Exploring Magnitude Estimation for Earthquake Early Warning Using Available P-Wave Time Windows Based on Chinese Strong-Motion Records.

Quickly determining earthquake size by extracting information after P-wave arrival is a critical issue for earthquake early warning systems. However, early warning parameters are often calculated using a fixed-length (3–5 s) P-wave time window for rapid magnitude estimation. In this paper, we directly investigate magnitude-scaling relationships within the available P-wave time window (APTW, defined as the window period starting from the trigger time of the P wave and ending at the arrival of the S wave) and explore a new real-time magnitude estimation approach (the APTW method). The results of an offline application demonstrate the good performance of the APTW method in terms of the stability of magnitude estimation for small to moderate earthquakes and improved estimation for large earthquakes. The APTW method can provide estimates earlier, and the estimated magnitudes are more stable. The proposed method of establishing magnitude relationships could provide an alternative choice for magnitude estimation in earthquake early warning systems. [ABSTRACT FROM AUTHOR]