An examination of τc-Pd earthquake early warning method using a strong-motion building array

The use of characteristic period τc and peak displacement amplitude Pd of the initial P wave in earthquake early warning (EEW) was proposed by Wu and Kanamori [1], [2], [3] and [4]. Here we apply this approach to strong-motion records from a building sensor array installed in Taitung County, Taiwan. This building was damaged during the 2006 Mw=6.1 Taitung earthquake with a peak ground velocity (PGV) of up to 38.4 cm/s at an epicentral distance of 14.5 km. According to our analysis, the peak displacement amplitude Pd is a better indicator for the destructiveness of an earthquake than τc because τc is more sensitive to the signal-to-noise ratio (SNR) than Pd. In accordance with previous studies, only the structurally damaging Taitung earthquake generated a Pd value larger than 0.5 cm (a threshold for identifying damaging events). Using Pd as an indicator for destructive earthquakes does not lead to missing or false alarms for EEW purposes.