Article
Computer Science, Interdisciplinary Applications
Teddi Herring, Lindsey J. Heagy, Adam Pidlisecky, Edwin Cey
Summary: In this study, a hybrid inversion algorithm that combines parametric and smooth inversion strategies was developed to improve the estimation of subsurface conductivity. Tested on synthetic models, the hybrid inversion showed better resolution of feature boundaries and magnitudes with fewer artifacts compared to the standard smooth inversion. The sensitivity analysis demonstrated successful recovery of subsurface features under different conditions, showcasing the potential of this hybrid inversion strategy in various applications.
COMPUTERS & GEOSCIENCES
(2022)
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Eusebio Stucchi, Azadeh Hojat
Summary: By utilizing a trained residual neural network as the forward operator in probabilistic inversions of electrical resistivity tomography data, this study provides a faster and more accurate approach compared to traditional methods, reducing computational workload. The method properly incorporates modelling errors and propagates them onto estimated model uncertainties, allowing for solving electrical resistivity tomography with limited hardware resources.
GEOPHYSICAL PROSPECTING
(2022)
Article
Environmental Sciences
Nikos Papadopoulos
Summary: This study explores the use of multicomponent geophysical techniques in revealing submerged antiquities in shallow coastal marine environments in the eastern Mediterranean, demonstrating their efficiency and potential in archaeological detection. The results highlight the significance of these methods in understanding complex archaeological sites.
Article
Biotechnology & Applied Microbiology
Ahmed S. Abu El Ata, Bassem S. Nabawy, Osman M. Badran
Summary: The study focuses on geoelectric surveys in the Ayun Mousa area to explore hidden springs, utilizing methods like self-potential measurements, vertical electrical resistivity, and electrical resistivity tomography. By analyzing anomalies and faults, the study successfully identifies known and unknown springs. This comprehensive approach provides valuable insights for further exploration and potential groundwater resource management.
ENVIRONMENTAL TECHNOLOGY & INNOVATION
(2021)
Article
Engineering, Civil
Seo Young Song, Bitnarae Kim, Ahyun Cho, Juyeon Jeong, Dongkweon Lee, Myung Jin Nam
Summary: Ground subsidence in urban areas is a serious problem, and geophysical surveys, such as electrical resistivity tomography (ERT), can be used to estimate the scale of subsidence. In this study, ERT was conducted near a road subsidence area and it was found that the nearby excavation site had an influence on the data interpretation.
GEOMECHANICS AND ENGINEERING
(2023)
Article
Geography, Physical
Hongwei Liu, Pooneh Maghoul, Ahmed Shalaby
Summary: The study proposes a novel algorithm for analyzing surface waves to accurately estimate the physical and mechanical properties of permafrost sites in response to the adverse effects of climate warming on the built environment in (sub-)arctic regions. It identifies two types of Rayleigh waves with differing sensitivities to different types of permafrost layers, providing a feasible method for early detection and warning systems.
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Azadeh Hojat
Summary: The proposed alternative ERT method utilizes ensemble smoother with multiple data assimilation to provide multiple realizations of resistivity values in the subsurface and reduce ill-conditioning of the inversion process. It allows for accurate uncertainty appraisal and can be applied to nonlinear inverse problems.
PURE AND APPLIED GEOPHYSICS
(2021)
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Eusebio Stucchi, Azadeh Hojat
Summary: The proposed gradient-based Markov chain Monte Carlo inversion algorithm accelerates sampling by using Hessian and gradient information to define a local, Gaussian proposal distribution, while also reducing computational costs through the use of a residual neural network and discrete cosine transform. The method is first tested on synthetic data and field measurements, and compared with other inversion techniques, demonstrating comparable uncertainty assessments and model predictions at significantly reduced computational cost.
NEAR SURFACE GEOPHYSICS
(2022)
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Eusebio Stucchi, Azadeh Hojat
Summary: To reduce computational cost and uncertainties in geophysical inversions, a deep learning algorithm is used to compress model and data spaces. Experimental results show that the compressed method provides comparable predictions and uncertainty assessments with traditional methods, but with a significant reduction in computational cost.
NEAR SURFACE GEOPHYSICS
(2022)
Article
Geochemistry & Geophysics
Mattia Aleardi, Alessandro Vinciguerra, Azadeh Hojat
Summary: Electrical resistivity tomography inversion is commonly solved using deterministic gradient-based methods, but accurate uncertainty assessments are impeded by local linearization of the inverse operator. Numerical Markov chain Monte Carlo algorithms provide accurate uncertainty appraisals, but require appropriate recipes to reduce computational effort for field data applications. The key to probabilistic inversion is defining an appropriate prior distribution of model parameters that incorporate spatial constraints, Gaussian priors oversimplify the parameter distribution in the presence of multimodality.
NEAR SURFACE GEOPHYSICS
(2021)
Article
Geosciences, Multidisciplinary
P. B. Wilkinson, J. E. Chambers, P. I. Meldrum, O. Kuras, C. M. Inauen, R. T. Swift, G. Curioni, S. Uhlemann, J. Graham, N. Atherton
Summary: This study tests and compares different methods for regularizing the time-lapse geoelectrical inverse problem, and finds that 4D inversion of the full data set performs the best, while windowed 4D inversion is also applicable in near real-time applications.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Rupesh, Prarabdh Tiwari, S. P. Sharma
Summary: Groundwater faces increasing threats of exploitation, requiring advanced methods for exploration of potential zones. The use of Electrical Resistivity Tomography (ERT) proved successful in delineating potential groundwater zones in a lateritic environment.
NATURAL RESOURCES RESEARCH
(2021)
Article
Geochemistry & Geophysics
E. Rizzo, V. Giampaolo, L. Capozzoli, G. De Martino, G. Romano, A. Santilano, A. Manzella
Summary: This paper describes a new experimental deep electrical resistivity acquisition method for exploring deep and shallow geothermal systems. The method provides a 3D resistivity distribution and can help tackle challenges and issues in geothermal wells.
PHYSICS OF THE EARTH AND PLANETARY INTERIORS
(2022)
Article
Geosciences, Multidisciplinary
Robin Thibaut, Thomas Kremer, Annie Royen, Bun Kim Ngun, Frederic Nguyen, Thomas Hermans
Summary: The current geophysical inversion paradigm based on Occam's principle may not be suitable for complex structures in the subsurface. An alternative Minimum Gradient Support (MGS) approach is proposed to compute sharp contrasts, but its performance is highly dependent on the selection of the focusing parameter beta. A new methodology is presented to incorporate prior information and improve imaging for resistivity and chargeability structures in real case studies, showing promising results in both synthetic and field data. The challenge of automatically selecting the beta parameter remains for future developments.
JOURNAL OF APPLIED GEOPHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Mattia Aleardi, Alessandro Vinciguerra, Azadeh Hojat
Summary: In this study, a novel approach to Electrical Resistivity Tomography (ERT) using Discrete Cosine Transform (DCT) reparameterization and Convolutional Neural Network is developed for fast inversion and reliable uncertainty assessment. DCT reduces network dimensionality, acts as a regularization operator to decrease unknown parameters, and maintains spatial continuity of resistivity values in the recovered solution.
JOURNAL OF APPLIED GEOPHYSICS
(2021)
Article
Environmental Sciences
Kleanthis Simyrdanis, Nikos Papadopoulos, Pantelis Soupios, Stella Kirkou, Panagiotis Tsourlos
SCIENCE OF THE TOTAL ENVIRONMENT
(2018)
Article
Geochemistry & Geophysics
Iraklis Giannakis, Panagiotis Tsourlos, Costas Papazachos, George Vargemezis, Antonios Giannopoulos, Nikos Papadopoulos, Fabio Tosti, Amir Alani
GEOPHYSICAL PROSPECTING
(2019)
Article
Geochemistry & Geophysics
M. H. Loke, N. Papadopoulos, P. B. Wilkinson, D. Oikonomou, K. Simyrdanis, D. F. Rucker
GEOPHYSICAL PROSPECTING
(2020)
Article
Archaeology
Nikos Papadopoulos, Dimitrios Oikonomou, Kleanthis Simyrdanis, Loke Meng Heng
Summary: The study investigates the efficiency of dynamic floating and submerged 3-D Electrical Resistivity Tomography (ERT) for mapping archaeological relics buried beneath the sediments in ultra-shallow marine environments. Comparative results reveal the superiority of the DD array in reconstructing the optimum resistivity inversion model.
ARCHAEOLOGICAL PROSPECTION
(2022)
Article
Geochemistry & Geophysics
Nikos Papadopoulos, Dimitrios Oikonomou, Gianluca Cantoro, Kleanthis Simyrdanis, Julien Beck
Summary: This study aims to adapt, test, and validate various geophysical mapping and imaging methods for reconstructing ancient built environments under water layers. By exploring the submerged prehistoric site of Lambayanna in Greece, the research demonstrates the complementary nature of multiple geophysical methods in underwater archaeological contexts, providing useful information for understanding complex archaeological sites around the Mediterranean. The successful transfer of established geophysical methods into the ultra-shallow aquatic environment presents an innovative approach for sustainable management of coastal cultural resources amidst climate change and sea-level rise risks.
NEAR SURFACE GEOPHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Kleanthis Simyrdanis, Nikos Papadopoulos, Dimitrios Oikonomou
Summary: This study investigates the applicability and effectiveness of an optimization technique based on the Jacobian matrix for electrical resistivity tomography data, selecting the most sensitive measurements to enhance the least distinguishable parameters in the reconstructed model. By modifying existing inversion programs, the Jacobian optimization approach allows for reconstructions with fewer measurements from the initial data set yet similar results to the original comprehensive data set.
APPLIED SCIENCES-BASEL
(2021)
Article
Computer Science, Information Systems
Christos Polykretis, Dimitrios D. Alexakis, Manolis G. Grillakis, Athos Agapiou, Branka Cuca, Nikos Papadopoulos, Apostolos Sarris
Summary: This study utilized GIS and remote sensing techniques to analyze and evaluate the impact of soil erosion on archaeological sites in Chania prefecture, Crete. The results showed that soil loss significantly affects the cultural heritage in the region, especially in the western part, necessitating the development of specific risk mitigation strategies.
Article
Environmental Sciences
Evagoras Evagorou, Athanasios Argyriou, Nikos Papadopoulos, Christodoulos Mettas, George Alexandrakis, Diofantos Hadjimitsis
Summary: This study evaluates the accuracy of bathymetric maps generated from multispectral satellite datasets acquired from different multispectral sensors. The blue and green bands obtained the best results with higher accuracy. The most accurate bathymetric maps were obtained using the WorldView 2 and the empirical model of the Ratio Transform algorithm.
Article
Agronomy
Wissal Issaoui, Dimitrios D. Alexakis, Imen Hamdi Nasr, Athanasios V. Argyriou, Evangelos Alevizos, Nikos Papadopoulos, Mohamed Hedi Inoubli
Summary: This study aims to assess the effectiveness of satellite image analysis techniques in detecting Olive Mill Wastewater (OMW) disposal sites in Mediterranean countries. The study collected spectral signatures of OMW and applied various spectral vegetation indices and image processing methods, as well as different classification algorithms, to detect and monitor these sites. The results show that Sentinel-2 and PlanetScope images have high efficiency in detecting and monitoring OMW disposal areas under different morphological environments.
Article
Green & Sustainable Science & Technology
Athanasios Argyriou, Christos Polykretis, Richard M. Teeuw, Nikos Papadopoulos
Summary: The key factors controlling slope instability include heavy rainfall, which is a major trigger for landslides. This study focused on using geoinformatic technologies to detect and assess landslides triggered by heavy rainstorms, as well as projecting potential hazard maps for future rainfall-triggered events in Crete, with the validation of outputs aiding in land-use planning and emergency response efforts.
Article
Environmental Studies
Christos Polykretis, Manolis G. Grillakis, Athanasios V. Argyriou, Nikos Papadopoulos, Dimitrios D. Alexakis
Summary: A hybrid landslide susceptibility model, combining different statistical analysis models, was proposed to generate a reliable LS map. The model showed better validation results compared to individual modeling.
Article
Archaeology
Stamatis Chatzitoulousis, Vlasis Vlasidis, Apostolos Sarris, Kalliopi Efkleidou, Eleni Kotjabopoulou, Nikos Papadopoulos, Nasos Argyriou, Jamie Donati, Meropi Manataki, Pedro Trapero-Fernandez
Article
Geochemistry & Geophysics
Kleanthis Simyrdanis, Ian Moffat, Nikos Papadopoulos, Jarrad Kowlessar, Marian Bailey
INTERNATIONAL JOURNAL OF GEOPHYSICS
(2018)
Article
Geosciences, Multidisciplinary
Athos Agapiou, Vasiliki Lysandrou, Apostolos Sarris, Nikos Papadopoulos, Diofantos G. Hadjimitsis
Article
Archaeology
William A. Parkinson, Attila Gyucha, Panagiotis Karkanas, Nikos Papadopoulos, Georgia Tsartsidou, Apostolos Sarris, Paul R. Duffy, Richard W. Yerkes
JOURNAL OF ARCHAEOLOGICAL SCIENCE-REPORTS
(2018)