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El-Hussain I. Deif A. Al-Jabri K. Mohamed A. M. E. Al-Rawas G. Toksöz M. N. Sundararajan N. El-Hady S. Al-Hashmi S. Al-Toubi K. Al-Saifi M. Al-Habsi Z. 《Natural Hazards》2013,69(3):1919-1950
Natural Hazards - Site characterization was carried out for Muscat region using the ambient noise measurements applying the horizontal-to-vertical spectral ratio (HVSR) technique and using active... 相似文献
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Development of ground-shaking maps for the Sultanate of Oman 总被引：1，自引：1，他引：0
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Sequence stratigraphy of the Lower Cenomanian Bahariya Formation, Bahariya Oasis, Western Desert, Egypt 总被引：1，自引：0，他引：1
The Lower Cenomanian Bahariya Formation corresponds to a second-order depositional sequence that formed within a continental shelf setting under relatively low-rate conditions of positive accommodation (< 200 m during 3–6 My). This overall trend of base-level rise was interrupted by three episodes of base-level fall that resulted in the formation of third-order sequence boundaries. These boundaries are represented by subaerial unconformities (replaced or not by younger transgressive wave ravinement surfaces), and subdivide the Bahariya Formation into four third-order depositional sequences.
The construction of the sequence stratigraphic framework of the Bahariya Formation is based on the lateral and vertical changes between shelf, subtidal, coastal and fluvial facies, as well as on the nature of contacts that separate them. The internal (third-order) sequence boundaries are associated with incised valleys, which explain (1) significant lateral changes in the thickness of incised valley fill deposits, (2) the absence of third-order highstand and even transgressive systems tracts in particular areas, and (3) the abrupt facies shifts that may occur laterally over relatively short distances. Within each sequence, the concepts of lowstand, transgressive and highstand systems tracts are used to explain the observed lateral and vertical facies variability.
This case study demonstrates the usefulness of sequence stratigraphic analysis in understanding the architecture and stacking patterns of the preserved rock record, and helps to identify 13 stages in the history of base-level changes that marked the evolution of the Bahariya Oasis region during the Early Cenomanian. 相似文献
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Human effects and environment impacts associated with nanoparticles generated from road traffic have recently attracted wide attention.Knowledge of the influencing variables on both number and mass of nanoparticles,sources,characteristics and limitations of advanced commercially accessible instruments for monitoring nanoparticles,are still scarce and not sufficient to make regulatory decision on solid particles smaller than 23 nm(SPN<23 nm).Given the harmful effects of nanoparticles on human health(i.e.visibility impairment,cardiac-rhythm disturbance,heart attacks,premature death,etc.),their control and assessment seem to be an absolute priority.In this overview,we classify and analyze the existing knowledge of nanoparticles in road traffic atmosphere,recent progress,and emerging priorities in research related to these topics.The major aspects of ongoing research in this field,and a brief discussion of the main sources of atmosphere nanoparticles are presented.The subsequent section focuses on the influencing parameters of nanoparticles including climate conditions,height above the road surface and distance between source(road traffic)and sampling site.The next section provides a comprehensive summary on sampling measurement methodologies and instrumental techniques.We also review the health and environment implications associated with particle exposure.Finally,an evaluation of the state of research related to nanoparticles together with highlights for future research activities are also presented. 相似文献
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Sultan Al-Yahyai Abeer Aulad Thani Noura Al-kaabi Khalifa Al-Sudairi Badriya Al-Mawali Issa Al Amri 《Arabian Journal of Geosciences》2017,10(4):76
An accurate tropical cyclone track and intensity forecast is very important for disaster management. Specialized numerical prediction models have been recently used to provide high-resolution temporal and special forecasts. Hurricane Weather Research and Forecast (HWRF) model is one of the emerging numerical models for tropical cyclone forecasting. This study evaluates the performance of HWRF model during the post monsoon tropical cyclone Nilofar on the north Indian Ocean basin. The evaluation uses the best track data provided by the Indian Meteorological Department (IMD) and the Joint Typhoon Warning Centre (JTWC). Cyclone track, central pressure, and wind speed are covered on this evaluation. Generally, HWRF was able to predict the Nilofar track with track error less than 230 km within the first 66 h of forecast time span. HWRF predicted more intense tropical cyclone. It predicted the lowest central pressure to be 922 hPa while it reached 950 hPa according to IMD and 937 hPa according to JTWC. Wind forecast was better as it predicted maximum wind speed of 122 kt while it reached 110 and 115 kt according to IMD and JTWC, respectively. 相似文献
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Mohammed A. Al-Wosabi Muhammad S. Khalifa Muayyad H. Khaiwka 《Arabian Journal of Geosciences》2011,4(3-4):607-623
The measured ranges of 60 benthic foraminiferal species of Umm er Radhuma Formation (UeR) (Paleocene–Early Eocene age) in five wells of Rub’ Al-Khali Basin, Saudi Arabia, and two surface sections (Wadi Mashib and Say’un), from Yemen, have been assembled by a graphic correlation technique into a composite standard section (CSS). This composite standard allows building a chronostratigraphic model subdividing UeR into 50 composite standard section time units. The adjustment of benthic foraminiferal ranges of the study area by a quantitative approach improved its resolution in correlation and enhances its potential in biozonation and dating. The analysis of graphic correlation technique reveals significant information regarding accumulation rate in the CSS and the individual sections. Generally, sediments of Paleocene–Early Eocene age in the study area are characterized by a low rate of accumulation. The Paleocene/Eocene boundary of Umm er Radhuma Formation is defined in the chronostratigraphic model to be at a composite standard section time units ?14.8. This boundary is projected into individual sections by the graphic correlation technique and allowed a precise correlation of these sections. A synchroneity analysis of composite standard section events is carried out and enabled testing of reliability of Umm er Radhuma Formation benthic foraminifera biozonation. 相似文献
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A. Deif I. El-Hussain K. Al-Jabri N. Toksoz S. El-Hady S. Al-Hashmi K. Al-Toubi Y. Al-Shijbi M. Al-Saifi 《Arabian Journal of Geosciences》2013,6(12):4947-4960
The Sultanate of Oman forms the southeastern part of the Arabian plate, which is surrounded by relatively high active tectonic zones. Studies of seismic risk assessment in Oman have been an important on-going socioeconomic concern. Using the results of the seismic hazard assessment to improve building design and construction is an effective way to reduce the seismic risk. In the current study, seismic hazard assessment for the Sultanate of Oman is performed through the deterministic approach with particular attention on the uncertainty analysis applying a recently developed method. The input data set contains a defined seismotectonic model consisting of 26 seismic zones, maximum magnitudes, and 6 alternative ground motion prediction equations that were used in four different tectonic environments: obduction zone earthquake (Zagros fold thrust belt), subduction zone earthquakes (Makran subduction zones), normal and strike-slip transform earthquakes (Owen and Gulf of Aden zones), and stable craton seismicity (Arabian stable craton). This input data set yielded a total of 76 scenarios at each point of interest. A 10 % probability that any of the 76 scenarios may exceed the largest median ground acceleration is selected. The deterministic seismic hazards in terms of PGA, 5 % damped spectral acceleration at 0.1, 0.2, 1.0 and 2.0 s are performed at 254 selected points. The ground motion was calculated at the 50th and 84th percentile levels for selected probability of exceeding the median value. The largest ground motion in the Sultanate of Oman is observed in the northeastern part of the country. 相似文献
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The Cambrian Araba Formation exposed in Gabal El Zeit and in the Sinai Peninsula unconformably overlies Precambrian basement rocks, and is in turn overlain unconformably by the Ordovician Naqus formation. The Araba Formation has been subdivided into three informal lithologic units: lower, middle and upper, from field observations. Seven sedimentary facies assignable to three facies associations (fluvial, tidal and coastal to open marine) are recognized within the Araba Formation. The lower unit comprises two main facies: matrix-supported conglomerate (facies-A) in the south (Gabal Araba and Wadi Feiran) and interbeds of granulestone and sandstone (facies-B) in the north (Gabal Dhalal and Taba) deposited in fluvial conditions. The middle unit includes four facies: cross-bedded sandstone (facies-C), thin laminated sandstone (facies-D), burrowed-massive sandstone (facies-E) and rhythmically bedded sandstone–mudstone (facies-F) deposited mainly under tidal conditions in the coastal zone. The upper unit consists mainly of interbeds of burrowed mudstone-siltstone, with Skolithos, probably deposited in open marine environment. The sequence records the southward transgression of the Tethys Ocean over a horst and graben system developed in the late Precambrian on the northern margin of the Arabo-Nubian continent. 相似文献
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Um Bogma area is the most famous mineralized locality in Sinai, Egypt. It is characterized by the presence of manganese, iron,
and copper deposits. Apart from the mill tailings and spoil heaps, the results indicated the decrease of soil contamination
downstream. As a result of random manganese mining activity in Um Bogma area, many hazardous elements such as iron, copper,
manganese, lead, and zinc as well as many others associating heavy metals such as arsenic, selenium, and sulfur are dispersed
in the environment. This study assesses and monitors the environmental impacts of such mining activities in the west central
Sinai, using multitemporal spectral remote-sensing sensors (MSS 1972, TM 1986, and ETM+7 2000). The results have shown the
very high potential of temporal imagery in mining-related contamination either directly through mineral and rock mapping of
the mining waste and residues and related contaminated areas. 相似文献