2024-11-13
Start of four-week experiment for fault characterisation
The FEAR project (Fault Activation and Earthquake Rupture) at the BedrettoLab aims to better understand how earthquakes form and evolve. Following the successful realisation of two initial injection experiments over several weeks in summer, the BedrettoLab team is now preparing the next large-scale experiment. Unlike the previous experiments, this one will take place in the new earthquake physics testbed which focuses on investigating a particular geological fault structure. The experiment will begin in mid-November and will last for four weeks. This long experimental period includes various injection tests in the first two weeks, and longer multi-day injections in weeks 3 and 4.
A deeper understanding of earthquakes
The upcoming experiment is dedicated to characterizing the target fault in the BedrettoLab, which crosses the FEAR testbed. This testbed is currently under development, including the excavation of a new side tunnel. Decisive for this upcoming experiment is a newly developed measuring probe (developed by Lawrence Berkeley National Laboratory LBNL) which will be used in two experimental boreholes to measure pressure changes and fault deformations directly on the target fault. With this probe slow fault deformation can be measured with high sensitivity and accuracy. This allows to study how earthquakes begin, and how fluid injections can increase the fault zone permeability.
Safety concept
To ensure a safe procedure, as for every BedrettoLab experiment, a stringent and conservative safety concept is being followed. The experiment control and monitoring systems are operated remotely, so that nobody is in the tunnel during high pressure injection phases. During injections, a team of seismologists and engineers is monitoring the experiment around the clock. Additionally, a Traffic Light System ensures that the experiment is stopped if predefined magnitude or ground shaking thresholds are exceeded. Further large-scale experiments in the framework of the FEAR project are planned for 2025.