Faster short-distance earthquake early warning using continued monitoring of filtered vertical displacement: A case study for the 2010 Jiasian, Taiwan, earthquake

摘要

We collected the strong-motion accelerograms from the 2010 Jiasian earthquake (M 6:4) that struck southern Taiwan recorded by the Taiwan Strong- Motion Instrumentation Program (TSMIP) stations to perform an off-line test for our proposed short-distance earthquake early-warning (EEW) approach. The 2010 Jiasian earthquake demonstrates the vital need for the short-distance EEW. The tested short-distance EEW method is a threshold-based approach relying on the amplitude of the filtered vertical displacement. Our result shows that the EEW lead times by the tested method are significantly improved compared to those of the current EEW systems (EEWS) in Taiwan for short-distance warning. For sites located at the epicentral distances of about 25 km the EEW lead times are of 2 to 4 s, ahead of the arrival of the strong ground acceleration. We propose that this threshold-based EEW method might be used for target areas and objects of those in the vicinity of seismogenic zones around the world where warnings are most needed.