Magnitude determination using cumulative absolute absement for earthquake early warning

Abstract

AbstractThe cumulative absolute absement (CAA) of the 3 s window after P-wave arrival can be used to estimate the magnitude ($${M}_{CAA}$$MCAA) of an earthquake. This method can achieve good results even when only the six stations nearest to the epicenter are used. The standard deviation between the estimated CAA magnitude ($${M}_{CAA}$$MCAA) and the moment magnitude ($${M}_{w}$$Mw) is found to be 0.3 when using either 6 or 20 stations. This means that$${M}_{CAA}$$MCAAcan be reliably predicted using the closest 6 stations. On the other hand, the magnitude ($${M}_{Pd}$$MPd) derived from$${P}_{d}$$Pdusing the closest 20 stations has a standard deviation of 0.4 between the estimated$${M}_{Pd}$$MPdand$${M}_{w}$$Mw. This suggests that CAA is a better magnitude determination parameter for the EEW system than$${P}_{d}$$Pd.