ACTIVE STRUCTURES IN CENTRAL UPPER RHINE GRABEN, SW GERMANY: NEW DATA FROM LANDAU AREA USING ELECTROMAGNETIC RADIATION (EMR) TECHNIQUE

Two conjugate sets of active faults oriented NNE-SSW and NNW-SSE have been detected at Landau
area in SW Germany. These faults follow the old trends of the rift-related structures predominating in the
Upper Rhine Graben, which originated during Late Eocene-Miocene time. Linear and horizontal
measurements were performed by using the Cerescope device and interpreted, applying the
Electromagnetic Radiation (EMR) Technique. Linear EMR-profiles were helpful for mapping active
faults, while the main horizontal stress (σH, N to NNE) was easily identified with EMR-horizontal
measurements. Reactivation of rift-related structures of the Upper Rhine Graben at Landau area produces
a new system of active shallow fractures following old trends, and has been detected through the present
study by Cerescope applying the EMR-Technique. The present results imply that the Enhanced
Geothermal System to the south of Landau has a great impact on reactivation of the pre-existing riftrelated
faults by mechanical hydro-fracturing occurring within the reservoir rocks underneath the area.