Articles | Volume 17, issue 2
https://doi.org/10.5194/se-17-275-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/se-17-275-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
17 Feb 2026
Research article |
| 17 Feb 2026
| 17 Feb 2026
Multi-scale hydraulic and petrophysical characterization of a heterogeneous fault zone in the Gotthard massif's crystalline basement
RWTH Aachen University, Engineering Geology and Hydrogeology, Aachen, Germany
Mohammedreza Jalali
RWTH Aachen University, Engineering Geology and Hydrogeology, Aachen, Germany
Alberto Ceccato
Department of Earth Sciences, Structural Geology and Tectonics Group, Geological Institute, ETH Zurich, Zurich, Switzerland
Alba Simona Zappone
Institute of Geology, ETH Zurich, Zurich, Switzerland
Giacomo Pozzi
Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
Valentin Gischig
Swiss Seismological Service, ETH Zurich, Zurich, Switzerland
Marian Hertrich
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Men-Andrin Meier
Institute of Geophysics, ETH Zurich, Zurich, Switzerland
Timo Seemann
RWTH Aachen University, Engineering Geology and Hydrogeology, Aachen, Germany
Hannes Claes
Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001, Heverlee, Belgium
Yves Guglielmi
Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley CA, 94720, USA
Domenico Giardini
Department of Earth Sciences, ETH Zürich, Sonneggstrasse 5, 8092 Zürich, Switzerland
Stefan Wiemer
Swiss Seismological Service, ETH Zurich, Zurich, Switzerland
Massimo Cocco
Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
Florian Amann
RWTH Aachen University, Engineering Geology and Hydrogeology, Aachen, Germany
Fraunhofer Research Institution for Energy Infrastructures and Geotechnologies IEG, Aachen, Germany
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Jordan Aaron, Larissa de Palézieux, Jake Langham, Valentin Gischig, Reto Thoeny, and Daniel Figi
Nat. Hazards Earth Syst. Sci., 26, 449–464, https://doi.org/10.5194/nhess-26-449-2026, https://doi.org/10.5194/nhess-26-449-2026, 2026
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In mid-May, 2023, the village of Brienz/Brinzauls in the Swiss canton of Graubunden was evacuated, and one month later a flowlike landslide emplaced with velocities of ~25 m/s and narrowly missed impacting the village. Landslides at this site have emplaced with velocities that can vary by 5 order-of-magnitude, a puzzling observation which we analyse in the present work. Our results show that the range of scenarios usually considered in landslide risk analyses must be expanded.
Maren Böse, Nadja Valenzuela, György Hetényi, Romain Roduit, Irina Dallo, Kerstin Bircher, John Clinton, Urs Fässler, Florian Haslinger, Tanja Jaeger, Michèle Marti, Roman Racine, Anne Sauron, Shiba Subedi, and Stefan Wiemer
EGUsphere, https://doi.org/10.5194/egusphere-2025-5726, https://doi.org/10.5194/egusphere-2025-5726, 2026
This preprint is open for discussion and under review for Geoscience Communication (GC).
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Although Switzerland faces only moderate seismic hazard, earthquakes remain the natural risk with the highest potential impact. Because most residents have never experienced a damaging event, education is essential for raising awareness and strengthening preparedness. Through a recent outreach project, we revived and expanded the seismo@school initiative in Switzerland by developing new multilingual teaching materials and activities, and by installing real-time seismic sensors in schools.
Ryan Schultz, Linus Villiger, Valentin Gischig, and Stefan Wiemer
EGUsphere, https://doi.org/10.5194/egusphere-2025-5806, https://doi.org/10.5194/egusphere-2025-5806, 2025
This preprint is open for discussion and under review for Solid Earth (SE).
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We use statistical tests to infer MMAX from an earthquake catalogue and focus on data from three underground laboratories with controlled injection experiments. There, we find clear evidence for MMAX bounds and corroborate interpretations of fracture growth against other geophysical studies. Unbound sequences occur when stimulation is directed towards pre-existing faults. The validation of our methods against well-studied cases is encouraging and will help validate future interpretations.
Laura Gabriel, Marian Hertrich, Christophe Ogier, Mike Müller-Petke, Raphael Moser, Hansruedi Maurer, and Daniel Farinotti
The Cryosphere, 19, 6261–6281, https://doi.org/10.5194/tc-19-6261-2025, https://doi.org/10.5194/tc-19-6261-2025, 2025
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Surface nuclear magnetic resonance (SNMR) is a geophysical technique directly sensitive to liquid water. We expand the limited applications of SNMR on glaciers by detecting water within Rhonegletscher, Switzerland. By carefully processing the data to reduce noise, we identified signals indicating a water layer near the base of the glacier, surrounded by ice with low water content. Our findings, validated by radar measurements, show SNMR's potential and limitations in studying water in glaciers.
Valentin Samuel Gischig, Antonio Pio Rinaldi, Andres Alcolea, Falko Bethman, Marco Broccardo, Kai Bröker, Raymi Castilla, Federico Ciardo, Victor Clasen Repollés, Virginie Durand, Nima Gholizadeh Doonechaly, Marian Hertrich, Rebecca Hochreutener, Philipp Kästli, Dimitrios Karvounis, Xiaodong Ma, Men-Andrin Meier, Peter Meier, Maria Mesimeri, Arnaud Mignan, Anne Obermann, Katrin Plenkers, Martina Rosskopf, Francisco Serbeto, Paul Selvadurai, Alexis Shakas, Linus Villiger, Quinn Wenning, Alba Zappone, Jordan Aaron, Hansruedi Maurer, Domenico Giardini, and Stefan Wiemer
Solid Earth, 16, 1153–1180, https://doi.org/10.5194/se-16-1153-2025, https://doi.org/10.5194/se-16-1153-2025, 2025
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Induced earthquakes present a major obstacle for developing geoenergy resources. These occur during hydraulic stimulations that enhance fluid pathways in the rock. In the Bedretto Underground Laboratory, hydraulic stimulations are investigated in a downscaled manner. A workflow to analyze the hazard posed by induced earthquakes is applied at different stages of the test program. The hazard estimates illustrate the difficulty in reducing the uncertainty due to the variable seismogenic responses.
Sandro Truttmann, Tobias Diehl, Marco Herwegh, and Stefan Wiemer
Solid Earth, 16, 641–662, https://doi.org/10.5194/se-16-641-2025, https://doi.org/10.5194/se-16-641-2025, 2025
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Our study investigates the statistical relationship between geological fractures and earthquakes in the southwestern Swiss Alps. We analyze how the fracture size and earthquake rupture are related and find differences in how fractures at different depths rupture seismically. While shallow fractures tend to rupture only partially, deeper fractures are more likely to rupture along their entire length, potentially resulting in larger earthquakes.
Kathrin Behnen, Marian Hertrich, Hansruedi Maurer, Alexis Shakas, Kai Bröker, Claire Epiney, María Blanch Jover, and Domenico Giardini
Solid Earth, 16, 333–350, https://doi.org/10.5194/se-16-333-2025, https://doi.org/10.5194/se-16-333-2025, 2025
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Several cross-hole seismic surveys in the undisturbed Rotondo granite are used to analyze the seismic anisotropy in the Bedretto Lab, Switzerland. The P and S1 waves show a clear trend of faster velocities in the NE–SW direction and slower velocities perpendicular to it, indicating a tilted transverse isotropic velocity model. The symmetry plane is mostly aligned with the direction of maximum stress, but also the orientation of fractures is expected to influence the velocities.
Raphael Burchartz, Timo Seemann, Garri Gaus, Lisa Winhausen, Mohammadreza Jalali, Brian Mutuma Mbui, Sebastian Grohmann, Linda Burnaz, Marlise Colling Cassel, Jochen Erbacher, Ralf Littke, and Florian Amann
EGUsphere, https://doi.org/10.5194/egusphere-2025-579, https://doi.org/10.5194/egusphere-2025-579, 2025
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In Germany, claystones are studied for their suitability as host-rocks for the disposal of high-level radioactive waste. The MATURITY project systematically investigates how gradual burial affects key barrier properties in the Lower Jurassic Amaltheenton Formation of the Lower Saxony Basin (Germany). Understanding these changes helps assess claystone suitability for long-term waste isolation, improving site selection for deep geological repositories.
Miriam Larissa Schwarz, Hansruedi Maurer, Anne Christine Obermann, Paul Antony Selvadurai, Alexis Shakas, Stefan Wiemer, and Domenico Giardini
EGUsphere, https://doi.org/10.5194/egusphere-2025-1094, https://doi.org/10.5194/egusphere-2025-1094, 2025
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This study applied fat ray travel time tomography to image the geothermal testbed at the BedrettoLab. An active seismic crosshole survey provided a dataset of 42'843 manually picked first breaks. The complex major fault zone was successfully imaged by a 3D velocity model and validated with wireline logs and geological observations. Seismic events from hydraulic stimulation correlated with velocity structures, "avoiding" very high and low velocities, speculatively due to stress gradients.
Marta Han, Leila Mizrahi, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 25, 991–1012, https://doi.org/10.5194/nhess-25-991-2025, https://doi.org/10.5194/nhess-25-991-2025, 2025
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Relying on recent accomplishments of collecting and harmonizing data by the 2020 European Seismic Hazard Model (ESHM20) and leveraging advancements in state-of-the-art earthquake forecasting methods, we develop a harmonized earthquake forecasting model for Europe. We propose several model variants and test them on training data for consistency and on a 7-year testing period against each other, as well as against both a time-independent benchmark and a global time-dependent benchmark.
Athanasios N. Papadopoulos, Philippe Roth, Laurentiu Danciu, Paolo Bergamo, Francesco Panzera, Donat Fäh, Carlo Cauzzi, Blaise Duvernay, Alireza Khodaverdian, Pierino Lestuzzi, Ömer Odabaşi, Ettore Fagà, Paolo Bazzurro, Michèle Marti, Nadja Valenzuela, Irina Dallo, Nicolas Schmid, Philip Kästli, Florian Haslinger, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 24, 3561–3578, https://doi.org/10.5194/nhess-24-3561-2024, https://doi.org/10.5194/nhess-24-3561-2024, 2024
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The Earthquake Risk Model of Switzerland (ERM-CH23), released in early 2023, is the culmination of a multidisciplinary effort aiming to achieve, for the first time, a comprehensive assessment of the potential consequences of earthquakes on the Swiss building stock and population. ERM-CH23 provides risk estimates for various impact metrics, ranging from economic loss as a result of damage to buildings and their contents to human losses, such as deaths, injuries, and displaced population.
Laurentiu Danciu, Domenico Giardini, Graeme Weatherill, Roberto Basili, Shyam Nandan, Andrea Rovida, Céline Beauval, Pierre-Yves Bard, Marco Pagani, Celso G. Reyes, Karin Sesetyan, Susana Vilanova, Fabrice Cotton, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 24, 3049–3073, https://doi.org/10.5194/nhess-24-3049-2024, https://doi.org/10.5194/nhess-24-3049-2024, 2024
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The 2020 European Seismic Hazard Model (ESHM20) is the latest seismic hazard assessment update for the Euro-Mediterranean region. This state-of-the-art model delivers a broad range of hazard results, including hazard curves, maps, and uniform hazard spectra. ESHM20 provides two hazard maps as informative references in the next update of the European Seismic Design Code (CEN EC8), and it also provides a key input to the first earthquake risk model for Europe.
Peter Achtziger-Zupančič, Alberto Ceccato, Alba Simona Zappone, Giacomo Pozzi, Alexis Shakas, Florian Amann, Whitney Maria Behr, Daniel Escallon Botero, Domenico Giardini, Marian Hertrich, Mohammadreza Jalali, Xiaodong Ma, Men-Andrin Meier, Julian Osten, Stefan Wiemer, and Massimo Cocco
Solid Earth, 15, 1087–1112, https://doi.org/10.5194/se-15-1087-2024, https://doi.org/10.5194/se-15-1087-2024, 2024
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We detail the selection and characterization of a fault zone for earthquake experiments in the Fault Activation and Earthquake Ruptures (FEAR) project at the Bedretto Lab. FEAR, which studies earthquake processes, overcame data collection challenges near faults. The fault zone in Rotondo granite was selected based on geometry, monitorability, and hydro-mechanical properties. Remote sensing, borehole logging, and geological mapping were used to create a 3D model for precise monitoring.
Maren Böse, Laurentiu Danciu, Athanasios Papadopoulos, John Clinton, Carlo Cauzzi, Irina Dallo, Leila Mizrahi, Tobias Diehl, Paolo Bergamo, Yves Reuland, Andreas Fichtner, Philippe Roth, Florian Haslinger, Frédérick Massin, Nadja Valenzuela, Nikola Blagojević, Lukas Bodenmann, Eleni Chatzi, Donat Fäh, Franziska Glueer, Marta Han, Lukas Heiniger, Paulina Janusz, Dario Jozinović, Philipp Kästli, Federica Lanza, Timothy Lee, Panagiotis Martakis, Michèle Marti, Men-Andrin Meier, Banu Mena Cabrera, Maria Mesimeri, Anne Obermann, Pilar Sanchez-Pastor, Luca Scarabello, Nicolas Schmid, Anastasiia Shynkarenko, Bozidar Stojadinović, Domenico Giardini, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 24, 583–607, https://doi.org/10.5194/nhess-24-583-2024, https://doi.org/10.5194/nhess-24-583-2024, 2024
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Seismic hazard and risk are time dependent as seismicity is clustered and exposure can change rapidly. We are developing an interdisciplinary dynamic earthquake risk framework for advancing earthquake risk mitigation in Switzerland. This includes various earthquake risk products and services, such as operational earthquake forecasting and early warning. Standardisation and harmonisation into seamless solutions that access the same databases, workflows, and software are a crucial component.
Irina Dallo, Michèle Marti, Nadja Valenzuela, Helen Crowley, Jamal Dabbeek, Laurentiu Danciu, Simone Zaugg, Fabrice Cotton, Domenico Giardini, Rui Pinho, John F. Schneider, Céline Beauval, António A. Correia, Olga-Joan Ktenidou, Päivi Mäntyniemi, Marco Pagani, Vitor Silva, Graeme Weatherill, and Stefan Wiemer
Nat. Hazards Earth Syst. Sci., 24, 291–307, https://doi.org/10.5194/nhess-24-291-2024, https://doi.org/10.5194/nhess-24-291-2024, 2024
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For the release of cross-country harmonised hazard and risk models, a communication strategy co-defined by the model developers and communication experts is needed. The strategy should consist of a communication concept, user testing, expert feedback mechanisms, and the establishment of a network with outreach specialists. Here we present our approach for the release of the European Seismic Hazard Model and European Seismic Risk Model and provide practical recommendations for similar efforts.
Matthias S. Brennwald, Antonio P. Rinaldi, Jocelyn Gisiger, Alba Zappone, and Rolf Kipfer
Geosci. Instrum. Method. Data Syst., 13, 1–8, https://doi.org/10.5194/gi-13-1-2024, https://doi.org/10.5194/gi-13-1-2024, 2024
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The gas equilibrium membrane inlet mass spectrometry (GE-MIMS) method for dissolved-gas quantification was expanded to work in water at high pressures.
Jens T. Birkholzer, Yves Guglielmi, and Christophe Nussbaum
Saf. Nucl. Waste Disposal, 2, 61–62, https://doi.org/10.5194/sand-2-61-2023, https://doi.org/10.5194/sand-2-61-2023, 2023
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This presentation discusses a series of in situ experiments of fault activation by fluid injection conducted in argillite rock at the Mont Terri underground research laboratory in Switzerland to better understand whether pressurization of natural faults can lead to their reactivation and permeability generation in case such features are present near disposal tunnels. Lessons learned from these experiments help inform the safety assessment of geologic disposal in argillite host rock.
Lisa Maria Ringel, Mohammadreza Jalali, and Peter Bayer
Hydrol. Earth Syst. Sci., 26, 6443–6455, https://doi.org/10.5194/hess-26-6443-2022, https://doi.org/10.5194/hess-26-6443-2022, 2022
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Fractured rocks host a class of aquifers that serve as major freshwater resources worldwide. This work is dedicated to resolving the three-dimensional hydraulic and structural properties of fractured rock. For this purpose, hydraulic tomography experiments at the Grimsel Test Site in Switzerland are utilized, and the discrete fracture network is inverted. The comparison of the inversion results with independent findings from other studies demonstrates the validity of the approach.
Alberto Ceccato, Giulia Tartaglia, Marco Antonellini, and Giulio Viola
Solid Earth, 13, 1431–1453, https://doi.org/10.5194/se-13-1431-2022, https://doi.org/10.5194/se-13-1431-2022, 2022
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The Earth's surface is commonly characterized by the occurrence of fractures, which can be mapped, and their can be geometry quantified on digital representations of the surface at different scales of observation. Here we present a series of analytical and statistical tools, which can aid the quantification of fracture spatial distribution at different scales. In doing so, we can improve our understanding of how fracture geometry and geology affect fluid flow within the fractured Earth crust.
Lisa Winhausen, Kavan Khaledi, Mohammadreza Jalali, Janos L. Urai, and Florian Amann
Solid Earth, 13, 901–915, https://doi.org/10.5194/se-13-901-2022, https://doi.org/10.5194/se-13-901-2022, 2022
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Triaxial compression tests at different effective stresses allow for analysing the deformation behaviour of Opalinus Clay, the potential host rock for nuclear waste in Switzerland. We conducted microstructural investigations of the deformed samples to relate the bulk hydro-mechanical behaviour to the processes on the microscale. Results show a transition from brittle- to more ductile-dominated deformation. We propose a non-linear failure envelop associated with the failure mode transition.
Xiaodong Ma, Marian Hertrich, Florian Amann, Kai Bröker, Nima Gholizadeh Doonechaly, Valentin Gischig, Rebecca Hochreutener, Philipp Kästli, Hannes Krietsch, Michèle Marti, Barbara Nägeli, Morteza Nejati, Anne Obermann, Katrin Plenkers, Antonio P. Rinaldi, Alexis Shakas, Linus Villiger, Quinn Wenning, Alba Zappone, Falko Bethmann, Raymi Castilla, Francisco Seberto, Peter Meier, Thomas Driesner, Simon Loew, Hansruedi Maurer, Martin O. Saar, Stefan Wiemer, and Domenico Giardini
Solid Earth, 13, 301–322, https://doi.org/10.5194/se-13-301-2022, https://doi.org/10.5194/se-13-301-2022, 2022
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Questions on issues such as anthropogenic earthquakes and deep geothermal energy developments require a better understanding of the fractured rock. Experiments conducted at reduced scales but with higher-resolution observations can shed some light. To this end, the BedrettoLab was recently established in an existing tunnel in Ticino, Switzerland, with preliminary efforts to characterize realistic rock mass behavior at the hectometer scale.
Lisa Winhausen, Mohammadreza Jalali, and Florian Amann
Saf. Nucl. Waste Disposal, 1, 301–301, https://doi.org/10.5194/sand-1-301-2021, https://doi.org/10.5194/sand-1-301-2021, 2021
Lisa Winhausen, Jop Klaver, Joyce Schmatz, Guillaume Desbois, Janos L. Urai, Florian Amann, and Christophe Nussbaum
Solid Earth, 12, 2109–2126, https://doi.org/10.5194/se-12-2109-2021, https://doi.org/10.5194/se-12-2109-2021, 2021
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An experimentally deformed sample of Opalinus Clay (OPA), which is being considered as host rock for nuclear waste in Switzerland, was studied by electron microscopy to image deformation microstructures. Deformation localised by forming micrometre-thick fractures. Deformation zones show dilatant micro-cracking, granular flow and bending grains, and pore collapse. Our model, with three different stages of damage accumulation, illustrates microstructural deformation in a compressed OPA sample.
Peter-Lasse Giertzuch, Joseph Doetsch, Alexis Shakas, Mohammadreza Jalali, Bernard Brixel, and Hansruedi Maurer
Solid Earth, 12, 1497–1513, https://doi.org/10.5194/se-12-1497-2021, https://doi.org/10.5194/se-12-1497-2021, 2021
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Two time-lapse borehole ground penetrating radar (GPR) surveys were conducted during saline tracer experiments in weakly fractured crystalline rock with sub-millimeter fractures apertures, targeting electrical conductivity changes. The combination of time-lapse reflection and transmission GPR surveys from different boreholes allowed monitoring the tracer flow and reconstructing the flow path and its temporal evolution in 3D and provided a realistic visualization of the hydrological processes.
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Short summary
We studied a deep fault zone in Switzerland to gain a better understanding of how water moves through faults and how this affects earthquake activity. Using field and laboratory tests, we found that flow is strongly controlled by open fractures and permeability changes significantly with scale. Small samples underestimate flow compared to larger tests. Our results show that faults are heterogeneous, highlighting the need for site-specific studies when assessing risks or planning experiments.
We studied a deep fault zone in Switzerland to gain a better understanding of how water moves...
