Real-time magnitude estimation and rapid fault characterization with GPS data for Earthquake Early Warning applications

We explore the application of 1Hz GPS data to Earthquake Early Warning and the use of the co-seismic ground deformation to provide a real-time estimation of the event magnitude and a near real-time characterization of the rupture area extension. GPS sensors are able to register directly the ground displacement without any risk of amplitude saturation and any need of complicated real-time corrections. Furthermore, they contain information about the static offset, i.e., the permanent ground deformation, which cannot be seen on common seismic instruments. The static offset is extracted from displacement geodetic time series and it is used in a real-time static slip inversion scheme to estimate the earthquake magnitude and slip distribution. We propose a “self- adapting” strategy which does not require restrictive prior assumptions about the ongoing earthquake.