4 SEPTEMBER, 2025
Newsletter
Monitoring Ground Stability in Geothermal Energy: An InSAR-Based Perspective
Geothermal energy is increasingly recognized as a reliable, low-emission, and scalable contributor to the global energy transition. However, as the geothermal sector expands into new geological environments and urban-adjacent areas, the challenges of maintaining long-term reservoir performance and surface stability are becoming more pronounced.
In this Newsletter, we look into this highly attractive and rapidly growing sector of alternative energy production and discuss the risks to the environment and the habitat, which the production of the geothermal energy bring about as well as most effective deformations monitoring techniques. Among these, surface deformation—such as subsidence, uplift, and lateral displacement—has emerged as a critical parameter for assessing the health and sustainability of geothermal operations.
While these phenomena are often subtle and develop gradually, they can indicate underlying issues with reservoir pressure, reinjection balance, and subsurface compartmentalization. Monitoring and understanding these surface responses is essential for operational planning, regulatory compliance, and community engagement.
Surface deformation in geothermal regions is primarily driven by fluid and thermal processes within the reservoir. Extraction of geothermal fluids alters the pressure regime, often leading to compaction in porous rock formations. Reinjection, depending on volume and distribution, may either mitigate or intensify these effects. The geometry of the reservoir, fault architecture, and fracture connectivity all influence the nature and extent of surface response.
Thermo-mechanical and poro-elastic effects, in combination with the natural heterogeneity of geothermal systems, can produce complex, time-dependent deformation patterns. These movements, although typically small in magnitude, are of significant operational and environmental interest due to their potential to affect infrastructure and surface assets, and to signal changes in reservoir behavior.
A well-documented case is the Landau geothermal plant in Germany (Fig.1,) where InSAR revealed clear surface changes following an injection well failure in 2013. Uplift of up to 33 mm occurred near the plant, spreading into the surrounding city by about 10 mm, while other parts of the reservoir showed subsidence of around 25 mm after operations were halted. This case highlights how injection/production imbalances can generate contrasting patterns of uplift and subsidence — early warnings that only satellite monitoring could capture (Henrion et al., 2019).
Interferometric Synthetic Aperture Radar (InSAR) is a satellite-based remote sensing technology capable of detecting millimeter-scale changes in the Earth’s surface over time. By analyzing the phase difference between radar signals acquired at different times, InSAR provides spatially extensive and temporally consistent deformation data.
This method offers several advantages for geothermal monitoring:
- Wide-area coverage, suitable for both remote and developed sites.
- High-resolution detection of vertical and horizontal surface motion.
- Non-intrusive data acquisition with no ground instrumentation required.
- Compatibility with time-series analysis and integration with reservoir models.
InSAR can reveal cumulative trends, seasonal variability, and abrupt anomalies, enabling a more complete understanding of surface–subsurface interactions.
The scientific community has increasingly embraced InSAR as a standard component of geothermal reservoir assessment. When combined with hydrogeological models, thermal simulations, and injection/production data, InSAR-derived deformation fields can be used to infer key reservoir properties and validate operational strategies.
Advanced processing techniques, including persistent scatterer and small baseline subset methods, have improved the reliability of InSAR results even in vegetated or topographically complex areas. These developments, coupled with new satellite constellations offering frequent, free observations, are reshaping how deformation monitoring is implemented across the sector.
In western Turkey’s major geothermal areas — Germencik and Kızıldere (Figs 2-3) — wide-area Sentinel-1 monitoring between 2014 and 2020 revealed strong correlations between production rates and subsidence. For example, subsidence exceeding 15 mm/year was concentrated around production wells, while reinjection zones were comparatively stable. At Kızıldere, surface deformation lagged power generation increases by about six months, reflecting reservoir pressure decline. Such insights demonstrate how InSAR can directly link field operations to surface responses, guiding drilling decisions and reinjection strategies (Aslan et al., 2022).
GeoKinesia for a long time has been an active advocate of the satellite-based monitoring methods, which serve as a powerful complements and enhancers to the traditional geotechnical and environmental monitoring techniques.
We strongly believe that better integration and more active use of remote sensing can significantly improve the efficiency of the monitoring frameworks and ultimately safety of mining operations, particularly critical in remote, vegetated, or resource-constrained settings where ground-based infrastructure is sparse or non-existent.
InSAR contributes not only to operational decision-making but also to long-term risk management, resource classification, and the development of sustainable geothermal practices.
GeoKinesia provides expert InSAR-based monitoring services tailored to the geothermal industry. Our approach transforms raw satellite data into actionable insights for operators, developers, and regulators. We assist stakeholders in understanding how the surface evolves over time in response to geothermal production and reinjection activities, and we help integrate deformation monitoring into daily operations and strategic planning.
Our services support early detection of anomalies, validation of reinjection effectiveness, and transparent communication with regulatory bodies and local communities. By providing independent, data-driven analysis, GeoKinesia strengthens geothermal project resilience and regulatory confidence.
As geothermal energy continues to expand its role in the global energy landscape, ensuring the stability of both subsurface and surface systems becomes increasingly important. InSAR offers a scientifically robust, cost-effective, and scalable solution for monitoring surface deformation linked to geothermal activity.
With the availability of high-quality satellite data and advanced processing tools, the geothermal sector now has the opportunity to make surface deformation monitoring a routine part of responsible, future-focused energy development.
From Germany to Turkey, InSAR has consistently proven its value: detecting accidents before they escalate, correlating production with reservoir pressure decline, and confirming the effectiveness of deep reinjection strategies. These case studies underscore why satellite monitoring is becoming indispensable for geothermal operators worldwide.
GeoKinesia is proud to support this transition, providing reliable, satellite-based insights that enhance the sustainability and performance of geothermal systems worldwide.
References
- Henrion, E., Doubre, C., & Masson, F. (2019). InSAR monitoring of surface displacements for a geothermal operation: the case of the Landau power plant, Germany.
- Aslan, G., Aydin, H., & Çakir, Z. (2022). Wide-area ground deformation monitoring in geothermal fields in western Turkey. Turkish Journal of Earth Sciences.
