Conference Articles

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Browsing Conference Articles by Discipline "Geography"

Now showing 1 - 20 of 24
  • Publication
    Assessing the Use of Oil and Gas Produced Water for Soil Aquifer Treatment in Abu Dhabi
    (2022)
    Pavlopoulos, Kosmas 
    ;
    Alomary, Hala
    ;
    Jisha, Ali
    ;
    Arangadi, Abdulfahim
    ;
    Moraitis, Daniel
    ;
    Alhseinat, Emad
    The United Arab Emirates originally lack for sufficient natural water resources. A major source of water in the UAE is groundwater, which includes water in surface wells that are normally renewed by seasonal rains, and deep wells which are refilled via ancient geological formations. The deficit in water availability due to the increasing demand and shortage in water resources availability can be met by utilizing non-conventional sources such as desalinated water, and recycling wastewater. This paper aims to present a scientific assessment of the possibility of using treated oil and gas-produced water for recharging the underground aquifer in Abu Dhabi through Soil aquifer treatment (SAT). Core samples from the unsaturated zone layers of sand, sandstone, siltstone, and conglomerates layers from the Abu Dhabi area were collected and characterized. Adsorption experiments have been carried out to investigate the capacity of the soil samples for the removal of hazardous contaminants i.e. heavy metals and dissolved organic from synthesized oil-produced water samples. The obtained data were used to calculate the required time for the hazardous contaminants to reach the underground water.
      103  77
  • Publication
    Geoarchaeological survey in the Wādī al-Kabīr basin, Wilāyāt Ibrī, Oman: A preliminary report (poster)
    (Archaeopress, 2014)
    Desruelles, Stéphane
    ;
    Fouache, Eric 
    ;
    Kondo, Y.
    ;
    Beuzen-Waller, T.
    ;
    Miki, T.
    ;
    Noguchi, A.
    This paper reports on the geoarchaeological survey in the Wādī al-Kabīr basin, located in the southern piedmont of the al-Hajar mountains, to the north-east of Ibrī, Oman. The goal of the survey was to understand the spatial patterns of human occupation of the region during the Late Pleistocene and Holocene, paying special attention to the development of landscape and topography. The survey comprised archaeological and geomorphological explorations. Both approaches employed satellite remote sensing and GIS-based mapping of surface features. From the geomorphological viewpoint, the survey area was an alluvial plain washed and surrounded by two major wadis - Wādī al-Kabīr and Wādī Khuwaybah. In this area, the archaeological team documented twenty-three sites and scatters. Middle to Late Palaeolithic artefacts were identified in the piedmont areas, while Holocene lithics, characterized by Fasad points, end-scrapers, and drills, were scattered on residual hills and terraces. The team identified a total of 246 cairns, most of which look like Hafit-type tombs. Some of the cairns were associated with lithic concentration. There was a Bronze Age and Islamic settlement on the terrace between the two wadis. At that site, called al-HasT, the team mapped at least five Bronze Age towers, two Umm an-Nar type graves, enclosure walls, irrigation channels with an aqueduct bridge, bunds to prevent floods, and traces of crop field boundaries and buildings. The results of systematic surface collection and soil sampling in the northern sector suggested that a Bronze Age settlement is probably present underneath the crop fields of the Islamic period.
      174
  • Publication
    Geologic environments for nuclear waste repositories
    (EDP Sciences, 2017)
    Pavlopoulos, Kosmas 
    ;
    Paleologos, E.K.
    ;
    Mohamed, A.-M.O.
    High-level radioactive waste (HLW) results from spent reactor fuel and reprocessed nuclear material. Since 1957 the scientific consensus is that deep geologic disposal constitutes the safest means for isolating HLW for long timescales. Nuclear power is becoming significant for the Arab Gulf countries as a way to diversify energy sources and drive economic developments. Hence, it is of interest to the UAE to examine the geologic environments currently considered internationally to guide site selection. Sweden and Finland are proceeding with deep underground repositories mined in bedrock at depths of 500m, and 400m, respectively. Equally, Canada's proposals are deep burial in the plutonic rock masses of the Canadian Shield. Denmark and Switzerland are considering disposal of their relative small quantities of HLW into crystalline basement rocks through boreholes at depths of 5,000m. In USA, the potential repository at Yucca Mountain, Nevada lies at a depth of 300m in unsaturated layers of welded volcanic tuffs. Disposal of low and intermediate-level radioactive wastes, as well as the German HLW repository favour structurally-sound layered salt stata and domes. Our article provides a comprehensive review of the current concepts regarding HLW disposal together with some preliminary analysis of potentially appropriate geologic environments in the UAE. © The Authors, published by EDP Sciences, 2017.
    Scopus© Citations 2  109
  • Publication
    Hyperspectral mapping of crust and mantle rocks in the UAE Al-Hajar mountains: Locating raw materials for Martian regolith simulants
    (2021)
    Pavlopoulos, Kosmas 
    ;
    Ioannou, Zach
    ;
    Moraetis, Daniel
    Hyperspectral mapping of crust and mantle rocks in the UAE Al-Hajar mountains: Locating raw materials for Martian regolith simulants. The objective of the present study is to identify rock lithologies which can be used to produce Mars regolith simulants. It is well known from Curiosity Rover data, that mafic and ultramafic components are the main constituents of the Martian surface regolith (Blake et al. 2013). We have acquired 9 rock samples taken from different locations and rock outcrops located in the Fujairah, Sharjah and Dubai emirates of the UAE and used to obtain crustal (mafic) and mantle (ultramafic) rock spectral signatures (Philips et al. 2006, Thomas et al. 2006). The samples are analyzed using X-ray fluorescence and X-ray diffraction techniques. Based on their mineralogical composition and characteristics we distinguished two main categories of rocks, close to the Hatta and Kahir areas. The analysis showed a range of SiO2 compatible with ultramafic to mafic rocks (43-46% ±1%) in the Hatta area and some samples with extreme high (73%±1%) or low (21%±1%) values of SiO2. The aforementioned extreme concentrations are possibly correlated to sedimentary or metasedimentary rocks. The mineralogy in the Hatta area comprised mainly of pyroxene and plagioclase and some amorphous material while the metasedimentary rocks are mainly rich in calcite and quartz. The Kahir area samples are showing a SiO2 content between ultramafic to mafic rocks (39-49% ±1%). The mineralogy in the Kahir samples comprised of pyroxene and plagioclase and in several samples the ultramafic rocks are exhibiting strong serpentinization (serpentine mineral). In addition to ground investigations, we have also mapped the extended regions that surround the areas of our rock samples using hyperspectral imagery obtained in 2009 and 2011 by the Hyperion instrument on the Earth Obserbation-1 (EO-1) satellite. Feature extraction and hyperspectral classification such as the supervised Spectral Angle Mapper (SAM) and Spectral Feature Fitting (SFF) methods are carried out to map the different lithologies in the extended regions of interest. We combine the ground truth spectral classification of our samples with the hyperspectral classification of the wider area to improve the accuracy of the mineral map around the Hatta and Kahir regions.
      54  36
  • Publication
    Jabal al-'Aluya: An inland Neolithic settlement of the late fifth millennium BC in the Ādam area, Sultanate of Oman
    (Archaeopress, 2013)
    Fouache, Eric 
    ;
    Beuzen-Waller, T.
    ;
    Lemee, M.
    ;
    Giraud, J.
    ;
    Gernez, G.
    Jabal al-'Aluya is a Neolithic site located at the foot of Jabal Salekh near Ādam, Sultanate of Oman. The evidence of dispersed occupation across the 65 ha of the site comprises 139 structures and lithic concentrations, including numerous Neolithic bifacial chert tools. Excavation of a U-shaped stone-hut dwelling in one of the three main zones of occupation at the site recorded post holes, a fireplace, and a pit with what is believed to be a grinding tool. The site is close to water and raw material sources, and geomorphological studies show that it is well preserved despite deflation. The location of the settlement in the inland region of Oman makes it all the more interesting and significant for our understanding of the Neolithic period in south-eastern Arabia, as almost all Neolithic sites excavated to date are located near the coastline.
      191  93
  • Publication
    Karst development in different tectonic settings (Middle East, Greece, South China), concept analysis and first findings towards hydrology modeling reconsideration
    (2022)
    Pavlopoulos, Kosmas 
    ;
    Moraetis, Daniel
    ;
    Fassoulas, Charalambos
    ;
    Mattern, Frank
    ;
    Scharf, Andreas
    ;
    Yu, Xuan
    ;
    Pennos, Christos
    ;
    Adamopoulos, Kostas
    ;
    Zacharias, Stylianos
    ;
    Hamdan, Hamdan
    ;
    Nikolaidis, Nikolaos
    As part of the International Geoscience IGCP-715 project, we present the core objective and preliminary analyses on the karst development of the study areas. Our aim is to further characterize the geomorphologic features of the extended karst of Koiliaris Critical Zone Observatory (KCZO), Crete, Greece. Simultaneously to better understand the main drivers of karst development we compare the CKZO karst system with other areas in different tectonic contexts such as Oman (Salma Plateau), the northern UAE and southern China (Guilin karst area). Hydrological studies and previous geomorphologic analysis of KCZO suggest that 27% of the total water budget is coming from the adjacent watershed in the east where an extensive karst system with two explored super-deep caves is situated (Liontari Cave-1100 m, Gourgouthakas Cave-1200 m). The area is build up by a continuous carbonate succession exceeding 5 km in depth, lying on top of the Hellenic subduction zone. Field work and Google Earth mapping show two dominantly striking directions of failures (fault, fracture surfaces), trending E-W to ESE-WNW (90-120°) and N-S to NNE-SSE (0-22.5°). The N-S surfaces are mainly fractures while the E-W ones are mainly thrusts and/or strike-slip faults with obvious large displacements of hundreds of meters. The karst development in a subduction zone with dramatic thrusting on the overriding plate has created super-deep caves which are controlled by the vertical bedding and a series of faults and fractures. The area exhibits two layers with different hydraulic properties, a fast water-transferring zone and a slower one which is consistent and supports the hypothesis of the hydrologic model. At the Salma Plateau, in Oman, the karstic system is related to rapid uplifted Eocene limestones that overlay the Semail Ophiolite. There is a large cave (Majilis Al Jinn) at an area of interconnected fractures (and/or faults?). It is the only karstic system presented inhere which has similarities with the karstic system in the KCZO. At the UAE and northern Oman (Musandam) is an active collision zone between Arabia and Eurasia with 2000-m-thick allochthonous Mesozoic limestones. The area lacks a subsurface karst system, and the only karst has developed in steep wadis. Finally, the Guilin area in China represents a former passive margin with Devonian limestone. It features a spectacular karst of conical peaks (fengcong) and tower peaks (fenglin). Caves exhibit mainly a horizontal development and there is no similarities to the KCZO.
      31  242
  • Publication
    Long-term sea level changes in the Saronic and Southern Euboean Gulfs
    (Archaeopress, 2020)
    Pavlopoulos, Kosmas 
    ;
    Fachard, Sylvian
    ;
    Vandarakis, D.
    ;
    Knodell, A.R.
    ;
    Kapsimalis, V.
      118  82
  • Publication
    Preliminary Tectonostratigraphy results from the Small Trocharis mountain, north-east Lefka Ori, Western Crete
    (2022)
    Pavlopoulos, Kosmas 
    ;
    Moraetis, Daniel
    ;
    Leontaritis, A.
    ;
    Fassoulas, C
    ;
    Alzhra, F
    ;
    Khan, H
    ;
    Scharf, Andreas
    ;
    Vaxevanopoulos, M
    ;
    Adamopoulos, K
    ;
    Digenis, Markos
    ;
    Pennos, Christos
    ;
    Nikolaidis, Nikolaos
    Preliminary tectonostratigraphy results from the Small Trocharis mountain, north-east Lefka Ori, western Crete. Highlight Here we describe our mapping results, for the updated stratigraphy of the Plattenkalk unit, and the tectonic contacts in Small Trocharis Mountain at northeast Lefka Ori of the island of Crete. The most prominent finding is that in the northeast , close to the peak of Ag Pneuma Melidoniou the thin bedded marble with silex (upper Jurassic-Eocene) is overlain by the upper Triassic to lower Jurassic white marble (Plattenkalk unit, both) and the contact between them appears as a primary conformable depositional contact. The previous shows a possible overturned structure. Background and Objective Nikolaidis et al. (2013) estimated the capacity of the karstic aquifer at 500x10 6 m 3 for the Koiliaris watershed and the associated extended karstified area outside the watershed. The extended karst area is delineated in the region of the two deepest caves (sinkholes) in Greece, the Liontari (1100 m deep) and the Gourgouthakas caves (1208 m deep). Our study covers the extended karstic watershed. The objective of this work, under the IGCP-715 project, is to update our existing understanding of the geological model in the area and as well as to provide detailed lithological and structural insights for the extended karst area.
      48  7
  • Publication
    Reconnaissance geophysical survey for the detection of salinization and stratigraphy in Thorikos Valley, Attica, Greece
    (European Association of Geoscientists and Engineers, EAGE, 2014)
    Apostolopoulos, G.
    ;
    Kallioras, A.
    ;
    Pavlopoulos, Kosmas 
    ;
    Stathopoulou, K.
    ;
    Vlassopoulou, A.
    A reconnaissance geophysical survey is a starting task of a multitasking collaboration to detect all hydrogeological (extent of salinization), stratigraphical, geological features of Thoriko valley in order to reconstruct the environment in ancient times as well as to interpret the position of the various archaeological monuments existing in the area. Electromagnetic measurements with conductivity meter, made in a quick mode with a cart dragged by car, have given, after data evaluation and filtering, valuable information regarding near surface salinization phenomenon. In addition ERT and IP profiles give deeper detection of this phenomenon discriminating media of various clayey content.
      56Scopus© Citations 6
  • Publication
    Relative Sea-Level Changes on the Southwestern Arabian Gulf since the Last Glacial Maximum
    (2022)
    Pavlopoulos, Kosmas 
    ;
    Fouache, Eric 
    ;
    Arhan, Damien
    Several works have been carried out regarding Late Pleistocene–Holocene sea-level changes in the Arabian Gulf. Nevertheless, a global and regional approach is still lacking, and some critical issues remain unsolved. In this paper, a review and a reinterpretation of all published data regarding sea-level changes in the area have been completed and compared with new results obtained from fieldworks carried out in Failaka Island, Kuwait, and in Abu Dhabi Emirate, United Arab Emirates. This work relies mostly on studying geomorphological sea-level indicators, such as beach rocks and beach ridges besides combining archaeological data. Results show different trends in vertical movement within the studied area since the Last Glacial Maximum, which cannot be explained alone by the existing sea-level model, implying different, specific and local factors, such as tectonic deformations and diapirism.
      78  8
  • Publication
    Retrieval of nearshore bathymetry in the Gulf of Chania, NW Crete, Greece, from WorldWiew-2 multispectral imagery
    (SPIE, 2018)
    Pavlopoulos, Kosmas 
    ;
    Drakopoulou, P.
    ;
    Kapsimalis, V.
    ;
    Parcharidis, I.
    Shallow water bathymetry is recognized as one of the most fundamental topics in environmental studies, seabed morphology research and management of the coastal zone. The detailed mapping as well as the long-term monitoring of the changes in shallow marine relief is important for the successful completion of coastal construction and environmental projects. In recent years, optical satellite imagery is proving to be a useful tool to determine coastal bathymetry, as it provides a time- A nd cost-effective solution to water depths estimation. In this paper, the two most popular and successful approaches for bathymetry retrieval, the Lyzenga (1985) linear bathymetry model and the Stumpf et al. (2003) ratio method, have been applied to Worldview-2 satellite imagery, in order to derive the more accurate bathymetric model for the shallow-water region of the Chania Gulf, located in NW Crete Island, Greece. This area is sea-grass free and is dominated by sandy substrate with a few rocky outcrops. The models are implemented over the total study area-no separation in subareas according to the bottom type. The results are compared with echo sounding ground truth depth data. The outcomes of the statistical analysis indicate that the linear model provides increased accuracy than the ratio one over the sandy bottom. On the contrary, in those parts covered by rocky bottoms, none of the two models provided satisfactory results. © 2018 SPIE.
    Scopus© Citations 3  57
  • Publication
    Searching for a Martian soil simulant in UAE & Al Hajar Mountains-First simulants CUOS and MUOS
    (2021)
    Pavlopoulos, Kosmas 
    ;
    Fikri, Mira
    ;
    Alhazba, Ali
    ;
    Pracejus, Bernhard
    ;
    Fernini, Illias
    ;
    Manousakis, Antonios
    ;
    Suleiman, Bashir
    ;
    Shameer, Mohamed
    ;
    Moraetis, Daniel
    This study presents the first results for creating a Martian soil simulant from rocks in UAE and Al Hajar mountains including Sultanate of Oman. The Martian soil composition is now well known from rover missions and it is a regolith of oceanic crust composition (basaltic). The presence of the most extensive oceanic crust in parts Al Hajar mountains (Semail Ophiolites) is a triggering fact to search the possibility to create Martian soil simulants. Inhere we have collected 13 samples from volcanic basalts, gabbro harzburgite laterites and we assessed the mineral composition. We demonstrate the mixing process of the various rocks to create soil simulants. We have created two simulants, CUOS and MUOS following the compositions of Curiosity Mission measurements and MMS-1 soil simulant supplied by the Martian Garden company. The CUOS soil simulant showed moderate to good fitting in the mineralogy with the Curiosity Mission analysis in Rocknest Portage, while we were not able to attain similar mineralogical composition between MUOS and MMS-1 due to lower plagioclase content in our samples.
      29