Understanding earthquake physics
Earthquakes are one of the most significant hazards for human society, and, at the same time, remain the most elusive. Improving the ability to forecast earthquakes is one of the main challenges remaining for the natural sciences. With the European Research Council (ERC) Synergy project “Fault Activation and Earthquake Rupture” (FEAR), a consortium of scientists from the Eidgenössiche Technische Hochschule Zürich (ETH Zurich) in Switzerland, the Rheinisch-Westfälische Hochschule (RWTH Aachen University) in Germany, and the Instituto Nazionale di Geofisica e Vulcanologia (INGV) in Italy are conducting a suite of ambitious experiments in the world-unique Bedretto Underground Laboratory for Geosciences and Geoenergy (BedrettoLab), an underground experimental facility in the Bedretto Tunnel, located at 1000m depth under the Swiss Alps.
The core idea of FEAR is to gain understanding on how earthquakes start and stop by using hydraulic stimulation to modify stress and initiate small non-damaging earthquakes (magnitude ~1.0 events on fault patches of 10-50m scale) on candidate faults in the vicinity of the Bedretto Tunnel. A dense network of multidisciplinary sensors will capture the rupture preparation phase, the earthquake rupture, and the post-rupture response of the rock mass. These experiments will give unprecedented up-close near-field insight into the physics of earthquake processes, contribute to pushing forward the current limits on earthquake predictability and advance the state-of-the-art in safe use of geoenergy.
Final construction phase of the new side tunnel has begun
The final construction phase of the new side tunnel has recently started. About 60 meters still need to be built using drill-and-blast excavation to complete the 120-meter-long tunnel. The side tunnel is expected to be completed in the fall.
Successful injection experiment at the new Earthquake Physics Testbed of the BedrettoLab
A three week long injection experiment at the new Earthquake Physics Testbed of the BedrettoLab was successfully completed in November and December 2024. The goal was to characterise how the target fault structure of the FEAR (Fault Activation and Earthquake Rupture) project responds to high-pressure water injection. The results will serve as a baseline for a series of experiments planned in the coming two years, which are aimed at understanding fault zone deformation processes.
After extensive preparation—including drilling boreholes, installing sensors, and manufacturing a specially designed fault deformation probe—the experiment commenced in late November. Over three weeks, approximately 1’100 cubic metres of water were injected into the target fault zone via two boreholes, using a custom designed remote control system. This volume is roughly equivalent to 5’600 bathtubs of water. Importantly, all water used was sourced from wells in the tunnel, ensuring no drinking water was wasted.
The injection was expected to induce a response in the fault structure due to increased pressure in the surrounding rock. Initial analysis indicates minor fault movements, with detailed calculations underway to determine the extent of this displacement. Additionally, the experiment revealed greater complexity in the fault zone than previously assumed. During high-pressure injection, small seismic events occurred more than 50 meters away from the injection site, and suggest the presence of an extensive fracture network.
These findings confirm that the fault zone can be activated, and provide crucial information for the design of the next FEAR experiments, which will focus on the controlled activation of specific fault zone segments.
Find out more about our experiments here
FEAR annual meeting 2025
The next FEAR annual meeting will be held in Airolo (Switzerland) from May 13–15, 2025.
FEAR Science day on 17th September 2024
The FEAR team met for two days at ETH Zurich to present their research and prepare the FEAR 1 Experiment. There were almost 40 participants and 13 presentations focused on the M0 experiment and the fault characterization in preparation for the FEAR1 experiment.
FEAR annual meeting (13-15th March 2024)
The FEAR annual meeting was held in Aachen this year from 13 to 15th March. The meeting included presentations and updates of each working group as well as poster sessions.
Besides fruitful discussions on FEAR and the upcoming experiments, some social activities like a geological tour of Aachen gave opportunities to broaden the horizon and also have some fun.