First feasibility demonstration of GNSS-seismology for anthropogenic earthquakes detection

High-rate GNSS has been proven effective in characterising waveforms and co-seismic displacements due to medium-to-strong natural earthquakes. No application focused on small magnitude events like shallow anthropogenic earthquakes, where displacements and noise have the same order of magnitude. We propose a procedure based on proper signal detection and filtering of the position and velocity time series obtained from high-rate (10 Hz) GNSS data processing with two intrinsically different approaches (Precise Point Positioning and variometry). We tested it on five mining tremors with magnitudes of 3.4-4.0, looking both at event detection and its kinematic characterisation. Here we show a high agreement, at the level of 1 s, between GNSS and seismic solutions for the earthquake first epoch detection. Also, we show that high-rate multi-constellation (GPS + Galileo) GNSS can reliably characterise low-magnitude shallow earthquakes in terms of induced displacements and velocities, and, including their peak values, respectively, at the level of very few millimetres and 1-2 cm/s, paving the way to the routine use of GNSS-seismology for monitoring human activities prone to cause small earthquakes and related potential damages.