011-01-01

111

Active synchronous counterclockwise rotation and northwards translation of Africa toward Eurasia during the Late Cretaceous: A paleomagnetic study on the Alkaline volcanic field of Wadi Natash (ca. 100-86Ma), South Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

In order to shed light on the paleo-tectonic movement of Africa during the Late Cretaceous, the two end members of the alkaline volcanic field of Wadi Natash (ca. 100-86Ma) in the South Eastern Desert of Egypt were studied paleomagnetically. The Wadi Natash volcanic field (24.5°N-34.25°E) is made up of a succession of differentiated flows grading from alkali olivine basalt [AOB] to trachyte-phonolite [Tr/Ph]. The oldest flows of the AOB (104±7 Ma) and the youngest Tr/Ph plugs and ring dykes (86Ma) as well as the interflows sandstones [ previously know as Nubian sandstone were sampled allover the field > 400km2. The isothermal remanent magnetization [IRM] study revealed that the remanence in Wadi Natash volcanics reside mainly in magnetite with some subsidiary goethite/hematite sites. On the other hand, goethite/hematite are the sole remanence carriers in the Nubian-type interflow sandstone. After the progressive stepwise thermal demagnetization of all samples, the visual isolation and subsequent calculation of the best-fit line of the characteristic remanence [ChRM] direction of each sample, followed by the calculation of the site and rock-unit means revealed that: 1- In the tilt-corrected coordinates, the mean ChRM of the oldest AOB flows [N=12 sites

Lotfy, H.

2009-04-01

112

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)

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.

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

2006-10-01

113

Effects of Protective Fencing on Birds, Lizards, and Black-Tailed Hares in the Western Mojave Desert  

Microsoft Academic Search

Lepus californicus  ), perennial plant cover, and structural diversity of perennial plants were evaluated from spring 1994 through winter 1995\\u000a at the Desert Tortoise Research Natural Area (DTNA), in the Mojave Desert, California. Abundance and species richness of birds\\u000a were higher inside than outside the DTNA, and effects were larger during breeding than wintering seasons and during a high\\u000a than a

MATTHEW BROOKS

1999-01-01

114

Nile River, Lake Nasser, Aswan Dam, Egypt  

NASA Technical Reports Server (NTRS)

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.

1991-01-01

115

Thermodynamic modelling of Sol Hamed serpentinite, South Eastern Desert of Egypt: Implication for fluid interaction in the Arabian-Nubian Shield ophiolites  

NASA Astrophysics Data System (ADS)

The Arabian-Nubian Shield is the largest tract of juvenile continental crust of the Neoproterozoic. This juvenile crust is composed of intra-oceanic island arc/back arc basin complexes and micro-continents welded together along sutures as the Mozambique Ocean was closed. Some of these sutures are marked by ophiolite decorated linear belts. The Sol Hamed ophiolite (808 ± 14 Ma) in southeastern Egypt at the Allaqi-Heiani-Onib-Sol Hamed-Yanbu arc-arc suture represents an uncommon example of rocks that might be less deformed than other ophiolites in the Arabian-Nubian Shield. In order to understand fluid-rock interactions before and during arc-arc collision, petrological, mineral chemistry, whole-rock chemistry and thermodynamic studies were applied to the Sol Hamed serpentinized ophiolitic mantle fragment. These studies reveal that the protolith had a harzburgite composition that probably originated as forearc mantle in the subducted oceanic slab. We propose that these rocks interacted with Ti-rich melts (boninite) in suprasubduction zone, which latter formed the Sol Hamed cumulates. Spinel's Cr# associated with the whole rock V-MgO composition suggest that the harzburgites are highly refractory residues after partial melting up to 29%. The melt extraction mostly occurred under reducing conditions, similar to peridotites recovered from the subducted lithosphere. Protolith alteration resulted from two stages of fluid-rock interaction. The first stage occurred as a result of infiltration of concentrated CO2-rich fluid released from carbonate-bearing sediments and altered basalt at the subduction zone. The alteration occurred during isobaric cooling at a pressure of 1 kbar. The fluid composition during the isobaric cooling was buffered by the metamorphic reactions. The second stage of fluid-rock interactions took place through prograde metamorphism. The increase in pressure during this stage occurred as a result of thrusting within the oceanic crust. In this process the forearc crust was loaded by roughly 20-30 km of overthrust rocks.

Abu-Alam, Tamer S.; Hamdy, Mohamed M.

2014-11-01

116

Thematic Mapper analysis to identify geomorphologic and sediment texture of El Tineh plain, north-western coast of Sinai, Egypt  

Microsoft Academic Search

Thematic Mapper data combined with field inspection are successfully applied to detect a wide variety of texture analysis of sediments and geomorphologic variability along the coastal plain of El Tineh bay at the north-western part of Sinai. Processing techniques used in this study include: image enhancement, principal component analysis (PCA), TM band ratios and supervised classification. The analysis of colour

K. H. M. DEWIDAR; O. E. Frihy

2003-01-01

117

GEOL 105, Earth Lab: SAND! A journey from mountains to beaches and western deserts Spring Term 2013 Professor David Harbor  

E-print Network

or Monday fly to St. George, UT to visit Coral Pink Sand Dunes near Kanab UT and Zion National Park. Return St George UT,) o Saltation and transportation: Modern desert dunes Coral Pink Sand Dunes State Park to the stunning cliffs of Zion National Park on the Colorado Plateau of Utah. Course Description: "Sand

Harbor, David

118

Magnetostratigraphy of the Western Borrego Badlands, Anza-Borrego Desert, California - Implications for Tectonics and Litho- and Biostratigraphic Control  

Microsoft Academic Search

Over 200 meters of non-marine fluvial-floodplain sediments and volcanic ashes are exposed in the Borrego Badlands as part of the northwest margin of the Borrego-San Filipe Basin in the Anza-Borrego Desert, Califorinia. Our stratigraphic and paleomagnetic investigations provide data regarding the age and character of the sediments and tectonics of the region. The intrabasin sediments in Mammoth Cove and Rainbow

P. Remeika; J. C. Liddicoat; S. Beske-Diehl

2008-01-01

119

Solar Energy for Rural Egypt  

NASA Astrophysics Data System (ADS)

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.

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

120

A gravity study of the Great Basin-Sonoran Desert transition zone, Basin and Range province, western United States  

E-print Network

geophysics of the western Cordillera: Geological Society of America Memoir 152, p, 111-144. Snyder, D. B. , and Carr, W. J. , 1984, Interpretation of gravity data in a complex volcano-tectonic setting, southwestern Nevada: Journal of Geophysical Research... geophysics of the western Cordillera: Geological Society of America Memoir 152, p, 111-144. Snyder, D. B. , and Carr, W. J. , 1984, Interpretation of gravity data in a complex volcano-tectonic setting, southwestern Nevada: Journal of Geophysical Research...

Brooks, Debra Ann

2012-06-07

121

Mesozoic and Cenozoic thermal history of the eastern Mojave Desert, California and western Arizona, with emphasis on the Old Woman Mountains area and the Chemehuevi metamorphic core complex  

SciTech Connect

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 {sup 40}Ar/{sup 39}Ar thermochronology and petrology/thermobarometry to rocks in this region provides information about the timing and nature of thrusting, plutonism, metamorphism, denudation, and detachment faulting. Orogenesis culminated during the Late Cretaceous when rocks exposed in the Old Woman-Piute, Chemehuevi, and Sacramento Mountains attained temperatures > 500C. High grade metamorphism of the Old Woman Mountains area was caused by the intrusion of the Old Woman-Piute batholith at 73 {plus minus} 1 Ma; Cretaceous mineral assemblages in Proterozoic pelites increase in grade from greenschist to upper amphibolite facies, and {sup 40}Ar/{sup 39}Ar hornblende ages from Proterozoic amphibolites decrease in age from {approximately} 1,600 Ma to 73 {plus minus} 1 Ma, in the direction of 73 Ma plutons. Pluton emplacement and metamorphism occurred at 3 to 3.5 kbars and 400 > 600C in the Piute Mountains, and 3.5 to 4.5 kbars and 530 to > 650C in the Old Woman Mountains. Following the Cretaceous, the eastern Mojave Desert underwent a period of cooling at a rate of 2 to 10C/Ma between 65 and 25 Ma. By 30 Ma rocks exposed in the Old Woman-Piute, Marble Ship, Clipper and Turtle Mountains were below {approximately} 100C. {sup 40}/{sup 39}Ar ages from the Sacramento Mountains suggest that mylonitization caused by the onset of regional extension occurred at 23 {plus minus} 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 {approximately} 180C and {approximately} 350C, respectively which suggests that this fault initiated at a dip of 5 to 30{degree}.

Foster, D.A.

1989-01-01

122

Evolution of rattlesnakes (Viperidae; Crotalus) in the warm deserts of western North America shaped by Neogene vicariance and Quaternary climate change.  

PubMed

During Pleistocene, the Laurentide ice sheet rearranged and diversified biotic distributions in eastern North America, yet had minimal physical impact in western North America where lineage diversification is instead hypothesized to result from climatic changes. If Pleistocene climatic fluctuations impacted desert species, the latter would reflect patterns of restricted gene flow concomitant with indications of demographic bottlenecks. Accordingly, molecular evidence for refugia should be present within these distributions and for subsequent range expansions as conditions improved. We sought answers to these questions by evaluating mitochondrial DNA (mtDNA) sequences from four species of rattlesnakes [Crotalus mitchellii (speckled rattlesnake), Crotalus cerastes (sidewinder), Crotalus tigris (tiger rattlesnake), Crotalus ruber (red diamond rattlesnake)] with distributions restricted to desert regions of southwestern North America. We inferred relationships using parsimony and maximum likelihood, tested intraspecific clades for population expansions, applied an isolation-with-migration model to determine bi-directional migration rates (m) among regions, and inferred divergence times for species and clades by applying a semiparametric penalized likelihood approach to our molecular data. Evidence for significant range expansion was present in two of eight regions in two species (Crotalus mitchellii pyrrhus, C. tigris region north). Two species (C. cerastes, C. mitchellii) showed a distribution concomitant with northward displacement of Baja California from mainland México, followed by vicariant separation into subclades. Effects of Pleistocene climate fluctuations were found in the distributions of all four species. Three regional diversification patterns were identified: (i) shallow genetic diversity that resulted from Pleistocene climatic events (C. tigris, C. ruber); (ii) deep Pleistocene divisions indicating allopatric segregation of subclades within refugia (C. mitchellii, C. cerastes); and (iii) lineage diversifications that extended to Pliocene or Late Miocene (C. mitchellii, C. cerastes). Clade-diversifying and clade-constraining effects impacted the four species of rattlesnakes unequally. We found relatively high levels of molecular diversification in the two most broadly distributed species (C. mitchellii, C. cerastes), and lower levels of genetic diversification in the two species (C. tigris, C. ruber) whose ranges are relatively more restricted. Furthermore, in several cases, the distributions of subspecies were not congruent with our molecular information. We suggest regional conservation perspectives for southwestern deserts cannot rely upon subspecies as biodiversity surrogates, but must instead employ a molecular and deep historical perspective as a primary mechanism to frame biodiversity reserves within this region. PMID:16968275

Douglas, Michael E; Douglas, Marlis R; Schuett, Gordon W; Porras, Louis W

2006-10-01

123

Military Review: Desert Shield/Desert Storm.  

National Technical Information Service (NTIS)

CONTENTS: CASCOM Support for DESERT SHIELD/DESERT STORM; Total Army CSS: Providing the Means for Victory; Logistics Automation Support for Desert Storm; Building the DESERT Logistics force; Depot operations Supporting DESERT SHIELD; The Readiness Group's ...

1991-01-01

124

Eternal Egypt  

NSDL National Science Digital Library

Available in English, French, and Arabic, Eternal Egypt is a website with a wealth of information on "the artifacts, characters, and places that together comprise the wonder that is Eternal Egypt." The website is organized so visitors can choose between a guided tour, begin with one of the cultural highlights (such as The Temple of Luxor or Part of a Wall of a Tomb), or simply explore and discover. A key feature of the website is the context provided in relation to various topics, so that a visitor can learn about the artifacts, but also how they connect to other people, places and artifacts, and where they fit in terms of an overall timeline and on a multimedia map of Egypt. Topics include: Arts and Crafts (Libraries, Architecture, Paintings and Relief, Sculpture, Humanities, Crafts), Science (Archaeology, Mathematics, Astronomy, Medicine, Social Science, Engineering), Agriculture (Irrigation, Herding, Farming, Crops), Commerce and Trade (Transportation), Government (Leaders, Seats of Power, Theocracy, Military), and Society and Culture (Family, Food and Drinks, Clothing, Sports and Entertainment, Religion and Spirituality).

125

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

E-print Network

5.5 Radiation Damage 16 5.6 Alpha-Dosage Filter 18 5.7 Alpha-Dosage Versus Helium Concentration Filter 19 6. Results 20 6.1 Detrital Zircon (U-Th)/He Data 20 6.2 Probability Density Diagrams 21 6.3 ZHe Data Presentation 21 6... and at lower temperatures than in lower-radiation grains. The amount of radiation damage on zircon limits the retentiveness of zircon with respect to helium. Final damage to the crystal is both time and temperature dependent due to recrystallization...

Glauser, Travis Robert

2010-12-13

126

Radiation synthesis of functionalized polypropylene fibers and their application in the treatment of some water resources in western desert of Egypt  

Microsoft Academic Search

Functionalized polypropylene (PP) fibers were prepared by radiation-induced graft copolymerization of acrylamide (AAm) and 4-vinyl pyridine (4VP) binary system onto the PP fibers. Preparation conditions such as type of solvent used, comonomer composition and total concentration were investigated to obtain a suitable grafting degree for the proposed application as a metal recovery polymer. The effect of pH on the chelation

A. El-Hag Ali; H. A. Shawky; M. H. El-Sayed; H. Ibrahim

2008-01-01

127

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

Microsoft Academic Search

Volatile oil composition of hydro-distilled (HD) and supercritical carbon dioxide (SC-CO2) 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-CO2 extracted oils. Nineteen constituents, which accounted for 89.32% of total constituents in HD oil, represented

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

2011-01-01

128

Ancient Egypt  

NSDL National Science Digital Library

Drawing on its superb collection of materials from archaeological excavations, the British Museum presents this extensive learning resource on Ancient Egypt. The site features texts, images, and interactive elements detailing Egyptian daily life, mythology, timekeeping, geography, architecture, governance, business, writing, and rituals of death. The material is clearly and simply written so that the site would be useful for primary school students, but it is informative and substantial enough to be of interest to college students and curious adults as well. Thoroughly hyperlinked and replete with images that can be enlarged for detailed perusal, the site goes beyond the typical teaser Websites so often posted by lesser museums.

129

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

NASA Astrophysics Data System (ADS)

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.

Izbicki, John A.; Radyk, John; Michel, Robert L.

2002-06-01

130

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

USGS Publications Warehouse

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.

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

2002-01-01

131

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

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.

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

2000-01-01

132

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

PubMed

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

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

2011-08-01

133

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

PubMed Central

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

2010-01-01

134

Desert dust in rural western US; the influence of dust storms, large particles, and land-use change on aerosol loads  

NASA Astrophysics Data System (ADS)

Atmospheric aerosols are common in urban settings as well as dryland rural environments and are important to both climate and biogeochemical cycling. Most urban and far traveled aerosols are less than 10 micrometers in diameter with many particles in the less than 2.5 or 1 micrometer-size classes. Small aerosols, including many generated by industrial activity, are the focus of federal environmental law and have a major impact on human health. In rural areas of the western US, however, these small industrially derived particles appear to make up a small part of the overall aerosol load. Rather, dust in the rural West is dominated by mineral aerosols including a large amount of particles that range in size from 10 to 40 microns. These particles can travel for hundreds of kilometers, particularly during periods when dust storms are common. In the dusty spring and summer periods in and around Canyonlands and Mesa Verde National Parks, large particles (particles greater than 10 micrometers in diameter) appear to contribute between 50 and 90% to the overall particle load several meters above the ground. During large dust storms, concentrations of total suspended particulates increase by a factor of 8 to 10 while particles less than 10 micrometers in diameter are minimally affected. The presence of large particles in the atmosphere of the rural West is notable for several reasons. First, the majority of the existing aerosol monitoring networks focus on the small particle-size classes of less than 2.5 and 10 microns. Because many aerosol-collection instruments are designed with specific particle-size cutoff criteria, these instruments and the networks that depend on them are effectively blind to the larger particles that can dominate aerosol loads in the West. Second, for large portions of the year including the spring and summer months when dust storms are common, large particles likely play a major role in visibility restrictions across the protected airsheds of the western US. Finally, the sources of large mineral aerosols are different from those of industrial aerosols that dominate urban areas, and thus the concentrations of large particles do not correspond with variations in urban concentrations of small industrial aerosols. Mineral aerosols are produced by both natural erosion of desert soils and the variety of human activities such as grazing, resource extraction, and recreation that lead to surface disturbance. In large areas of the rural West, resource extraction and recreational activities have been increasing leading to the potential for increases in mineral aerosol concentrations. Without improved monitoring capabilities that focus on these large particles, any potential long-term changes in large-particle aerosol loads in the rural west will continue to go undetected.

Parks, D.; MacDonald, A. E.; Rosen, R. D.; Edmonds, H. N.; Key, E.; Swanberg, N.; Wiseman, W. J.; Sandgathe, S. A.; Neff, J. C.; Fernandez, D.; Munson, S.; Reynolds, R. L.

2011-12-01

135

Megaliths and Neolithic astronomy in southern Egypt  

NASA Astrophysics Data System (ADS)

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.

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

1998-04-01

136

Desert dust aerosol air mass mapping in the western Sahara, using particle properties derived from space-based multi-angle imaging  

Microsoft Academic Search

ABSTRACT 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 suborbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible

Ralph Kahn; Andreas Petzold; Manfred Wendisch; Eike Bierwirth; Tilman Dinter; Michael Esselborn; Marcus Fiebig; Birgit Heese; Peter Knippertz; Detlef Müller; Alexander Schladitz; Wolfgang von Hoyningen-Huene

2009-01-01

137

Desert dust aerosol air mass mapping in the western Sahara, using particle properties derived from space-based multi-angle imaging  

Microsoft Academic Search

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 suborbital aerosol measurements into the satellite's larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol

RALPH K AHN; P ETZOLD; M A NFRED; W E NDISCH; E IKE B IERW; M ICHAEL E SSELBORN; M A RCUS; F IEBIG; PETER K NIPPERTZ; A LEXANDER

2009-01-01

138

Geography of Ancient Egypt  

NSDL National Science Digital Library

This activity focuses on the importance of geographic features and the abundance of natural resources that helped ancient Egypt become the world's first superpower. Students will learn about the geography and resources available to the ancient Egyptians. Read each question below carefully. Using the following maps: modern political map geographical features map natural resources map archaeological sites map And the following features on the Egypt's Golden Empire website: natural resources farming Answer each question below using as much detail as possible. What countries border modern-day Egypt? (modern political map) Name the major bodies of water that surround an are a part of Egypt. (modern political map) What ...

Myers, Mr.

2010-09-30

139

Dust Plume off the Coast of Egypt  

NASA Technical Reports Server (NTRS)

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.

2007-01-01

140

Food Deserts  

Microsoft Academic Search

Food deserts and accessibility represent a new frontier in the assault of life-threatening, dietrelated diseases, including diabetes, obesity, hypertension, and atherosclerosis. Scholars represent the research literature from diverse disciplines, such as anthropology, agriculture, sociology, economics, marketing, public policy, sociology, and social epidemiology. Applied sociology has not contributed to this important conversation. Applied sociology's integration and use of theory, methods, and

Anthony Troy Adams; Monika J. Ulrich; Amanda Coleman

2010-01-01

141

Discovering Deserts.  

ERIC Educational Resources Information Center

Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Discovering Deserts." Contents are organized into the following sections: (1)…

Braus, Judy, Ed.

1985-01-01

142

Debt Relief for Egypt?  

Microsoft Academic Search

The government of Egypt recently stated that external financial assistance is necessary in the present economic situation and has expressed a strong preference for receiving it in part via debt relief. Williamson and Khan explore whether there is a case for debt relief and if so what form this relief should take. They review the cases of Egypt in an

John Williamson; Mohsin S. Khan

2011-01-01

143

Nile behaviour and Upper Palaeolithic humans in Upper Egypt  

NASA Astrophysics Data System (ADS)

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

Vermeersch, Pierre M.

2014-05-01

144

Structural constraints on the evolution of the Meatiq Gneiss Dome (Egypt), East-African Orogen  

NASA Astrophysics Data System (ADS)

Amphibolite-grade quartzofeldspathic gneiss domes surrounded by greenschist-grade island arc and ophiolitic assemblages is a characteristic feature of the Arabian-Nubian Shield in the Eastern Desert of Egypt. The mode of formation of these domes, including the Meatiq Gneiss Dome, is controversial, as is the protolith age of these gneisses. Reinvestigation of selected segments of the Eastern Desert Shear Zone (EDSZ), a high-strain zone separating the eugeoclinal units from the underlying quartzofeldspathic gneisses show it to be a top-to-the NW shear zone which was later folded about a NW-SE trending fold axis (long axis of the gneiss dome). Kinematic indicators (shear bands, duplex structures, etc.) along the north-eastern and south-western flanks of the dome therefore show apparent left-lateral and right-lateral strike-slip displacement across the EDSZ. These observations are in conflict with most previous tectonic models which link formation of the dome to extension in a NW-SE oriented corridor bordered by two sub-parallel left-lateral NW-SE oriented strike-slip faults. Emplacement of upper crustal, low-grade, eugeoclinal rocks tectonically on top of middle crustal amphibolite-grade quartzofeldspathic gneisses indicates that the EDSZ may represents an extensional fault with a possible break-away zone in the southern part of the Eastern Desert. Alternatively it can be explained as the result of two (or more) tectonometamorphic events with an intervening episode of erosion and exhumation of high grade rocks prior to emplacement of the eugeoclinal thrust complex. Recent U-Pb TIMS ages on syntectonic orthogneisses and post-tectonic granites in the area show that shearing and subsequent doming must be younger than 630 Ma, possibly as young as 600 Ma.

Andresen, A.; Augland, L. E.; Boghdady, G. Y.; Lundmark, A. M.; Elnady, O. M.; Hassan, M. A.; Abu El-Rus, M. A.

2010-07-01

145

Types of Deserts  

NSDL National Science Digital Library

Deserts are classified by their location and dominant weather pattern into several types: trade wind, midlatitude, rain shadow, coastal, monsoon, or polar deserts. Former desert areas presently in nonarid environments are paleodeserts, and extraterrestrial deserts exist on other planets. This site, produced by the U.S. Geological Survey, describes each type of desert using text and photographs.

146

Desert USA: Desert Animals and Wildlife  

NSDL National Science Digital Library

This great educational website about Desert Animals and Wildlife was created by DesertUSA, a publication designed to explore and educate about "the beauty, life, and culture of North American deserts." The Desert Animals and Wildlife homepage contains extensive lists of links to sites for different Mammals, Birds and Fish, Reptiles and Amphibians, and Insects and Spiders. The animal link selections include the Mexican Gray Wolf, Desert Pupfish, Desert Iguana, and Finback Whale just to name a few. The specific animal pages include photos and information categorized in areas such as Distribution, Habitat, Description, and Life Cycle. There is a feature link to a webpage on Desert Animal Survival, a list of links to relevant DesertUSA Articles and Information, and links to websites dedicated to other DesertUSA subjects such as Plants / Wildflowers, and Peoples and Cultures.

147

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)

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.

Zoheir, Basem; Emam, Ashraf

2014-11-01

148

Bio-Climatic Analysis and Thermal Performance of Upper Egypt A Case Study Kharga Region  

E-print Network

of the oases in the westren desert of Egypt. It required the capital of the new wadi (Al Wadi Al Gadeed Government). The climate of this oasis is caricaturized by; aridity, high summer daytime temperature, large diurnal temperature variation, low relative...

Khalil, M. H.

2012-01-01

149

Desert USA: Desert Plants and Wildflowers  

NSDL National Science Digital Library

Desert plants have adapted to the extremes of heat and aridity by using both physical and behavioral mechanisms, much like desert animals. The ingenuity and variety of these many adaptations are explored in a set of links to wildflowers, cacti and succulents, trees, shrubs, and grasses. Links to related topics such as desert plant survival, wildflower articles, and others are also included.

2000-01-01

150

What Makes a Desert a Desert?  

ERIC Educational Resources Information Center

Presents background information and activities which focus on definition of a desert, locations of deserts, and factors influencing locations. Activities include objective(s), recommended age level(s), subject area(s), list of materials needed, and procedures. Two ready-to-copy pages with desert landforms and temperature/rainfall data are…

NatureScope, 1985

1985-01-01

151

Phytomonitoring the unique colonization of oil-contaminated saline environment by Limoniastrum monopetalum (L.) Boiss in Egypt.  

PubMed

A site that covers over 20 acres of coastal saline depression in the western Mediterranean coastal desert of Egypt (El-Hammra station, the main crude oil pipeline terminal in Al-Alamein) is contaminated with crude oil spill as a result of activities from refineries, oilfield blowouts, tanker and pipeline break-ups. This area, prior to contamination, was dominated by different common halophytes. However, Limoniastrum monopetalum is now the only species found growing in the oil-contaminated soil. A specific question addressed in the present study was: what are the biochemical changes occurring in a desert plant growing in oil-contaminated soils? Major metabolites such as proline, betaine, free amino acids, fatty acid esters and mineral elements were studied. The plant samples were collected from the oil-contaminated, as well as noncontaminated, sites. The higher concentration in the selected organic metabolites in the plants growing in the contaminated site compared to those in noncontaminated site may be due to differences in a number of receptors. The sensitivity of such receptors for the environmental signal that cause differences in genetic expression leads to differences in physiological processes. The change in the landscape of the contaminated area and the elimination of the natural vegetation, except L. monopetalum, may explain the competitive balance toward the oil-resistant species. PMID:12046949

Hussein, Hussein S; Terry, Norman

2002-04-01

152

Safsaf Oasis, Egypt  

NASA Technical Reports Server (NTRS)

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.

1998-01-01

153

Desert Dust Aerosol Air Mass Mapping in the Western Sahara, Using Particle Properties Derived from Space-Based Multi-Angle Imaging  

NASA Technical Reports Server (NTRS)

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 suborbital aerosol measurements into the satellite s larger regional context. On three moderately dusty days during which coincident observations were made, MISR mid-visible aerosol optical thickness (AOT) agrees with field measurements point-by-point to within 0.05 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 (1) highlight regional gradients in the mix of dust and background spherical particles, (2) identify a dust plume most likely part of a density flow and (3) show an aerosol air mass containing a higher proportion of small, spherical particles than the surroundings, that appears to be aerosol pollution transported from several thousand kilometres away.

Kahn, Ralph; Petzold, Andreas; Wendisch, Manfred; Bierwirth, Eike; Dinter, Tilman; Esselborn, Michael; Fiebig, Marcus; Heese, Birgit; Knippertz, Peter; Mueller, Detlef; Schladitz, Alexander; Von Hoyningen-Huene, Wolfgang

2008-01-01

154

Geologic and hydrologic controls on the movement of water through a thick, heterogeneous unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California  

NASA Astrophysics Data System (ADS)

A two-dimensional, axially symmetric, unsaturated flow model was developed to test hypotheses about geologic and hydrologic controls on the movement of water through the thick, heterogeneous, unsaturated zone underlying Oro Grande Wash in the Mojave Desert, California. Heterogeneity within the unsaturated zone was simulated with multiple realizations of subsurface geology estimated on the basis of transition probability/Markov chain statistics. Model results show lateral spreading of water away from the wash was best approximated by realizations that include thin, horizontally extensive clay layers that impede the downward movement of water. There was a wide range in model responses for these realizations, and the movement of water through unsaturated zones containing thin, horizontally extensive clay layers may be more difficult to predict than water movement through unsaturated zones where clay layers are less extensive. For realizations having less extensive clay layers, the range of model responses decreased with time, and model results became increasingly similar as water encountered larger volumes of material.

Izbicki, John A.

2002-03-01

155

The Politics of Educational Transfer and Policymaking in Egypt  

ERIC Educational Resources Information Center

For the past two centuries, western modern education has informed education policies and practices in Egypt. However, few researchers have analyzed the historical or current politics of educational transfer in this country. This article investigates the ways in which foreign transfer has influenced Egyptian education, both historically and…

Ibrahim, Ali S.

2010-01-01

156

MEDIA MESSAGES AND WOMEN'S BODY PERCEPTIONS IN EGYPT  

Microsoft Academic Search

This study explores the association between media exposure and women's body perceptions in Egypt. The thin ideal perpetuated through the media, eating disorders and body dissatisfaction and drive for thinness were thought to be a culturally linked phenomena confined to Western societies. This study has contributed to the debate on cultural determinism of eating disorders and body dissatisfaction in women

SHAIMA RAGAB

157

Dwarfs in ancient Egypt.  

PubMed

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

Kozma, Chahira

2006-02-15

158

Nile River Delta, Egypt  

NASA Technical Reports Server (NTRS)

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.

1984-01-01

159

Nile Delta, Egypt  

NASA Technical Reports Server (NTRS)

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.

1982-01-01

160

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

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.

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

2009-01-01

161

Desert Voices: Southwestern Children's Literature.  

ERIC Educational Resources Information Center

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)

Polette, Keith

1997-01-01

162

Desert USA: Desert Animals And Wildlife  

NSDL National Science Digital Library

It is a miracle that life can survive in the extreme conditions of the desert. Users can learn about mammals (including wolves), insects and spiders, fish and birds(including hawks), and reptiles and amphibians (including rattlesnakes) that have adapted and, in fact, thrive in the harsh desert ecosystems. Links to related topics such as animal survival in the desert and animal rescues are included.

2000-01-01

163

Feasibility study of brackish water desalination in the Egyptian deserts and rural regions using PV systems  

Microsoft Academic Search

Fresh water is the most important source for life on the earth. In the Egyptian deserts and rural areas, there is a shortage of fresh water in spite of the presence of large sources of brackish water. Solar energy is abundant in these remote areas of Egypt, where the amount of sunshine hours is around 3500 h\\/year. This paper introduces

G. E Ahmad; J Schmid

2002-01-01

164

Orphanages in Egypt  

Microsoft Academic Search

This is an ethnographic study of girls’ orphanages in Egypt. It examines cultural notions of unwanted children and explores the attitudes, perceptions and managerial practices of six orphanages in and around Cairo. The institutions are characterized by various styles of surrogate mothering, educational and administrative practices, occupational training, and the marital aspirations and attitudes of their occupants.

Jacqueline A. Gibbons

2005-01-01

165

Egypt: The Integrative Revolution.  

National Technical Information Service (NTIS)

A new political elite emerged in Egypt from the revolution of 1952. There are important differences but no great cultural cleavage between the old politicians and the military-political elite. Not only is the present political culture integrative; its exp...

L. Binder

1965-01-01

166

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

NASA Astrophysics Data System (ADS)

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.

Nicoll, Kathleen

2004-03-01

167

Proterozoic deformation of the East Saharan Craton in Southeast Libya, South Egypt and North Sudan  

NASA Astrophysics Data System (ADS)

The basement areas in Southeast Libya, South Egypt and North Sudan, west of the Nile, between Gebel Uweinat and the Bayuda Desert, are part of an approximately 1000-km-wide, complexly folded, polymetamorphic zone with a regional N-NNE-NE-ENE trend of foliation and fold axis. Since this belt extends southwestward into the area of Zalingei in the southern Darfur block (West Sudan), it is named the Northern Zalingei fold zone. Sr and Nd isotopic studies suggest that this zone is older than Pan-African and further indicate that, apart from Archean rocks in the Gebel Uweinat area, this belt is of Early-Middle Proterozoic age. An Early-Middle Proterozoic three-stage deformational and anatectic event established the present-day fold and fault geometry in the western parts of this zone in the Gebel Uweinat—Gebel Kamil area. The Pan-African tectono-thermal episode was most effective in the eastern part of the belt, near the boundary with the Nubian Shield volcano-sedimentary-ophiolite-granitoid assemblages. It caused migmatization, granite emplacement, mylonitization and large-scale wrench faulting which was related to Late Proterozoic accretionary and collisional events of the Arabian-Nubian Shield with the margin of the East Saharan Craton.

Schandelmeier, H.; Richter, A.; Harms, U.

1987-09-01

168

Egypt Service Provision Assessment Survey, 2002.  

National Technical Information Service (NTIS)

The 2002 Egypt Service Provision Assessment Survey (ESPA) was designed to collect information on the provision of reproductive health and child health services in Egypt in order to complement the information obtained through the 2000 Egypt Demographic and...

2003-01-01

169

Desert Soils Surfaces and soils in deserts  

E-print Network

, dunes and sand sheets; stabilized dunes #12;2 ARIDISOLS a. Light in color (tan, grey) b. Shallow soil carbonate) e. Low translocation rates for water, chemicals and nutrients f. Low rates of weathering and soilDesert Soils #12;Surfaces and soils in deserts differ from those found in humid environments ­ can

170

Where Deserts Form  

NSDL National Science Digital Library

Most of Earth's deserts can be found in dry areas created by global circulation patterns. The deserts of our world are not restricted by latitude, longitude, or elevation. This site, produced by the U.S. Geological Survey, uses text and pictures to describe how atmospheric circulation patterns influence the locations of deserts on Earth and possibly on other terrestrial planets as well.

171

Mental health in Egypt.  

PubMed

The concepts and management of mental health in Egypt are presented from the Pharaonic era through the Islamic Renaissance until today. Papyri from the Pharaonic period show that Soma and Psyche were not differentiated and mental disorders were described as symptoms of the heart and uterus. Although theories of causation were of a mystical nature, mental disorders were treated on a somatic basis. In the Islamic era, mental patients were neither maltreated nor tortured as a consequence of the belief that they may be possessed by a good Moslem genie. In the 14th century mental disorders was one of the four departments in Cairo's Kalawoon Hospital, a precursor of the place of psychiatry in general hospitals that was accepted in Europe six centuries later. The mental health services in Egypt today are described, and transcultural studies carried out in Egypt of the prevalence and phenomenology of anxiety, schizophrenia, depression, suicide, conversion and obsessive compulsive disorders are reviewed. The psychiatric services for children are in their infancy. Since 1983 the common and semi-accepted use of hashish has been joined by abuse by heroin and other substances. PMID:16342608

Okasha, Ahmed

2005-01-01

172

New Paleocene Sepiid Coleoids (Cephalopoda) from Egypt: Evolutionary Significance and Origin of the Sepiid 'Rostrum'  

PubMed Central

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

Kostak, Martin; Jagt, John W. M.; Speijer, Robert P.; Stassen, Peter; Steurbaut, Etienne

2013-01-01

173

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

174

What's It Like Where You Live? Desert  

NSDL National Science Digital Library

This site provides excellent background information on deserts. Large print and superb pictures make this site very appealing to younger students. Topics include: What is a Desert Like?, Types of Deserts, What causes Deserts?, Deserts of the World, Desert Plants, Desert Animals, and links to other desert sites.

2002-01-01

175

Egypt at the crossroads.  

PubMed

Egypt is the location of the 1994 International Population and Development Conference. Conditions in Egypt due to expected population growth rates are anticipated as headed for "ecological breakdown." There is loss of prime agricultural land to urban expansion and difficulties in providing employment and vital services. The fertility decline to 4 children/family is still inadequate to meet resource needs; a 2-child family norm must be adopted because the country can barely meet the needs of 90 million people. Cairo is becoming a mega-city of squatter settlements and slums. Population densities approach 140,000/sq. kilometers. The family planning (FP) program receives top political support. The contraceptive prevalence rate has risen to just over 50%, a 10% increase since 1988. Egypt is the first Muslim country to surpass the 50% mark. Credit for this accomplishment is given to public information and education campaigns to reduce family size, expansion of maternal and child health services and FP, the cooperation of Muslim clerics, and better educated women. Nongovernmental organizations have played an active role in FP. The future challenge is to improve services and outreach and keep up with demand. Attitudes in rural areas have changed, so that desiring children to help with farm work is the exception. Progress on arresting environmental destruction has not been as successful. There are still poor irrigation practices. The breadbasket the Nile River sustained no longer exists; Egypt is a net importer of food. Water shortages and water quality limit productivity. 57.2 billion cu. meters out of 58.4 billion cu. meters of freshwater available from the Nile River are used primarily for irrigation of the 17.6 million hectares of agricultural land along the river and its delta. Salts have polluted the river from fertilizers and pesticides and municipal and industrial wastes. Industrial dumping is illegal, but continues. Treatment plants are inadequate and water pipes are in need of repair. In order to meet water needs in the year 2000, irrigation water needs to be reclaimed. There is a race against time toe correct mismanagement. PMID:12344703

Hinrichsen, D

1992-01-01

176

Why Are Deserts Dry?  

NSDL National Science Digital Library

The deserts of the world today are not the deserts of the planet's past. Fossilized hippopotamus and elephant bones tell us that the Sahara, for instance, was a much moister and more hospitable environment 8,000 years ago than it is now. Each of the Earth's modern deserts are a consequence of one of the following mechanisms: air mass subsidence, rain shadows, distant moisture sources, or cold offshore temperatures at the sea's surface. This site uses text and scientific illustrations to describe how each of these mechanisms results in the occurrence of deserts.

177

The politics of educational transfer and policymaking in Egypt  

Microsoft Academic Search

For the past two centuries, western modern education has informed education policies and practices in Egypt. However, few\\u000a researchers have analyzed the historical or current politics of educational transfer in this country. This article investigates\\u000a the ways in which foreign transfer has influenced Egyptian education, both historically and currently. It concludes that current\\u000a Egyptian education is a product of inappropriately

Ali S. Ibrahim; UNESCO IBE

2010-01-01

178

Reclaiming freshwater sustainability in the Cadillac Desert.  

PubMed

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

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

2010-12-14

179

Desert Storm environmental effects  

Microsoft Academic Search

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

E. W. Kimball

1992-01-01

180

STONE PAVEMENTS IN DESERTS  

Microsoft Academic Search

Stone pavements are armored surfaces comprising intricate mosaics of coarse particles, usually only one or two stones thick, set on or in fine material. They occur widely in many unvegetated areas, and preeminently in hot deserts. Pavement studies in several deserts, and especially in Chile and California, suggest that: 1) deflation may be a relatively unimportant process of pavement formation;

RONALD U. COOKE

1970-01-01

181

Animals of the Desert.  

ERIC Educational Resources Information Center

Provides background information and student activities on how desert animals have adapted to dryness and heat, how and when animals move on the desert, and nocturnal/diurnal animals. Each activity includes objective(s), recommended age level(s), subject area(s), list of materials needed, and procedures. Ready-to-copy pages are included for a…

NatureScope, 1985

1985-01-01

182

Egypt's next steps Ahmed Zewail  

E-print Network

change in Egypt, not just cosmetic alterations. There are several reasons for the current uprising with the government. The corruption resulting from this marriage and the constant demands for bribes by officials has

Zewail, Ahmed

183

The effect of drought on four plant communities in the northern Mojave Desert  

SciTech Connect

Desert plant communities contain many perennial plant species that are well adapted to arid environments; therefore, one would intuitively believe that perennial desert species readily survive drought conditions. Abundant research on plant-soil-water relationships in North American deserts has shown that many species can maintain water uptake and growth when the soil-water potential is low. Little research, however, has focused on how prolonged drought conditions affect plant species in vegetation associations in desert ecosystems. A prolonged and widespread drought occurred in much of the western United States, including the Northern Mojave Desert, from 1987 through 1991. During this drought period vegetation characterization studies, initiated in 1990, by the US Department of Energy (DOE) at Yucca Mountain, Nevada, allowed EG and G Energy Measurements to collect data that could be used to infer how both desert vegetation associations and desert plant species reacted to a prolonged drought. This paper presents the preliminary results.

Schultz, B.W. [Desert Research Inst., Reno, NV (United States); Ostler, W.K. [EG and G Energy Measurements, Inc., Las Vegas, NV (United States)

1993-12-31

184

Deserts : geology and resources  

USGS Publications Warehouse

Approximately one-third of the Earth's land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals. Deserts stark, sometimes mysterious worlds have been portrayed as fascinating environments of adventure and exploration from narratives such as that of Lawrence of Arabia to movies such as "Dune." These arid regions are called deserts because they are dry. They may be hot, they may be cold. They may be regions of sand or vast areas of rocks and gravel peppered with occasional plants. But deserts are always dry. Deserts are natural laboratories in which to study the interactions of wind and sometimes water on the arid surfaces of planets. They contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Because deserts are dry, they are ideal places for human artifacts and fossils to be preserved. Deserts are also fragile environments. The misuse of these lands is a serious and growing problem in parts of our world.

Walker, Alta Sharon

1996-01-01

185

Desert Shield and Desert Storm Emerging Observations.  

National Technical Information Service (NTIS)

The enclosed final report is the culmination of the U.S. Army Armor Center effort to collect Desert Shield/Storm emerging observations and provide them to the Total Armor Force (TAF) and other selected agencies. The report is a compilation of a year long ...

1991-01-01

186

Demographic and Health Survey 2000: Egypt.  

National Technical Information Service (NTIS)

The 2000 Egypt Demographic and Health Survey is the latest round of a series of surveys carried out in Egypt that have provided information on fertility behavior and its determinants, particularly contraceptive use. The EDHS findings are important in moni...

A. A. Way, F. El-Zanaty

2001-01-01

187

Egypt: Security, Political, and Islamist Challenges.  

National Technical Information Service (NTIS)

This monograph approaches three issues in contemporary Egypt: failures of governance and political development, the continued strength of Islamism, and counterterrorism. Egypt is a major power and political force in the Middle East, as well as a recipient...

S. Zuhur

2007-01-01

188

Annualization of Rodent Burrow Clusters and Winterfat Decline in a Salt-Desert Community  

Microsoft Academic Search

Winterfat (Ceratoides lanata) is dominant or codomi- nant on much of the 16 million ha of salt-desert shrublands of Western North America. This species is in decline in much of the Great Basin and has been so for 20+ years at the Desert Experi- mental Range (DER), Pine Valley, UT. Previously, winterfat dominanted vegetation on rodent burrow clusters (RBCs), land-

Stanley G. Kitchen; Gary L. Jorgensen

189

What is Desert RATS?  

NASA Video Gallery

The mission manager and test coordinators for the 2011 mission explain why Desert RATS was started 14 years ago, questions being studied in this year's activities, technologies being tested and the...

190

The Desert Blooms!  

NSDL National Science Digital Library

This activity attempts to clear up the common misconception that deserts are always hot, totally dry, and uninhabitable. Learners listen to poetry and use picture books and other resources to discover that the desert is actually full of life! Learners develop group and individual poems. This activity is featured on pp.27-29 of the "One With the Earth: Native Americans and the Natural World" multidisciplinary unit of study for kindergarten through third grade.

Indianapolis, The C.

2014-04-30

191

The use of multifrequency and polarimetric SIR-C/X-SAR data in geologic studies of Bir Safsaf, Egypt  

USGS Publications Warehouse

Bir Safsaf, within the hyperarid 'core' of the Sahara in the Western Desert of Egypt, was recognized following the SIR-A and SIR-B missions in the 1980s as one of the key localities in northeast Africa, where penetration of dry sand by radar signals delineates previously unknown, sand-buried paleodrainage valleys ('radar-rivers') of middle Tertiary to Quaternary age. The Bir Safsaf area was targeted as a focal point for further research in sand penetration and geologic mapping using the multifrequency and polarimetric SIR-C/X-SAR sensors. Analysis of the SIR-C/X-SAR data from Bir Safsaf provides important new information on the roles of multiple SAR frequency and polarimetry in portraying specific types of geologic units, materials, and structures mostly hidden from view on the ground and on Landsat TM images by a relatively thin, but extensive blanket of blow sand. Basement rock units (granitoids and gneisses) and the fractures associated with them at Bir Safsaf are shown here for the first time to be clearly delineated using C- and L-band SAR images. The detectability of most geologic features is dependent primarily on radar frequency, as shown for wind erosion patterns in bedrock at X-band (3 cm wavelength), and for geologic units and sand and clay-filled fractures in weathered crystal-line basement rocks at C-band (6 cm) and L-band (24 cm). By contrast, Quaternary paleodrainage channels are detectable at all three radar frequencies owing, among other things, to an usually thin cover of blow sand. The SIR-C/X-SAR data investigated to date enable us to make specific recommendations about the utility of certain radar sensor configurations for geologic and paleoenvironmental reconnaissance in desert regions.Analysis of the shuttle imaging radar-C/X-synthetic aperture radar (SIR-C/X-SAR) data from Bir Safsaf provides important new information on the roles of multiple SAR frequency and polarimetry in portraying specific types of geologic units, materials, and structures mostly hidden from view on the ground and on Landsat images by a relatively thin, but extensive blanket of blow sand. Basement rock units and associated fractures at the Bir Safsaf are clearly delineated using C- and L-band SAR images. The detectability of most geologic features depend primarily on radar frequency. The SIR-C/X-SAR data also provide recommendations about the utility of certain radar configurations for geologic and paleoenvironmental reconnaissance in deserts.

Schaber, G.G.; McCauley, J.F.; Breed, C.S.

1997-01-01

192

Prophylaxis of traveler's diarrhea in Egypt: Results of a double blind controlled study  

Microsoft Academic Search

Summary Diarrhea represents the most frequent health problem of Western tourists visiting subtropical and tropical areas. Antibiotic prophylaxis has been suggested by some authors but may not be generally advisable because of adverse drug effects. In the present study we investigated the prophylaxis of traveler's diarrhea using a combination of tannalbuminate and ethacridin-lactate. During a 16-day cruise in Egypt, 77

R. Raedsch; I. Walter-Sack; P. R. Galle; B. Kommerell

1991-01-01

193

Geoenvironmental studies on conservation of archaeological sites at Siwa oasis, Egypt  

Microsoft Academic Search

Siwa oasis is located in the extreme western part of the Egyptian western desert. There are several archaeological sites in the oasis; the most distinct ones are Alexander the Great temple at Aghormi hill and the Gebel El Mota tomb excavations. They have suffered due to deterioration and cracks of different kinds and some parts are getting worse as rock

Hani A. M. Ibrahim; Gamal E. Kamh

2006-01-01

194

Alexandria (Al Iskandariya), Egypt  

NASA Technical Reports Server (NTRS)

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.

2002-01-01

195

EVOLUTION AFTER THE FLOOD: PHYLOGEOGRAPHY OF THE DESERT FISH  

Microsoft Academic Search

The Bonneville Basin and upper Snake River drainage of western North America underwent extensive hydrological changes during the late Pleistocene, potentially influencing the geographic distribution and evolutionary trajectories of aquatic species that occupied this region. To test this hypothesis, I reconstructed the phylogeographic history of the desert fish Utah chub (Gila atraria) by examining 16 populations that span the natural

JERALD B. JOHNSON

196

Representing Place: “Deserted Isles” and the Reproduction of Bikini Atoll  

Microsoft Academic Search

Bikini Atoll has been reshaped through time according to Western mythologies regarding “deserted” islands. Geographers have increasingly recognized that landscapes are shaped by the ways human agents conceptualize places. Ideals that shape places are not only based on interpretations of a given place, however, but are also formed by the semiotic linking of representations of similar landscapes. Conceptualizations of Bikini

Jeffrey Sasha Davis

2005-01-01

197

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)

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.

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

2013-08-01

198

Optical characteristics of desert dust as used in LOWTRAN: Mojave desert dust versus the LOWTRAN 7 dust model  

Microsoft Academic Search

As previously reported aerosol size and composition and meteorological data were collected at three sites (Tehachapi Pass and Rogers and China Lake dry lake beds) in the western Mojave Desert in the summer of 1990. Aerosol size distributions exhibit the usual accumulation and wind speed dependent dust modes. The dust mode aerosols are illite clay. Their composition is wind speed

Philip L. Walker; Larry A. Mathews

1995-01-01

199

Tectonic framework of northeast Egypt and its bearing on hydrocarbon exploration  

SciTech Connect

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.

Khalil, M. [Gulf of Suez Petroleum Company, Cairo (Egypt); Moustafa, A.R.

1995-08-01

200

Operation Desert Storm  

Microsoft Academic Search

This paper presents a description of the objectives, planning, observations, and reports of a Department of Veteran's Affairs Social Work Outreach Team's efforts to work with soldiers returning from Operation Desert Storm. The soldiers reported experiences with discrimination, low morale, sexual harassment, and fear.

Lola West; Susan O. Mercer; Edith Altheimer

1993-01-01

201

Desert Storm communications  

Microsoft Academic Search

An overview of the communication network that supported Operation Desert Storm is presented. The system, which maintained a 98% availability rate, supported 700000 telephone calls and 152000 messages per day. More than 30000 radio frequencies were managed to provide necessary connectivity and to ensure minimum interference. The roles of communications satellites, switched networks and terrestrial systems, and packet-switched networks and

J. S. Toma

1992-01-01

202

Sounds of the Desert.  

ERIC Educational Resources Information Center

Discusses the program called "Sounds of the Desert" that celebrates the Southwest indigenous culture and focuses on understanding music in relation to history and culture. Emphasizes the study of Mariachi music that is being taught alongside band, orchestra, and chorus from the third grade to senior high in many Tucson (Arizona) schools. (CMK)

McCullough-Brabson, Ellen; Achilles, Elayne; Ashcraft, Joan

1997-01-01

203

Plants of the Desert.  

ERIC Educational Resources Information Center

Provides background information and student activities on plants of the desert, including various adaptations for life with limited water supplies. Each activity includes objective(s), recommended age level(s), subject area(s), list of materials needed, and procedures. A ready-to-copy student worksheet is included. (DH)

NatureScope, 1985

1985-01-01

204

Geospatial Revolution: Food Deserts  

NSDL National Science Digital Library

Food deserts refer to a lack of easy access to nutritious food. They exist all over America as an outcome of poverty. This video from Penn State Public Broadcasting’s Geospatial Revolution shows how geospatial technology can help change this reality.

Wpsu

2010-11-11

205

Comparison of Growth and Stress in Resident Redband Trout Held in Laboratory Simulations of Montane and Desert Summer Temperature Cycles  

Microsoft Academic Search

Within their native range in western North America, resident redband trout Oncorhynchus mykiss gairdneri occupy stream habitat from high mountains to low desert. To better understand the temperature tolerance, growth, and stress physiology of native redband trout populations and compare the resilience and responses to reciprocal environments of stocks adapted to desert or montane conditions, we conducted controlled laboratory trials.

John D. Cassinelli; Christine M. Moffitt

2010-01-01

206

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

NASA Technical Reports Server (NTRS)

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.

Jacobberger, P. A.

1987-01-01

207

Namib Desert, Namibia, Africa  

NASA Technical Reports Server (NTRS)

One of the driest regions on Earth, the Namib Desert, Namibia, Africa (23.0N, 15.0E) lies adjacent to the Atlantic coast but upwelling oceanic water causes a very stable rainless atmosphere. The few local inland rivers do not reach the sea but instead appear as long indentations where rivers penetrate the dune fields and end as small dry lakes. The vast dune fields are the result of sands deposited over millions of years by the stream flow.

1990-01-01

208

Namib Desert, Namibia, Africa  

NASA Technical Reports Server (NTRS)

One of the driest regions on Earth, the Namib Desert, Namibia, Africa (23.0N, 15.0E) lies adjacent to the Atlantic coast but the upwelling oceanic water causes a very stable rainless atmosphere. The few local inland rivers do not reach the sea but instead, appear as long indentations where they penetrate the dune fields and end as small dry lakes. The vast dune fields are the result of sands deposited over millions of years by the stream flow.

1990-01-01

209

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

PubMed Central

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

Koberl, Martina; Muller, Henry; Ramadan, Elshahat M.; Berg, Gabriele

2011-01-01

210

Egypt: Modern human origins and early civilizations  

Microsoft Academic Search

Wendorf, Fred, Romuald Schild, Angela E. Close, and Associates. Egypt during the Last Interglacial: The Middle Paleolithic of Bir Tarfawi and Bir Sahara East. New York: Plenum Press, 1993. xi + 596 pp. including chapter references and index. $95.00 cloth.Trigger, Bruce G. Early Civilizations: Ancient Egypt in Context. Cairo: The American University in Cairo Press, 1993. x + 158 pp.

Robert J. Wenke

1998-01-01

211

Benchmarking performance: Environmental impact statements in Egypt  

Microsoft Academic Search

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

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

2011-01-01

212

Interdisciplinary Graduate Internship Opportunities Desert Archaeology, Inc.  

E-print Network

Interdisciplinary Graduate Internship Opportunities ARIZONA Desert Archaeology, Inc. Desert to regulatory compliance. Interested in sponsoring graduate internships William Doelle, President Desert credit by working on research projects or campaigns. The purpose of the internship program is to provide

Watkins, Joseph C.

213

Center for Desert Archaeology Archaeology Southwest  

E-print Network

Center for Desert Archaeology Archaeology Southwest Center for Desert Archaeology Archaeology Southwest Archaeology Southwest is a Quarterly Publication of the Center for Desert Archaeology Volume 22 ongoing archaeological investigation of Ancestral Pueblo community organization

Kohler, Tim A.

214

Delineation of Shallow Subsurface Structure by Azimuthal Resistivity Sounding and Joint Inversion of VES-TEM Data: Case Study near Lake Qaroun, El Fayoum, Egypt  

Microsoft Academic Search

An azimuthal resistivity survey was conducted at the transition zone between the desert area and the cultivated land near\\u000a Lake Qaroun, Egypt. This area has been affected by an east-west trending fault system as indicated from the surface geology.\\u000a Apparent resistivity values were plotted along azimuth on a polar diagram. Resistivity anomalies, for most of the AB\\/2 values\\u000a with long

Usama Massoud; Gad El Qady; Mohamed Metwaly; Fernando Santos

2009-01-01

215

Workshop on Extraterrestrial Materials from Cold and Hot Deserts  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

216

Workshop on Extraterrestrial Materials from Cold and Hot Deserts  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

217

Space Radar Image of Safsaf Oasis, Egypt  

NASA Technical Reports Server (NTRS)

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.

1994-01-01

218

Meta-analysis indicates lack of local adaptation of Schistosoma mansoni to Biomphalaria alexandrina in Egypt.  

PubMed

In Egypt, reclaiming portions of the desert using water from the Nile has resulted in large-scale invasion of Biomphalaria alexandrina in these regions. Studies exploring the local adaptation of Schistosoma mansoni to its snail host have been carried out to predict the extension of schistosomiasis to newly reclaimed areas. A meta-analysis of the relevant reports was conducted to compare the different biological characteristics of sympatric and allopatric Schistosoma mansoni and Biomphalaria alexandrina using different experimental designs. The results showed that there were no significant differences in the biological characteristics of sympatric and allopatric populations. The experimental design of some of the studies analyzed was found to affect the total cercarial production. The distance between the origin of the parasite and that of the snail did not affect any of the biological characteristics. The results showed that there is no evidence of local adaptation between Schistosoma mansoni and Biomphalaria alexandrina; however, the parasite is adapted to its intermediate host throughout the water bodies located in Egypt. The absence of local adaptation between Schistosoma mansoni and Biomphalaria alexandrina is likely of critical importance in predicting public health risks engendered by future reclaimed agriculture projects. Indeed, these results could assist in determining the appropriate balance between the development of water resource projects and schistosomiasis control in Egypt. PMID:24442240

Abou-El-Naga, Iman Fathy

2014-03-01

219

Desert Storm: air assault communications  

Microsoft Academic Search

The development of the US Army's 101st Airborne Division (Air Assault) Signal Battalion's command and control communications system from base-camp communications system into a system that provided division offensive communications which spanned more than 1000 miles and supported air assault ground and air combat offense operations in Iraq during Operations Desert Shield and Desert Storm is discussed. The forward operating

D. P. Salerno

1992-01-01

220

Rig design overcomes desert conditions  

SciTech Connect

The author describes how rig components on various sizes of rigs are unitized for ease of transport from point-to-point in desert terrain. Also discussed are maintenance and special equipment required to protect machinery from the harsh desert environment of sandstorms and high temperature.

Fowler, N.W.

1981-10-01

221

Physiological Adaptation in Desert Birds  

NSDL National Science Digital Library

This peer-reviewed article from BioScience journal is about adaptations desert birds. We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement in the wild. We argue that selection has reduced oxygen consumption at the tissue level under basal conditions for birds living in deserts. We document that total evaporative water loss--the sum of cutaneous water loss (CWL) and respiratory water loss--is reduced in desert birds, and present evidence that changes in CWL are responsible for this pattern. The diminution in CWL is attributable to changes in the lipid structure of the stratum corneum of the skin, the physical barrier to diffusion of water vapor. Finally, we show linkages between physiology and life-history attributes of larks along an aridity gradient; birds from deserts have not only a reduced rate of metabolism but also a small clutch size and slow nestling development. Hence, attributes of physiology are correlated with traits that directly affect reproductive success. Our hope is that we will prompt students to question the notion that birds do not possess physiological adaptations to the desert environment, and raise the specter of doubt about "preadaptation" in birds living in deserts.

JOSEPH B. WILLIAMS and B. IRENE TIELEMAN (;)

2005-05-01

222

Lost in the Desert!  

NSDL National Science Digital Library

Students learn about the interconnectedness of the body, with a particular focus on the skin as one of the most important homeostatic organ systems, in this case study in which the protagonist sets out on a three-hour drive across the Arizona desert to meet his fiancee in California, and never shows up. The case was designed to be used with students in a lower-level anatomy and physiology class who are interested in pursuing careers in nursing, occupational therapy, and other health related fields.

Evans, David L.

2002-01-01

223

Space Radar Image of Giza Egypt - with enlargement  

NASA Technical Reports Server (NTRS)

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.

1994-01-01

224

Geoenvironmental studies on conservation of archaeological sites at Siwa oasis, Egypt  

Microsoft Academic Search

Siwa oasis is located in the extreme western part of the Egyptian western desert. There are several archaeological sites in\\u000a the oasis; the most distinct ones are Alexander the Great temple at Aghormi hill and the Gebel El Mota tomb excavations. They\\u000a have suffered due to deterioration and cracks of different kinds and some parts are getting worse as rock

Hani A. M. Ibrahim; Gamal E. Kamh

2006-01-01

225

Faunal remains from a Middle Pleistocene lacustrine marl in Dakhleh Oasis, Egypt: palaeoenvironmental reconstructions  

Microsoft Academic Search

Vertebrates and invertebrates associated with lithic artifacts are reported from a later middle Pleistocene horizon in Dakhleh Oasis, probably dating to isotope stage 7. This represents the first middle Pleistocene fauna of this stage from a site in the Egyptian Western Desert and demonstrates the presence of extensive permanent lakes along the margin of the Libyan Escarpment. The fauna includes

C. S Churcher; M. R Kleindienst; H. P Schwarcz

1999-01-01

226

Application of geochemical parameters for classification of crude oils from Egypt into source-related types  

Microsoft Academic Search

Seven crude oils representing the different petroleum-bearing basins in the Western Desert were characterized by a variety of biomarker and nonbiomarker parameters. For comparison, one crude oil from the Gulf of Suez region has also been studied. The oils have been analyzed for geochemical biomarkers using GC and GC-MS techniques. The results reveal significant differences within the oils that suggest

M. Sh El-Gayar; A. R Mostafa; A. E Abdelfattah; A. O Barakat

2002-01-01

227

Supersymmetry without the Desert  

SciTech Connect

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){sub R} gauge fields, as well as by anomaly mediation, at a scale not far above the weak scale. We study the resulting pattern 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.

Nomura, Yasunori; Poland, David

2006-09-26

228

Space Radar Image of Nile River Delta, Egypt  

NASA Technical Reports Server (NTRS)

This spaceborne radar image shows the area just north of the city of Cairo, Egypt, where the Nile River splits into two main branches. The Rosetta Branch is the curving dark line in the center of the image and the Damietta Branch is the curving dark line in the lower right of the image. The light blue area on the right half of the image is a portion of the Nile River Delta. The thinner, straighter lines and the small network of gold lines are irrigation canals. There are more than 10,000 kilometers of canals throughout the Nile Delta. A transition zone of irrigated fields is shown in blue and yellow between the irrigated delta and the surrounding desert. The desert is the dark blue area on the left side of the image lacking the pattern of irrigated fields. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on October 4, 1994, onboardthe space shuttle Endeavour. The image is 75 kilometers by 60 kilometers (46 miles by 37 miles) and is centered at 30.2 degreesnorth latitude, 31.1 degrees 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 the ratio of C-band and L-band, horizontally transmitted and received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to PlanetEarth program.

1994-01-01

229

Livestock grazing and the desert tortoise in the Mojave Desert  

USGS Publications Warehouse

A large part of the Mojave Desert is not in pristine condition, and some current conditions can be related to past grazing-management practices. No information could be found on densities of the desert tortoise (Gopherus agassizii) or on vegetative conditions of areas that had not been grazed to allow managers a comparison of range conditions with data on tortoises. Experimental information to assess the effect of livestock grazing on tortoises is lacking, and researchers have not yet examined whether the forage that remains after grazing is sufficient to meet the nutritional needs of desert tortoises.

Oldemeyer, John L.

1994-01-01

230

Orbital and Ground-penetrating Radar Studies of Mars-analog Terrain in Egypt  

NASA Astrophysics Data System (ADS)

Several study groups have endorsed the concept of flying an imaging synthetic aperture radar (SAR) in orbit that would penetrate areas of thin surface cover revealing underlying terrain and providing additional information on surface roughness, physical properties and composition. Egypt provides many excellent terrestrial field sites to study both the processes that we expect to be revealed in a Mars SAR Mission, as well as the stratigraphic setting of past depositional environments that are similar to those seen in southern Egypt. We have used terrestrial orbital radar data for southern Egypt, comparing geologic materials and boundaries mapped in the field and with visible wavelengths (from Landsat) to those discerned via Shuttle Imaging Radar (SIR) -C, and field checking key sites to determine the depth, physical characteristics and types of geologic boundaries that contribute to the radar returns. In addition to stratigraphic mapping of the thickness and extent of near-surface units in the field, we have used ground-penetrating radar (GPR) to determine the lateral extent and depth of subsurface interfaces. In this manner, we expect to learn more about the capabilities and limitations of orbital and ground-based systems, the trade-offs between frequency, polarization and resolution in Mars-like terrain for detecting buried interfaces and structures, and more about the geologic history of southern Egypt. Several studies have concentrated on one of the areas of prominent radar-detected channels near Bir Safsaf in the southwest desert, we have concentrated on the Bir Kiseiba region, an area where the mixture of gravel spreads, buried paleochannels, and alluvium creates a setting that may mimic outflow deposit locations on Mars. While bedrock incised channels may stand out in SAR images because of a near-surface, sharp dielectric interface (such as those at Safsaf and in northern Sudan), the more complex problem of distinguishing fluvial patterns in Mars-like alluvial environments requires additional study.

Maxwell, T. A.; Grant, J. A.; Campbell, B. A.

2007-05-01

231

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)

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

Abdelaziz Ali Ismael, Abdulaziz Mohamed

232

Economics of Processing Tomatoes in Egypt.  

National Technical Information Service (NTIS)

The report in Arabic has an English summary. Consumption of processed tomato products has been rising dramatically, leading to sharply increased imports. Egypt processes only about 1 percent of its tomato production; the industry currently is not economic...

A. K. M. Ashry

1983-01-01

233

Gender and Generational Change in Egypt  

E-print Network

marriage crisis was, in addition to serving as a means through which to protest Britishmarriage crisis in Egypt at the turn of the 20 th century became an issue through which social anxiety surrounding British

Sieverding, Maia

2012-01-01

234

Developing a solar energy industry in Egypt  

E-print Network

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 ...

AbdelMessih, Sherife (Sherife Mohsen)

2009-01-01

235

The boatbuilding industry of New Kingdom Egypt  

E-print Network

freshly cut timber from Lebanon to Egypt would undoubtedly cause great damage through shrinkage and splitting due to accelerated drying; cutting in the winter when sap content is lowest certainly helps to prevent this. The best way to season... environment for several more months of drying. " These are the exact steps which Wenamun seems to have taken. A slow journey over the sea to Egypt would have guaranteed a gradual transition of temperature and humidity, while the remaining period of drying...

Monroe, Christopher Mountfort

2012-06-07

236

Boats of Egypt before the old kingdom  

E-print Network

BOATS OF EGYPT BEFORE THE OLD KINGDOM A Thesis By STEPHEN MICHAEL VINSON Submitted to the Graduate Col 1 ega of Texas AAM University in partial fulfillment of the requirements for the degree of MASTER OF ARTS August l987 Major Subject...: Anthropology BOATS OF EGYPT BEFORE THE OLD KINGDOM A Thesis By STEPHEN MICHAEL VINSON Aooroved as to style and content bv". Georg F. Bass (Chairman of Committee) Richard Steff'y (Member) Clinton A, Phillips (Member) Frederick H. Van Doorninck...

Vinson, Steve

2012-06-07

237

Evolutionary hotspots in the Mojave Desert  

USGS Publications Warehouse

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.

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

238

Suicide trends in Upper Egypt.  

PubMed

Suicide is an important problem, ranking among the top 10 causes of death for individuals in all ages in developed countries. This article is a retrospective study evaluating suicide cases in Assiut, one of the largest provinces in Egypt, from 2005 to 2009. There were 117 cases, of which involved 68 male victims (58.12%) and 49 women (41.88%). Suicide rates ranged from 0.6 to 0.8 per 100,000. Age predominance was from 20 to ?30 years. The method of suicide was different between male and female victims, as male victims tried to use more violent methods than females. The most common cause of death in men was usage of toxins and by hanging 29% and 28%, respectively, while in women was usage of toxins (70%). This study showed that suicide rates have increased since 1987, indicating a grave problem that needs to be solved. PMID:22900760

Abdel Moneim, Wafaa M; Yassa, Heba A; George, Safaa M

2012-09-01

239

Gujarat, Western India  

NASA Technical Reports Server (NTRS)

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.

2002-01-01

240

75 FR 58353 - Business Development Mission to Egypt and Morocco  

Federal Register 2010, 2011, 2012, 2013

...Egypt and the largest city in Africa. A majority of the nation's...modern business district, an airport terminal and a soccer stadium...EgyptMoroccoTM@trade.gov. Africa, Near East and South Asia Sal Tauhidi, Tel:...

2010-09-24

241

Mate desertion in the snail kite  

USGS Publications Warehouse

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.

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

1988-01-01

242

HIV infection in Egypt: a two and a half year surveillance.  

PubMed

From April 1986 to mid-October 1988, 19,767 blood samples from individuals of 27 Governorates in Egypt were screened for antibodies to HIV-1. Risk groups included: drug addicts, prostitutes, patients with sexually transmitted diseases or fever of unknown origin, blood or blood product recipients, patients with mental disorders, and contacts of HIV-infected persons. Sera from routine blood donors and foreigners were also tested. All samples which reacted repeatedly by commercial ELISAs were assessed by Western blot (DuPont) for confirmation. Results indicated that 139 (0.70%) of the sera produced repeatedly reactive results by ELISA. Sixty-nine of these were confirmed by Western blot as HIV seropositive. This constituted 0.35% of the total population tested. Only 26 (0.15%) of the Egyptians tested were positive and a total of seven sero-positive individuals were classified as having clinical AIDS. All Egyptian blood donors were negative. Data generated during this 2.5-year HIV serosurvey indicate that the prevalence of confirmed HIV infection in Egypt was exceptionally low, and suggest that HIV is not endemic in Egypt, since all 26 sero-positive Egyptians were linked to HIV exposure abroad. PMID:2325196

Constantine, N T; Sheba, M F; Watts, D M; Farid, Z; Kamal, M

1990-04-01

243

Optical characteristics of desert dust as used in LOWTRAN: Mojave desert dust versus the LOWTRAN 7 dust model  

NASA Astrophysics Data System (ADS)

As previously reported aerosol size and composition and meteorological data were collected at three sites (Tehachapi Pass and Rogers and China Lake dry lake beds) in the western Mojave Desert in the summer of 1990. Aerosol size distributions exhibit the usual accumulation and wind speed dependent dust modes. The dust mode aerosols are illite clay. Their composition is wind speed independent for speeds up to 10 m/s, i.e. there is no silicate mode. Dust mass is wind speed independent up to 7 m/s. Beyond that, dust mass is exponentially related to wind speed by m equals 0.55 exp (0.59 u). Dust mass computed from the measured size distributions also exhibits the 7 m/s threshold. These characteristics are significantly different from the dust model used in LOWTRAN7/MODTRAN (based on Sahara data) which uses a large particle silicate mode in placed of the dust mode. It needs to be determined whether the optical properties of the two dust models are different enough to warrant changing the model in LOWTRAN. Their optical properties (extinction, albedo and asymmetry factor) from 2 to 12 (mu) are compared and used in LOWTRAN 7 for a variety of geometries and wind speeds. Perhaps two desert dust models should be used, one for an old desert such as the Sahara and another one for young deserts.

Walker, Philip L.; Mathews, Larry A.

1995-06-01

244

Incidence and socioeconomic determinants of abortion in rural Upper Egypt  

Microsoft Academic Search

Because of a growing cultural and religious sensitivity and controversy over reproductive health issues, particularly abortion, this area remains relatively unexplored in Egypt. This study was conducted using a participatory approach to determine the morbidity and determinants of abortion in rural Upper Egypt. In all, 1025 women from six villages in Upper Egypt were included in the study. Information regarding

KM Yassin

2000-01-01

245

Analysis of utilization of desert habitats with dynamic simulation  

USGS Publications Warehouse

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.

Williams, B.K.

1986-01-01

246

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

Microsoft Academic Search

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,

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

2009-01-01

247

Pinacate beetle from the Mojave desert  

NSDL National Science Digital Library

The beetle's outer covering helps it survive in the harsh desert environment. These beetles also give off an unpleasant smell to deter predators. Beetles and other insects are eaten in the desert for their water and nutrient content.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2007-01-13

248

Intercalibration of GOES Imager visible channels over the Sonoran Desert  

NASA Astrophysics Data System (ADS)

Geostationary Operational Environmental Satellites (GOES) have been observing the Western Hemisphere since the late 1970s, providing valuable information for weather forecast and climate change studies. Due to the lack of an onboard calibration device for the visible channel, accurate reflectance of the visible channel data depends on vicarious calibration methods to provide postlaunch calibration coefficients to compensate for the degraded responsivity. In this study, the Sonoran Desert, which can be viewed by both GOES-East and GOES-West satellites, is used to intercalibrate the visible channels on board the three-axis stabilized GOES satellite Imagers traceable to the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6 (C6) calibration standard. It was found that when the anomalous reflectance in 2004 and 2005 are excluded, the Sonoran Desert is radiometrically, spatially, and spectrally stable at the GOES viewing geometries and thus can be considered as a pseudo-invariant calibration site to develop long-term GOES Imager visible data set. To characterize the desert target reflectance with the MODIS data, GOES observations over 1 year period are used to convert the MODIS reflectance to the GOES viewing and solar illumination geometries. The spectral band adjustment factor for each GOES Imager visible channel is generated with a set of clear-sky Hyperion measurements. A trending algorithm, which consists of a polynomial function for the description of instrument degradation performance and two sine terms for the impacts of the seasonal variations of the solar zenith angle and atmospheric components, is applied to fit the time series of prelaunch calibrated reflectance. The combined calibration uncertainty of the desert calibration method is less than 4% at the Aqua MODIS C6 calibration standard. The difference of the postlaunch calibration coefficients between the desert calibration and the current GOES visible operational calibration methods is mainly within 5%.

Yu, Fangfang; Wu, Xiangqian; Grotenhuis, Michael; Qian, Haifeng

2014-07-01

249

Space science education for postgraduate students in Minoufiyia University, Egypt  

NASA Astrophysics Data System (ADS)

In 1986 the author with his colleagues in the Physics Department, Faculty of Science, Minoufiyia University, Minoufiyia, Egypt created a new branch in the physics department, to award the M.Sc. and Ph.D. degree in Atmospheric physics. Courses in solar, solar-terrestrial, and atmospheric physics were necessary for M.Sc. and Ph.D. students, because they not studded it before in the undergraduate level. Till now, seven students obtained on M.Sc. degree, and two students obtained on Ph.D. from the Physics Department of Minoufiya University in Solar, Solar-Terrestrial, and Space Physics, and there are one Ph.D and two M.Sc. under the awarding. This current extend to other six Egyptian Universities (Cairo, Ain Shams, Helwan, Alexandria, Mansoura, and Minua), where five students obtained on Ph.D degree, and thirteen students obtained on M.Sc. in Solar, Solar-terrestrial, and Space Physics from the six universities under the supervision of the author. In April 2002 the author succeeded to obtain on the agreement of the Minoufiyia University Council by construction Space Research Center, as a first center for space research in the Egyptian Universities (20 Universities), as a part from the Desert Environment Research Institute for temporal time, then after the growth, it will be independent center. Beside the research work in space science and technology, the center have the validity to award Diploma, M.Sc and Ph.D. in space science for postgraduate students. There are different courses in space science and technology for each level of the three degrees. According to the program of the European Mediterranean Countries (TEMPS III) for developing the higher education level, the center constructed a project for developing space science and technology education in the center in collaboration with European Universities and Space Research Centers. This paper explain in detail the experience in Space Science Education in Minoufiya University, and how expand it to the other universities in Egypt.

Mosalam Shaltout, M. A.

250

In Texas, the distributions of desert mule deer (Odocoileus hemionus eremicus) and  

E-print Network

In Texas, the distributions of desert mule deer (Odocoileus hemionus eremicus) and white hemionus eremicus) and white-tailed deer (Odocoileus virginianus) in west central Texas. We captured 18-tailed deer (Odocoileus virginianus) over- lap in portions of the Trans-Pecos region, the western edge

McIntyre, Nancy E.

251

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 ...

252

Mammal and Flea Relationships in the Great Basin Desert: From H. J. Egoscue's Collections  

Microsoft Academic Search

Host-parasite association among 58 flea species parasitizing 40 mammal species in the Great Basin Desert of the western United States was investigated. Increased flea species richness was correlated with larger geographic ranges and stable locomotion of hosts. Hosts from habitats of moderately low productivity (sage and grass) and of Peromyscus maniculatus size, 10-33 g, had the highest flea species richness.

Robert L. Bossard

2006-01-01

253

Dispersal of Two Species of Trichoptera from Desert Springs: Conservation Implications for Isolated vs Connected Populations  

Microsoft Academic Search

During the Pleistocene, when the climate was wetter and cooler, aquatic habitats in the Great Basin of western North America were much more extensive and connected. As the climate warmed over the last 10?000 years, many of these habitats dried but others remained as isolated springs and inland lakes. The isolation of desert springs and lack of dispersal between populations

Marilyn J. Myers; F. A. H. Sperling; V. H. Resh

2001-01-01

254

Geographic overview: Climate, phenology, and disturbance regimes in steppe and desert communities  

Microsoft Academic Search

In midwestern steppes, precipitation peaks in summer, whereas west of the Rocky Mountains, steppes are characterized by summer drought. In western deserts, the amount of precipitation is highly variable. These different climatic regimes result in differences in prevalence of and resilience to disturbances such as herbivory, and differences in susceptibility to invasion by exotic plants and animals. The timing and

B. J. Weddell

255

Native Perennial Grass Communities of the Carson Desert of Northwestern Nevada  

Microsoft Academic Search

Ahstract-A generalized distribution of the perennial grasses in the western Great Basin reveals an inter-mixing of species of the two grass Tribes Hordeae and Agrostideae (following the nomencla­ ture of Hitchcock 1950). The dominant genera are Agropyron and Achnatherum -Hesperostipa. In the Lahontan trough of the Carson Desert, a third Tribe of grasses, Zoysieae, is represented by Hilaria jamesii. The

James A. Young; Charlie D. Clements

1999-01-01

256

Project Desert Shield-Preschool Style.  

ERIC Educational Resources Information Center

Describes Project Desert Shield, a curriculum that preschool children and teachers at a U.S. military base in Germany developed to embrace and constructively deal with the interests and concerns of the children about Operation Desert Shield/Desert Storm through dramatic play. (Author/BB)

Suskind, Diane

1993-01-01

257

Desert-Adapted Crocs Found in Africa  

NSDL National Science Digital Library

This National Geographic site details the discovery of several small communities of crocodiles living on the southern edge of Africa's Sahara in desert conditions. The desert crocodiles have apparently adapted to the changing environment in northern Africa; 8,000 to 10,000 years ago, what is now desert was probably lush savannah and grasslands.

Mayell, Hillary; News, National G.

258

Desert Dreams RSVP: sustainabilityevents@asu.edu  

E-print Network

Desert Dreams RSVP: sustainabilityevents@asu.edu Parking and directions: sustainability screening of an award-winning film, Desert Dreams. Desert Dreams showcases five seasons of life Harkins Valley Art Theater 509 S. Mill Ave Tempe, AZ 85281 7:00 p.m. showtime6:30 p.m. doors open

Zhang, Junshan

259

GEOLOGICAL NOTE Desert Pavement: An Environmental Canary?  

E-print Network

GEOLOGICAL NOTE Desert Pavement: An Environmental Canary? P K. Haft Division of Earth and Ocean 27708 Ie-mail: /wff@geo.duke_eciul ABSTRACT Ongoing ctisruption of ancient, varnished desert pavement that the pavement disturbances reported here ~ue rarc on the millcnnhll time scale of desert varnish format ion

Ahmad, Sajjad

260

Center for Desert Archaeology Archaeology Southwest  

E-print Network

Center for Desert Archaeology Archaeology Southwest Center for Desert Archaeology Archaeology Southwest Issue Editors: Jesse A. M. Ballenger and Vance T. Holliday Archaeology Southwest is a Quarterly Publication of the Center for Desert Archaeology Volume 23, Number 3 Summer 2009 TM Paleoindians

Holliday, Vance T.

261

Ancient Land Law: Mesopotamia, Egypt, Israel  

Microsoft Academic Search

This Article provides an overview of the land regimes that the peoples of Mesopotamia, Egypt, and Israel created by law and custom between 3000 B.C. and 500 B.C. One purpose of the endeavor is narrowly pedagogic. In the United States, students who enroll in courses on property law traditionally have found the history of land law treated in highly stylized

Robert C. Ellickson; Charles Di A. Thorland

1995-01-01

262

Review of parasitic zoonoses in egypt.  

PubMed

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

Youssef, Ahmed I; Uga, Shoji

2014-03-01

263

Journey to Egypt: A Board Game  

ERIC Educational Resources Information Center

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…

Selvidge, Ellen

2006-01-01

264

Women's "Justification" of Domestic Violence in Egypt  

ERIC Educational Resources Information Center

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…

Yount, Kathryn M.; Li, Li

2009-01-01

265

Numerical taxonomy of Galium (Rubiaceae) in Egypt  

Microsoft Academic Search

On the basis of fifty morphological characters, including vegetative parts, flowers, fruits, seeds, pollen grains, and anatomical structure, a systematic study of 13 taxa belonging to genus Galium (Rubiaceae) from Egypt was conducted by means of numerical analysis. Four branches and clusters were distinguished. Representatives of these groups were clustered together according to characters with high factor loading in the

Kadry N. Abdel Khalik; Monier M. Abd El-Ghani; Ahmed El Kordy

266

Censorship and Security Agents Pervade Egypt's Universities  

ERIC Educational Resources Information Center

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…

Mills, Andrew

2008-01-01

267

Desert Babies Face Harsh Childhood  

NSDL National Science Digital Library

The phenomenon is the relationships between the animals and plants that inhabit the Sonoran Desert. The video shows a wide variety of animals raising their young, feeding, sheltering and protecting them. The video includes numerous examples of interactions between living things in this environment.

268

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

SciTech Connect

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.

Aadland, R.K.; Schamel, S.

1988-08-01

269

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

PubMed Central

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

Andersen, Gidske L.; Krzywinski, Knut

2007-01-01

270

Group Structure and Female Cooperative Networks in Australia's Western Desert  

E-print Network

women maintained access to same-sex kin over the lifespan. Our results show that adult women had more same-sex kin and more closely related kin present than adult men, and they retained these links after marriage. Maternal co- residence was more prevalent for married women than for married men

Gurven, Michael

271

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

Federal Register 2010, 2011, 2012, 2013

...Significant Objects Imported for Exhibition Determinations: ``Hall of Ancient Egypt'' AGENCY...State pertaining to the exhibition ``Hall of Ancient Egypt.'' The...objects to be included in the exhibition ``Hall of Ancient Egypt,''...

2013-05-07

272

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

NASA Technical Reports Server (NTRS)

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.

Arvidson, Raymond E.

1997-01-01

273

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

E-print Network

2008 Accepted 15 April 2009 Available online xxx Keywords: Archaeobotany Domestic ovicaprines Dung, 2002). It has a slightly sloping floor of about 41 mwide and 10­20 m deep (Fig. 2). The Tree Shelter). It is a local cliff foot recession, at the southern side of the wadi bed, of about 6 m deep, 4 m wide at its

Marinova, Elena

274

Mineralogy and genesis of secondary uranium deposits, Um Ara area, south eastern desert, Egypt  

Microsoft Academic Search

Secondary U mineralisation is found in the oxidised zone pervading fractured albitised and alkali-feldspar granites emplaced at the northern boundary of Um Ara Pluton. It occurs as stains along crevices and fracture surfaces and as acicular crystals filling cavities. X-ray diffraction and SEM were used to identify secondary U minerals and the associated alteration products. Uranophane and ?-uranophane are the

Y. H. Dawood; H. H. Abd El-Naby

2001-01-01

275

Prehistoric occupation of the eastern desert, Egypt: a key to landform analysis  

SciTech Connect

Surface scatters of lithic artifacts on Quaternary faulted relict surfaces and terrace flights represent the first Prehistoric sites reported from the west bank, Gulf of Suez. These aid in analyzing the geomorphifc history of the Gulf, a Neogene rift valley. Diagnostic artifacts include Lower Palaeolithic choppers and Acheulean hand axes; Middle Palaeolithic Levallois flakes and points, denticulate scrapers, and a discoidal core; Late Palaeolithic blade and scrapers and blades; and a Neolithic tanged point, side scraper, and chipped axe. Tectonic and climatic changes are indicated by vertical distribution of Prehistoric sites. Similar artifact assemblages at different relative elevations on bedrock horsts imply laterally varying tectonic uplift rates. Large elevation differences between Middle and Late Palaeolithic-bearing alluvial terraces indicate rapid erosional landscape change. This allows tentative correlation of widely separated terrace flights and indicates the latest possible age of drainage abandonment. Considerable climatic amelioration would have been required for Prehistoric occupation of this arid region. Sites were probably situated above then-active drainages. Additionally, today's limited rainfall cannot account for the amount of erosion since Prehistoric occupation. Therefore, at least three pluvials, corresponding to the Lower, Middle, and Late Palaeolithic, are postulated; these apparently controlled both landscape development and human occupation of this marginal ecosystem. Archaeological analysis can thus be useful as a tool for semiquantitative evaluation of erosion cycles and uplift rates.

Gawarecki, S.L.; Hoffman, M.A.; Perry, S.K.

1985-01-01

276

Stratigraphy, Petrography, and Petrophysical Properties of the Subsurface Upper Cretaceous Sediments, Northwestern Desert, Egypt  

Microsoft Academic Search

In this article, 33 core samples and 160 ditch samples of Upper Cretaceous age were studied at different depths from Horus well 1. Stratigraphic, petrographic, and petrophysical studies and well log analysis are used to study and evaluate the rock units. The studied core samples are dolomite (Abu Roash formation), shaly limestone, and argillaceous sandstone (Bahariya formation). The depositional environments

I. M. Hassanien; S. I. Soliman

2010-01-01

277

Upper cretaceous ammonites of Duwi Formation in Gabal Abu Had and Wadi Hamama, Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

This paper is an attempt to clarify the paleontologic, chronostratigraphic, paleoecologic and biogeographic relations of the heteromorph and sphenodiscid ammonites. The specimens were collected from sharply defined stratigraphic horizons of the Duwi Formation in two sections exposed at G. Abu Hab and Wadi Hamama to the northeast of Qena. Two ammonite zones are recorded in the Duwi Formation: Libycoceras ismaeli (Zittel) Zone and Bostrychoceras polyplocum Zone. The ammonites of the first zone are restricted to the first lower phosphate bed and are only represented by a frequent association of the species Libycoceras ismaeli. This zone defines the base of the Duwi Formation in the area of study. The second zone in the topmost part of the formation is rich in the index species and the other heteromorph ammonites. It is represented by a bed of very hard limestone of thickness about 20 cm at top of the Duwi Formation. The maximum bulk thickness of the formation is 105 m. The stratigraphic range of the fossils of both zones assigns a Campanian age for the sediments of the Duwi Formation in the area of study. Furthermore, the Campanian-Maastrichtian boundary is fixed above the bed with Bostrychoceras polyplocum. The Libycoceras ismaeli (Zittel) is found in a stratigraphic position lower than that published before. The paleontological study of the ammonites led to the recognition of 11 species belonging to 6 genera ( Libycoceras Hyatt, Nostoceras Hyatt Solenoceras Conrad, Bostrychoceras Hyatt, Baculites Lamarck, Exiteloceras Hyatt), and representing 3 families (Sphenodiscidae, Hyatt; Nostoceratidae, Hyatt and Baculitidae Meek). Two new subspecies are described Solenocera a humei aequicostata and Exiteloceras unciforme Lewy qenaense, besides many species which are recorded for the first time in the Egyptian ammonites, they include the followings: Solenoceras cf. reesidei, S. humei densicostata, Nostoceras (Planstoceras) rehavami, Nostoceras cf. dracone and Baculites scotti. Paleoecologically, the Libycoceratids from the base of Duwi Formation lived in Late Campanian partly isolated marine basin of abnormal bottom conditions. On the other hand, the mode of life of the heteromorph ammonites collected from the topmost part of the formation was diverse.

Hamama, H. H.; Kassab, A. S.

278

Distribution of desert varnish in Arizona  

NASA Technical Reports Server (NTRS)

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.

Elvidge, Christopher D.

1989-01-01

279

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

E-print Network

. Page . . 6 . . 13 . . 27 INTRODUCTION Although the effects of overpopulation on a global scale have been fiercely debated in scientific, political, and religious circles for decades, a large amount of demographic and scientific data indicates... major change of direction took place for Egypt when Napoleon occupied Egypt in 1798 with the aim of disrupting the British trade link with India (Butt 1988:36). Although Napoleon was eventually forced out, it was not before Egypt was exposed...

Carr, Aline B.

2012-06-07

280

Desert Dust Kills Florida Fish  

NSDL National Science Digital Library

This news article details a red tide event that was spread across the Atlantic by a combination of storms in the Sahara Desert region and easterly trade winds that spread fertilized or nutrient overloaded soils to the Gulf of Mexico and Florida coastal regions. The article includes options to listen to the story via streaming audio and downloading capability. It also features colorful pictures and animations provided by NASA satellites. Related weblinks are included.

Barry, Patrick L.

2009-07-07

281

Summer Monsoon, Kalahari Desert, Africa  

NASA Technical Reports Server (NTRS)

The Kalahari Desert in southern Africa (28.0S, 26.0E) had not experienced significant rainfall for several months until the onset of the summer monsoon as illustrated by the several large thunderheads peaking above the storm clouds. The summer monsoon, with its associated thunderstorms, generally lasts from November through March and contributes almost all of the annual rainfall to this environmentally sensitive region.

1992-01-01

282

Desert Dust Kills Florida Fish  

NSDL National Science Digital Library

This news article details a red tide event that was spread across the Atlantic by a combination of storms in the Sahara Desert region and easterly trade winds that spread fertilized or nutrient overloaded soils to the Gulf of Mexico and Florida coastal regions. The article includes options to listen to the story via streaming audio and downloading capability. It also features colorful pictures and animations provided by NASA satellites. Related weblinks are included.

Barry, Patrick L.; Nasa

283

Hazard Impact And Genetic Development Of SandDunes West Of Nile Valley Egypt Egypt  

NASA Astrophysics Data System (ADS)

A SE. dune field extends west of Nile Vally (west Samalut). The dune movement and sand encroachment on the cultivated fields along the margins of the Nile flood plain represents a permanent threat to soil productivity and agricultural production in this region. In this study, the dunes has been investigated by producing geological and geomorphological maps by using Landsa ETM images for the area surrounding the dune field. Fifty sand samples had been collected from sand dunes and 5 samples were collected from substratum. Each field observation locality could be considered as a profile across the sand dune direction of movements. The sand samples are sieved and the separate samples weighed. Carrying out the collective diagrams using the computer program SITA. The granulometric indices were calculated, that is the mean grain diameter, standard deviation (measure of sorting) and skeweens Besides the sand grain features were analyzed, that is grain rounding with the use of a graniformameter, and by undertaking laboratory investigations on samples collected from various dunes. The laboratory investigations involve different granulometric parameters such as the grain rounding and frosting in the binocular microscope and morphoscopic studies. Morphoscopic studies using scanning electronic microscope (SEM) elucidate the surface process affected on sand grains. These dunes seem to have their source from a location found to the north, east and from the substratum of the dunes probably from the extensive sand and gravel deposits of Oligocene and Miocene and Quaternary age. While the sand are shiny and more rounded mat grains in the northern part of these dunes to fluvial processes. However it is not excluded that part of the sediments of the dunes are old intensively reworked aeolian sediments moving in the Western Desert during various arid phases of the Quaternary. SE movement of sands due to wind and become more markedly "aeolinized" in this direction by including less rounded and striated sand grains. They also include less clay material toward the south.

Asayed El Gammal, El; El Din El Sayed, Alaa

2010-05-01

284

Contributions of sandy lands and stony deserts to long-distance dust emission in China and Mongolia during 2000 2006  

NASA Astrophysics Data System (ADS)

More than 400 Moderate Resolution Imaging Spectroradiometer (MODIS) images of dust storm events were collected and analyzed, and individual events were tracked back to their origins. Dust tracks were determined from color composite images, brightness temperature difference (BTD) and the NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory model. The results showed that five regions (sandy lands in central Inner Mongolia and the adjacent area of Mongolia; the Gobi Desert in Xinjiang and Gansu provinces, western Inner Mongolia, and the adjacent southwestern area of Mongolia; the Gobi Desert in southern Mongolia and the adjoining area of northern Inner Mongolia; sandy lands and deserts around the middle reaches of the Yellow River; and the area rimming the Taklimakan Desert) were the main contributors to long-lived mineral dusts in northern China and Mongolia. Of these dust production areas, sandy lands and stony deserts, rather than the sandy deserts of Inner Mongolia and Mongolia, were found to be the dominant dust sources, accounting for more than 75% of regional dust emission events. Dust events in the Taklimakan Desert were often local phenomena, although they could also be transported eastward if they were uplifted high enough to escape the enclosing topographic highs. Dust sources in northwestern China are mainly alluvial fans and dry lake and river beds. Success in identifying the sources and trajectories of Asian dust storms would guide future ground-based research and steppe degradation countermeasures and help reduce the uncertainties in modern modeling of Asian dust.

Zhang, Baolin; Tsunekawa, Atsushi; Tsubo, Mitsuru

2008-02-01

285

Tick paralysis: first zoonosis record in Egypt.  

PubMed

Tick paralysis caused by the secretion of toxin with saliva while taking a blood meal is an important veterinary disease, but is rare in humans. Although it has certain geographical proclivities, it exists worldwide. Tick paralysis was demonstrated for the first time in Egypt among four children living in rural area at Giza Governorate. The clinical pictures were confused with rabies; myasthensia gravis; botulism; diphtheritic polyneuropathy encountered in rural areas. The recovery of tick infesting the four little children and negative clinical and laboratory data of all diseases denoted tick paralysis. The encountered ticks infesting their animals were Rhipicephalus sanguineus on dogs, Hyalomma dromedarii on camels and Hyalomma anatolicum excavatum and Haemaphysalis sp. on goats. The case was recognized as first record of tick paralysis in Egypt. PMID:22662597

Mosabah, Amira A Abd El-rahman; Morsy, Tosson A

2012-04-01

286

The temperature responses of soil respiration in deserts: a seven desert synthesis  

Microsoft Academic Search

The temperature response of soil respiration in deserts is not well quantified. We evaluated the response of respiration to\\u000a temperatures spanning 67°C from seven deserts across North America and Greenland. Deserts have similar respiration rates in\\u000a dry soil at 20°C, and as expected, respiration rates are greater under wet conditions, rivaling rates observed for more mesic\\u000a systems. However, deserts differ

Jessica M. Cable; Kiona Ogle; Richard W. Lucas; Travis E. Huxman; Michael E. Loik; Stanley D. Smith; David T. Tissue; Brent E. Ewers; Elise Pendall; Jeffrey M. Welker; Therese N. Charlet; Meagan Cleary; Alden Griffith; Robert S. Nowak; Matthew Rogers; Heidi Steltzer; Patrick F. Sullivan; Natasja C. van Gestel

2011-01-01

287

CFB Goose Bay and Operation “Desert Shield”  

Microsoft Academic Search

Canada committed forces to the American-led Coalition in the 1990–1991 campaign to liberate Kuwait (Operation DESERT SHIELD and Operation DESERT STORM). The Navy played an important role in the naval portion in this campaign known as Operation DESERT STORM. Canadian CF-18s provided defensive combat air patrols over the Persian Gulf region (less Kuwait and Iraq). Canadian soldiers helped guard prisoners

James R. McKay

2012-01-01

288

Teaching the Concept of Desert Ecosystem  

Microsoft Academic Search

EnglishIn order to test the possibilities of the desert as an educational resource for ecosystem study a development programme was started at the Institute for Desert Research in Israel in 1972. The objectives of the investigation were:(1) To study the structure and function of a loessial plain and rocky hill?top ecosystem in the Negev desert highlands.(2) To develop an ecology

Moshe Shachak

1979-01-01

289

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

USGS Publications Warehouse

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.

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

2011-01-01

290

Murder or Not and other Egypt Stuff  

NSDL National Science Digital Library

The students will discover information about Egypt and decide if the, boy king, Tutankhamun, was murdered or died of natural causes. The first two sites will lead the students to discover all about: *Geography *Egyptian People and their Life Styles *Death and Burial *Egyptian Mythology *Pyramids *Temples and the Pharaohs *Egyptian Writing On the third site the students will learn all about King Tut and write a persuasive essay; taking a stand on if he was murdered or not. The ...

Niebergall, Mrs.

2007-11-06

291

Sea Breezes over the Red Sea: Affect of topography and interaction with Desert Convective Boundary Layer  

NASA Astrophysics Data System (ADS)

Thermodynamic structure of sea-breeze, its interaction with coastal mountains, desert plateau and desert convective boundary layer have been investigated in the middle region of the Red Sea around 25°N, at the Western coast of Saudi Arabia. Sea and land breeze is a common meteorological phenomenon in most of the coastal regions around the world. Sea-Breeze effects the local meteorology and cause changes in wind speed, direction, cloud cover and sometimes precipitation. The occurrence of sea-breeze, its intensity and landward propagation are important for wind energy resource assessment, load forecasting for existing wind farms, air pollution, marine and aviation applications. The thermally induced mesoscale circulation of sea breeze modifies the desert Planetary Boundary Layer (PBL) by forming Convective Internal Boundary Layer (CIBL), and propagates inland as a density current. The leading edge of the denser marine air rapidly moves inland undercutting the hot and dry desert air mass. The warm air lifts up along the frontal boundary and if contains enough moisture a band of clouds is formed along the sea breeze front (SBF). This study focuses on the thermodynamic structure of sea-breeze as it propagates over coastal rocky mountain range of Al-Sarawat, east of the Red Sea coast, and the desert plateau across the mountain range. Additional effects of topographical gaps such as Tokar gap on the dynamics of sea-land breezes have also been discussed. Interaction of SBF with the desert convective boundary layer provide extra lifting that could further enhance the convective instability along the frontal boundary. This study provides a detailed analysis of the thermodynamics of interaction of the SBF and convective internal boundary layer over the desert. Observational data from a buoy and meteorological stations have been utilized while The Advanced Research WRF (ARW) modeling system has been employed in real and 2D idealized configuration.

Khan, Basit A.; Stenchikov, Georgiy; Abualnaja, Yasser

2014-05-01

292

Power and Gender in Ancient Egypt: The Case of Hatshepsut  

ERIC Educational Resources Information Center

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,…

Hilliard, Kristina; Wurtzel, Kate

2009-01-01

293

“Breaking the bureaucracy”: drug registration and neocolonial relations in Egypt  

Microsoft Academic Search

According to the Egyptian Ministry of Health, the per capita use of prescription drugs in Egypt is amongst the highest in the world. Multinational pharmaceutical companies license their proprietary products for manufacture and sale in Egypt through their Egyptian subsidiaries. A Ministry of Health Committee reviews and approves for sale all drugs marketed in the country. Aside from being an

Robert A. Rubinstein

1998-01-01

294

Tech Talk for Social Studies Teachers: Ancient Egypt.  

ERIC Educational Resources Information Center

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)

Pahl, Ronald H.

1998-01-01

295

WIND ATLAS FOR EGYPT: MEASUREMENTS, MICRO AND MESOSCALE MODELLING  

Microsoft Academic Search

The results of a comprehensive, 8-year wind resource assessment programme in Egypt are presented. The objective has been to provide reliable and accurate wind atlas data sets for evaluating the potential wind power output from large electricity-producing wind turbine installations. The regional wind climates of Egypt have been determined by two independent methods: a traditional wind atlas based on observations

Niels G. Mortensen; Jens Carsten Hansen; Jake Badger; Bo H. Jørgensen; Charlotte B. Hasager; Uwe S. Paulsen; Ole F. Hansen; Karen Enevoldsen

296

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...

297

Desert Studies May 29 -July 23, 2014  

E-print Network

speakers and specialists in desert ecology provide a broad overview of natural and human ecology through and political issues that affect the management of semi-arid lands in the West. Topics include wilderness to Edible, Medicinal & Useful Plants ­ June 7-8; Ray Vizgirdas, Ventura Fish and Wildlife Office ­ Desert

Barrash, Warren

298

US Air Force communications in Desert Storm  

Microsoft Academic Search

The US Central Command Air Forces' (USCENTAF) communications network for Operations Desert Shield and Desert Storm is described. The Central Command Air Forces network utilized 27 SatCom terminals, 27 automatic switches, and 27 terrestrial links and had the responsibility of providing air traffic services across six countries at 24 locations handling 350000 flight operations. The system complexity and air traffic

D. D. McKenzie

1992-01-01

299

Three Books for a Desert Island  

Microsoft Academic Search

Being forced to pack for a Desert Island stay definitely focuses the mind. No need for the business suit and dress shoes, but a swimsuit, sunblock, and a hat are essentials. If it’s really a desert, then the umbrella can stay home, but the portable CD player, lots of batteries, and a stack of CD’s take on new importance. (This

Tony Wasserman

2000-01-01

300

Microbiology and Moisture Uptake of Desert Soils  

Microsoft Academic Search

We have initiated an interdisciplinary study of the microbiology and water content of desert soils to better understand microbial activity in extreme arid environments. Water is the one constituent that no organism can live without; nevertheless, there are places on Earth with an annual rainfall near zero that do support microbial ecosystems. These hyperarid deserts (e.g. Atacama and the Antarctic

M. E. Kress; E. P. Bryant; S. W. Morgan; S. Rech; C. P. McKay

2005-01-01

301

Desert Gardening 101: Steps to Starting a  

E-print Network

Desert Gardening 101: Steps to Starting a Vegetable Garden Tuesday, September 27, 2011 9:00 ­ 10 Alliance Permaculture Design Course just recently. She is keenly interested in food forests, native food garden in the Southwest desert. Also, Evan from Sunizona Family Farms will offer samples of their organic

Hall, Sharon J.

302

Before you arrive... Drylands, Deserts & Desertification 2012  

E-print Network

1 Before you arrive... Drylands, Deserts & Desertification 2012 November 12-15, 2012 Sede Boqer that you can use to layer. Sde Boqer is part of the Negev desert, and will be cool in the mornings, warm on spending the weekend in any of the conference venues, please make sure to order food in advance, as almost

Prigozhin, Leonid

303

Teaching the Concept of Desert Ecosystem.  

ERIC Educational Resources Information Center

Evaluates an educational program carried out at the Institute for Desert Research in Israel, to test the possibilities of the desert as an educational resource for ecosystem study. The results of teaching a field-oriented ecology course are presented. (HM)

Shachak, Moshe

1979-01-01

304

Magnetic Analysis Techniques Applied to Desert Varnish  

NASA Technical Reports Server (NTRS)

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).

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

2003-01-01

305

Being Logical About Desert Island Reading  

Microsoft Academic Search

To begin with, I refuse to be stranded on a desert island: sand without vegetation, hot sun, and salty water are just not conducive to good thinking. So let’s get into deserted tropical island mood, which is what everyone else has been doing. First, let’s wind time back to around 1978. This is important because our bodies can do without

Alex Borgida

2002-01-01

306

Desert Amplification of Greenhouse Gas Warming  

NASA Astrophysics Data System (ADS)

Surface temperatures over the Sahara and Arabian Deserts are increasing at a rate that is 3.5 times that of the global mean. These regions have warmed by 1.4 K between 1980 and 2012. In the tropical (and global) mean, added energy incident at the surface due to increased concentrations of greenhouse gases is used partly to increase the surface temperature, and partly to evaporate water. The resulting atmospheric water vapor anomaly is effectively mixed vertically and horizontally throughout the tropics on annual time scales, and amplifies the greenhouse effect (increased longwave back radiation to the surface) everywhere, including over the deserts. But, on the desert surface, evaporative cooling is disabled and the enhanced longwave energy incident on the surface serves only to increase surface temperature. Despite the fact that this desert amplification mechanism should operate over any dry surface, the other deserts of the world are not exhibiting accelerated warming. Each of these deserts is smaller than the Sahara/Arabian Desert area, and various regional processes dominate over the desert amplification mechanism.

Cook, K. H.

2013-12-01

307

On carbon sequestration in desert ecosystems  

USGS Publications Warehouse

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.

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

2009-01-01

308

The Role of Desalination in Meeting Water Supply Demands in Western Asia  

Microsoft Academic Search

The increasing gap between the supply and demand for water in the Economic and Social Commission of Western Asia (ESCWA) member countries: Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Palestine, Qatar, Saudi Arabia, United Arab Emirates, and Yemen) can be attributed to the limited availability of surface water, mining of fossil groundwater sources, and water pollution mainly of shallow aquifers,

Mohamed J. Abdulrazzak; Mey Jurdi; Shiraz Basma

2002-01-01

309

Associations between Leaf Structure, Orientation, and Sunlight Exposure in Five Western Australian Communities  

Microsoft Academic Search

Five plant communities in Western Australia, as well as selected desert and Rocky Mountain species of the western USA, were surveyed to evaluate associations among leaf structure, orientational properties, and the sunlight exposure and precipitation characteristic of each community. Selected leaf structural features have been associated previously with photosynthetic function and included shape, thickness, the ratio of thickness to width,

William K. Smith; David T. Bell; Kelly A. Shepherd

1998-01-01

310

Optical characteristics of desert dust  

NASA Astrophysics Data System (ADS)

We have been conducting research aimed at enabling prediction of desert optical environments from meteorological and satellite observations. To this end we have been collecting aerosol size distributions, visibility and meteorological data continuously for the past year at 2 sites in the Mojave Desert of California. Optical properties of dust are calculated from these data for a great variety of meteorological conditions. The concentration of dust particles is strongly dependent on wind speed for speeds greater than a threshold (7 m/s at Edwards and 15 m/s at China Lake). For individual wind episodes there is a clear relationship between wind speed and dust mass. However, that relationship changes from event to event leading to noisy summary plots; thus, indicating that other factors, such as dust sources, also influence dust loading. The HYPACT program is used to map out the sources, concentration and flow of dust. HYPACT is a pollution transport program that uses RAMS meteorological code output for input. HYPACT can calculate concentration forward in time from an assumed emission source or backward in time from an observation site. This facilitates the location of dust sources and the calculation of dust concentrations along air streams. Once dust concentrations are known and assuming the particle size distributions are the same as at the measurement sites knowledge of IR extinction is no longer confined to just the measurement sites.

Walker, Philip L.; Blomshield, Fred

2002-08-01

311

Solar energy utilization: a key to employment generation in the Indian Thar Desert  

Microsoft Academic Search

The Western Rajasthan commonly known as the `Indian Thar Desert' is characterised by harsh climatic conditions with active dunal activities. Precipitation (150 420mm\\/yr) is far lower than evapotranspiration potentials (1500 2000mm\\/yr). Ground water is limited and often brakish and high (75 100m) water table. Solar intensity in the region varies from 5.85 to 6.44kWh\\/m2\\/day. Further, peculiarity of the region is

Harpal Singh; A. K. Singh; P. B. L. Chaurasia

2005-01-01

312

EVOLUTION AFTER THE FLOOD: PHYLOGEOGRAPHY OF THE DESERT FISH UTAH CHUB  

Microsoft Academic Search

Abstract. The Bonneville Basin and upper,Snake River drainage,of western,North America,underwent,extensive hydrological changes during the late Pleistocene, potentially influencing the geographic distribution and evolutionary trajectories of aquatic species that occupied this region. To test this hypothesis, I reconstructed the phylogeographic history of the desert fish Utah chub (Gila atraria) by examining,16 populations,that span the natural distribution of this species across the

Jerald B. Johnson

2002-01-01

313

Paleowetlands and regional climate change in the central Atacama Desert, northern Chile  

Microsoft Academic Search

Widespread, organic-rich diatomaceous deposits are evidence for formerly wetter times along the margins of the central Atacama Desert, one of the driest places on Earth today. We mapped and dated these paleowetland deposits at three presently waterless locations near Salar de Punta Negra (24.5°S) on the western slope of the Andes. Elevated groundwater levels supported phreatic discharge into wetlands during

Jay Quade; Jason A. Rech; Julio L. Betancourt; Claudio Latorre; Barbra Quade; Kate Aasen Rylander; Timothy Fisher

2008-01-01

314

Infiltration Through Desert Pavements, Mojave Desert, CA, USA  

NASA Astrophysics Data System (ADS)

Desert pavements consist of a surface layer of closely packed gravel that overlies thin, gravel-poor vesicular A (Av) soil horizon. Pavements are prominent features in arid and semi-arid environments and can be found on a variety of landforms of significantly diverse ages ranging from Holocene to Tertiary. Well-developed Av profiles form distinct and highly structured prismatic peds. These fine-grained, structured soils can exhibit drastically reduced infiltration rates, rendering some localized areas nearly impermeable and greatly impacting soil development, plant and biota diversity, and groundwater recharge. We sought to study how desert pavement development can impact the hydraulic conductivity characteristics in localized areas (order of 10s of cm). Field sites were chosen at the Mojave Natural Preserve, near Kelso Dunes, CA, USA, which has been the location of considerable prior research by the second author. The sites vary by parent material, clay and silt content, surface age, and variable degree of surface clast cover. Transects were chosen that traversed pavement surfaces of variable development (well developed to poorly developed). Hydraulic conductivity was determined with a tension infiltrometer conducted at different tensions and initial water contents (to better estimate the potential for preferential flow). Sites with dry initial conditions were first analyzed at zero tensions to promote inter-ped flow. After allowing soil peds to hydrate and expand, the tests were run again at a range of soil tensions to promote matrix flow. Differences in saturated conductivities (measured and fitted) were attributed to preferential flow around desiccated peds. Soil texture and structure were measured and described, respectively, allowing for the correlation of conductivity functions to soil surface age and physical characteristics.

Young, M. H.; McDonald, E. V.; Caldwell, T. C.; Benner, S. G.

2003-04-01

315

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

USGS Publications Warehouse

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.

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

2003-01-01

316

Effects of added Zn, Ni and Cd on desert shrubs grown in desert soil  

SciTech Connect

Desert shrubs - Ambrosia dumosa, Lycium andersonii, Larrea tridenata, and Ephedra nevadensis wre grown in a glasshouse in desert (calcarous) soil with different levels of added Zn, Ni, and Cd. The objective was to study effects of the metals on growth and yield and uptake and translocation of metals in desert plant species which are common in the Mojave Desert (areas of Nevada and southeast California). Zinc and Cd considerably decreased yields of all four species. Yields of E. nevadensis were increased by Ni at 250 and 500 mg/kg applied to desert soil. Ephedra nevadensis was more tolerant of Ni than were the other three desert shrubs. Some interactions were observed among various elements: manganese concentration was increased in shrubs by Zn. Particularly, application of Ni reduced the concentrations of Zn and Mn over the control.

Patel, P.M.; Wallace, A.; Romney, E.M.; Alexander, G.V.

1980-01-01

317

Prevalence of HIV infection and AIDS in Egypt over four years of surveillance (1986-1990).  

PubMed

Serosurveys were conducted from April 1986 to March 1990 to determine the prevalence of HIV-1 infections among Egyptians and foreigners. Sera from 29,261 high risk individuals and blood or blood product donors in Egypt, and from 10,326 foreigners were tested for HIV-1 antibodies by a recombinant HIV-1 and a recombinant combination HIV-1/HIV-2 enzyme immunoassay (EIA). Any serum found to be repeatedly reactive by EIA was tested by Western blot for confirmation of HIV-1 infection. The overall prevalence of HIV-1 infection among the Egyptians was 0.18% (54/29,261); of which 4.8% (28/582) were blood and factor VIII recipients, 0.15% (3/1961) drug addicts, 0.18% (3/1650) fever of unknown origin patients, 0.23% (6/2602) sexually transmitted disease patients, 1.9% (5/269) HIV-1 contacts, 0.07% (7/9778) international travellers, and 0.02% (2/12,070) blood/product donors. Evidence of HIV-1 infection was not demonstrated among 349 prostitutes. The prevalence of HIV-1 antibody among foreigners was 0.97% (100/10,326), who were mainly (94%) from other African countries. Among the total 54 HIV infected Egyptians, 20 developed AIDS, and at least 12 have died. Only one of the 100 infected foreigners was diagnosed with AIDS. While the number of AIDS cases has increased in Egypt over 18 months October 1988-March 1990, the overall prevalence of new HIV infections has decreased since 1988 and endemic transmission has not been documented in Egypt. PMID:8459484

Watts, D M; Constantine, N T; Sheba, M F; Kamal, M; Callahan, J D; Kilpatrick, M E

1993-04-01

318

Microphytic crusts: 'topsoil' of the desert  

USGS Publications Warehouse

Deserts throughout the world are the home of microphytic, or cryptogamic, crusts. These crusts are dominated by cyanobacteria, previously called blue-green algae, and also include lichens, mosses, green algae, microfungi and bacteria. They are critical components of desert ecosystems, significantly modifying the surfaces on which they occur. In the cold deserts of the Colorado Plateau (including parts of Utah, Arizona, Colorado, and New Mexico), these crusts are extraordinarily well-developed, and may represent 70-80% of the living ground cover.

Belnap, Jayne

1990-01-01

319

Libyan Desert Glass: New field and Fourier transform infrared data  

NASA Astrophysics Data System (ADS)

Results are presented of new geological observations and laboratory analyses on Libyan Desert Glass (LDG), a unique kind of impact glass found in Egypt, probably 28.5-29.4 million years in age. A new LDG occurrence has been discovered some 50 km southward of the main LDG occurrences in the Great Sand Sea. From Fourier transform infrared (FTIR) analysis, the molecular structure of LDG is refined and significant differences are shown between LDG specimens and other pure silica glasses (fulgurite, industrial fused quartz, and amorphous biogenic silica) that are related to differences in their structures. The slight variations observed here for the mean Si-O-Si angle between the different glasses are attributed to their thermal histories. With regard to the other glasses analyzed, the LDG infrared spectral parameters point to a higher ratio of discontinuities and defects in the tetrahedral (SiO4) network. The quantitative mineralogical constitutions of sandstones and quartzites from the LDG geological setting were analyzed by FTIR. Cretaceous sandstones have a specific composition (about 90 wt% quartz, 10% dickite), clearly different from the Paleozoic ones (about 90 wt% quartz, but ?7% kaolinite). It is shown that the reddish silts bearing the LDG are constituted mainly of microquartz enriched with dickite, whose particle size distribution is characteristic of fluvio-lacustrine deposits, probably Oligocene to Miocene in age. The target rocks, most probably quartz sand, resulted from the weathering (loss of the cementing microquartz) of the Cretaceous sandstones from the Gilf Khebir Plateau with deposition in a high-energy environment.

Fröhlich, F.; Poupeau, G.; Badou, A.; Le Bourdonnec, F. X.; Sacquin, Y.; Dubernet, S.; Bardintzeff, J. M.; Véran, M.; Smith, D. C.; Diemer, E.

2013-12-01

320

Water use, productivity and interactions among desert plants. Final report  

SciTech Connect

On the Colorado Plateau, precipitation comes either from winter storms generated in the Gulf of Alaska or from summer convection storms generated by the Arizona monsoon system. Understanding the current seasonal and regional patterns of precipitation inputs into an ecosystem has ramifications at several levels: on carbon and mineral cycling at the ecosystem level, on biodiversity at the community level, and on productivity and adaptation at the population and species levels. The interior deserts of Arizona, Nevada, and Utah represent the driest regions of western North America, resulting from a combination of rainshadow effects and either the southern limits of winter moisture input or the northern limits of summer moisture input or both. Shifts in strengths of storm-generating conditions in the Pacific and in the Gulf influence both the magnitude and seasonality of soil moisture availability and therefore constrain periods of primary productivity activity in these aridland ecosystems. One major consequence predicted by global climate change scenarios is a change in monsoonal (summer) precipitation; it will increase in some areas and decrease in others. A second is increased soil temperatures and increased interior drought associated with ocean-land temperature disequilibrium. This project focused on the influence of variations in summer moisture input on structure-function relationships within a cold desert ecosystem on the Colorado Plateau. The primary field sites were located at Stud Horse Point, Utah, located on the Utah-Arizona boundary in the Glen Canyon National Recreation Area and at the Arizona monsoon boundary region.

Ehleringer, J.R.

1996-09-01

321

Multiroute memories in desert ants  

PubMed Central

When offered a permanent food source, central Australian desert ants, Melophorus bagoti, develop individually distinct, view-based foraging routes, which they retrace with amazing accuracy during each foraging trip. Using a particular channel setup connected to an artificial feeder, we trained M. bagoti ants to either two or three inward routes that led through different parts of their maze-like foraging grounds. Here, we show that ants are able to adopt multiple habitual paths in succession and that they preserve initially acquired route memories even after they have been trained to new routes. Individual ants differ in the consistency with which they run along habitual pathways. However, those ants that follow constant paths retain their route-specific memories for at least 5 days of suspended foraging, which suggests that even multiple route memories, once acquired, are preserved over the entire lifetime of a forager. PMID:18160534

Sommer, Stefan; von Beeren, Christoph; Wehner, Rudiger

2008-01-01

322

Desert Dust and Monsoon Rain  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

323

Desert Dust Satellite Retrieval Intercomparison  

NASA Technical Reports Server (NTRS)

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.

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

324

Desert R.A.T.S. 2011  

NASA Video Gallery

Desert Research And Technology Studies (D-R.A.T.S) kicks off an exciting new year of field testing. The crew is back in action, testing communication scenarios for near-Earth asteroids, and two new...

325

Selfhood and social distance: toward a cultural understanding of psychiatric stigma in Egypt.  

PubMed

Psychiatric stigma is a concept that is often used uncritically by policy-makers to explain the underutilization of professional psychiatric services in non-Western societies. Stigma, however, is a multi-determined process manifestations and effects of which cannot be viewed separately from the larger social and cultural context. The present paper presents the results of a qualitative study of psychiatric stigma in Egypt from the perspective of lay respondents. A vignette method was used to elicit judgments of social distance and qualitative responses to stories depicting psychosis, depression, alcohol abuse and a 'possession state' from 208 respondents recruited through their places of work. The results indicated that while stigma does exist in Egypt, the form that it takes must be understood with reference to Egyptian notions of selfhood that locate behavioral disturbances in the intersubjective rather than intrapsychic realm. On the one hand, individual blame is diffused as responsibility for the illness and its cure is placed in the social, not personal (or biological) realm. On the other, behavioral disorders that threaten the social fabric of society are particularly stigmatized and often met with social rejection. PMID:15955396

Coker, Elizabeth M

2005-09-01

326

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

SciTech Connect

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.

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

2012-04-24

327

Lyme Disease Agent in Egypt. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

We here report our findings after evaluating individuals from various geographical locations in Egypt for exposure to Borrelia burgdorferi. Our initial screening of sera collected from high-risk individuals with fever or unknown origin (FUO) or meningitis...

J. N. Woody, N. T. Constantine, R. L. Haberberger, T. G. Schwan

1989-01-01

328

Post-Mubarak Egypt: The Dark Side of Islamic Utopia  

E-print Network

for the strict application of Sharia law in Egypt evidently did not deter voters. These results, along Colonel Qadhafi's ban on polygamy since that law is considered "contrary to Sharia." Other Islamists

Anat, Maril,

329

UNDP initiates MicroStart in Egypt to alleviate poverty.  

PubMed

The UN Development Program, in alliance with Egypt's Social Fund for Development, has agreed to pilot a MicroStart project under its Job Creation Programme as a means to promote income generation among the poor. This project aims to improve access in appropriating financial services offered by local organizations to the economically active poor in order to enhance their economic activities. The success to date has been limited and outreach to women is often restricted to special women-only projects, although some organizations have experimented with solidarity group lending in Egypt. In achieving a major objective of MicroStart in Egypt, it will be necessary to detect the compatibility of group lending methodologies in Egypt as well as to examine other appropriate mechanisms for increasing outreach to women. PMID:12349339

Beattie, I

1999-01-01

330

Renewable energy in Egypt: an analysis of options  

SciTech Connect

This report contains an analysis of various renewable energy options from the standpoint of Egypt's energy needs and its social and economic development. The report presents recommendations for USAID assistance in renewable energy development.

Trehan, R.K.; Connelly, J.T.; El Sawy, A.H.; Leigh, J.G.; Sharp, E.G.

1980-07-01

331

Orbital migration and the brown dwarf desert  

E-print Network

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.

Philip J. Armitage; Ian A. Bonnell

2002-10-08

332

Duration-specific marital fertility in Egypt.  

PubMed

Because of the discovery of substantial underreporting of births, deaths, marriages, and divorces in Egypt, the original report of the Committee on Population and Demography on duration-secific fertility rates of married women in Egypt was modified by using estimated calculations of these vital statistics. The original report involved the calculation of duration-specific fertility rates of married women in Egypt by first estimating the number of currently married women at each duration (by single years of duration under duration 5, and by 5-year intervals of duration up to duration 20). The calculation required data on the annual number of marriages and on the number of divorces each year, classified by duration of marriage, and estimated of the number of deaths of married persons of each sex by duration of marriage. From these data, it is possible to estimate at each date the number of marriages still intact of those that took place 0-1, 1-2, 2-3, 3-4, 4-5, 5-10, 10-15, and 15-20 years earlier. Deficits in the recorded number of marriages cause implausible variations in duration-specific fertility. It is important to discover the extent to which the recent apparent increase in birthrate is genuine, and the extent to which it is the result of improved registration. Factors causing an increase in fertility could be increase in the fraction of the population of childbearing age that is currently married; reduction in the interbirth intervals in the early years of marriage as a result of shorter average period of breastfeeding; or reduction in the practice of contraception or in the effectiveness of such practice. Duration-specific fertility rates were recalculated for 1966-79 by estimating the number of currently married women at each duration of marriage. If registered data are accurate, there was a slight increase in marital fertility after 1975 or 1976, and a large increase in 1979. The sharp rise in 1979 should not be accepted without study of registration procedures. Underregistration of births in the early 1970s was estimated at 4%. Since births are recorded by year of registration rather than year of occurrence, improved registration might include not only a more complete record of current births, but also the backlog of previously unregistered events. PMID:12266317

Coale, A J; El-atoum, S

1982-01-01

333

Female circumcision is curbed in Egypt.  

PubMed

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

Wiens, J

1996-08-01

334

Geochemical registers of Late Quaternary paleoclimatic conditions at Sonora and Chihuahua Deserts, Mexico: comparison and synthesis  

NASA Astrophysics Data System (ADS)

Sonora and Chihuahua Deserts form the southwestern and southeastern parts of North American Desert system and spread over at least 5 different states in the northern Mexico. Presently, Sonora Desert receives annual precipitation in a bi-modal distribution, whereas Chihuahua Desert receives dominant summer precipitation. Paleoclimatic registers from Mojave Desert suggest that the spatial extent and magnitude of both the summer and winter precipitation varied during the last glacial period and such fluctuations were linked to the volume of the Laurentide ice sheet, changing winter-summer insolation, North Atlantic climatic variability and ENSO dynamics. We present multi-elemental concentrations, magnetic susceptibility, organic and inorganic carbon from 750 cm long sediment core collected from paleolake San Felipe (31°N, western Sonora Desert) and 970 cm long sediment core collected from paleolake Babicora (29°N, western Chihuahua Desert) in order to understand the paleohydrological and paleoclimatic evolution in the arid region of northern Mexico. 6 AMS 14C dates constrain the San Felipe sediment core between 49 cal kyr BP and present. Similarly, 8 AMS 14C dates put the Babicora core in the age bracket between 76 cal kyr BP and present with two different hiatus at 4-8 cal kyr BP and 40-45 cal kyr BP. Due to the special geomorphology of San Felipe basin, Ti concentration was used as a proxy for pluvial discharge and to differentiate regimes of dominant summer and winter precipitation. Aeolian deposition was constrained at >48 cal kyr BP. Period of lower pluvial discharge during 14-48 cal kyr BP is related to a regime of dominant winter frontal storms. During 3-14 cal kyr BP, higher catchment erosion and transportation of REE bearing heavy minerals into the basin are possibly as a result of higher pluvial discharge related to a regime of dominant summer precipitation. In paleolake Babicora, high resolution Ti suggests higher pluvial inflow prior to 60 cal kyr BP (H 6). Gradually decreasing pluvial discharge and increasing aeolian activities occurred during 45-60 cal kyr BP (H 5 to H 6) and corresponds to a warmer Greenland and higher solar activity. High amplitude fluctuations of pluvial discharge continued since Heinrich 4 and highest abundance of ostracode valves suggest alkaline conditions during 45-30 cal kyr BP and this lake desiccated periodically in the last 12 cal kyr BP.

Roy, P.; Perez-Cruz, L. L.; Lozano-Garcia, S.

2011-12-01

335

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

NASA Technical Reports Server (NTRS)

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.

1992-01-01

336

Childhood unintentional injuries surveillance in Ismailia governorate, Egypt  

Microsoft Academic Search

ObjectiveTo determine the epidemiology and risk factors of childhood injuries in Ismailia governorate Egypt.MethodsThis is the Egyptian chapter of the Global Childhood Unintentional Injury Surveillance study, which employed quota sampling of children 0–11 years old presenting to the Emergency Department. This surveillance was conducted in the University Hospital of Suez Canal University Egypt, for selected months in 2007. Children with

H El-Sayed; A Hyder; O Zekry; D Sugerman; S Abdel-Hamid; H Abbas; P Puvanachandra

2010-01-01

337

Reproductive doe traits of the Nubian (Zaraibi) goats in Egypt  

Microsoft Academic Search

Nubian does from the hot arid climate of upper Egypt were evaluated for productive and reproductive traits under Nile Delta (lower Egypt) conditions. The mean values for age at first kidding, abortion rate, and mortality rate were 691 days, 1.4 and 26.8%, respectively. Corresponding values for litter size at birth and weaning were 2.9 and 2.3 kids, respectively, and for

I. F. M Marai; E. I Abou-Fandoud; A. H Daader; A. A Abu-Ella

2002-01-01

338

The USAID\\/Government of Egypt's Schistosomiasis Research Project (SRP)  

Microsoft Academic Search

Schistosomiasis is the major public health problem in rural Egypt, with almost six million Egyptians infected as at mid-1996. In 1983, the prevalence of schistosomiasis in rural Egypt was greater than 50%[1], but a ten-year campaign of diagnosis and treatment has reduced the prevalence and intensity of infection. Parallel to this campaign, the government of the USA has funded a

T. El Khoby; N. Galal; A. Fenwick

1998-01-01

339

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

PubMed Central

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

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

2014-01-01

340

Genetic linkage between the Yellow River, the Mu Us desert and the Chinese Loess Plateau  

NASA Astrophysics Data System (ADS)

Arid and semi arid northern China holds some of the world's most significant sand sea and loess deposits. In particular, arguably the most important late Cenozoic wind-blown dust archives on land are exposed on the Chinese Loess Plateau. The origin of this loess-forming dust and its relationship to adjacent sand seas is unclear and has been the subject of considerable debate. Polarization of opinion over the sources of loess also reflects uncertainty over its relationship to large river systems and to the sources of proximal desert sands. It is critical to resolve this in order to elucidate the origins of sand seas, to determine the activity of past dust emitting regions and to fully exploit loess climate archives. Here we combine zircon U-Pb, fission-track and double dating with heavy mineral analysis to test the role of proximal deserts and rivers in contributing dust to the Loess Plateau. We focus on the Mu Us desert to test hypotheses over its sediment sources and because previous studies have often presented contrasting interpretations over its importance as a loess source. Spatial complexity of zircon ages and heavy mineral assemblages in Mu Us sand rules out significant aeolian mixing and shows that grains originating in northern Tibet dominate in the western Mu Us, with local sources dominating in the east of the desert. The western Mu Us far-travelled grains are shown to be delivered by the Yellow River and associated systems. Crucially, the western Mu Us grains and Yellow River grains show U-Pb age distributions and heavy mineral assemblages virtually identical to those of the Quaternary loess. Thus, our results demonstrate that the Yellow River and associated systems transports large quantities of sediment from northern Tibet to the Mu Us desert and further suggest that the river contributes a significant volume of material to the Loess Plateau. This provides the first evidence of a genetic link between the Yellow River and formation of the Chinese Loess Plateau and suggests a greater role for fluvial activity in past dust and desert sand sea formation.

Stevens, T.; Carter, A.; Watson, T. P.; Vermeesch, P.; Andò, S.; Bird, A. F.; Lu, H.; Garzanti, E.; Cottam, M. A.; Sevastjanova, I.

2013-10-01

341

Math Around the World (Part 1): Egypt  

NSDL National Science Digital Library

Throughout the week, we will be studying Math in different cultures around the world incuding African, Indian, Babylonian, Mayan and others. Our first area of study will be Egypt, home to some of the greatest mathematical-based structures in the world. Any guesses to what those might be? _ _ R _ _ _ D S Today\\'s lesson will focus on several aspects of Egyptian Math. First, let\\'s learn where Math came from. After reading the information from the link below, please write down your opinion and reasoning on a separate sheet of paper. Was Mathematics Invented or Discovered? Now let\\'s read about the History of Egyptian Math: History of Egyptian Math Overview of Egyptian Math For the rest of today\\'s ...

Hoskins, Mr.

2005-11-20

342

Logistics Management Systems in Desert Shield/Desert Storm: How Well Did They Do.  

National Technical Information Service (NTIS)

Desert Shield/Desert Storm was a resounding logistical success. Record am personnel and tonnage were moved across record distances in record times. This is an effort truly worthy of praise. It is also a effort worthy of close review and analysis. This pap...

G. R. Gustafson

1992-01-01

343

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

ERIC Educational Resources Information Center

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…

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

2004-01-01

344

Pollen–vegetation–climate relationships in some desert and desert-steppe communities in northern China  

Microsoft Academic Search

In this paper, we consider the relationship between pollen assemblages, vegetation and climate in some desert and desert-steppe areas in northern China using both surface soil samples and pollen trap samples. Discriminant analysis shows that samples originating from different climatic or geographical regions can be separated reliably on the basis of pollen assemblage regardless of sample type. DCCA analysis indicates

Yuecong Li; M. Jane Bunting; Qinghai Xu; Suxue Jiang; Wei Ding; Lingyun Hun

2011-01-01

345

The rural and the rotund? A critical interpretation of food deserts and rural adolescent obesity in the Canadian context.  

PubMed

Resting on the notion that rural spaces are "food deserts," rural adolescents are increasingly regarded as a "problem population" in Western obesity narratives. Using qualitative data gleaned from interviews with 51 teenage participants from rural areas across Canada, this paper focuses on the ways in which obesity is constructed as a rural disease in the Canadian context, demonstrating in particular how discourses of food deserts and related rural obesity rely on classist imaginings of obesity as a working-class embodiment. The paper will further question the understanding of the rural as a food desert, showing the ways in which rural teens acquire fresh, healthy foods in part through an informal economy of food growing and sharing. PMID:23694820

McPhail, Deborah; Chapman, Gwen E; Beagan, Brenda L

2013-07-01

346

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

SciTech Connect

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.

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

2009-04-01

347

A population genetic approach to investigate effects of urbanization and habitat fragmentation on the Western black widow spider, Latrodectus hesperus  

E-print Network

on the Western black widow spider, Latrodectus hesperus Lindsay S. Miles,1,3 Robert Ziemba,2 J. Chadwick Johnson; Schocat et al. 2004). The Western black widow spider, Latrodectus hesperus, is an urban exploiter consistent with fragmentation, isolation, and recent colonization relative to desert black widow populations

Hall, Sharon J.

348

Leishmaniasis transmission: distribution and coarse-resolution ecology of two vectors and two parasites in Egypt  

E-print Network

: Leishmania. and L. major existed in northern and central Sinai, and in the northwest of Egypt. Suitable environments for L. major and L. tropica were identified in the northern and central Sinai, Suez Canal, central Egypt, and in narrow zones...

Samy, Abdallah Mohammed; Campbell, Lindsay P.; Peterson, A. Townsend

2014-01-01

349

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

Federal Register 2010, 2011, 2012, 2013

...Determinations: ``Egypt's Mysterious Book of the Faiyum'' SUMMARY: Notice is hereby...the exhibition ``Egypt's Mysterious Book of the Faiyum,'' imported from abroad...display of the exhibit objects at The Walters Art Museum, Baltimore, MD, from on or...

2013-07-26

350

DR. MELINDA HARTWIG A Lecture by the American Research Center in Egypt Northwest Chapter  

E-print Network

. MELINDA HARTWIG A Lecture by the American Research Center in Egypt and Civilization DR. MELINDA HARTWIG is an Associate Professor of Art History of ancient Egypt and the ancient Mediterranean basin. She received her Ph

Hochberg, Michael

351

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

Federal Register 2010, 2011, 2012, 2013

...for Exhibition Determinations: ``Ancient Egypt--Art and Magic: Treasures From the Foundation Gandur pour L'Art, Geneva...be included in the exhibition ``Ancient Egypt--Art and Magic: Treasures from the Foundation Gandur pour L'Art,...

2011-11-29

352

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

Federal Register 2010, 2011, 2012, 2013

...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 temporary exhibition within the United...

2013-04-04

353

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

354

Background-like nitrate in desert air  

NASA Astrophysics Data System (ADS)

The atmospheric nitrogen cycle is a key process driving the earth's environmental evolution. Current model studies require knowledge of NOx soil emissions from various land types, but desert emissions remain unquantified or are not addressed with high confidence. Our measurements at two observatories in Taklimakan desert during a dust episode showed an approximately stable and dust-independent nitrate in the air. Its concentration estimated from PM2.5, PM10 and TSP samples under non-dust, floating dust and dust storm conditions was 3.81 ± 1.24 ?g m-3, 2.95 ± 0.69 ?g m-3, 4.99 ± 1.71 ?g m-3, respectively, despite the more-than-one-order difference of dust loading. This concentration was much larger than that in remote marine and tropical forest air. Comprehensive investigation revealed a similar presence of nitrate in other desert air. The nitrate was hypothesized to be the consequence of the conversion of NOx released from desert soils. These results indicate a background-like nitrate and active reactions of nitrogen compounds in desert air.

Wu, Feng; Zhang, Daizhou; Cao, Junji; Zhang, Ting; An, Zhisheng

2014-02-01

355

Adaptation: A Way of Life, Plant and Animal Desert Adaptations  

NSDL National Science Digital Library

This document provides several activities that show how desert plants and animals are well-adapted to life in the desert and thrive on little moisture and high temperatures. There are extension lessons as well as a drawing activity.

2003-06-10

356

Lidar Measurements for Desert Dust Characterization: An Overview.  

National Technical Information Service (NTIS)

We provide an overview of light detection and ranging (lidar) capability for describing and characterizing desert dust. This paper summarizes lidar techniques, observations, and fallouts of desert dust lidar measurements. The main objective is to provide ...

A. Omar, A. Papayannis, D. Mueller, G. Pappalardo, L. Mona, M. Vaughan, N. Sugimoto, Z. Liu

2012-01-01

357

Third-party reproductive assistance around the Mediterranean: comparing Sunni Egypt, Catholic Italy and multisectarian Lebanon  

Microsoft Academic Search

The article examines religious and legal restrictions on third-party reproductive assistance in three Mediterranean countries: Sunni Egypt, Catholic Italy and multisectarian Lebanon. In Egypt, assisted reproduction treatments are permitted, but third parties are banned, as in the rest of the Sunni Islamic world. Italy became similar to Egypt with a 2004 law ending third-party reproductive assistance. In multisectarian Lebanon, however,

Marcia C. Inhorn; Pasquale Patrizio; Gamal I. Serour

2010-01-01

358

78 FR 23208 - Importation of Fresh Oranges and Tangerines From Egypt Into the United States  

Federal Register 2010, 2011, 2012, 2013

...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...

2013-04-18

359

Lake-desert evolution during Holocene in Ulan Buh Desert, China  

NASA Astrophysics Data System (ADS)

Ulan Buh desert locates at the northwest China with an area of ~10,000 Km2, surrounded by Yellow River (east), Langshan Mountain (north), Bayan Urals Mountain (west), and Helan Mountian (south). The desert in the north is just adjacent to the Hetao Plain, an important historical site along the boundary of Han nation and northern minorities in ancient China. Human being activity has been strong in this area since then. It has scientific significance of tracking the desert evolution process during Holocene in this area. Optical stimulated luminescence (OSL) dating was applied to a series of aeolian sand-lacustrine deposit sequences that are distributed in north part of Ulan Buh Desert. Differential GPS measurements were collected to obtain the accurate elevation of these lacustrine remains. The dating results show that these lacustrine remains have almost same deposit sequence, same elevation and same deposit age, indicating the fact that these lacustrine remains belonged to a paleolake which covered the entire northern part of Ulan Buh Desert. Aeolian activities continued from early Holocene till about 8.3ka, and the mega Ulan Buh paleolake covered northern parts of the desert from 8.3 to 7.0ka. Since then, the paleolake shrank and broke into parts after about 6.5ka ago, and the environmental driving force switched back to aeolian activities again. The formation of modern Ulan Buh Desert is found to be synchronous with the disappearance of the paleolake.

Zhao, H.; Li, G.; Chen, F.; Jin, M.

2010-12-01

360

Desert pavements and associated rock varnish in the Mojave Desert: How old can they be?  

NASA Astrophysics Data System (ADS)

Desert pavements are common features of arid landscapes and have been widely used as a relative age indicator of the geomorphic surfaces upon which they are developed. In this study I examined the patterns of pavement development as a function of elevation in the Mojave Desert as well as the causes for the gradual disappearance of pavement at high elevations. Pavement density, as measured by percentage of pebble coverage, decreases systematically with elevation gain by ˜3% per 100 m, from 95% coverage below 500 m to less than 60% at 1700 m. Plants appear to be the main agent of pavement disruption; plant density decreases as pavement density increases. Burrowing by rodents and crusting by cryptobiota also disrupt pavement development at higher elevation. During the last glacial maximum, plant communities were displaced 1000 1400 m downward in the Mojave Desert. Pavements today generally do not survive above the blackbush (Coleogyne ramossisma)-sagebrush (Artemisia tridentata) zone. Evidence from packrat middens shows that these and other plants typical of high elevations today grew as low as 300 400 m during the last glacial maximum. I suggest that during the last glacial maximum, desert pavements were confined to the lowest alluvial fans of Death Valley and adjoining low valleys. No alluvial desert pavements above ˜400 m in the region are older than the latest Pleistocene. By the same reasoning, desert varnish on desert pavements above 400 m may all be Holocene in age, except where developed on stable boulders.

Quade, Jay

2001-09-01

361

Summer and winter drought in a cold desert ecosystem (Colorado Plateau) part I: effects on soil water and plant water uptake  

Microsoft Academic Search

We investigated the effects of winter and summer drought on plants of the Colorado Plateau in western North America. This winter-cold, summer-hot desert region receives both winter and summer precipitation. Droughts were imposed for two consecutive years using rainout shelters. Here, we examine drought effects on the hydrologic interactions between plants and soil. We chose three perennial species for this

S. Schwinning; B. I. Starr; J. R. Ehleringer

2005-01-01

362

When science became Western: historiographical reflections.  

PubMed

While thinking about the notion of the "global" in the history of the history of science, this essay examines a related but equally basic concept: the idea of "Western science." Tracing its rise in the nineteenth century, it shows how it developed as much outside the Western world as within it. Ironically, while the idea itself was crucial for the disciplinary formation of the history of science, the global history behind this story has not been much attended to. Drawing on examples from nineteenth-century Egypt and China, the essay begins by looking at how international vectors of knowledge production (viz., missionaries and technocrats) created new global histories of science through the construction of novel genealogies and through a process of conceptual syncretism. Turning next to the work of early professional historians of science, it shows how Arabic and Chinese knowledge traditions were similarly reinterpreted in light of the modern sciences, now viewed as part of a diachronic and universalist teleology ending in "Western science." It concludes by arguing that examining the global emergence of the idea of Western science in this way highlights key questions pertaining to the relation of the history of science to knowledge traditions across the world and the continuing search for global histories of science. PMID:20575492

Elshakry, Marwa

2010-03-01

363

Economic analysis of critical habitat designation for the desert tortoise (Mojave population)  

USGS Publications Warehouse

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

Schamberger, Mel; MacGillvray, Timothy J.; Draper, Dirk D.

1993-01-01

364

Effects of fire on belowground biomass in Chihuahuan desert grassland  

E-print Network

Effects of fire on belowground biomass in Chihuahuan desert grassland SHAYLA A. BURNETT,1 on belowground biomass in Chihuahuan desert grassland. Ecosphere 3(11):107. http://dx.doi.org/10.1890/ES12-00248.1 Abstract. Grasslands occupy large areas in the northern Chihuahaun Desert. These grasslands, dominated

365

Role of pioneer species in revegetation of disturbed desert areas  

Microsoft Academic Search

The northern Mojave Desert, as are many deserts, is characterized in part by small fertile islands in which exist individual shrub clumps each containing two or more plants. These fertile sites promote characteristic organization of both plant and animal activity in the desert. Destruction of these fertile sites make revegetation extremely difficult because most seedlings germinate in these sites. Some

A. Wallace; E. M. Romney

1980-01-01

366

Critical Zones in Desert Fog: Aids to Multiscale Navigation  

E-print Network

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

Furnas, George W.

367

Geophysical Investigations of the Smoke Creek Desert and their Geologic Implications, Northwest Nevada and Northeast California  

USGS Publications Warehouse

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.

Ponce, David A.; Glen, Jonathan M.G.; Tilden, Janet E.

2006-01-01

368

A Reservoir of Nitrate Beneath Desert Soils  

USGS Publications Warehouse

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.

Walvoord, M.A.; Phillips, F.M.; Stonestrom, D.A.; Evans, R.D.; Hartsough, P.C.; Newman, B.D.; Striegl, R.G.

2003-01-01

369

Safe transport of radioactive materials in Egypt  

NASA Astrophysics Data System (ADS)

In Egypt the national regulations for safe transport of radioactive materials (RAM) are based on the International Atomic Energy Agency (IAEA) regulations. In addition, regulations for the safe transport of these materials through the Suez Canal (SC) were laid down by the Egyptian Atomic Energy Authority (EAEA) and the Suez Canal Authority (SCA). They are continuously updated to meet the increased knowledge and the gained experience. The technical and protective measures taken during transport of RAM through SC are mentioned. Assessment of the impact of transporting radioactive materials through the Suez Canal using the INTERTRAN computer code was carried out in cooperation with IAEA. The transported activities and empty containers, the number of vessels carrying RAM through the canal from 1963 to 1991 and their nationalities are also discussed. The protective measures are mentioned.A review of the present situation of the radioactive wastes storage facilities at the Atomic Energy site at Inshas is given along with the regulation for safe transportation and disposal of radioactive wastes

El-Shinawy, Rifaat M. K.

1994-07-01

370

Controls on sediment production in two U.S. deserts  

USGS Publications Warehouse

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.

Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

2014-01-01

371

An analysis of Saharan desert dust over Mediterranean Basin  

NASA Astrophysics Data System (ADS)

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.

Guarnieri, F.; Calastrini, F.; Busillo, C.; Pasqui, M.; Capecchi, V.

2012-04-01

372

Controls on sediment production in two U.S. deserts  

NASA Astrophysics Data System (ADS)

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.

Belnap, Jayne; Walker, Beau J.; Munson, Seth M.; Gill, Richard A.

2014-09-01

373

Density currents as a desert dust mobilization mechanism  

NASA Astrophysics Data System (ADS)

The formation and propagation of density currents are well studied processes in fluid dynamics with many applications to other science fields. In the atmosphere, density currents are usually meso-?/? mechanisms and are often associated with storm downdrafts. These storms are responsible for the formation of severe dust episodes (haboobs) over desert areas. In the present study, the formation of a convective cool pool and the associated dust mobilization is examined for a representative event over the western part of Sahara desert. The physical processes involved in the mobilization of dust are described in the framework of the integrated atmospheric-air quality RAMS/ICLAMS model. Dust is effectively produced due to the development of near surface vortices and increased turbulence mixing along the frontal line. Increased dust emissions and recirculation of the elevated particles inside the density current head result in the formation of a moving "dust wall". Transport of the uplifted dust in higher layers - outside of the density current - occurs mainly in three ways: (1) uplifting of preexisting dust over the frontal line with the aid of the strong updraft (2) entrainment at the upper part of the density current head due to turbulent mixing (3) vertical mixing after the dilution of the system. The role of the produced dust in the associated convective cloud system was found to be limited. Proper representation of convective processes and dust fluxes requires the use of high resolution (cloud resolving) model configuration and online parameterization of dust production. Haboob-type of dust storms are effective dust sources and should be treated accordingly in dust modeling applications.

Solomos, S.; Kallos, G.; Mavromatidis, E.; Kushta, J.

2012-08-01

374

Density currents as a desert dust mobilization mechanism  

NASA Astrophysics Data System (ADS)

The formation and propagation of density currents are well studied processes in fluid dynamics with many applications in other science fields. In the atmosphere, density currents are usually meso-?/? phenomena and are often associated with storm downdrafts. These storms are responsible for the formation of severe dust episodes (haboobs) over desert areas. In the present study, the formation of a convective cool pool and the associated dust mobilization are examined for a representative event over the western part of Sahara desert. The physical processes involved in the mobilization of dust are described with the use of the integrated atmospheric-air quality RAMS/ICLAMS model. Dust is effectively produced due to the development of near surface vortices and increased turbulent mixing along the frontal line. Increased dust emissions and recirculation of the elevated particles inside the head of the density current result in the formation of a moving "dust wall". Transport of the dust particles in higher layers - outside of the density current - occurs mainly in three ways: (1) Uplifting of preexisting dust over the frontal line with the aid of the strong updraft (2) Entrainment at the upper part of the density current head due to turbulent mixing (3) Vertical mixing after the dilution of the system. The role of the dust in the associated convective cloud system was found to be limited. Proper representation of convective processes and dust mobilization requires the use of high resolution (cloud resolving) model configuration and online parameterization of dust production. Haboob-type dust storms are effective dust sources and should be treated accordingly in dust modeling applications.

Solomos, S.; Kallos, G.; Mavromatidis, E.; Kushta, J.

2012-11-01

375

Summer and winter drought in a cold desert ecosystem (Colorado Plateau) part II: effects on plant carbon assimilation and growth  

Microsoft Academic Search

We investigated the effects of winter and summer drought on a shrub\\/grass community of the Colorado Plateau in western North America, a winter-cold, summer-hot desert that receives both winter and summer precipitation. Summer, winter and yearlong drought treatments were imposed for 2 consecutive years using rainout shelters. We chose three perennial species for this study, representing different rooting patterns and

S. Schwinning; B. I. Starr; J. R. Ehleringer

2005-01-01

376

Geology and petroleum prospectivity of Officer basin, Western Australia  

Microsoft Academic Search

The Officer basin is a large 390,000 km² (150,579 mi²) intracratonic basin underlying the Gibson and Great Victoria Deserts in Western Australia and adjoining parts of South Australia. It contains a sedimentary sequence, up to 6 km (19,685 ft) thick, composed predominantly of upper Proterozoic beds. The stratigraphy of the Proterozoic sequence is poorly known, but it appears to be

D. M. Brown; J. Karajas

1983-01-01

377

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

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.

Martin, B.A.; Saiki, M.K.

2009-01-01

378

Children Living through a Desert Storm.  

ERIC Educational Resources Information Center

This paper reports a small naturalistic study of how affluent American children (mostly aged 11 and 12) reacted to Operation Desert Storm as depicted on television. Interviews indicated the war had a deep impact on many children, with children empathizing with the wounded but proud of being Americans and resenting the invasion of injured people's…

Rosenfeld, Alvin A.

1993-01-01

379

Fog deposition to the Atacama desert  

Microsoft Academic Search

In the Atacama Desert, one of the driest places on earth, fog deposition plays an important role for the water balance and for the survival of vulnerable ecosystems. The eddy covariance method, previously applied for the quantification of fog deposition to forests in various parts of the world, was used for the first time to measure deposition of fog water

A. Westbeld; O. Klemm; F. Griessbaum; E. Sträter; H. Larrain; P. Osses; P. Cereceda

2010-01-01

380

Digital Expansion of the Desert Fireball Network  

NASA Astrophysics Data System (ADS)

The Desert Fireball Network is being upgraded with high resolution digital observatories, and an automated data pipeline. The network stands at 15 fully automated stations. By end-August 2014 it will have grown to 35 covering ~1.3 million km2.

Bland, P. A.; Towner, M. C.; Paxman, J. P.; Howie, R. M.; Sansom, E. K.; Cupak, M.; Benedix, G. K.; Tingay, S. J.; Harrison, J. A.; Dyl, K. A.; Bevan, A. W. R.; Galloway, M. J.

2014-09-01

381

National Aeronautics and Space Administration Desert RATS  

E-print Network

.nasa.gov/exploration/analogs. #12;2011 History The first Desert RATS mission was held in 1997 with four people who believed NASA surfaces. Now more than 100 people from nine NASA centers, multiple universities, industry and geologists living in the Space Exploration Vehicle for weeks at a time, robots scouting out locations

382

Desert Culture Area. Native American Curriculum Series.  

ERIC Educational Resources Information Center

One in a series of Native American instructional materials, this booklet introduces elementary students to the history and culture of the Navajo, Pueblo, and other Indian tribes of the southwest desert. Written in simple language, the booklet provides background information, activities, legends, and illustrations. Topics include the climate of the…

Ross, Cathy; Fernandes, Roger

383

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...

384

Desert pavement study at Amboy, California  

NASA Technical Reports Server (NTRS)

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.

Williams, S.; Greeley, R.

1984-01-01

385

BEST MANAGEMENT PRACTICES & GUIDANCE MANUAL: DESERT  

E-print Network

Scott Flint Environmental Program Manager ECOSYSTEM CONSERVATION DIVISION Kevin Hunting Deputy Director, California Department of Fish and Game, U.S. Bureau of Land Management, and U.S. Fish and Wildlife ServiceCALIFORNIA ENERGY COMMISSION BEST MANAGEMENT PRACTICES & GUIDANCE MANUAL: DESERT RENEWABLE ENERGY

386

STONE PAVEMENTS IN DESERTS! RONALD U. COOKE  

E-print Network

STONE PAVEMENTS IN DESERTS! RONALD U. COOKE ABSTRACT. Stone pavenlents are armored surfaces compnsing intricate mosaics of coarse particles, usually only one or two stones thick, set on or in fine processes, nlay vary greatly from place to place. STONE pavements are defined as armored surfaces comprising

Ahmad, Sajjad

387

Landscape Sustainability in a Sonoran Desert City  

Microsoft Academic Search

The objective of this paper is to discuss concepts of landscape sustainability in the Phoenix metropolitan area. Phoenix is situated in the greater Salt River Valley of the lower Sonoran Desert in the southwest United States. In this paper I use the ecological frameworks of ecosystem services and resiliency as a metric for understanding landscape sustainability. An assessment of landscape

Chris A. Martin

2008-01-01

388

SPOT multitemporal calibration over stable desert areas  

Microsoft Academic Search

SPOT absolute and multitemporal calibration is achieved using the on-board lamp plus regular checks over White Sands or other test sites which radiance is derived from ground measurements during the satellite overpass. In order to develop another independent method to monitor the long term evolution of the cameras sensitivity, systematic acquisitions of stable desert areas have been decided. The choice

Patrice J. Henry; Magdeleine C. Dinguirard; Madeleine Bodilis

1993-01-01

389

Hydrotaxis of Cyanobacteria in Desert Crusts  

Microsoft Academic Search

We studied the migration of cyanobacteria in desert crusts from Las Bárdenas Reales (Spain). The crusts were almost exclusively colonized by the filamentous cyanobacterium Oscillatoria, which formed a dense layer approximately 600 µm thick located between 1.5 and 2.1 mm deep. Laboratory and field experiments showed that saturation of the crust with liquid water induced a migration of the cyanobacteria

O. Pringault; F. Garcia-Pichel

2004-01-01

390

Ground surface features of the Taklimakan Desert  

Microsoft Academic Search

In an attempt to utilize satellite data to obtain land surface features of Taklimakan Desert in China, in situ measurements of spectral reflectance of the land surface is made the portable spectro radiometer in the spectral range of 400 ? 2500 nm. The analyses of the data show following features. (1) The difference in spectral reflectance of different soils is

T. Ishiyama; K. Tsuchiya; S. Sugihara

1996-01-01

391

Desert Research and Technology Studies 2008 Report  

NASA Technical Reports Server (NTRS)

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.

Romig, Barbara; Kosmo, Joseph; Gernhardt, Michael; Abercromby, Andrew

2009-01-01

392

Belowground productivity of two cool desert communities  

Microsoft Academic Search

A new technique based upon the dilution of C14\\/C12 ratios in structural carbon of root systems during the course of the growing season was used to evaluate belowground turnover or productivity of two cool desert communities in northern Utah, USA. This technique provides a measure of turnover of the root system of established perennial plant communities avoiding many of the

M. M. Caldwell; L. B. Camp

1974-01-01

393

Vegeta&on in Desert Discharge area  

E-print Network

Vegeta&on in Desert Discharge area #12;Regional Flow System of the High Plains Aquifer #12;High Plains Aquifer #12;Characteris&cs of the high plains aquifer · Also known as the Ogallala aquifer · A water table aquifer · Nearsurface sand and gravel deposits are formed as alluvium deposited

Pan, Feifei

394

Endolithic microbial life in hot and cold deserts  

NASA Technical Reports Server (NTRS)

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.

Friedmann, E. I.

1980-01-01

395

Seismic hazard assessment in Aswan, Egypt  

NASA Astrophysics Data System (ADS)

The study of earthquake activity and seismic hazard assessment around Aswan is very important due to the proximity of the Aswan High Dam. The Aswan High Dam is based on hard Precambrian bedrock and is considered to be the most important project in Egypt from the social, agricultural and electrical energy production points of view. The seismotectonic settings around Aswan strongly suggest that medium to large earthquakes are possible, particularly along the Kalabsha, Seiyal and Khor El-Ramla faults. The seismic hazard for Aswan is calculated utilizing the probabilistic approach 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 eight ground motion spectral periods and for a return period of 475 years, which is deemed appropriate for structural design standards in the Egyptian building codes. The results were also displayed in terms of uniform hazard spectra for rock sites at the Aswan High Dam for return periods of 475 and 2475 years. In addition, the ground-motion levels are also deaggregated at the dam site, in order to provide insight into which events are the most important for hazard estimation. The peak ground acceleration ranges between 36 and 152 cm s-2 for return periods of 475 years (equivalent to 90% probability of non-exceedance in 50 years). Spectral hazard values clearly indicate that compared with countries of high seismic risk, the seismicity in the Aswan region can be described as low at most sites to moderate in the area between the Kalabsha and Seyial faults.

Deif, A.; Hamed, H.; Ibrahim, H. A.; Abou Elenean, K.; El-Amin, E.

2011-12-01

396

Attitudes towards women who work in Egypt  

Microsoft Academic Search

This study investigates Egyptian society’s attitudes towards women who work held by a sample of 217 participants. The subjects completed the newly developed multidimensional aversion to women who work scale (MAWWWS). The study validates the scale in a non-western context. The results reveal that, contrary to our expectation, Egyptian students have very similar attitudes towards women who work to those

Mohamed M. Mostafa

2003-01-01

397

Estimating wildfire risk on a Mojave Desert landscape using remote sensing and field sampling  

USGS Publications Warehouse

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.

Van Linn, Peter F., III; Nussear, Kenneth E.; Esque, Todd C.; DeFalco, Lesley A.; Inman, Richard D.; Abella, Scott R.

2013-01-01

398

Grain-size study of aeolian sediments found east of Kumtagh Desert  

NASA Astrophysics Data System (ADS)

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.

Liu, Benli; Qu, Jianjun; Ning, Duihu; Gao, Yanhong; Zu, Ruiping; An, Zhishan

2014-06-01

399

Species and community response to above normal precipitation following prolonged drought in the northern Mojave Desert  

SciTech Connect

Little information is available on how desert plant communities that are dominated by perennial species respond to normal and above normal precipitation following prolonged drought. Intuitively, one would expect total canopy cover to increase. Whether a concomitant increase in the density of perennial species also occurs is unknown. Even less is known about how individual species respond to above normal precipitation following drought. From 1987 through 1991 a prolonged drought occurred in much of the western United States, including the northern Mojave Desert. In March 1991 the northern Mojave Desert received well above normal precipitation. The following two winters (December--March) also had above normal precipitation (150 to 200 % of normal, unpublished data). Ongoing vegetation characterization studies by the US Department of Energy (DOE) at Yucca Mountain, Nevada, allowed EG&G Energy Measurements to collect data that could be used to infer how both vegetation associations and individual species respond to above normal precipitation following prolonged drought. This paper reports the preliminary results.

Schultz, B.W. [Nevada Univ., Reno, NV (United States). Desert Research Inst.; Ostler, W.K. [EG and G Energy Measurements, Inc., Las Vegas, NV (United States)

1993-12-31

400

Burrow Occupancy Patterns of the Western Burrowing Owl in Southern Nevada  

Microsoft Academic Search

Understanding long-term patterns of burrow occupancy for the Western Burrowing Owl (Athene cunicularia hypugaea) is necessary for the conservation of this species, especially in arid, desert ecosystems where burrow occupancy data are lacking. Monthly burrow monitoring was conducted over a 4-year period (19972001) in southern Nevada to determine burrow occupancy patterns of Burrowing Owls and to evaluate the effects of

Derek B. Hall Paul D. Greger

2009-01-01

401

Tackling Poverty-Migration Linkages: Evidence from Ghana and Egypt  

ERIC Educational Resources Information Center

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…

Sabates-Wheeler, Rachel; Sabates, Ricardo; Castaldo, Adriana

2008-01-01

402

An epizootic of equine influenza in Upper Egypt in 2000  

Microsoft Academic Search

Summary This study describes an epizootic of respiratory tract disease caused by influenza virus infection in a large population of equines in Luxor and Aswan, Upper Egypt, during the winter of 2000. The epizootic started in January and the infection rate reached its peak in February before gradually decreasing until the end of April, 2000. Horses, donkeys and mules of

Abd El-Rahim; M. Hussein; Nadi El-Sayed

2004-01-01

403

The development of Islamic finance: Egypt as a case study  

Microsoft Academic Search

Purpose – The purpose of this paper is to analyze the political and economic dilemma that Islamic finance (IF) poses on some Muslim Governments of either encouraging or restraining this global phenomenon; in spite of their awareness of the developmental role that IF plays. Egypt, in this concern represents a peculiar example where government's policies apparently determine the performance of

Sherin Galal Abdullah Mouawad

2009-01-01

404

Self-Help Housing in Egypt: A Student Design Competition.  

National Technical Information Service (NTIS)

Urban Egypt's need for housing is among the most pressing in the Third World, with annual urban growth estimated at 4% and with 1,000 new migrants appearing daily in Cairo. Existing housing is substandard, overcrowded, and lacking in water and sanitary fa...

O. Akin

1980-01-01

405

Published: 23 June 2011 Another Revolution Afoot in Egypt  

E-print Network

. The youth movement is aware that old visions can not take Egypt into the future. So in the months since lived the resounding impact of President Nasser's vision of constructing the Aswan High Dam and spirit of their movement -- which they fear could be overtaken by "politics as usual" rooted in the past

Zewail, Ahmed

406

Menstrual Hygiene among Adolescent Schoolgirls in Mansoura, Egypt  

Microsoft Academic Search

Learning about menstrual hygiene is a vital aspect of health education for adolescent girls. This study among 664 schoolgirls aged 14–18 in Mansoura, Egypt, asked about type of sanitary protection used, frequency of changing pads or cloths, means of disposal and bathing during menstruation. Girls were selected by cluster sampling technique in public secondary schools in urban and rural areas.

Abdel-Hady El-Gilany; Karima Badawi; Sanaa El-Fedawy

2005-01-01

407

[Egypt: Selected Readings, Egyptian Mummies, and the Egyptian Pyramid.  

ERIC Educational Resources Information Center

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…

National Museum of Natural History, Washington, DC.

408

Using Social Studies Themes to Investigate Modern Egypt  

ERIC Educational Resources Information Center

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…

Hubbard, Janie

2010-01-01

409

The Great Pyramid Builders: An Integrated Theme on Ancient Egypt  

ERIC Educational Resources Information Center

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.…

Stone, Brian

2008-01-01

410

Nine Revived Records to the Flora of Egypt  

Microsoft Academic Search

Specimens of Asclepias flavida N.E.Br. (Asclepiadaceae), Boscia salicifolia Oliv. (Capparaceae), Cicer arietinum L. (Leguminosae-Papilionoideae), Euphorbia nutans Lag. (Euphorbiaceae), Lepidium virginicum L. (Cruciferae), Oldenlandia fasatigiata Bremek. var. fastigiata, Oldenlandia hedyotoides (Fish. & Mey.) Boiss. (Rubiaceae), Premna resinosa Schauer (Verbenaceae) and Vernonia cinerascens Schultz Bip. (Compositae), collected from Egypt, were located in the two herbaria CAI and CAIM. All nine species were

Adel El-Gazzar; Ali A. Hammouda

411

Profiling organ donors in Egypt using intelligent modeling techniques  

Microsoft Academic Search

Purpose – This study uses intelligent modeling techniques with the purpose of examining the effect of various demographic, cognitive and psychographic factors on organ donation in Egypt. Design\\/methodology\\/approach – Two artificial neural network models (multi-layer perceptron neural network and probabilistic neural network) are compared to two standard statistical methods (linear discriminant analysis and logistic regression). The variable sets considered are

M. Mostafa

2008-01-01

412

Burden of stroke in Egypt: current status and opportunities.  

PubMed

Middle East and North Africa (MENA) countries have a diversity of populations with similar life style, dietary habits, and vascular risk factors that may influence stroke risk, prevalence, types, and disease burden. Egypt is the most populated nation in the Middle East with an estimated 85.5 million people. In Egypt, according to recent estimates, the overall prevalence rate of stroke is high with a crude prevalence rate of 963/100?000 inhabitants. In spite of disease burden, yet there is a huge evidence practice gap. The recommended treatments for ischemic stroke that are guideline include systematic supportive care in a stroke unit or stroke center is still deficient. In addition, the frequency of thrombolysis in Egypt is very low for many reasons; the major one is that the health insurance system is not covering thrombolysis therapy in nonprivate sectors so patients must cover the costs using their own personal savings; otherwise, they will not receive treatment. Another important factor is the pronounced delay in prehospital and in hospital management of acute stroke. Improvement of stroke care in Egypt should be achieved through multi and interdisciplinary approach including public awareness, physicians' education, and synergistic approach to stroke care with Emergency Medical System. PMID:25041503

Abd-Allah, Foad; Moustafa, Ramez Reda

2014-12-01

413

Perfectionism and Self Concept among Primary School Children in Egypt  

ERIC Educational Resources Information Center

Introduction: The main purpose of this study is to explore the correlation between dimensions of perfectionism and self-concepts among school aged students in Egypt. Method: Two hundred-eighty four children (fifth and sixth graders) participated in this study. The mean age of the participants was 144.37 months, SD 6.36. Pearson correlation…

Tofaha, Gamal Al Sayed; Ramon, Patricia Robledo

2010-01-01

414

Water desalination: An imperative measure for water security in Egypt  

Microsoft Academic Search

Water Desalination is an indispensable industry for the most of the Arab countries. In the last four decades, the number and capacities of desalination units have increased dramatically (45% Multi-Stage Flash (MSF) and 42% Reverse Osmosis (RO) of world capacity); especially in the Gulf States. Almost all available conventional water resources in Egypt - represented by the Nile water, renewable

Alaa El-Sadek

2010-01-01

415

Avian Influenza Vaccination of Poultry and Passive Case Reporting, Egypt  

PubMed Central

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

Grosbois, Vladimir; Jobre, Yilma; Saad, Ahmed; El Nabi, Amira Abd; Galal, Shereen; Kalifa, Mohamed; El Kader, Soheir Abd; Dauphin, Gwenaelle; Roger, Francois; Lubroth, Juan; Peyre, Marisa

2012-01-01

416

Design a Book: A Quest in Ancient Egypt  

ERIC Educational Resources Information Center

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…

Cooper, David

2005-01-01

417

Identity, Culture and Democratization: The Case of Egypt  

Microsoft Academic Search

This article seeks to present an alternative approach to understanding the failure of democratization in the Arab world by locating the problem of democracy-building within the logic of the process of reproducing national identity and culture. The conceptual framework draws on the writings of Antonio Gramsci and postcolonial theorists such as Edward Said. Taking Egypt as a case study, I

Nicola Pratt

2005-01-01

418

Trichodinid ectoparasites (Ciliophora: Peritrichida) of some River Nile fish, Egypt  

Microsoft Academic Search

Four species of trichodinid ectoparasites (Ciliophora: Peritrichida) were collected from the gills of the following River Nile fish in Egypt: Hydrocynus forskalii, Mormyrus kannume, Schilbe mystus. These species are: Trichodina heterodentata Duncan, 1977, Trichodina fahaka sp. n., Trichodinella epizootica Raabe, 1950, Tripartiella dactylodentata sp. n. Photomicrographs and morphometric data are presented for each species.

Khaled A. S Al-Rasheid; Mohammed A Ali; Thabit Sakran; Abdel Azeem Abdel Baki; Fathy A Abdel Ghaffar

2000-01-01

419

Trichodinid ectoparasites (Ciliophora: Peritrichida) of some River Nile fish, Egypt.  

PubMed

Four species of trichodinid ectoparasites (Ciliophora: Peritrichida) were collected from the gills of the following River Nile fish in Egypt: Hydrocynus forskalii, Mormyrus kannume, Schilbe mystus. These species are: Trichodina heterodentata Duncan, 1977, Trichodina fahaka sp. n., Trichodinella epizootica Raabe, 1950, Tripartiella dactylodentata sp. n. Photomicrographs and morphometric data are presented for each species. PMID:10882902

Al-Rasheid, K A; Ali, M A; Sakran, T; Abdel Baki, A A; Abdel Ghaffar, F A

2000-08-01

420

Alternative protein sources for fish feeds in Egypt  

Microsoft Academic Search

SUMMARY - In order to reduce reliance on fishmeal in fish feed formulations, several alternative protein sources or supplements were tested in Egypt. Feeding trials on Nile and blue tilapias, Oreochromis niloticus and O. aureus, gilthead seabream, Sparus aurata, European seabass, Dicentrarchus labrax, and mullet, Mugil cephalus, were conducted. The main target was the efficient utilization of waste animal and

E. A. Wassef

421

African Refugees in Egypt: Trauma, Loss, and Cultural Adjustment  

ERIC Educational Resources Information Center

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…

Henry, Hani M.

2012-01-01

422

Scribing Work Songs at an Archeological Dig in Egypt  

ERIC Educational Resources Information Center

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…

Poppe, Donna

2011-01-01

423

Fascioliasis prevalences among animals and human in Upper Egypt  

Microsoft Academic Search

Coprological surveys on animal and human fascioliasis were performed in Qena, a governorate located in Upper Egypt. Animal and human stool samples were collected from four localities: Abu-Tesht, Qena, Armant, and Isna. A total of 297 stool samples from different animals were examined. These samples are (105 cows, 163 buffaloes and 29 sheep). The overall prevalence was 30.3% and including

Abdel-Nasser A. Hussein; Refaat M. A. Khalifa

2010-01-01

424

Two decades of CGE modelling lessons from models for Egypt  

Microsoft Academic Search

Egypt's exceptional experience of two decades of CGE modelling is used to derive lessons for comparable analysis for other countries, give important issues for CGE modelling in general and give future modellers a guide to build on the older modelling experience. It can be derived from the CGE studies of the Egyptian economy that the model closure and the parameters

Mark Thissen

1998-01-01

425

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...

426

We must unleash the power of Egypt's youth  

E-print Network

country. Egypt is rich in human capital but it suffers from appallingly low levels of literacy. With 85 million people, nearly half of them on the poverty line, the No 1 issue It had no hero of Left or Right or the Right. Nor did it have slogans such as "Death to America", "War with Israel" or "Islam is the solution

Zewail, Ahmed

427

New Small Manufacturing Firm Formation and Regional Development in Egypt  

Microsoft Academic Search

This paper sets out to contribute to a better understanding of small firm formation and the role these firms play in the economy in terms of job creation. Moreover, it aims at formulating policy guidelines to assist the formation of Small Manufacturing Firms (SMFs). The research establishes that the formation of new SMFs in Egypt is the product of a

Amr A. Elleithy

1996-01-01

428

CHARACTERIZATION OF THE WASTE ROCK AND PIT WALLS AT THE JUNDEE GOLD MINE SITE IN WESTERN AUSTRALIA AND IMPLICATIONS FOR LONG-TERM ISSUES1  

Microsoft Academic Search

The Jundee mine site is an open pit and underground gold mine located 50 km northeast of the township of Wiluna in central Western Australia's desert. Jundee lies within the Archaean Yandal greenstone belt of the Western Australian goldfield. The area is deeply weathered and overlain by a thin veneer of alluvium and ferricrete. With the exception of satellite pits,

Shannon Shaw; Jason Martin; Greg Meiers; Mike O'Kane; Christoph Wels

429

Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert  

PubMed Central

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

Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

2013-01-01

430

Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert.  

PubMed

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

Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

2013-08-01

431

Banded iron-formations of late Proterozoic age in the central eastern desert, Egypt: geology and tectonic setting.  

USGS Publications Warehouse

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.

Sims, P. K.; James, H. L.

1984-01-01

432

Depositional styles of Early Ediacaran terrestrial volcanosedimentary succession in Gebel El Urf area, North Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

Located 100 km northwest of Hurghada, the volcanosedimentary successions of Gebel El Urf is exposed between latitude 27° 45' 30? and 27° 51' 00? N and longitude 32° 49' 00? and 32° 59' 00? E. The volcanosedimentary successions of Gebel El Urf crop out in an area dominated by different Late Proterozoic plutonic complexes. Both, erosional and intrusive contacts with different granitoid units have been identified. Two SHRIMP ages have been obtained from crystal-rich and lithic-poor ignimbrites yielding 615 ± 4 and 616.0 ± 5.4 Ma placing the evolution of the inter-montane basins, described here, into the Early Ediacaran. In the Gebel El Urf area, a southeastward dipping succession (Gebel El Urf Succession, GUS) of ca. 2000 m thickness rests on coarse-grained granite with an erosional unconformity. Another succession present in the area (Wadi Kefri Succession, WKS) represents volcanogenic sediments which exhibit degrees of metamorphic overprint. In places, it is presumed to be older than GUS. For the GUS, 14 lithofacies types have been differentiated and grouped to seven lithofacies associations. Subdivided into four depositional phases, GUS starts with a thick, massive and clast-supported conglomerate of alluvial fan facies (well-rounded clasts up to 100 cm). GUS continues with pelitic to sandy-turbiditic lacustrine and sandy braided river deposits with occasional volcanic glassy fragments (now illite) (Phase 2). The upper half of the GUS is dominated by volcanic deposits, starting with a 50 m thick package of alternating ignimbrites and synvolcanic sedimentary mass flow deposits, the latter related to phreatomagmatic vents (Phase 3). A thick succession of welded to non-welded ignimbrites follows, with one 20 m intercalation of coarse well-rounded conglomerates (Phase 4). Numerous SiO 2-rich and - poor dykes and sills emplaced into GUS. The GUS development displays a cycle from high to low energy sedimentation and back, under humid climatic conditions. Phase 2 was characterized by extension and down faulting of basin shoulders. Tectonic activity presumably also led to damming of the river creating a sweat water lake. Volcanism commenced with small vents during Phase 2 and terminated with voluminous eruptions in Phase 4.

Eliwa, Hassan; Breitkreuz, Christoph; Khalaf, Ibrahim; Gameel, Khaled El

2010-06-01

433

Strain analysis and microstructural evolution characteristic of neoproterozoic rocks associations of Wadi El Falek, centre Eastern Desert, Egypt  

NASA Astrophysics Data System (ADS)

The estimation of finite strain in rocks is fundamental to a meaningful understanding of deformational processes and products on all scales from microscopic fabric development to regional structural analyses. The Rf/? and Fry methods on feldspar porphyroclasts and mafic grains from 5 granite, 1 metavolcanic, 3 metasedimentary and 1 granodiorite samples were used in Wadi El Falek region. Finite-strain data shows that a high to moderate range of deformation of the granitic to metavolcano-sedimentary samples and axial ratios in the XZ section range from 1.60 to 4.10 for the Rf/? method and from 2.80 to 4.90 for the Fry method. Furthermore, the short axes are subvertical associated with a subhorizontal foliation. We conclude that finite strain in the deformed granite rocks is of the same order of magnitude as that from metavolcano-sedimentary rocks. Furthermore, contacts formed during intrusion of plutons with some faults in the Wadi El Falek area under brittle to semi-ductile deformation conditions. In this case, finite strain accumulated during superimposed deformation on the already assembled nappe structure. It indicates that the nappe contacts formed during the accumulation of finite strain.

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

2012-09-01

434

Radioelement distributions in the Proterozoic granites and associated pegmatites of Gabal El Fereyid area, Southeastern Desert, Egypt.  

PubMed

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

Abd El-Naby, H H; Saleh, G M

2003-10-01

435

Bringing water to the desert  

SciTech Connect

More than 40 years ago, the US Dept. of Interior's Bureau of Reclamation proposed a grand scheme for meeting the water demands of arid central and southern Arizona. The plan: Construct a 330-mile-long system of concrete-lined canals, inverted siphons, tunnels, pumping plants, and pipelines to convey water from the Colorado River on Arizona's western border across the state. People scoffed. They said it could never be done. During the fall of 1992, Reclamation will prove those doubters wrong as it completes the New Waddell dam and Waddell Pump-Generating Plant on the Agua Fria River northwest of Phoenix. The Waddell complex will substantially complete the Central Arizona Project (CAP), which will deliver an average of 1.5 million acre-feet of water each year to cities and industries, Indian communities, and farmers. The water will largely replace existing ground water uses and supplement surface water supplies. The CAP also will provide hydroelectric generation, flood control, recreation, and fish and wildlife benefits. The New Waddell Dam is at the site of the existing Lake Pleasant and Waddell Dam 30 miles northwest of Phoenix. Reclamation built a 5-mile canal, leading from the CAP aqueduct north, to deliver water to the Waddell complex. At the Waddell Pump/Generating Plant, water from the canal will be pumped with four reversible pump/generator units and four pumping-only units into Lake Pleasant during the winter, when energy costs for pumping are low. Water then will be released from the lake into the aqueduct for irrigation and electrical generation during the summer months. Thus, the plant will operate as a [open quotes]seasonal[close quotes] pumped-storage facility. New Waddell Dam will help ensure the CAP's reliability by providing a water supply (the stored water in Lake Pleasant) even if diversions from the Colorado river into the aqueduct have to be temporarily halted. It will also reduce summer pumping requirements from the Colorado River.

Barnes, M.J.

1992-10-01