Article
Engineering, Environmental
Greg A. Oldenborger
Summary: The study experimentally validated a near-linear relationship between electrical conductivity and temperature in NaCl solutions, providing a foundation for geophysical studies of permafrost terrain at subzero temperatures. By extending the temperature-conductivity compensation equation, accurate compensation for the temperature dependence of electrical conductivity can be achieved at -9 degrees C.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2021)
Article
Environmental Sciences
Wouter Deleersnyder, David Dudal, Thomas Hermans
Summary: This paper proposes an appraisal tool for evaluating the inconsistency between the inversion model and multidimensional data, using a normalized gradient calculated based on multidimensional forward modeling. Additionally, an alternative approach is suggested to account for imperfect forward modeling with low computational cost. The method is demonstrated on an AEM survey, revealing potential problematic zones in the estimated fresh-saltwater interface.
Article
Geochemistry & Geophysics
J. Porte, F. Bretaudeau, J. F. Girard
Summary: Frequency-dependent complex resistivity (CR) is used to study the properties of Earth materials and the interaction between pore spaces and fluids. We developed a modeling and inversion code to consider the electromagnetic (EM) induction in the data and successfully recovered the CR and its frequency variation from CSEM data.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Engineering, Civil
Patrizio Torrese, Giorgio Pilla
Summary: The geophysical surveys in the Oltrepo Pavese plain sector of the Po Valley, Northern Italy, revealed the presence of structural discontinuities and saline paleo-water uprising in the alluvial aquifer. The study defined the localization and trace of an important tectonic discontinuity, responsible for deepening the bedrock and the presence of deep, saline paleo-waters. The surveys also highlighted irregular contact between the alluvial aquifer and the bedrock, shaped by tectonics and paleo-river erosion, influencing the flow of contaminated water towards the aquifer.
JOURNAL OF HYDROLOGY
(2021)
Article
Computer Science, Interdisciplinary Applications
Michael Weiss, Maya Neytcheva, Thomas Kalscheuer
Summary: We develop an efficient and robust iterative framework for solving linear system of equations in geophysical controlled-source electromagnetic applications, and demonstrate its robustness and computational advantage through numerical experiments.
COMPUTATIONAL GEOSCIENCES
(2023)
Article
Soil Science
Erika Lueck, Julien Guillemoteau, Jens Tronicke, Udo Rummel, Wilfried Hierold
Summary: This study examines the combination of electrical resistivity mapping and point observations of soil moisture to infer the spatial and temporal variability of soil moisture. The research found that their experimental and data analysis strategies represent a reliable approach to establish site-specific models and estimate three-dimensional moisture distribution including temporal variations.
Article
Geochemistry & Geophysics
Feiyan Wang, Zhengyong Ren, Lihong Zhao
Summary: The study presents a goal-oriented adaptive finite-element algorithm for accurately modeling marine controlled-source electromagnetic responses. By approximating the solutions to both the primal and dual problems, it can flexibly handle complex geological settings and survey geometries. The method demonstrates robustness in dealing with both moderate and strong electrical anisotropy.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Geosciences, Multidisciplinary
Duygu Kiyan, Volker Rath, Mark R. Muller, Mohammednur D. Ture, James Hodgson
Summary: Over the past decade, Geological Survey Ireland has acquired airborne electromagnetic data for the Tellus project, and developed the open-source toolbox aempy to facilitate data interpretation and modeling. Implemented in Python, aempy is adaptable for specific educational and research objectives, allowing for 1-D inversion modeling with processed frequency-domain airborne electromagnetic data.
JOURNAL OF APPLIED GEOPHYSICS
(2022)
Article
Geochemistry & Geophysics
Paula Rulff, Laura M. Buntin, Thomas Kalscheuer
Summary: A 3-D forward modelling code was developed for controlled source electromagnetic problems, balancing solution accuracy and problem size through goal-oriented mesh refinement. Improvements were made in error estimation for complex models, including weighting adjoint source terms, optimizing for conductivity contrasts, and formulating element-wise estimators relative to electromagnetic field amplitudes.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Environmental Sciences
Pauline Kessouri, Tim Johnson, Frederick D. Day-Lewis, Chen Wang, Dimitrios Ntarlagiannis, Lee D. Slater
Summary: This study investigates the long-term impacts of active remediation on treated aquifers by analyzing geophysical signals, showing a correlation with the formation of polarizable, dispersed iron sulfide minerals in the treated zones. Conductivity and phase angle measurements distinguish between treated and untreated areas, providing valuable insights into postremediation effects.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Geosciences, Multidisciplinary
Natalie Y. Smeltz, Kenneth W. W. Sims, Bradley J. Carr, Andrew D. Parsekian
Summary: The hydrothermal system in Yellowstone National Park provides a unique opportunity to study the complex interaction between deep hydrothermal fluids and near subsurface groundwater. This study aims to understand the spatial relationships and hydrologic mixing processes in this system.
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2022)
Article
Geochemistry & Geophysics
Dieter Werthmuller, Raphael Rochlitz, Octavio Castillo-Reyes, Lindsey Heagy
Summary: The study compared the use of open-source codes for large-scale 3-D controlled-source electromagnetic surveys, demonstrating that these codes can compute comparable CSEM responses for challenging models. It also highlighted various issues that need to be addressed and emphasized the importance of appropriately discretizing the model. The research provided accurate responses for different models and mesh types, showcasing the significance of the chosen discretization method.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Geochemistry & Geophysics
Dana E. Peterson, Carol A. Finn, Paul A. Bedrosian
Summary: Water-saturated, hydrothermally altered rocks weaken volcanic edifices, leading to increased risk of sector collapses and mass flows of unconsolidated debris. Airborne geophysical measurements can be used to identify hydrothermally altered areas at Iliamna Volcano and suggest its instability.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Alexander Prikhodko, Andrei Bagrianski, Petr Kuzmin, Aamna Sirohey
Summary: The mineral resources exploration industry has high efficiency requirements for geophysical technologies, and airborne electromagnetic technologies have been used for subsurface exploration due to their low cost and ability to rapidly acquire data over large areas. However, limitations on the depth of investigation and technical specifications of these systems hinder their application in certain geoelectrical conditions and geographical terrains. Methods utilizing natural electromagnetic fields in the audio frequency range have significantly increased the depth of investigation and sensitivity to a wide range of resistivity contrasts.
Article
Engineering, Marine
Gang Li, Fugui Tang, Chaofan Li, Wen Lei, Ying Liu
Summary: Gas hydrate is considered as a new energy resource, but it can also be a major greenhouse gas and pose a severe hazard to offshore infrastructures. Therefore, it is crucial to investigate the gas hydrate and its environmental impacts. Geophysical seismic reflection data and marine controlled-source electromagnetic data can be effectively used to detect gas hydrate.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
