Exploring for geothermal potential outside the city of Munich, Germany

Stadtwerke München (SWM), the city utility of Munich continues its effort to expand the development of its geothermal district heating plans. At the moment, in the southeastern district various rods with geophones have been set up with cables on the side of roads

These highly sensitive devices were installed by SWM last month in Ottobrunn, Hohenbrunn, Höhenkirchen-Siegertsbrunn, Brunnthal and Sauerlach. They are also in some places in Aying, Taufkirchen, Neubiberg, Unterhaching, Putzbrunn and Grasbrunn.

The SWM wants to investigate the geothermal potential in the greater Munich area. The hot thermal water in the deeper underground is already used by the geothermal plants in Kirchstochach, Dürrnhaar and Sauerlach.

Now the municipal utilities want to exploit the deep geothermal potential in the vicinity of the plants and will carry out seismic measurements on an area of ??approximately 177 square kilometers by the end of March.

This is done using the environmentally friendly vibroseismic method. Special vibro vehicles generate sound waves that are reflected in the subsurface in the border area of ??various rock formations.

The highly sensitive geophones on the earth’s surface measure the reflected sound waves. 3D data of the subsurface are then created from the resulting data.

Vibro vehicles travel along the measurement lines to different points in the measurement area at the same time and lower a vibrating plate to the ground at defined stimulation points. From there, vibrations are sent into the underground for 60 seconds.

The vehicle then drives to the next excitation point 30 meters away. Since each point is only driven once, the operating noise of the vehicle and the vibrations of the vibrating plates are only perceptible for a short time.

Noise and short-term traffic disruptions occur during the measurements. The vibrations can only be felt by people in closer proximity to the vehicles.

Source: Hallo Muenchen