Geophysical Imaging and Monitoring
Near-surface geoscience in Naples
Posted on 2025/09/11
The European Association of Geoscientists and Engineers (EAGE) is a global professional, not-for-profit association for geoscientists and engineers with approximately 19,000 members worldwide. From September 8 to 11, 2025, the 31st Meeting of Environmental and Engineering Geophysics (EAGE NSG) took place in Neapel, Italy. The conference serves as a platform for exchanging knowledge and advancements in the field of near-surface geophysics.
This year was special as the event combined five conferences in parallel and was hosted in the beautiful city of Naples, Italy.
GIM researchers presented two contributions, which are also available in the form of extended abstracts (see below).
Impressions
Contributions
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Dynamic Optimized Experimental Design Strategies for Geoelectrical Monitoring of Subsurface Flow Processes
2025 |
NSG 2025: 31st Meeting of Environmental and Engineering Geophysics, Sep 2025, Volume 2025, doi:10.3997/2214-4609.202520112
Abstract
This study explores ERT survey optimization techniques for monitoring dynamic subsurface processes. Building on well established Optimized Experimental Design (OED) algorithms, we propose a model-driven design that focuses the measurement on those regions of the model space that are affected by the underlying transport process at a specific time step. The approach incorporates a time-dependent focusing mask and accounts for parameter uncertainty by incorporating a variety of hydraulic parameter distributions into the focusing process. We further introduce a hybrid OED strategy that effectively reduces simulation uncertainties by including the already acquired data of past monitoring steps into the evaluation process.
Cite as
Menzel, N. and Uhlemann S. and Wagner, F.M. (2025): Dynamic Optimized Experimental Design Strategies for Geoelectrical Monitoring of Subsurface Flow Processes. . https://doi.org/10.3997/2214-4609.202520112
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Time-Lapse Petrophysical Joint Inversion of Electrical Resistivity and Seismic Refraction Data for Ground Ice Quantification
2025 |
NSG 2025: 31st Meeting of Environmental and Engineering Geophysics, Sep 2025, Volume 2025, doi:10.3997/2214-4609.202520247
Abstract
Permafrost warming poses significant environmental and infrastructural challenges, including greenhouse gas release and increased landslide risks necessitating quantitative monitoring. Non-invasive geophysical methods, especially seismic and electrical techniques, are suitable because ice exhibits higher P-wave velocity and electrical resistivity than unfrozen water, making them sensitive to changes in ground ice content. However, single-method approaches can be ambiguous; for example, both ice and air act as electrical insulators. To address this, a petrophysical joint inversion (PJI) method was developed that estimates volumetric fractions of liquid water, ice, and air from apparent resistivity and seismic traveltime data. A remaining ambiguity is between ice and rock matrix content, as high ice content can mimic low porosity. We extended the PJI along the time axis, assuming constant porosity, and introduced temporal regularization to enforce smooth parameter evolution. Synthetic experiments demonstrate that the time-lapse PJI improves porosity and ice estimation compared to the traditional PJI, enhancing ground ice quantification from surface geophysical data. Future work includes refining regularization parameters, incorporating advanced petrophysical models, extending to additional geophysical methods, and integrating thermal-hydraulic process models to further enhance the reliability and applicability of geophysical monitoring, contributing to a deeper understanding of permafrost responses to environmental changes.
Cite as
Wagner, F.M. and Klahold, J. and Hilbich, C. and Hauck, C. (2025): Time-Lapse Petrophysical Joint Inversion of Electrical Resistivity and Seismic Refraction Data for Ground Ice Quantification. . https://doi.org/10.3997/2214-4609.202520247