Laboratory Details

Bedretto Underground Laboratory for Geosciences and Geoenergies (BedrettoLab)

Description

The Bedretto Underground Laboratory for Geosciences and Geoenergies (BedrettoLab) is a unique meso-scale infrastructure ideal for hypothesis driven and fundamental research as well as for cutting-edge technology demonstrations. Its mission is to advance transdisciplinary research in geoenergy applications and in frontier geoscience research.

The BedrettoLab offers the possibility to perform cutting-edge experiments by means of plugging new sensors to the existing infrastructure, testing novel data acquisition techniques and stimulation protocols, as well as setting up dedicated experiments on geochemistry, geology, geophysics, and hydrogeology in all testbeds.

Monitoring

We have designed multi-disciplinary and multi-scale monitoring systems that combine sensors from seismology, applied geophysics, hydrology, and geomechanics. The multi-sensor monitoring network is installed inside boreholes (some up to 300 m length), drilled from the Bedretto tunnel. Boreholes are sealed with a purpose-made cementing system to reach rock integrity within the experiment volume. Such monitoring network incorporates different sensor types, such as piezoelectric accelerometers (PAS), in situ acoustic emission (AE) sensors, fiber-optic cables for distributed acoustic sensing (DAS), distributed strain sensing (DSS) and distributed temperature sensing (DTS), fiber Bragg grating (FBG) sensors, geophones, ultrasonic transmitters, pore pressure sensors, tiltmeters, strain and displacement sensors.

Geothermal Testbed (GTB)

For the development of large-scale deep reservoirs for water circulation, storage, and extraction of geothermal energy. Several boreholes for stimulation and monitoring are equipped with an extensive 3D multi-domain geophysical monitoring array (Plenkers et al., 2023) and a fluid injection control system, which has been used for various fluid injection experiments since 2022 (Ma et al. ; Obermann et al., 2024; Gischig et al., in prep.).

Earthquake Physics Testbed (ETB)

At the BedrettoLab small earthquakes can be generated under controlled conditions at +1 km depth and 10-100 m scale. This is facilitated by the FEAR tunnel, which runs parallel to the target fault at a horizontal distance of 40 m, towards the south-west from the Bedretto tunnel. A dense monitoring system of 40 monitoring and injection boreholes allows to measure multi-resolution of earthquake data. This testbed is expansible; it can accommodate various experiment setups with focus on the safe use of geoenergy and predictability of earthquakes.

Huddle testbed

It consists of 13 seismic sensors, which have been co-located to benchmark sensor and datalogger performance across a wide frequency (100-1000 Hz) and amplitude range, ultimately to allow optimal sensor selection for experiment design. Sensors deployed in the huddle test are:

• Post-hole broadband seismic + force-balanced accelerometer (Cascadia)
• Broadband seismometers (STS2, trillium)
• Short period seismometers (lennartz 5s, 1s)
• Force balanced accelerometers (episensor)
• MEM accelerometer (3C, 1C)
• Borehole geophone (MBAS)
• Piezometers (Acoustic Emission sensors GMuG)
• DAS fiber

Deep Life Observatory

Geobiological research in the BedrettoLab focuses on the study of organisms living at the energy limit of life. It features a variety of dedicated field instruments and borehole infrastructure throughout the tunnel, either in the geothermal testbed or in unexplored areas.

References

Ma, X., et al., 2022, Multi-disciplinary characterizations of the BedrettoLab – a new underground geoscience research facility, Solid Earth, 13, 301–322, DOI: [https://doi.org/10.5194/se-13-301-2022, 2022](https://doi.org/10.5194/se-13-301-2022, 2022).

Plenkers K, et al., 2023, Multi-Disciplinary Monitoring Networks for Mesoscale Underground Experiments: Advances in the Bedretto Reservoir Project, Sensors, 23(6):3315, DOI: https://doi.org/10.3390/s23063315.

Mesimeri, M., et al., 2025, Multiscale Seismic Monitoring in the Bedretto Underground Laboratory for Geosciences and Geoenergies (BULGG). Seismological Research Letters, 96 (1): 182–191. DOI: https://doi.org/10.1785/0220240128.