High-resolution imaging of the near-surface structures of critical objects is necessary in various applications including geohazard studies, the structural health of artificial structures, and generally in environmental seismology. This study explores the use of fiber optic sensor technology in active seismic surveys to monitor the embankment structure of the Rybnik Reservoir in Poland. We discuss the technical aspects, including sensor types and energy sources, and provide a comparison of the data collected with a standard geophone-based survey conducted simultaneously. A thorough data processing methodology is presented to directly compare both datasets. The results show a comparable data quality, with DAS offering significant advantages in terms of both the spatial and temporal resolution, facilitating more accurate interpretations. DAS demonstrates its ability to operate effectively in complex geological environments, such as areas with high seismic noise, rough terrain, and variable surface conditions, making it highly adaptable for monitoring critical infrastructure. Additionally, DAS provides long-term monitoring capabilities, essential for ongoing structural health assessments and geohazard detection. For example, the multichannel analysis of surface waves (MASW) using DAS data clearly identifies S-wave velocities down to 13 m with an RMS error of 3.26%, compared to an RMS error of 6.2% for geophone data. Moreover, the DAS-based data were easier to process and interpret. The integration of DAS with traditional seismic data can provide a more comprehensive understanding of subsurface properties, facilitating more accurate and reliable geophysical assessments over time. This innovative approach is particularly valuable in challenging environments, underscoring its importance in monitoring critical infrastructure.

Every dam site must have a complete stability assessment and seismic integrity evaluation under high ground vibration because aging, foundation deterioration, seepage phenomena, internal erosion, cavities, and cracks have resulted in dam damage. Often ERT technique and in-situ measurement in boreholes are used to monitor the state of the dam. In this project, we propose to use variety of seismic techniques both active and passive seismic combined with 3D ERT and spectral GPR measurements on the same profile. In this study, compression and shear wave velocities were integrated to delineate elastic properties of the dam's materials and evaluate the seismic stability subjected to local soil stiffness and site response at the Rybnik dam and Orzepowice embankment, Poland. To asses those values we used seismic travel time tomography for general recognition of spatial differences, MASW technique to assess water infiltration and reflection seismic imaging to recognize the geological structures under the dam. Here we present initial results and gathered data. We used standard standalone 3C seismic stations combined with Distributed Accousting Sensing (DAS). As sources both sledgehammer and industrial S wave source were used. This setup allows comparison of multicomponent data for both source types. We plan to record seismic data on exactly the same lines next year to obtain time laps observation and recognize the different in the medium. This research was funded by National Science Centre, Poland (NCN) project number 2022/45/B/ST10/00658.

Every dam site must have a complete stability assessment and seismic integrity evaluation under high ground vibration because aging, foundation deterioration, seepage phenomena, internal erosion, cavities, and cracks have resulted in dam damage. Often ERT technique and in-situ measurement in boreholes are used to monitor the state of the dam. In this project, we propose to use variety of seismic techniques both active and passive seismic combined with 3D ERT and spectral GPR measurements on the same profile.In this study, compression and shear wave velocities were integrated to delineate elastic properties of the dam's materials and evaluate the seismic stability subjected to local soil stiffness and site response at the Rybnik dam and Orzepowice embankment, Poland. To asses those values we used seismic travel time tomography for general recognition of spatial differences, MASW technique to assess water infiltration and reflection seismic imaging to recognize the geological structures under the dam.Here we present initial results and gathered data. We used standard standalone 3C seismic stations combined with Distributed Accousting Sensing (DAS). As sources both sledgehammer and industrial S wave source were used. This setup allows comparison of multicomponent data for both source types. This research was funded by National Science Centre, Poland (NCN) project number 2022/45/B/ST10/00658.

The long-term stability and reactivation potential of large landslides are primarily controlled by their deep internal structure, the geometry and connectivity of shear planes, fault systems, and subsurface hydraulic pathways. Despite their importance, these features remain difficult to investigate, and geophysical methodologies capable of resolving those at sufficient resolution and depth are still not fully established. This study addresses this challenge through a comprehensive, multi-method geophysical investigation of the Cisiec landslide, located in the Żywiec district of southern Poland.The study area comprises a forested clearing surrounded by meadow terrain, with the landslide moving predominantly east–northeast and exhibiting an elevation difference of approximately 100 m between its crown and toe. Annual monitoring campaigns, including drone-based photogrammetry and laser scanning, as well as geophysical measurements like seismic or resistivity tomography, conducted between 2018 and 2022, provided valuable insights into the general geometry and kinematics of the landslide. Still, process-understanding of the complex and non-linear landslide behaviour could not be fully obtained. These datasets allowed the construction of a preliminary structural models and indicated temporal variability in displacement patterns; however, the nature of movement along individual slip surfaces remained unresolved. In particular, it was unclear whether deformation occurred as a coherent, uniform displacement or as a progressive, sequential sliding process involving multiple layers or discrete blocks. Furthermore, the role of groundwater circulation within the landslide body and its influence on mechanical stability could not be conclusively determined.To overcome these limitations, we conducted advanced geophysical surveys during dedicated field campaigns in October 2024 and April 2025. The investigation integrated high-resolution seismic imaging based on Distributed Acoustic Sensing (DAS) with Spectral Ground Penetrating Radar (SGPR) and a suite of electrical and electromagnetic methods, including Electrical Resistivity Tomography (ERT), Frequency Domain Electromagnetics (FDEM), Time Domain Electromagnetic (TDEM) soundings, and Spectral Induced Polarization (SIP). Each technique was carefully selected and optimized to resolve complementary aspects of the landslide architecture, ranging from shallow deformation features to deeper structural controls and subsurface hydraulic pathways.The combined dataset provided a detailed, multi-scale image of the landslide, revealing significant spatial heterogeneity in both mechanical and hydrogeological properties. Seismic imaging resolved fine-scale structural and geomechanical variations, while electrical and electromagnetic methods highlighted zones of enhanced moisture content and groundwater flow. The results confirm a division of the landslide into three distinct kinematic zones and reveal previously unresolved shallow slip surfaces and groundwater-related effects. Notable observations include focused groundwater discharge at the lower slope and an anomalous signal attenuation zone near the crown, interpreted as evidence of microseismic activity and the development of a potential new failure zone. These findings demonstrate the value of integrated, high-resolution geophysical approaches for improving conceptual models of complex landslide systems and for supporting long-term hazard assessment.

This presentation summarizes a project focused on the seismic imaging and time-lapse monitoring of dams, embankments, and landslides using seismic and complementary geophysical methods. These structures are particularly sensitive to environmentally induced changes, such as variations in water saturation driven by climate variability and human activity, which can significantly affect their stability and long-term performance.This study presents the results of repeated geophysical surveys conducted in 2023 and 2024 to investigate seepage and under-seepage processes in critical infrastructure related to the Rybnik water reservoir in southern Poland. To analyse the state of the embankment and dam, we used a combination of seismic, CCR, and ERT methods, supported by observations with a DAS system and an innovative Spectral GPR. Using repeated surveys, we were able to image not only spatial inhomogeneities but also changes in the structure related to different water tables and water saturation in the studied Earth-filled objects. Moreover, between the two surveys, maintenance works were performed to limit excessive seepage in the embankment. This action reduced seepage by 30%, but geophysical data enabled a spatial evaluation of the works and identified areas that require future monitoring.Besides standard analysis in the form of ERT and seismic tomography, we utilised high-resolution seismic data recorded at a 2 m horizontal spacing for reflection imaging. This allowed us to recognise geological structures below man-made structures and the effects of the old river bed located beneath the construction. An additional 3C geophone was used for the seismic survey, allowing for precise analysis of P and S waves. This resulted in Vp/Vs analysis of the objects. Moreover, the combination of P and S wave reflection images provides insight into detailed structures that cannot be recognised with standard methods.Finally, we utilised the DAS system to further increase the spatial resolution of the seismic data. A comparison of DAS and horizontal geophone data shows that DAS provides long-term monitoring capabilities, essential for ongoing structural health assessments and geohazard detection. For example, the multichannel analysis of surface waves (MASW) using DAS data clearly identifies S-wave velocities down to 13 m with an RMS error of 3.26%, compared to an RMS error of 6.2% for geophone data.In addition, seismic tomography was applied to the Cisiec landslide (Żywiec district, southern Poland), where time-lapse velocity models are used to track hydrologically driven changes in subsurface properties associated with slope instability.This research was funded by National Science Centre, Poland (NCN) project number 2022/45/B/ST10/00658.