The FEAR project is a high-risk high-gain interdisciplinary attempt to advance the understanding of earthquake processes and significantly push forward the current limits on earthquake predictability. It is unique and ground-breaking in several aspects:
The FEAR project is an integrated science program spanning a wide range of observational scales, from laboratory experiments, to in-situ labs and naturally occurring earthquakes. The in-situ BedrettoLab experiments in FEAR will stimulate earthquakes with rupture surfaces on the order of 10-50m, producing events in the magnitude range -2 to 1. There are no existing studies on induced ruptures of this scale. Studies on this scale are required to bridge laboratory experiments (1-10cm sample sizes, magnitude -4), previous deep experiments (10cm-1m, magnitude -2), and natural events (100m -10km, magnitude 2-6). Laboratory testing of representative rock samples on state-of-the-art frictional and fracture machines, complemented by numerical modelling, will tackle the challenge of upscaling the insights gained on the FEAR scale of induced events to that of larger, naturally occurring earthquakes.
In FEAR, we will be activating a natural fault in a tectonically active mountain belt under controlled conditions. With hydraulic stimulation, we will have unprecedented control of stress and rupture conditions on the target faults. We will be able to characterize boundary conditions and test constitutive relations in ways not yet tried.
FEAR will install a dense custom array of multidisciplinary, next-generation sensors in boreholes at very close distances to earthquake-generating faults. We will apply innovative analysis techniques, greatly improving our ability to monitor and image faulting processing. The seismic monitoring system will be capable of detecting earthquakes in the magnitude range -4 to 2.
The on-going observed seismicity from the real-time seismic monitoring system, in conjunction with predicted seismicity levels from models of seismicity as a function of stress preconditioning, will be brought together in an adaptive traffic light system (ATLS) with automated decision-making for mitigating risk due to induced seismicity during the Bedretto tunnel experiments.