We designed a prototype AI algorithm capable to estimate almost instantaneously the magnitude of large earthquakes from PEGS (and PEGS exclusively) recorded by seismometers in Japan (Licciardi et al., Nature, 2022). The algorithm outperforms existing early warning systems for Magnitude ≥ 8.3 earthquakes, which can be already transformative for tsunami warning. We applied this algorithm to Chile and concluded that the present seismic network there is to sparse for PEGS-based early warning applications (Arias et al., JGR Solid Earth, 2023).
In parallel, we designed a complementary early warning AI algorithm for Magnitude ≤ 8 earthquakes. This approach uses 3 seconds of "classical" seismic signal recorded by a single seismic station to rapidly estimate the earthquake location and magnitude (Lara et al., in review at JGR Solid Earth). We implemented this algorithm in the early warning system of Peru, currently in construction. We are now complementing the Peruvian system with the PEGS-based algorithm.
We stacked all the GPS data ever recorded before large earthquakes after projecting the measurements in the direction of expected motion assuming precursory slip on the fault. We found evidence that earthquakes likely start, on average, with a precursory phase of slow slip in the ~2 hours preceding large events (Bletery and Nocquet, Science, 2023).