Abstract:Earthquake early warning (EEW) systems—as effective tools for seismic hazard mitigation—offer advance alerts several to tens of seconds before the onset of destructive ground motions, prompting the deployment of emergency measures to minimize casualties and property losses. Specifically, these intricate systems rely on rapid and precise real-time magnitude estimations based on EEW parameters for disaster mitigation. To accelerate magnitude estimation speeds, considering 821 records of 190 earthquakes (3.1≤M≤6.6) that struck the Gansu Province and surrounding regions from 2012 to 2020, we examine the correlation between two EEW parameters (characteristic period τc and displacement amplitude Pd) and peak parameters (peak ground velocity and displacement) under varying conditions: vertical component, horizontal component, and mean value of the three components of a P-wave at 1-10 s. Subsequently, it establishes a fast calculation model for early warning magnitude estimations. Finally, the estimated magnitudes (ME) are compared with those recorded by the China Earthquake Networks Center (MC). Results reveal that while changes in time window durations influence the estimation outcomes, variations in P-wave components exert negligible effects. Moreover, the Pd-based model outperforms the τc-based model in predicting the fitting degree, mean value, and standard deviation of the predicted residuals, as well as the residual distribution. Thus, considering the time scale of real-time parameters, magnitude estimations, and the requirement of timely EEW information release, applying the Pd-based model after 3 s of vertical P-wave arrival is recommended for rapid real-time magnitude estimations by EEW systems in the study area.
