144 results on '"Pantelis Soupios"'
Search Results
2. Reconstruction of the Subsurface of Al-Hassa Oasis Using Gravity Geophysical Data
- Author
-
Abid Khogali, Konstantinos Chavanidis, Panagiotis Kirmizakis, Alexandros Stampolidis, and Pantelis Soupios
- Subjects
gravity survey ,3D modeling ,Ghawar oilfield ,subsurface complexity ,Saudi Arabia ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Al-Hassa city, located in Eastern Saudi Arabia, boasts the world’s largest oasis and the most expansive naturally irrigated lands. Historically, a total of 280 natural springs facilitated significant groundwater discharge and irrigation of agricultural land. Furthermore, the water in certain springs formerly had a high temperature. The spatial variability of the water quality was evident. At the same time, Al-Hassa Oasis is situated on the northeastern side of the Ghawar field, which is the largest conventional onshore oil field in the world in terms of both reserves and daily output (approximately 3.8 mmb/d). The aforementioned traits suggest an intricate subsurface that has not yet been publicly and thoroughly characterized. Due to the presence of significant cultural noise caused by agricultural and nearby industrial activities, a robust, easy-to-use, and accurate geophysical method (gravity) was used to cover an area of 350 km2, producing the 3D subsurface model of the study area. A total of 571 gravity stations were collected, covering the whole Al-Hassa Oasis and parts of the nearby semi-urban areas. The gravity data were corrected and processed, and a 3D inversion was applied. The resulting 3D geophysical subsurface modeling unveiled an intricate subterranean configuration and revealed lateral variations in density, indicating the presence of a potential salt dome structure, as well as fracture zones that serve as conduits or obstacles to the flow of the subsurface fluids. This comprehensive modeling approach offers valuable insights into the subsurface dynamics of the broader study area, enhancing our understanding of its qualitative tectonic and hydraulic features and their impacts on the area’s natural resources, such as groundwater and hydrocarbons.
- Published
- 2024
- Full Text
- View/download PDF
3. Bayesian Experimental Design for Efficient Sensor Placement in Two-Dimensional Electromagnetic Imaging
- Author
-
Ali Imran Sandhu, Ben Mansour Dia, Oliver Dorn, and Pantelis Soupios
- Subjects
Electromagnetic imaging ,Bayesian experimental design ,optimal sensor placement ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
Careful sensor placement is crucial in electromagnetic imaging experiments as it significantly impacts the quality and accuracy of the measurements. This study examines the placement of a network of sensors to advance the Bayesian learning with the aim of achieving a minimal level of uncertainty in a qualitative imaging regime. The quality of the measured data, associated with a network of sensors, is assessed by computing the expected text Kullback-Leibler divergence between the prior and the posterior distributions, wherein the Laplace approximation is invoked to reduce the associated computational cost. The numerical experiment is carried out to evaluate various sensor placement scenarios to identify the network geometry that can enhance the quality of inversion.
- Published
- 2023
- Full Text
- View/download PDF
4. Multi-frequency wavefield modeling of acoustic VTI wave equation using physics informed neural networks
- Author
-
Ali Imran Sandhu, Umair bin Waheed, Chao Song, Oliver Dorn, and Pantelis Soupios
- Subjects
Helmholtz equation ,physics informed neural networks (PINNs) ,wavefield modeling ,seismic anisotropy ,wave propagation ,Science - Abstract
Incorporating anisotropy is crucial for accurately modeling seismic wave propagation. However, numerical solutions are susceptible to dispersion artifacts, and they often require considerable computational resources. Moreover, their accuracy is dependent on the size of discretization, which is a function of the operating frequency. Physics informed neural networks (PINNs) have demonstrated the potential to tackle long-standing challenges in seismic modeling and inversion, addressing the associated computational bottleneck and numerical dispersion artifacts. Despite progress, PINNs exhibit spectral bias, resulting in a stronger capability to learn low-frequency features over high-frequency ones. This paper proposes the use of a simple fully-connected PINN model, and evaluates its potential to interpolate and extrapolate scattered wavefields that correspond to the acoustic VTI wave equation across multiple frequencies. The issue of spectral bias is tackled by incorporating the Kronecker neural network architecture with composite activation function formed using the inverse tangent (atan), exponential linear unit (elu), locally adaptive sine (l-sin), and locally adaptive cosine (l-cos) activation functions. This allows the construction of an effectively wider neural network with a minimal increase in the number of trainable parameters. The proposed scheme keeps the network size fixed for multiple frequencies and does not require repeated training at each frequency. Numerical results demonstrate the efficacy of the proposed approach in fast and accurate, anisotropic multi-frequency wavefield modeling.
- Published
- 2023
- Full Text
- View/download PDF
5. Application of Electromagnetic Methods for Reservoir Monitoring with Emphasis on Carbon Capture, Utilization, and Storage
- Author
-
César Barajas-Olalde, Donald C. Adams, Ana Curcio, Sofia Davydycheva, Ryan J. Klapperich, Yardenia Martinez, Andri Y. Paembonan, Wesley D. Peck, Kurt Strack, and Pantelis Soupios
- Subjects
CO2 storage monitoring ,fluid imaging ,controlled-source electromagnetics (CSEM) ,magnetotelluric (MT) survey ,CCUS ,EOR ,Mineralogy ,QE351-399.2 - Abstract
The Controlled-Source ElectroMagnetic (CSEM) method provides crucial information about reservoir fluids and their spatial distribution. Carbon dioxide (CO2) storage, enhanced oil recovery (EOR), geothermal exploration, and lithium exploration are ideal applications for the CSEM method. The versatility of CSEM permits its customization to specific reservoir objectives by selecting the appropriate components of a multi-component system. To effectively tailor the CSEM approach, it is essential to determine whether the primary target reservoir is resistive or conductive. This task is relatively straightforward in CO2 monitoring, where the injected fluid is resistive. However, for scenarios involving brine-saturated (water-wet) or oil-wet (carbon capture, utilization, and storage—CCUS) reservoirs, consideration must also be given to conductive reservoir components. The optimization of data acquisition before the survey involves analyzing target parameters and the sensitivity of multi-component CSEM. This optimization process typically includes on-site noise measurements and 3D anisotropic modeling. Based on our experience, subsequent surveys tend to proceed smoothly, yielding robust measurements that align with scientific objectives. Other critical aspects to be considered are using magnetotelluric (MT) measurements to define the overall background resistivities and integrating real-time quality assurance during data acquisition with 3D modeling. This integration allows the fine tuning of acquisition parameters such as acquisition time and necessary repeats. As a result, data can be examined in real-time to assess subsurface information content while the acquisition is ongoing. Consequently, high-quality data sets are usually obtained for subsequent processing and initial interpretation with minimal user intervention. The implementation of sensitivity analysis during the inversion process plays a pivotal role in ensuring that the acquired data accurately respond to the target reservoirs’ expected depth range. To elucidate these concepts, we present an illustrative example from a CO2 storage site in North Dakota, USA, wherein the long-offset transient electromagnetic method (LOTEM), a variation of the CSEM method, and the MT method were utilized. This example showcases how surface measurements attain appropriately upscaled log-scale sensitivity. Furthermore, the sensitivity of the CSEM and MT methods was examined in other case histories, where the target reservoirs exhibited conductive properties, such as those encountered in enhanced oil recovery (EOR), geothermal, and lithium exploration applications. The same equipment specifications were utilized for CSEM and MT surveys across all case studies.
- Published
- 2023
- Full Text
- View/download PDF
6. Utilization of adaptive neuro-fuzzy interference system and functional network in prediction of total organic carbon content
- Author
-
Osama Siddig, Hany Gamal, Pantelis Soupios, and Salaheldin Elkatatny
- Subjects
Total organic carbon ,Well logs ,Devonian shale ,Functional network ,Adaptive neuro-fuzzy interference system ,Science ,Technology - Abstract
Abstract This paper presents the application of two artificial intelligence (AI) approaches in the prediction of total organic carbon content (TOC) in Devonian Duvernay shale. To develop and test the models, around 1250 data points from three wells were used. Each point comprises TOC value with corresponding spectral and conventional well logs. The tested AI techniques are adaptive neuro-fuzzy interference system (ANFIS) and functional network (FN) which their predictions are compared to existing empirical correlations. Out of these two methods, ANFIS yielded the best outcomes with 0.98, 0.90, and 0.95 correlation coefficients (R) in training, testing, and validation respectively, and the average errors ranged between 7 and 18%. In contrast, the empirical correlations resulted in R values less than 0.85 and average errors greater than 20%. Out of eight inputs, gamma ray was found to have the most significant impact on TOC prediction. In comparison to the experimental procedures, AI-based models produces continuous TOC profiles with good prediction accuracy. The intelligent models are developed from preexisting data which saves time and costs. Article highlights In contrast to existing empirical correlation, the AI-based models yielded more accurate TOC predictions. Out of the two AI methods used in this article, ANFIS generated the best estimations in all datasets that have been tested. The reported outcomes show the reliability of the presented models to determine TOC for Devonian shale.
- Published
- 2021
- Full Text
- View/download PDF
7. Mineralogical, Elemental, and Spatial Variability of Volcaniclastics in Fluvio‐Coastal‐Aeolian Sedimentary Systems and Their Insights for Mineral Sorting on Mars
- Author
-
Ignatius Argadestya, Abduljamiu O. Amao, Candice C. Bedford, Pantelis Soupios, and Khalid Al‐Ramadan
- Subjects
volcaniclastic ,fluvial ,coastal ,aeolian ,parabolic dune ,Mars ,Astronomy ,QB1-991 ,Geology ,QE1-996.5 - Abstract
Abstract This study investigates the mineralogical, elemental, and spatial variability from source (proximal) to sink (distal) of Merapi basalt‐andesitic stratovolcano (Java, Indonesia) to better constrain volcaniclastic mineral sorting in fluvial, aeolian, and coastal environments. Merapi volcaniclastics are products of an active volcano with an ongoing quadrennial eruption, which can provide insights to constrain Mars' older and more recent volcaniclastics by focusing on anorthite, albite, and pyroxenes found on Mars' surface. We collected stream sediment samples across the Opak River that connects Merapi with the Indian Ocean. In addition to grain size analysis, all collected samples were subjected to X‐ray diffractometer and X‐ray fluorescence to quantify their mineralogical and elemental composition, respectively, like the CHEMIN instrument used by the Curiosity rover on Mars to investigate the geochemistry and mineralogy of geological units in Gale crater. Implementation of multivariate statistical analysis based on principal component analysis and Hierarchical Clustering of Principal Component are able to discriminate between fluvial, fluvio‐coastal‐aeolian, and marine influenced deposits. The quantitative assessment shows that the dominant mineralogy is influenced by pyroclastic materials dominated by plagioclase feldspars (albite and anorthite), followed by pyroxenes (augite and enstatite). Alteration modeling of Merapi samples favors a fluvial depositional environment rather than mass‐wasting from the crater rim for Gale crater rocks (i.e., Pahrump Hills, Hartmann's Valley, Karasburg, Sutton Island member) on Mars.
- Published
- 2022
- Full Text
- View/download PDF
8. Application of Combined Local and Global Optimization Algorithms in Joint Interpretation of Direct Current Resistivity and Seismic Refraction Data: A Case Study of Dammam Dome, Eastern Saudi Arabia
- Author
-
Paul Edigbue, Ismail Demirci, Irfan Akca, Hamdan Hamdan, Panagiotis Kirmizakis, Pantelis Soupios, Markos Tranos, Israa S. Abu-Mahfouz, Emin Candansayar, Sherif Hanafy, and Abdullatif Al-Shuhail
- Subjects
direct current resistivity ,seismic refraction ,local optimization ,global optimization ,joint inversion ,Dammam Dome ,Chemical technology ,TP1-1185 - Abstract
The main geological structures in the Dammam Dome are defined by integrating geophysical measurements and applying new methodological approaches. Dammam Dome is characterized by a well-developed fracture/joints system; thus, high complexity of the subsurface is expected. Direct Current Resistivity (DCR) and Seismic Refraction (SR) geophysical survey aimed to map the Dammam Dome’s near-surface features. The geophysical data were acquired along two profiles in the northern part of Dammam Dome. To maximize the results from conducting DCR and SR measurements over a complex area, a combined local and global optimization algorithm was used to obtain high-resolution near-surface images in resistivity and velocity models. The local optimization technique involves individual and joint inversion of the DCR and SR data incorporating appropriate regularization parameters, while the global optimization uses single and multi-objective genetic algorithms in model parameter estimation. The combined algorithm uses the output from the local optimization method to define a search space for the global optimization algorithm. The results show that the local optimization produces satisfactory inverted models, and that the global optimization algorithm improves the local optimization results. The joint inversion and processing of the acquired data identified two major faults and a deformed zone with an almost N–S direction that corresponds with an outcrop were mapped in profile one, while profile two shows similar anomalies in both the resistivity and velocity models with the main E–W direction. This study not only demonstrates the capability of using the combined local and global optimization multi-objectives techniques to estimate model parameters of large datasets (i.e., 2D DCR and SR data), but also provides high-resolution subsurface images that can be used to study structural features of the Dammam Dome.
- Published
- 2022
- Full Text
- View/download PDF
9. A Comprehensive Study of Local, Global, and Combined Optimization Methods on Synthetic Seismic Refraction and Direct Current Resistivity Data
- Author
-
Paul Edigbue, Ismail Demirci, Irfan Akca, Hamdan Ali Hamdan, Panagiotis Kirmizakis, Pantelis Soupios, Emin Candansayar, Sherif Hanafy, and Abdullatif Al-Shuhail
- Subjects
individual inversion ,joint inversion ,seismic refraction ,direct current resistivity ,combined local and global optimization ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Most geophysical inversions face the problem of non-uniqueness, which poses a challenge in the mapping and delineation of the subsurface anomalies. To tackle this challenge, a combined local and global optimization approach is considered for jointly inverting two-dimensional direct current resistivity (DCR) and seismic refraction (SR) data that aim to estimate the corresponding physical model parameters. In this combined approach, the output of the local optimization method is used to determine the search space and tuning parameters for the global optimization algorithm. The multi-objective genetic algorithm (non-dominated sorting genetic algorithm) was utilized to jointly optimize the objective functions of two different methods. Because the genetic algorithm is a population-based optimization method, it requires numerous forward calculations. To deal with the expected high computational cost associated with this approach, parallel computing was utilized for the forward function evaluations to reduce the run time of the entire process. The proposed approach was tested using synthetic two-dimensional resistivity and velocity models that had three different types of anomalies (dyke, positive, and combined positive and negative). The results showed an improvement in the anomaly delineation in the output of the combined local and global optimization method compared with the local optimization method. Additionally, similar synthetic models were tested using only the single objective global optimization algorithm (conventional global optimization), which showed promising anomaly delineation.
- Published
- 2022
- Full Text
- View/download PDF
10. Comprehensive Geophysical Study at Wabar Crater, Rub Al‐Khali Desert, Saudi Arabia
- Author
-
Sherif M. Hanafy, Pantelis Soupios, Alexandros Stampolidis, Christian Bender Koch, Khalid Al‐Ramadan, Abdullatif Al‐Shuhail, Theis Solling, and Ignatius Argadestya
- Subjects
magnetic ,TEM ,seismic ,GPR ,Astronomy ,QB1-991 ,Geology ,QE1-996.5 - Abstract
Abstract Interest in impact craters on the earth's surface has increased worldwide and is being investigated by using remote sensing, geological, boreholes, geophysical, and laboratory measurements. These measurements are used to build dynamic models to study crater formation. In this work, the near‐crater sediments at the young Wabar crater field in Saudi Arabia have been investigated using magnetic, transient electromagnetic (TEM), seismic, and ground‐penetrating radar (GPR) methods. The main objectives of this research were to (a) explore the possibility of any remnant major pieces of the meteorite, (b) investigate the meteoroid direction, and (c) map the deformational structures associated with the meteorite impact. Our results show five different magnetic anomaly types and three layers in the subsurface. The maximum depth of deformation due to the impact of the meteorite is about 25 m as shown by the seismic travel time tomogram, the quasi‐2D TEM, and the 3D GPR model. TEM survey confirmed the geometrical characteristics of the major crater and located another small crater (known as Philby‐A). The magnetic survey shows no evidence of any remnant major pieces of the meteorite; however, it was used to trace ejecta material containing highly dilute magnetic material. The magnetic carrier is most likely spheres of metal incorporated in the black/green glasses. During the expedition, many small pieces of the meteoroid were found and collected for further geochemical analysis. Based on the geophysical findings, the meteorite direction was found to be from north to south.
- Published
- 2021
- Full Text
- View/download PDF
11. First High-Power CSEM Field Test in Saudi Arabia
- Author
-
Abdul Latif Ashadi, Yardenia Martinez, Panagiotis Kirmizakis, Tilman Hanstein, Xiayu Xu, Abid Khogali, Andri Yadi Paembonan, Ahmed AlShaibani, Assem Al-Karnos, Maxim Smirnov, Kurt Strack, and Pantelis Soupios
- Subjects
magnetotellurics ,controlled-source electromagnetics ,LOTEM ,oilfields characterization and monitoring ,energy transition ,Mineralogy ,QE351-399.2 - Abstract
We conducted an initial high-power CSEM (controlled-source electromagnetic method) survey in a coastal salt-flat area in the broader area of Half Moon Bay, in the southern part of Dammam Peninsula in the eastern province of Saudi Arabia. The primary purpose of this work was to verify the technology, but we were also able to detect and characterize potential economic brines in the study area. For a high-quality data acquisition, several transmitter–receiver configurations, different acquisition parameters, and passive and active EM data were collected, evaluated, processed, and interpreted to characterize the subsurface. The long-offset EM (LOTEM) and the focused-source EM (FSEM) were the optimum configurations due to the high-quality of the collected data. This is a starting point for using the CSEM method towards the O&G, geothermal, CO2 sequestration, groundwater, lithium brine, and other natural resources’ exploration and exploitation in the Gulf countries.
- Published
- 2022
- Full Text
- View/download PDF
12. Estimating Soil Clay Content Using an Agrogeophysical and Agrogeological Approach: A Case Study in Chania Plain, Greece
- Author
-
George Kritikakis, Eleni Kokinou, Nikolaos Economou, Nikolaos Andronikidis, John Brintakis, Ioannis N. Daliakopoulos, Nektarios Kourgialas, Aikaterini Pavlaki, George Fasarakis, Nikolaos Markakis, Pantelis Soupios, Thrassyvoulos Manios, and Antonios Vafidis
- Subjects
soil water ,irrigation ,geological formations ,electrical resistivity ,induced polarization ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Thorough knowledge of soil lithology and its properties are of considerable importance to agriculture. These parameters have a direct impact on water permeability and the content of the water in soil, which represent significant factors in crop yield, decisively determining the design of irrigation systems and farming processes. In the framework of this study, and considering the inevitable impacts of climate change, the rational management of water resources and the optimization of irrigation through innovative technologies become of significant importance. Thus, we propose an interdisciplinary approach based on robust techniques from the allied fields of earth (geological mapping, geophysical methods) and soil sciences (sampling, mechanical analysis) assisted by statistics and GIS techniques. Clay or the sum of clay and silt soil content is successfully determined from the normalized chargeability using induced polarization and electrical resistivity techniques. Finally, we distinguished three classes (S1, S2 and S3) considering the clay or the sum of clay and silt soil content in the study area (a) based on the dry period geophysical data and (b) using as classification criterion the spatial distribution of the geological formations.
- Published
- 2022
- Full Text
- View/download PDF
13. Historic Underground Silver Mine Workings Detection Using 2D Electrical Resistivity Imaging (Durango, Mexico)
- Author
-
Hector R. Hinojosa, Panagiotis Kirmizakis, and Pantelis Soupios
- Subjects
mineral exploration ,geoelectrical methods ,2D imaging ,near-surface ,Mexico ,Mineralogy ,QE351-399.2 - Abstract
This paper presents an underground silver mining operation outside Gomez Palacio, Durango, Mexico, terminated around the 1930s, of which previous knowledge of its operations was poor. Durango’s current silver exploration campaigns are likely to overlook historic silver mining sites due to interest in specific prospect regions. A two-dimensional (2D) Electrical Resistivity Imaging (ERI) survey coupled with reconnaissance of the area was performed at this historic silver mining site. The exploration campaign aimed to find the abandoned mineshaft, map its subsurface extent, and explore the occurrence of mineralization zones (silver ore). The ERI survey comprised five profiles measured with the extended dipole-dipole array with a consistent electrode spacing of 5 m. The smooth, robust, and damped least-squares inversion methods were used to invert the 2D data. Our field observations and ERI survey results collectively reveal the following findings: (a) reconnaissance reveals mining infrastructure consistent with historical mining activity; the infrastructure includes a complex of habitational rooms, an ore-processing pit near a concrete slab next to a dirt road, and two limestone-wall structures interpreted as the entrance of abandoned backfilled mineshafts named Mesquite and Lechuguilla; (b) high-resistivity anomalies suggest vestiges of shallow, underground mine workings including backfilled mineshafts that connect a mine gallery complex, and (c) various low-resistivity anomalies, juxtaposed against mine galleries, suggestive of unmined shallow vein-type and manto-type mineralization of hydrothermal origin. The imaging depth is estimated at ~65 m. Underground silver mining moved southwards and was limited to ~40 m depth.
- Published
- 2022
- Full Text
- View/download PDF
14. Remote Sensing, Geophysics, and Modeling to Support Precision Agriculture—Part 1: Soil Applications
- Author
-
Arya Pradipta, Pantelis Soupios, Nektarios Kourgialas, Maria Doula, Zoi Dokou, Mohammad Makkawi, Mohammed Alfarhan, Bassam Tawabini, Panagiotis Kirmizakis, and Mohamed Yassin
- Subjects
soil properties ,precision agriculture ,sustainable development ,remote sensing ,agricultural geophysics ,numerical approaches ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Sustainable agriculture management typically requires detailed characterization of physical, chemical, and biological aspects of soil properties. These properties are essential for agriculture and should be determined before any decision for crop type selection and cultivation practices. Moreover, the implementation of soil characterization at the beginning could avoid unsustainable soil management that might lead to gradual soil degradation. This is the only way to develop appropriate agricultural practices that will ensure the necessary soil treatment in an accurate and targeted way. Remote sensing and geophysical surveys have great opportunities to characterize agronomic soil attributes non-invasively and efficiently from point to field scale. Remote sensing can provide information about the soil surface (or even a few centimeters below), while near-surface geophysics can characterize the subsoil. Results from the methods mentioned above can be used as an input model for soil and/or soil/water interaction modeling. The soil modeling can offer a better explanation of complex physicochemical processes in the vadose zone. Considering their potential to support sustainable agriculture in the future, this paper aims to explore different methods and approaches, such as the applications of remote sensing, geophysics, and modeling in soil studies.
- Published
- 2022
- Full Text
- View/download PDF
15. Remote Sensing, Geophysics, and Modeling to Support Precision Agriculture—Part 2: Irrigation Management
- Author
-
Arya Pradipta, Pantelis Soupios, Nektarios Kourgialas, Maria Doula, Zoi Dokou, Mohammad Makkawi, Mohammed Alfarhan, Bassam Tawabini, Panagiotis Kirmizakis, and Mohamed Yassin
- Subjects
irrigation ,crop growth ,precision agriculture ,remote sensing ,agro-geophysics ,modeling ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
Food and water security are considered the most critical issues globally due to the projected population growth placing pressure on agricultural systems. Because agricultural activity is known to be the largest consumer of freshwater, the unsustainable irrigation water use required by crops to grow might lead to rapid freshwater depletion. Precision agriculture has emerged as a feasible concept to maintain farm productivity while facing future problems such as climate change, freshwater depletion, and environmental degradation. Agriculture is regarded as a complex system due to the variability of soil, crops, topography, and climate, and its interconnection with water availability and scarcity. Therefore, understanding these variables’ spatial and temporal behavior is essential in order to support precision agriculture by implementing optimum irrigation water use. Nowadays, numerous cost- and time-effective methods have been highlighted and implemented in order to optimize on-farm productivity without threatening the quantity and quality of the environmental resources. Remote sensing can provide lateral distribution information for areas of interest from the regional scale to the farm scale, while geophysics can investigate non-invasively the sub-surface soil (vertically and laterally), mapping large spatial and temporal domains. Likewise, agro-hydrological modelling can overcome the insufficient on-farm physicochemical dataset which is spatially and temporally required for precision agriculture in the context of irrigation water scheduling.
- Published
- 2022
- Full Text
- View/download PDF
16. Gravity Survey on the Oil-Bearing Dammam Dome (Eastern Saudi Arabia) and Its Implications
- Author
-
Konstantinos Chavanidis, Alexandros Stampolidis, Panagiotis Kirmizakis, Markos Tranos, Maurizio Fedi, Roman Pasteka, Khalid Al-Ramadan, SanLinn Kaka, Grigorios N. Tsokas, and Pantelis Soupios
- Subjects
gravity survey ,Dammam Dome ,KFUPM ,Saudi Arabia ,Zagros orogeny ,Science - Abstract
A detailed gravity survey with 235 measurements was carried out at the King Fahd University of Petroleum and Minerals campus, which is located at the crest of the oil-bearing Dammam Dome (Eastern Province of Saudi Arabia). This survey allows us to better understand the geometry of the underlying Dammam Dome and its tectonic regime. The acquired data were processed using conventional gravity data reduction techniques. The effectiveness of terrain correction was evaluated using several recently developed algorithms. Afterward, processed data were subject to geophysical filters for edge detection (terracing transformation and horizontal gradient) and depth estimation (tilt derivative and 3D inversion). 3D Bouguer maps were generated and compared to the proposed geological models for the Dammam Dome. The results show the existence of ENE-WSW striking tectonic lines, where two nearly vertical, km long tectonic lines were predominant. The orientation of these tectonic lines defines an NNW-SSE trend for the least principal stress axis (σ3) and an ENE-WSW trend for the σ1σ2 stress plane of the driving stress regime, fitting well with the transtension stress regime recently suggested for the area. More importantly, the results of this study demonstrate that the Dammam Dome was affected by the intraplate stresses transferred from the convergence between the Arabian and Eurasian plates along the Zagros orogeny.
- Published
- 2022
- Full Text
- View/download PDF
17. Adsorption of Arsenic on Fe-Modified Biochar and Monitoring Using Spectral Induced Polarization
- Author
-
Panagiotis Kirmizakis, Bassam Tawabini, Omer Muhammad Siddiq, Dimitrios Kalderis, Dimitrios Ntarlagiannis, and Pantelis Soupios
- Subjects
biochar ,arsenate ,wastewater ,spectral induced polarization ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
This work demonstrates the potential of Fe-modified biochar for the treatment of arsenic (As) simulated wastewater and the monitoring of adsorption in real-time. Specifically, we propose the utilization of date-palm leaves for the production of biochar, further modified with Fe in order to improve its adsorption function against inorganic pollutants, such as As. Both the original biochar and the Fe-modified biochar were used for adsorption of As in laboratory batch and column experiments. The monitoring of the biochar(s) performance and As treatment was also enhanced by using the spectral induced polarization (SIP) method, offering real-time monitoring, in addition to standard chemical monitoring. Both the original and the Fe-modified biochar achieved high removal rates with Fe-modified biochar achieving up to 98% removal of As compared to the 17% by sand only (control). In addition, a correlation was found between post-adsorption measurements and SIP measurements.
- Published
- 2022
- Full Text
- View/download PDF
18. Seismic Risk Assessment of Chania, Greece, Using an Integrated Computational Approach
- Author
-
Ioannis Koutsoupakis, Yiannis Tsompanakis, Pantelis Soupios, Panagiotis Kirmizakis, SanLinn Kaka, and Costas Providakis
- Subjects
seismic hazard ,assessment ,seismic risk ,vulnerability ,GIS-based tools ,interdependencies ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
This study develops a comprehensive seismic risk model for the city of Chania, in Greece, which is located ina highly seismic-prone region due to the occurrenceof moderate to large earthquakes because of the nearby major subduction zone between African and Eurasian tectonic plates. The main aim is to reduce the seismic risk for the study area by incorporating the spatial distribution of the near-surface shear wave velocity model and the soil classification, along with all possible seismic sources, taking into account historical events. The study incorporates and correlates various ground motion scenarios and geological fault zones as well as information on existing buildings to develop a seismic risk model using QuakeIST software, and then the seismic hazard and a realistic prediction of resulting future adverse effects are assessed. The developed model can assist the municipal authorities of Chania to be prepared for potential seismic events, as well as city planners and decisionmakers, who can use the model as an effective decision-making tool to identify the seismic vulnerability of the city buildings and infrastructure. Thus, this study enables the implementation of an appropriate and viable earthquake-related hazards strategy to mitigate damage and losses in future earthquakes.
- Published
- 2021
- Full Text
- View/download PDF
19. Subsurface Geological Characterization of the Late Neogene–Quaternary Argive Basin, Peloponnese, Greece Using Transient Electromagnetic Data and Vintage Stratigraphic Logs
- Author
-
Hector R. Hinojosa-Prieto, Pantelis Soupios, and Pavel Barsukov
- Subjects
time domain EM ,subsurface exploration ,integrated subsurface imaging ,Geology ,QE1-996.5 - Abstract
The onshore and offshore clastic deposits of the Argive Basin and the Argolic Gulf, respectively, in Peloponnese, Greece, form a Late Neogene–Quaternary half-graben that connects with the Aegean Sea. The onshore Late Neogene–Quaternary sequence, comprised of chaotically intercalated cohesive and granular clastic deposits, is in angular unconformity with bedrock comprised of Triassic–Upper Cretaceous strongly-weathered, highly-fractured karstic limestones thrusted against Paleogene flysch deposits. While the surface geology of the Argive Basin is well-known, the subsurface geology remains both poorly mapped and understood. We utilized transient electromagnetic (TEM) soundings coupled with 185 vintage stratigraphic logs, current surface geology knowledge, and insights from available geophysical surveys to characterize the subsurface conditions of this sedimentary basin. We estimated the thickness of the young deposits (the depth to bedrock) and detected potential subsurface tectonic structures. The TEM-FAST 48HPC data acquisition system with integrated inversion and visualization software package was used with a single-loop dimension of 50 m × 50 m to collect a total of 329 TEM soundings at 151 stations scattered throughout the basin. The TEM station spacing varied from 200 to 750 m allowing the mapping of 80 km2. The total depth of investigation with the inverted TEM data and the lithology logs was 130 m and 183 m, respectively. The joint interpretation produced several quasi-two-dimensional electrical resistivity profiles that traverse the sedimentary basin in various azimuths and depth slices of average electrical resistivity covering the basin. The depth slices and the vintage stratigraphic logs revealed an uneven bedrock topography overlain by an irregularly thick (over 180 m) Late Neogene–Quaternary heterolithic sediment cover.
- Published
- 2021
- Full Text
- View/download PDF
20. Investigating the Structure of a Coastal Karstic Aquifer through the Hydrogeological Characterization of Springs Using Geophysical Methods and Field Investigation, Gökova Bay, SW Turkey
- Author
-
Çağdaş Sağır, Bedri Kurtuluş, Pantelis Soupios, Korhan Ayrancı, Erkan Düztaş, Murat Ersen Aksoy, Özgür Avşar, Günseli Erdem, Emrah Pekkan, Mustafa Can Canoğlu, SanLinn I. Kaka, and Moumtaz Razack
- Subjects
electrical resistivity tomography ,induced polarization ,3D imaging ,karstic aquifer ,Hydraulic engineering ,TC1-978 ,Water supply for domestic and industrial purposes ,TD201-500 - Abstract
The electrical resistivity tomography method has been widely used in geophysics for many purposes such as determining geological structures, water movement, saltwater intrusion, and tectonic regime modeling. Karstic springs are important for water basin management since the karst systems are highly complex and vulnerable to exploitation and contamination. An accurate geophysical model of the subsurface is needed to reveal the spring structure. In this study, several karst springs in the Gökova Bay (SW, Turkey) were investigated to create a 3D subsurface model of the nearby karstic cavities utilizing electrical resistivity measurements. For this approach, 2D resistivity profiles were acquired and interpreted. Stratigraphically, colluvium, conglomerate, and dolomitic-limestone units were located in the field. The resistivity values of these formations were determined considering both the literature and field survey. Then, 2D profiles were interpolated to create a 3D resistivity model of the study area. Medium-large sized cavities were identified as well as their locations relative to the springs. The measured resistivities were also correlated with the corresponding geological units. The results were then used to construct a 3D model that aids to reveal the cavity geometry in the subsurface. Additionally, several faults are detected and their effect on the cavities is interpreted.
- Published
- 2020
- Full Text
- View/download PDF
21. Integrated Approaches to Soil Contamination Monitoring
- Author
-
Pantelis Soupios, Victor Kavvadias, Katherine Huddersman, Francesco Sdao, and Dimitrios Ntarlagiannis
- Subjects
Agriculture (General) ,S1-972 ,Environmental sciences ,GE1-350 - Published
- 2016
- Full Text
- View/download PDF
22. Electrical Imaging for Geohazard and Environmental Monitoring
- Author
-
Vincenzo Lapenna, Sabatino Piscitelli, and Pantelis Soupios
- Subjects
Geophysics. Cosmic physics ,QC801-809 - Published
- 2012
- Full Text
- View/download PDF
23. The Galatas Survey: The Socio-Economic and Political Development of a Contested Territory in Central Crete during the Neolithic to Ottoman Periods
- Author
-
L. Vance Watrous, D. Matthew Buell, Eleni Kokinou, Pantelis Soupios, Apostolos Sarris and L. Vance Watrous, D. Matthew Buell, Eleni Kokinou, Pantelis Soupios, Apostolos Sarris
- Published
- 2017
24. Α study on the Gas-bearing Miocene Sediments of MESSARA Basin in Crete (Greece) by Using Seismic Reflection, Geochemical and Petrophysical Data
- Author
-
George Panagopoulos, Antonios Vafidis, Pantelis Soupios, and Emmanouil Manoutsoglou
- Subjects
Multidisciplinary - Abstract
The focus on exploiting natural gas resources has been increased in the recent years since it was characterized as the transitional fuel to a net-zero era. Consequently, a reevaluation of the gas resources under a new perspective seems to be logical. Within this context, the gas-bearing Miocene sediments of the Messara basin in Crete (Greece) are discussed in this paper. The gas shows have been first reported during the 1990’s, without being thoroughly evaluated. This paper presents the interpretation of eight legacy onshore seismic reflection lines, which led to the construction of the 3D subsurface structural model of the Neogene Messara basin. The seismic data reveals the basin depocenter which accommodates approximately 1500 m of the Miocene sediments. The relationship of the Miocene deposits with the existence of shallow gas is also examined and discussed. New organic geochemical results combined with the published geochemical data are used to discuss the gas generation potential of the Miocene sediments. The porosity and permeability measurements on surface samples are also presented to describe the reservoir characteristics. The integration of the data mentioned above suggests that the Miocene sediments of the Messara basin comprise intervals with adequate organic matter to generate the observed gasses and good reservoir sandstones to accumulate the generated gas. The gas might have been trapped by lateral and vertical facies changes which provide efficient stratigraphic trapping mechanisms.
- Published
- 2022
25. Surface-to-Borehole Electromagnetics Using an Array System: A Case Study for Co2 Monitoring and the Energy Transition
- Author
-
Kurt M. Strack, Cesar Barajas-Olalde, Sophia Davydycheva, Yardenia Martinez, and Pantelis Soupios
- Abstract
Fluid imaging technologies are used in a wide range of E&P applications. Among geophysical methods, electromagnetics (EM) determines subsurface resistivities and thus responds to fluid changes. On the path to zero carbon footprint, the most significant potential for EM lies in monitoring geothermal, carbon capture, utilization and storage (CCUS), and enhancing oil recovery (EOR). To optimize reservoir fluid monitoring, we calibrate surface measurements to well logs resulting in a 3D anisotropic model consistent with borehole data. This is done before and after depletion or injection to estimate a time-lapse reservoir response. As part of a carbon capture and storage project, we carried out baseline measurements and validated the surface EM data to the 3D anisotropic borehole model. The monitoring workflow for this project can easily be adapted for other applications to support the energy transition. From this, we learned that measurement accuracy requirements higher than 1 % because we are often imaging small anomalies. While there are always limits in acquisition set by industrial noise, we derived two ways of increasing the anomaly. One is by using, similar to a borehole focused logs, focusing methods in the acquisition setup. This is still subject to measurement accuracy limitations and limited to electric fields only. Another way is to add borehole sensors that increase the sensitivity by around a factor of 10. While shallow (around 50 m) is sufficient, they can be extended to deeper borehole sensors, bringing the measurements close to the anomaly and is thus the preferred approach. This, in combination with calibration back to the 3D anisotropic borehole log allows you to certify the data for its information content. This will give you quantifiable ways to derive risk values and significantly reduce acquisition and monitoring operations cost.
- Published
- 2022
26. Integrated environmental characterization and assessment of an exposed historic manure repository
- Author
-
Panagiotis Kirmizakis, Hector R. Hinojosa-Prieto, Fotios Bilias, and Pantelis Soupios
- Subjects
Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
27. Removal of arsenic from contaminated groundwater using biochar: a technical review
- Author
-
Pantelis Soupios, Bassam Tawabini, Dimitrios Ntarlagiannis, and O. M. Siddiq
- Subjects
Pollution ,Pollutant ,Environmental Engineering ,Resource (biology) ,media_common.quotation_subject ,Human decontamination ,010501 environmental sciences ,01 natural sciences ,Environmental protection ,Environmental engineering science ,Biochar ,Sustainability ,Environmental Chemistry ,Environmental science ,General Agricultural and Biological Sciences ,Groundwater ,0105 earth and related environmental sciences ,media_common - Abstract
Groundwater is considered as the primary source of drinking water in many countries around the world. For maintaining resource sustainability, clean and safe groundwater is a priority for water authorities worldwide. Unfortunately, groundwater resources are susceptible to various types of pollution, with arsenic (As) being a major pollutant in certain areas due to natural or anthropogenic activities. Due to its adverse health effects, As, a class-1 carcinogen, has been a topic of intense research. The technical difficulty and high cost incurred by conventional treatment systems for As removal have led many researchers to work on developing efficient, eco-friendly, and cost-effective technologies for the treatment of groundwater sources. Biochar has been widely used as an adsorbent for the decontamination of groundwater. High As removal rates have been achieved following metal (Fe, Zn, Mn) impregnation and magnetic modification to biochar. Despite numerous researches on biochar for As removal, very limited efforts have been made for upscaling to a convenient treatment system. Thus, this review highlights key findings of previous studies required for pragmatic applications. Following up with future trends, an overview is given on real-time monitoring techniques that can be combined with biochar for evaluating adsorption studies. Furthermore, research opportunities that exist in biochar adsorption studies have also been identified. This technical review is aimed for scientists, scholars and researchers as a supplementary guide for understanding As decontamination processes, highlighting the role of biochar as an adsorbent and conceptualizing the prospects of integration of real-time monitoring techniques.
- Published
- 2021
28. Joint Inversion of Seismic and DC Geophysical Data Using Local and Global Optimization Algorithms
- Author
-
Paul Edigbue, Ismail Demirci, Hamdan Hamdan, Abdullatif Al-Shuhail, Irfan Akca, Pantelis Soupios, and Emin Candansayar
- Abstract
Geophysical inversion is usually carried out to quantitatively analyze the earth model and estimate its physical properties. Successful delineation of these properties such as layer boundaries, or other near-surface structures are crucial to understand the near-surface inhomogeneity. In this study, we focus on the use of joint inversion of seismic refraction and geoelectrical resistivity datasets using local and global optimization methods. The idea is to integrate the two optimization techniques to minimize the challenges faced by each algorithm when applied alone. This hybrid algorithm (local and global) is applied on synthetic data representing simple resistivity and velocity models. About 70% of the anomalies in both seismic and DC resistivity methods were reconstructed in terms of amplitude and geometry using the local optimization algorithm, while the global optimization algorithm shows improved results as it reconstructed about 80% of the amplitude and geometry of the anomalies in both geophysical methods. The result of the synthetic application shows that the hybrid algorithm provides promising outputs in terms of resolution, geometry and amplitude of the anomalies, and computation run time.
- Published
- 2022
29. A web-based GIS platform supporting innovative irrigation management techniques at farm-scale for the Mediterranean island of Crete
- Author
-
Nektarios N. Kourgialas, Angelos Hliaoutakis, Athanasios V. Argyriou, Giasemi Morianou, Apostolos E. Voulgarakis, Eleni Kokinou, Ioannis N. Daliakopoulos, Dimitrios Kalderis, Konstantinos Tzerakis, Georgios Psarras, Nikos Papadopoulos, Thrassyvoulos Manios, Antonios Vafidis, and Pantelis Soupios
- Subjects
Crops, Agricultural ,Internet ,Soil ,Environmental Engineering ,Agricultural Irrigation ,Farms ,Greece ,Geographic Information Systems ,Environmental Chemistry ,Water ,Agriculture ,Pollution ,Waste Management and Disposal - Abstract
The aim of this paper is the creation of an integrated and free-access web platform for parcel irrigation water management on a large spatial scale (Water District of Crete, in Greece) in order to: a) accurately determine the irrigation needs of the main crops for Crete such as olives, citrus, avocados and vineyards, b) design strategies, for optimal adaptation of the agricultural sector in the context of climate change, and c) incorporate the dynamic integration of the above information through the creation of a digital platform. In the proposed decision-making system, essential factors are taken into account, such as real-time meteorological data, information about the type and spatial distribution of the agricultural parcels in Crete, algorithms for calculation crop evapotranspiration per development stage and age of the crops, satellite remote sensing techniques in combination with field surveys to depict accurate soil texture map for the whole island of Crete as well as sustainable cultivation practices for saving water per crop and parcel geomorphology. Based on the proposed decision-making system, users will have the opportunity in any specific location/farm in Crete to know the irrigation needs of the crops in real-time and obtain information about proper climate-water adaptation practices. The main novelty points of the proposed platform include the derivation of parcel-level soil texture data from Sentinel-2 satellite imagery and field samples, the comprehensiveness of the irrigation management information, the relatively low data requirements and the application interface simplicity provided to the end-user.
- Published
- 2022
30. Preliminary assessment on the application of biochar and spectral‐induced polarization for wastewater treatment
- Author
-
Pantelis Soupios, Panagiotis Kirmizakis, Dimitrios Ntarlagiannis, and Dimitris Kalderis
- Subjects
010504 meteorology & atmospheric sciences ,Spectral induced polarisation ,Environmental remediation ,010502 geochemistry & geophysics ,01 natural sciences ,Industrial wastewater treatment ,chemistry.chemical_compound ,Geophysics ,chemistry ,Environmental chemistry ,Biochar ,Degradation (geology) ,Phenol ,Sewage treatment ,Polarization (electrochemistry) ,Geology ,0105 earth and related environmental sciences - Abstract
In this work, we explore the use of biochar as a remediation agent, and the sensitivity of the spectral‐induced polarization method as a remediation monitoring aid. Biochar amended columns were fully saturated with industrial wastewater (olive oil mill waste) with very high concentration of phenols (∼2485 mg/L) and other substances. The biochar‐amended columns achieved very high removal rates of phenols compared to the control (sand only). Geophysical monitoring over the duration of the experiment (10 days) showed changes in the spectral‐induced polarization signal (imaginary conductivity) consistent with phenol removal as confirmed by geochemical monitoring. This experiment confirmed the utility of biochar as a remediation agent. Furthermore, spectral‐induced polarization can serve as long‐term, high resolution, monitoring aid in organic contaminant degradation processes.
- Published
- 2020
31. Gravity Survey of King Fahd University of Petroleum and Minerals Dammam Dome, Saudi Arabia
- Author
-
Pantelis Soupios, Alexandros Stampolidis, Maurizio Fedi, SanLinn Kaka, Khalid Al-Ramadan, Gregory Tsokas, and Roman Pasteka
- Abstract
The study area is a part of Dammam Dome that is situated at King Fahd University of Petroleum & Minerals (KFUPM) campus, Dhahran, Kingdom of Saudi Arabia. The gravity survey was conducted as a pilot case study to explore part of Dammam Dome in greater detail. Gravity data were collected solely during night hours due to low noise levels. A significant part of the survey was conducted during the summer holiday period, , when there was no student are on campus. A total of 235 gravity measurements were made using a Scintrex CG5 gravitometer, while a Trimble R10+ differential GPS (DGPS) was used to measure the stations’ location and elevation with the highest accuracy. All gravity data were reduced using several algorithms, and their outcomes were cross-compared. The Complete Bouguer anomaly map for the campus was then generated. Several enhancement filters including edged detection and shallow to deeper source separation were applied. Data were inverted, and 2.5D and 3D models were created to image the subsurface conditions. The main purpose of this study is to better understand the subsurface geology, tectonic settings of the Dammam Dome by applying the high-resolution gravity method before carrying out any comprehensive geophysical (seismic) 3D survey.
- Published
- 2021
32. Seismic Risk Assessment of Chania, Greece, Using an Integrated Computational Approach
- Author
-
Pantelis Soupios, Panagiotis Kirmizakis, Costas P. Providakis, SanLinn I. Kaka, Ioannis Koutsoupakis, and Yiannis Tsompanakis
- Subjects
Ground motion ,Technology ,QH301-705.5 ,assessment ,QC1-999 ,vulnerability ,Vulnerability ,interdependencies ,Assessment ,Seismic hazard ,Large earthquakes ,Seismic risk ,General Materials Science ,Biology (General) ,QD1-999 ,Instrumentation ,Vulnerability (computing) ,Fluid Flow and Transfer Processes ,seismic hazard ,seismic risk ,GIS-based tools ,Subduction ,Physics ,Process Chemistry and Technology ,Interdependencies ,Wave velocity ,General Engineering ,Engineering (General). Civil engineering (General) ,Computer Science Applications ,Chemistry ,TA1-2040 ,Seismology - Abstract
Summarization: This study develops a comprehensive seismic risk model for the city of Chania, in Greece, which is located ina highly seismic-prone region due to the occurrenceof moderate to large earthquakes because of the nearby major subduction zone between African and Eurasian tectonic plates. The main aim is to reduce the seismic risk for the study area by incorporating the spatial distribution of the near-surface shear wave velocity model and the soil classification, along with all possible seismic sources, taking into account historical events. The study incorporates and correlates various ground motion scenarios and geological fault zones as well as information on existing buildings to develop a seismic risk model using QuakeIST software, and then the seismic hazard and a realistic prediction of resulting future adverse effects are assessed. The developed model can assist the municipal authorities of Chania to be prepared for potential seismic events, as well as city planners and decisionmakers, who can use the model as an effective decision-making tool to identify the seismic vulnerability of the city buildings and infrastructure. Thus, this study enables the implementation of an appropriate and viable earthquake-related hazards strategy to mitigate damage and losses in future earthquakes. Παρουσιάστηκε στο: Applied Sciences
- Published
- 2021
- Full Text
- View/download PDF
33. Comprehensive Geophysical Study at Wabar Crater, Rub Al‐Khali Desert, Saudi Arabia
- Author
-
Khalid Al-Ramadan, Abdullatif A. Al-Shuhail, Alexandros Stampolidis, Ignatius Argadestya, Pantelis Soupios, Theis I. Sølling, Christian Koch, and Sherif M. Hanafy
- Subjects
QE1-996.5 ,magnetic ,Outcrop ,GPR ,Astronomy ,Geochemistry ,Drilling ,QB1-991 ,Geology ,Environmental Science (miscellaneous) ,Impact crater ,Remote sensing (archaeology) ,Ground-penetrating radar ,TEM ,seismic ,General Earth and Planetary Sciences - Abstract
Interest in impact craters on the earth's surface has increased worldwide and is being investigated by using remote sensing, geological, boreholes, geophysical, and laboratory measurements. These measurements are used to build dynamic models to study crater formation. In this work, the near‐crater sediments at the young Wabar crater field in Saudi Arabia have been investigated using magnetic, transient electromagnetic (TEM), seismic, and ground‐penetrating radar (GPR) methods. The main objectives of this research were to (a) explore the possibility of any remnant major pieces of the meteorite, (b) investigate the meteoroid direction, and (c) map the deformational structures associated with the meteorite impact. Our results show five different magnetic anomaly types and three layers in the subsurface. The maximum depth of deformation due to the impact of the meteorite is about 25 m as shown by the seismic travel time tomogram, the quasi‐2D TEM, and the 3D GPR model. TEM survey confirmed the geometrical characteristics of the major crater and located another small crater (known as Philby‐A). The magnetic survey shows no evidence of any remnant major pieces of the meteorite; however, it was used to trace ejecta material containing highly dilute magnetic material. The magnetic carrier is most likely spheres of metal incorporated in the black/green glasses. During the expedition, many small pieces of the meteoroid were found and collected for further geochemical analysis. Based on the geophysical findings, the meteorite direction was found to be from north to south.
- Published
- 2021
34. Subsurface Geological Characterization of the Late Neogene–Quaternary Argive Basin, Peloponnese, Greece Using Transient Electromagnetic Data and Vintage Stratigraphic Logs
- Author
-
Pavel Barsukov, Hector R. Hinojosa-Prieto, and Pantelis Soupios
- Subjects
geography ,QE1-996.5 ,Flysch ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Lithology ,Bedrock ,Inversion (geology) ,integrated subsurface imaging ,Geology ,Sedimentary basin ,010502 geochemistry & geophysics ,01 natural sciences ,Unconformity ,Paleontology ,subsurface exploration ,Clastic rock ,General Earth and Planetary Sciences ,time domain EM ,Paleogene ,0105 earth and related environmental sciences - Abstract
The onshore and offshore clastic deposits of the Argive Basin and the Argolic Gulf, respectively, in Peloponnese, Greece, form a Late Neogene–Quaternary half-graben that connects with the Aegean Sea. The onshore Late Neogene–Quaternary sequence, comprised of chaotically intercalated cohesive and granular clastic deposits, is in angular unconformity with bedrock comprised of Triassic–Upper Cretaceous strongly-weathered, highly-fractured karstic limestones thrusted against Paleogene flysch deposits. While the surface geology of the Argive Basin is well-known, the subsurface geology remains both poorly mapped and understood. We utilized transient electromagnetic (TEM) soundings coupled with 185 vintage stratigraphic logs, current surface geology knowledge, and insights from available geophysical surveys to characterize the subsurface conditions of this sedimentary basin. We estimated the thickness of the young deposits (the depth to bedrock) and detected potential subsurface tectonic structures. The TEM-FAST 48HPC data acquisition system with integrated inversion and visualization software package was used with a single-loop dimension of 50 m × 50 m to collect a total of 329 TEM soundings at 151 stations scattered throughout the basin. The TEM station spacing varied from 200 to 750 m allowing the mapping of 80 km2. The total depth of investigation with the inverted TEM data and the lithology logs was 130 m and 183 m, respectively. The joint interpretation produced several quasi-two-dimensional electrical resistivity profiles that traverse the sedimentary basin in various azimuths and depth slices of average electrical resistivity covering the basin. The depth slices and the vintage stratigraphic logs revealed an uneven bedrock topography overlain by an irregularly thick (over 180 m) Late Neogene–Quaternary heterolithic sediment cover.
- Published
- 2021
35. Utilization of Artificial Neural Network in Predicting the Total Organic Carbon in Devonian Shale Using the Conventional Well Logs and the Spectral Gamma Ray
- Author
-
Osama Siddig, Pantelis Soupios, Salaheldin Elkatatny, and Ahmed Abdulhamid Mahmoud
- Subjects
General Computer Science ,Correlation coefficient ,Article Subject ,General Mathematics ,Computer applications to medicine. Medical informatics ,Well logging ,R858-859.7 ,Neurosciences. Biological psychiatry. Neuropsychiatry ,Soil science ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Correlation ,020401 chemical engineering ,Sensitivity (control systems) ,0204 chemical engineering ,0105 earth and related environmental sciences ,Total organic carbon ,Artificial neural network ,General Neuroscience ,General Medicine ,Carbon ,Data point ,Gamma Rays ,Environmental science ,Neural Networks, Computer ,Oil shale ,RC321-571 ,Research Article - Abstract
Due to high oil and gas production and consumption, unconventional reservoirs attracted significant interest. Total organic carbon (TOC) is a significant measure of the quality of unconventional resources. Conventionally, TOC is measured experimentally; however, continuous information about TOC is hard to obtain due to the samples’ limitations, while the developed empirical correlations for TOC were found to have modest accuracy when applied in different datasets. In this paper, data from Devonian Duvernay shale were used to develop an optimized empirical correlation to predict TOC based on an artificial neural network (ANN). Three wells’ datasets were used to build and validate the model containing over 1250 data points, and each data point includes values for TOC, density, porosity, resistivity, gamma ray and sonic transient time, and spectral gamma ray. The three datasets were used separately for training, testing, and validation. The results of the developed correlation were compared with three available models. A sensitivity and optimization test was performed to reach the best model in terms of average absolute percentage error (AAPE) and correlation coefficient (R) between the actual and predicted TOC. The new correlation yielded an excellent match with the actual TOC values with R values above 0.93 and AAPE values lower than 14%. In the validation dataset, the correlation outperformed the other empirical correlations and resulted in less than 10% AAPE, in comparison with over 20% AAPE in other models. These results imply the applicability of this correlation; therefore, all the correlation’s parameters are reported to allow its use on different datasets.
- Published
- 2021
36. 3D modelling of a hydrological structure combining spatial data science and geophysics: Application to a coastal aquifer system in the island of Crete, Greece
- Author
-
Emmanouil Varouchakis, Leonardo Azevedo, Ioannis Trichakis, George P. Karatzas, Seifeddine Jomaa, and Pantelis Soupios
- Subjects
3d modelling ,coastal aquifer ,crete ,hydrological modelling - Abstract
Groundwater resources in Mediterranean coastal aquifers are under threat due to overexploitation and climate change impacts, resulting in saltwater intrusion. This situation is deteriorated by the absence of sustainable groundwater resources management plans. Efficient management and monitoring of groundwater systems requires interpreting all sources of available data. This work aims at the development of a set of plausible 3D geological models combining 2D geophysical profiles, spatial data analytics and geostatistical simulation techniques. The resulting set of models represents possible scenarios of the structure of the coastal aquifer system under investigation. Inverted resistivity profiles, along with borehole data, are explored using spatial data science techniques to identify regions associated with higher uncertainty. Relevant parts of the profiles will be used to generate 3D models after detailed Anisotropy and variogram analysis. Multidimensional statistical techniques are then used to select representative models of the true subsurface while exploring the uncertainty space. The resulting models will help to identify primary gaps in existing knowledge about the groundwater system and to optimize the groundwater monitoring network. A comparison with a numerical groundwater flow model will identify similarities and differences and it will be used to develop a typical hydrogeological model, which will aid the management and monitoring of the area's groundwater resources. This work will help the development of a reliable groundwater flow model to investigate future groundwater level fluctuations at the study area under climate change scenarios.
- Published
- 2021
37. Monitoring time evolution of self-potential anomaly sources by a new global optimization approach. Application to organic contaminant transport
- Author
-
Eleonora Vitagliano, Payal Rani, Rosa Di Maio, Ester Piegari, Leopoldo Milano, Pantelis Soupios, Rani, P., Piegari, E., DI MAIO, Rosa, Vitagliano, E., Soupios, P., and Milano, L.
- Subjects
Mediterranean climate ,Hydrogeology ,010504 meteorology & atmospheric sciences ,Environmental remediation ,Anomaly (natural sciences) ,0207 environmental engineering ,Soil science ,02 engineering and technology ,Contamination ,Organic contaminated soil, Self-potential monitoring, Global optimization, Contamination source identification ,01 natural sciences ,Vadose zone ,Environmental science ,Diffusion (business) ,020701 environmental engineering ,Global optimization ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
Complex interactions among organic contaminant, soil and water change the electrical properties of the subsurface often causing strong self-potential (SP) anomalies, whose monitoring is proposed as a useful tool to determine the temporal evolution of the contaminant plumes. In the present study, we focus on the problem of organic contaminant transport related to olive oil mill wastes (OOMWs), which represent an important environmental problem in Mediterranean countries. The diffusion of the contaminants into the subsurface is studied by using a global optimization procedure on SP data measured, at different times, in a well-studied contaminated pilot area located next to the Keritis river in western Crete island (Greece). Despite the complex hydrogeological conditions related to the proximity to both the Keritis river and a small seasonal stream, the analysis of five SP datasets acquired along the same profile shows that the proposed hybrid Genetic-Price algorithm is able to reproduce the main features of the SP signals, thus identifying probable multiple SP anomaly sources and their changes over time. In particular, preferential horizontal pathways of OOMW and their migration in the vadose zone during the summer season were identified, providing some useful insights for future planning of remediation actions.
- Published
- 2019
38. SpaCeborne SAR Interferometry as a Noninvasive tool to assess the vulnerability over Cultural hEritage sites (SCIENCE)
- Author
-
Vassiliki Sythiakaki, Dionysia Michalopoulou, Constantinos Loupasakis, Dionysia Mavromati, Eleni Grigorakou, Rozalia Christodoulopoulou, Vasiliki Eleutheriou, Panagiotis Elias, Georgia Kalousi, Pantelis Soupios, Eleni Kanaki, Zeinep Achmet, Michalis Fragkiadakis, Issaak Parcharidis, Theodoros Gatsios, and Athanasia-Maria Tompolidi
- Subjects
Cultural heritage ,Interferometry ,Geography ,business.industry ,Environmental resource management ,Vulnerability ,business - Abstract
Cultural heritage is a key element of history as the ancient monuments and archaeological sites enrich today’s societies and help connect us to our cultural origins. The project entitled ''SpaCeborne SAR Interferometry as a Nonivasive tool to assess the vulnerability over Cultural hEritage sites (SCIENCE)'' has as ultimate objective to predict the vulnerability of the archaeological sites to ground deformation in time and space and protect them against natural/man-made damage. The SCIENCE project aims to develop, demonstrate, and validate, in terms of geotechnical local conditions and monuments’ structural health, SAR interferometric techniques to monitor potential ground deformation affecting the archaeological sites and monuments of great importance. During the last few years, spaceborne Synthetic Aperture Radar (SAR) interferometry has proven to be a powerful remote sensing tool for detecting and measuring ground deformation and studying the deformation’s impact on man-made structures. It provides centimeter to millimeter resolution and even single buildings/monuments can be mapped from space. Considering the limitations of conventional MT-InSAR techniques, such as Persistent Scatterers Interferometry (PSI), in this project a two-step Tomography-based Persistent Scatterers (PS) Interferometry (Tomo-PSInSAR) approach is proposed for monitoring ground deformation and structural instabilities over the Ancient City Walls (Ming Dynasty) in Nanjing city, China and in the Great Wall in Zhangjiakou, China. The Tomo-PSInSAR is capable of separating overlaid PS in the same location, minimizing the unfavorable layover effects of slant-range imaging in SAR data. Moreover, the demonstrations are performed on well-known test sites in China and in Greece, such as: a) Ming Dynasty City Walls in Nanjing, b) Great Wall in Zhangjiakou, c) Acropolis complex of Athens and d) Heraklion walls (Crete Island), respectively.In particular, in the framework of SCIENCE project are processed several radar datasets such as Sentinel 1 A & B data of Copernicus program and the high resolution TerraSAR-X data. The products of Persistent Scatterers Interferometry (PSI) are exported in various formats for the identification of the persistent scatterers using high resolution optical images, aerial photographs and fusing with high accuracy Digital Surface Models (DSM). In addition, the validation of the results is taking place through in-situ measurements (geological, geothechnical e.t.c) and data for the cultural heritage sites conditions.SCIENCE project’s final goal is the risk assessment analysis of the cultural heritage monuments and their surrounding areas aiming to benefit institutions, organizations, stakeholders and private agencies in the cultural heritage domain through the creation of a validated pre-operation non-invasive system and service based on earth observation data supporting end-user needs by the provision knowledge about cultural heritage protection. In conclusion, SCIENCE project is composed by a bilateral consortium of the Greek delegation of Harokopio University of Athens, National Technical University of Athens, Terra Spatium S.A, Ephorate of Antiquities of Heraklion (Crete), Acropolis Restoration Service (Athens) of Ministry of Culture and Sports and by the Chinese delegation of Science Academy of China (Institute of Remote Sensing and Digital Earth) and International Centre on Space Technologies for Natural and Cultural Heritage (HIST) under the auspices of UNESCO (HIST-UNESCO).
- Published
- 2021
39. 3D modelling of a hydrological structure combining spatial data science and geophysics: Application to a coastal aquifer system in the island of Crete, Greece
- Author
-
Seifeddine Jomaa, João Lino Pereira, Ioannis Trichakis, Leonardo Azevedo, George P. Karatzas, Pantelis Soupios, and Emmanouil A. Varouchakis
- Subjects
Coastal aquifer ,Earth science ,Spatial analysis ,Geology - Abstract
Groundwater resources in Mediterranean coastal aquifers are under threat due to overexploitation and climate change impacts, resulting in saltwater intrusion. This situation is deteriorated by the absence of sustainable groundwater resources management plans. Efficient management and monitoring of groundwater systems requires interpreting all sources of available data. This work aims at the development of a set of plausible 3D geological models combining 2D geophysical profiles, spatial data analytics and geostatistical simulation techniques. The resulting set of models represents possible scenarios of the structure of the coastal aquifer system under investigation. Inverted resistivity profiles, along with borehole data, are explored using spatial data science techniques to identify regions associated with higher uncertainty. Relevant parts of the profiles will be used to generate 3D models after detailed Anisotropy and variogram analysis. Multidimensional statistical techniques are then used to select representative models of the true subsurface while exploring the uncertainty space. The resulting models will help to identify primary gaps in existing knowledge about the groundwater system and to optimize the groundwater monitoring network. A comparison with a numerical groundwater flow model will identify similarities and differences and it will be used to develop a typical hydrogeological model, which will aid the management and monitoring of the area's groundwater resources. This work will help the development of a reliable groundwater flow model to investigate future groundwater level fluctuations at the study area under climate change scenarios. This work was developed under the scope of the InTheMED project. InTheMED is part of the PRIMA programme supported by the European Union’s Horizon 2020 research and innovation programme under grant agreement No 1923.
- Published
- 2021
40. Combining geophysics and material science for environmental remediation: Real-time monitoring of Fe-biochar arsenic wastewater treatment
- Author
-
Bassam Tawabini, Dimitrios Kalderis, M.O. Siddiq, Pantelis Soupios, Dimitrios Ntarlagiannis, and Panagiotis Kirmizakis
- Subjects
Environmental Engineering ,Spectral induced polarisation ,Environmental remediation ,Health, Toxicology and Mutagenesis ,Materials Science ,Public Health, Environmental and Occupational Health ,chemistry.chemical_element ,General Medicine ,General Chemistry ,Pollution ,Arsenic ,Water Purification ,Wastewater ,chemistry ,Environmental chemistry ,Charcoal ,Biochar ,Environmental Chemistry ,Environmental science ,Sewage treatment ,Adsorption ,Environmental Restoration and Remediation ,Water Pollutants, Chemical - Abstract
In a column set-up, Fe modified biochar produced from date palm leaves was used to remove As (1 mg L−1) from a laboratory-prepared wastewater. The wastewater treatment process was monitored in real-time by spectral induced polarization (SIP), over a wide range of frequencies (0.01–1000 Hz). Both 5 and 10% biochar-amended columns achieved As removal exceeding 98%. The SIP parameters appear to be sensitive on As removal processes, with the recorded trend following the conventional geochemical monitoring, while offering higher temporal resolution.
- Published
- 2020
41. Neotectonic control on drainage systems: GIS-based geomorphometric and morphotectonic assessment for Crete, Greece
- Author
-
Athanasios V. Argyriou, Richard Teeuw, Apostolos Sarris, and Pantelis Soupios
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Subduction ,Landform ,Drainage basin ,Morphotectonics ,Geology ,010502 geochemistry & geophysics ,01 natural sciences ,Tectonics ,Geoinformatics ,Geomorphometrics ,Earth Sciences ,Drainage ,Geomorphology ,0105 earth and related environmental sciences - Abstract
Geomorphic indices can be used to examine the geomorphological and tectonic processes responsible for the development of the drainage basins. Such indices can be dependent on tectonics, erosional processes and other factors that control the morphology of the landforms. The inter-relationships between geomorphic indices can determine the influence of regional tectonic activity in the shape development of drainage basins. A Multi-Criteria Decision Analysis (MCDA) procedure has been used to perform an integrated cluster analysis that highlights information associated with the dominant regional tectonic activity. Factor Analysis (FA) and Analytical Hierarchy Process (AHP) were considered within that procedure, producing a representation of the distributed regional tectonic activity of the drainage basins studied. The study area is western Crete, located in the outer fore-arc of the Hellenic subduction zone, one of the world's most tectonically active regions. The results indicate that in the landscape evolution of the study area (especially the western basins) tectonic controls dominate over lithological controls.
- Published
- 2017
42. Recent advances in the application of nanomaterials for the remediation of arsenic-contaminated water and soil
- Author
-
Leila Alidokht, Pantelis Soupios, Ioannis Anastopoulos, Alireza Khataee, Dimitrios Kalderis, Dimitrios Ntarlagiannis, and Bassam Tawabini
- Subjects
Contaminated soils ,Environmental remediation ,Process Chemistry and Technology ,Engineered nanomaterials ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Nanomaterials ,Contaminated water ,chemistry ,Chemical Engineering (miscellaneous) ,Environmental science ,Leaching (agriculture) ,0210 nano-technology ,Waste Management and Disposal ,Arsenic ,0105 earth and related environmental sciences - Abstract
This review specifically deals with the latest advances in the application of nanotechnologies and nanocomposites for remediation of arsenic (As)-contaminated water and soil. Remediation mechanisms generally include physicochemical adsorption and (photo)chemical redox reactions and filtration. Recently, various types of engineered organic/inorganic nanocomposites have been designed in membrane forms, embedded structures, or composites with extraordinary physical-chemical properties, and outstanding capacity for removal or immobilization of As in contaminated sites. In the present article, we give an overview of engineered nanomaterials developed recently (2017–2021) and their interaction mechanisms with As in contaminated water and soil. Emerging approaches include the development of bio-nanocomposites and nanomaterials that show both oxidative and adsorptive capacities. For the first time, we set out to perform a comprehensive assessment of the advantages of nanomaterials in As-contaminated soils with the focus on the mechanisms of decreasing bioavailability and leaching of As. Although great researches have been developed, serious study gaps and a new direction to future researches have been identified.
- Published
- 2021
43. Geological and geophysical investigations of an engineering site characterization for construction purposes in Western Saudi Arabia
- Author
-
Abdullah Abobakr Al-Mashhor, SanLinn I. Kaka, Mansour A. Al-Garni, Pantelis Soupios, Markos D. Tranos, Anastasios Plougarlis, Abdullatif A. Al-Shuhail, and Paul Edigbue
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Bedrock ,Geophysics ,Fault (geology) ,010502 geochemistry & geophysics ,Geologic map ,01 natural sciences ,Depth sounding ,Lead (geology) ,Fracture (geology) ,Electrical resistivity tomography ,Subsurface flow ,Geology ,0105 earth and related environmental sciences - Abstract
Characterizing subsurface site conditions and understanding main geological features are critical components of any safety assessment for any construction, particularly defining subsurface flow paths and weakness (i.e. fracture and fault) zones. Poor definition of flow paths and weakness zones may lead to serious hazards during construction. This study, integrating geophysical and geological investigations, is undertaken to enhance the understanding of both surface and subsurface complexities of an engineering site characterization located in western Saudi Arabia near Red Sea. Two geophysical investigations, Electrical Resistivity Tomography (ERT) and Transient Electromagnetic (TEM), were carried out to characterize the subsurface of the study area. A total of three ERT profiles and sixteen TEM sounding measurements was conducted in the study area. Geological investigation was mainly focused to understanding geological features and bedrock conditions of the two opposite river's abutments at the study site. Geophysical results show NNE-SSW and NNW-SSE fault zones which were confirmed by in-situ geological inspections and by satellite images. The results also reveal the presence of geothermal fluids validated by the observation of hot water flowing in the river along the measurements. This study demonstrates that the integrated geophysical and geological investigations provide means to infer geothermal fluids, locate fractures, and fault zones. This study enabled us to characterize and locate the geological structural framework as well as possible geothermal fluids existence in the study area.
- Published
- 2021
44. Two dimensional joint inversion of direct current resistivity, radio-magnetotelluric and seismic refraction data: An application from Bafra Plain, Turkey
- Author
-
Antonis Vafidis, M.E. Candansayar, Pantelis Soupios, and İsmail Demirci
- Subjects
Hydrogeology ,010504 meteorology & atmospheric sciences ,Inversion (meteorology) ,010502 geochemistry & geophysics ,01 natural sciences ,Synthetic data ,Weighting ,Depth sounding ,Geophysics ,Magnetotellurics ,Electrical resistivity and conductivity ,Seismic refraction ,Seismology ,Geology ,0105 earth and related environmental sciences - Abstract
Direct current resistivity, radio-magnetotelluric and seismic refraction methods are widely used in the identification of near surface structures with collected data generally being interpreted separately. In recent decades, the use of joint inversion algorithms in geosciences has become widespread to identify near surface structures. However, there is no developed joint inversion algorithm using direct current resistivity, radio-magnetotelluric and seismic refraction methods. In this study, we developed a new two-dimensional joint inversion algorithm for direct current resistivity, radio-magnetotelluric and seismic refraction data based on a cross gradient approach. In addition, we proposed a new data weighting matrix to stabilize the convergence behavior of the joint inversion algorithms. We used synthetic data to show the advantage of the algorithm. The developed joint inversion algorithm found resistivity and velocity models that are better than the individual inversion of each data set. We also tested an algorithm with the field data collected in the Bafra Plain (Samsun, Turkey) to investigate saltwater intrusion. In comparing the field data inversion results with the sounding log, it can be seen that the developed joint inversion algorithm with the proposed data weighting matrix recovered the resistivity and velocity model better than the individual inversion and classical joint inversion of each data set. Our results showed that a more unique hydrogeological scenario might be obtained, especially in highly conductive media, with the joint usage of these methods. (C) 2017 Elsevier B.V. All rights reserved.
- Published
- 2017
45. Field-scale electrical geophysics over an olive oil mill waste deposition site: Evaluating the information content of resistivity versus induced polarization (IP) images for delineating the spatial extent of organic contamination
- Author
-
Dimitrios Ntarlagiannis, Lee Slater, Pantelis Soupios, and Judith Robinson
- Subjects
Observational error ,Hydrogeology ,010504 meteorology & atmospheric sciences ,Mineralogy ,Conductivity ,Contamination ,010502 geochemistry & geophysics ,01 natural sciences ,Induced polarization ,Plume ,Geophysics ,Data acquisition ,Electrical resistivity and conductivity ,Geology ,0105 earth and related environmental sciences - Abstract
We performed 2D resistivity and IP measurements over a known olive oil mill waste plume at a site in western Crete, Greece. The objectives of the survey were: (1) to determine whether IP is more diagnostic in delineating the spatial extent of the plume relative to resistivity measurements alone; (2) to evaluate whether the additional information content obtained from IP is worth the effort given longer data acquisition times and higher measurement errors that inevitably characterize field IP data acquisition. Complex conductivity inversion of the field IP dataset revealed that the organic plume is characterized as a region of high electrical conductivity (real part of complex conductivity) consistent with the conceptual model for the electrical structure of a biodegraded LNAPL contaminant plume. The plume is also characterized by a region of high polarizability (imaginary part of complex conductivity) that is more localized to the known plume location (based on conventional monitoring) relative to the high conductivity region in the electrical conductivity image. This observation is attributed to the fact that electrical conductivity is more strongly controlled by hydrogeological and geological characteristics of the site that mask the response from the biodegraded plume. This result encourages the use of field IP to improve the spatial delineation of organic contamination in the subsurface. However, more laborious field procedures are required to acquire reliable field IP data and the inversion of field IP data remains more challenging than resistivity data alone.
- Published
- 2016
46. Combining electromagnetic measurements in the Mygdonian sedimentary basin, Greece
- Author
-
Pantelis Soupios, U.A. Autio, Alexandros Savvaidis, Mehrdad Bastani, and M. Yu. Smirnov
- Subjects
geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Exploration geophysics ,Inversion (meteorology) ,Geophysics ,Structural basin ,Sedimentary basin ,010502 geochemistry & geophysics ,01 natural sciences ,Magnetotellurics ,Static shift ,Impedance tensor ,Seismology ,Geology ,0105 earth and related environmental sciences ,Controlled source - Abstract
We present a novel approach where time-domain electromagnetic (TEM) data are transformed and subsequently used in two-dimensional (2-D) magnetotelluric inversion of the determinant of the impedance tensor. The main idea is to integrate TEM with magnetotelluric (MT) data to produce subsurface electrical resistivity models. Specifically, we show that 2-D MT data inversion of the determinant of the impedance tensor supported by inclusion of TEM–MT-transformed data has superior resolution at the near surface and at the same time static shift afflicting the MT data can be addressed. Thus, the approach allows for practical express integration of TEM data with MT measurements as opposed to a full combined 3-D inversion, which requires significant resources. The approach is successfully applied in the Mygdonian sedimentary basin located in Northern Greece. In addition to TEM and MT data, also controlled source — and radiomagnetotelluric data are available from the Mygdonian basin, which have been subjected to 2-D analysis previously. We have extended the analysis to a full 3-D inversion using ModEM code. All obtained models are analysed and are in a good agreement.
- Published
- 2016
47. Investigating the Structure of a Coastal Karstic Aquifer through the Hydrogeological Characterization of Springs Using Geophysical Methods and Field Investigation, Gökova Bay, SW Turkey
- Author
-
Mustafa Can Canoğlu, SanLinn I. Kaka, Emrah Pekkan, Pantelis Soupios, Murat Ersen Aksoy, Günseli Erdem, Moumtaz Razack, Çağdaş Sağır, Erkan Düztaş, Özgür Avşar, Korhan Ayrancı, and Bedri Kurtuluş
- Subjects
lcsh:Hydraulic engineering ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,induced polarization ,Aquatic Science ,010502 geochemistry & geophysics ,01 natural sciences ,Biochemistry ,Induced polarization ,lcsh:Water supply for domestic and industrial purposes ,lcsh:TC1-978 ,3D imaging ,Spring (hydrology) ,Saltwater intrusion ,Electrical resistivity tomography ,0105 earth and related environmental sciences ,Water Science and Technology ,Colluvium ,lcsh:TD201-500 ,geography ,geography.geographical_feature_category ,Hydrogeology ,Geophysics ,Karst ,Tectonics ,electrical resistivity tomography ,karstic aquifer ,Geology - Abstract
The electrical resistivity tomography method has been widely used in geophysics for many purposes such as determining geological structures, water movement, saltwater intrusion, and tectonic regime modeling. Karstic springs are important for water basin management since the karst systems are highly complex and vulnerable to exploitation and contamination. An accurate geophysical model of the subsurface is needed to reveal the spring structure. In this study, several karst springs in the Gö, kova Bay (SW, Turkey) were investigated to create a 3D subsurface model of the nearby karstic cavities utilizing electrical resistivity measurements. For this approach, 2D resistivity profiles were acquired and interpreted. Stratigraphically, colluvium, conglomerate, and dolomitic-limestone units were located in the field. The resistivity values of these formations were determined considering both the literature and field survey. Then, 2D profiles were interpolated to create a 3D resistivity model of the study area. Medium-large sized cavities were identified as well as their locations relative to the springs. The measured resistivities were also correlated with the corresponding geological units. The results were then used to construct a 3D model that aids to reveal the cavity geometry in the subsurface. Additionally, several faults are detected and their effect on the cavities is interpreted.
- Published
- 2020
48. Integrated use of satellite remote sensing, GIS, and ground spectroscopy techniques for monitoring olive oil mill waste disposal areas on the island of Crete, Greece
- Author
-
Apostolos Sarris, Chariton Kalaitzidis, Pantelis Soupios, Dimitrios D. Alexakis, and Nikos Papadopoulos
- Subjects
Image fusion ,Spectral signature ,010504 meteorology & atmospheric sciences ,business.industry ,0211 other engineering and technologies ,Environmental pollution ,Context (language use) ,02 engineering and technology ,Vegetation ,01 natural sciences ,Global Positioning System ,General Earth and Planetary Sciences ,Environmental science ,Satellite ,business ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing ,Waste disposal - Abstract
Olive oil mill wastes OOMW constitute a major pollution factor in olive-growing regions and an important problem to be solved for the agricultural industry. Olive oil mill wastes are normally deposited in tanks, or directly into the soil or even on adjacent torrents, rivers, and lakes, posing a high risk of environmental pollution in regard to public health. This study aims to develop integrated satellite remote sensing, geographical information systems GIS, and ground spectroscopy methodologies to detect and monitor OOMW disposal areas on the island of Crete, Greece in the Southeastern Mediterranean. More than 1000 disposal tanks were mapped through an extended global positioning system GPS survey that took place throughout the island. Satellite images of both high IKONOS and medium Landsat 8 OLI Operational Land Imager resolution were preprocessed and analysed by applying geometric, radiometric, and atmospheric corrections. A library with a spectral signature of OOMW including both different time periods and satellite sensors was developed. At the same time, ground spectroscopy campaigns were carried out and a complementary spectral signature library was developed. The narrow band reflectance of ground measurements was recalculated using the relative response filters of the corresponding satellite sensors. Both libraries were compared for their accuracy through statistical approaches and the optimum spectral range for detecting OOMW areas was estimated. Subsequently, further auxiliary image-processing techniques such as image fusion, linear spectral unmixing LSU, false-colour composites FCCs, image classification, and principal component analysis PCA were applied to satellite images to enhance OOMW patterns, and an innovative OOMW detection index for Landsat 8 was developed. In addition, several vegetation indices were applied and compared in regard to their efficiency in detecting waste ponds. Finally an integrated, semi-automatic methodology was developed in the GIS environment employing classification algorithms for the detection of waste ponds. This study highlights the potential of satellite remote sensing, GIS, and ground spectroscopy in the semi–automatic detection of OOMW disposal areas in the context of the Mediterranean landscape.
- Published
- 2016
49. Regional tectonic model of Southern, Central part of the Mygdonian basin (Northern Greece) by applying 3D Transient Electromagnetic Modeling
- Author
-
Pavel Barsukov, Pantelis Soupios, and Payal Rani
- Subjects
Southern central ,010504 meteorology & atmospheric sciences ,Fracture zone ,Structural basin ,Induced seismicity ,010502 geochemistry & geophysics ,01 natural sciences ,Tectonics ,Geophysics ,Computational electromagnetics ,Transient (oscillation) ,Geothermal gradient ,Geology ,Seismology ,0105 earth and related environmental sciences - Abstract
This study aims to define the geotectonic characteristics of the Mygdonia basin by using 3D Transient Electromagnetic (TEM) technology. The Mygdonian basin is located between Volvi and Langada lakes around 45 km North-East of Thessaloniki city in northern Greece and presents very high seismicity. To define the tectonic regime of the area, a detailed electromagnetic survey was performed along with the geological and lithological study of the area. The TEM data were acquired using the TEM-FAST 48 instrument for 485 soundings in 159 locations. The 1-D and 2-D interpretation of the TEM data indicate the tectonic characteristics of the area. 3D modeling applied to TEM data highlighted the fracture zone in the investigated area. The geothermal field of Apollonia is also depicted. The results are validated with the previous EM (AMT, RMT, and MT) data acquired in the study area studies.
- Published
- 2020
50. Comparing multi-criteria methods for landslide susceptibility mapping in Chania Prefecture, Crete Island, Greece
- Author
-
Maria Kouli, Constantinos Loupasakis, D. Rozos, Pantelis Soupios, and Filippos Vallianatos
- Subjects
Thematic map ,Geography ,Multi criteria ,Elevation ,Landslide ,Sample (statistics) ,Rate curve ,Landslide susceptibility ,Cartography ,Weighting - Abstract
In this work, two multi-criteria methods, an expert-based, semi-quantitative, relative weighting – rating approach, the weighted linear combination (WLC) and a quantitative, statistical method, the weights of evidence (WoE) approach were applied for landslide susceptibility zonation mapping in the Chania Prefecture of Crete Island, Greece. Several thematic maps representing various landslide casual factors, such as geological formations, faults proximity, elevation, slope gradient, aspect and curvature, rivers proximity, precipitation, roads proximity and land use types; have been generated in a GIS environment. Two landslide susceptibility maps were created; one for each method. The maps were compared and validated using the success rate curve (SRC) analysis. The resulting landslide susceptibility maps have uncertainties introduced due to the subjective knowledge of experts in the case of WLC method and to the quality of the recorded landslides sample in the case of the WoE method. Both approaches produced almost equally accurate maps with the WoE method to produce slightly superior predictions.
- Published
- 2018
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.