2014-2018 Earthquake Gravity Alert
The goal of this project is to assess the feasibility of a new earthquake early warning system using detection of the gravity perturbation from the mass redistribution during the first seconds of fault rupture. With respect to the conventional early-warning systems based on difference in speed between P-waves (faster, harmless) and S-waves (slower, destructive), a gravity-based alert is much faster, since the gravity perturbation is practically instantaneous. Preliminary results show that this system can increase the warning times of the conventional early-warning systems, reduce the blind zone (zone around the epicenter with no alert), and improve the prompt estimation of the earthquake magnitudes. According to our preliminary results, current seismometers and gravimeters are not sensitive enough to be used in an early-warning gravity-based system. For this reason we turn our attention toward other detector concepts, such as torsion bar antennas, currently under development for the detection of gravitational waves.