Geodetic monitoring of surface deformation for mitigating induced seismicity in Bavarian geothermal operations

Geothermal energy is a significant source of clean, renewable energy, and the Bavarian Molasse Basin demonstrates exceptional potential for its development. Over the past two decades, the region has made remarkable progress in harnessing geothermal energy. Between 1998 and 2021, a total of 30 deep geothermal energy projects were implemented in Bavaria, with 24 systems currently in operation.  Munich is a leader among European cities in utilizing centralized geothermal systems, with plans to fully cover the city’s energy needs through geothermal resources by 2040.However, the operation of geothermal power plants can induce seismic activity and alter the stress-strain state of the subsurface, posing potential threats to the environment and population. Induced seismicity is a key issue for geothermal projects worldwide, where its occurrence has caused significant delays in development and, in some cases, damage to buildings and infrastructure.To evaluate the impact of geothermal activity on surface deformation, we processed a dense network of Sentinel-1 interferograms (2018-2021) using Small Baseline Subset (SBAS) InSAR time-series analysis through NASA's Alaska Satellite Facility (ASF) OpenSARLab. This approach enabled us to generate high-precision cumulative displacement and velocity maps across Munich and its surrounding areas over the three-year period.Our analysis revealed localized ground uplift throughout the region, with pronounced deformation rates near certain geothermal plants, in some cases reaching a few cm/year. These uplift patterns appear to correlate with geothermal operations, particularly reservoir pressure changes and fluid reinjection.  In contrast, areas of subsidence, observed away from geothermal sites, appear to result from natural geological processes such as sediment compaction, groundwater extraction, and karstification.These findings are vital for seismic hazard assessments, as surface deformation is closely tied to induced seismicity in geothermal environments. The study underscores the importance of advanced geodetic monitoring techniques, such as InSAR, for evaluating seismic risks and ensuring the sustainable development of geothermal energy resources.