Decades of intensive salt extraction have created large cavities, known as caverns, at depths of 1,000 to 1,500 meters in the subsurface around Gronau, Epe. Most of these caverns are now used to store natural gas - a major economic factor for the region. However, underground operations can lead to changes on the surface, for example by causing ground movements. Comprehensive geological and environmental monitoring of the region is therefore necessary. This is the aim of the project “Radar Remote Sensing Epe W-E Movement” (REWE), a research collaboration between the FZN, Uniper Energy Storage and EFTAS.GeoIT.

Radar interferometry enables horizontal ground movements to be detected and measured with millimeter precision using data from the Sentinel-1 satellite. © European Ground Motion Service

In order to obtain a holistic picture of the subsurface movements in the cavern field in Epe, the researchers are combining different monitoring methods: open geodata, data from radar remote sensing and operational data from the cavern field. The combination of these data will enable a detailed analysis of not only vertical but also horizontal ground movements in an east-west direction for the first time.