In order to understand the characteristics of ground motion in Taiwan, particularly for the urban areas, during strong earthquakes. CWB has gradually build a large number of free-field strong-motion stations since 1991, forming the Taiwan Strong Motion Instrumentation Program network TSMIP. Till now, the network consists of more than 700 free-field strong-motion stations. Fig.1 shows the distribution of the observation stations. The strong-motion seismographs are all equipped with the FBA (Force Balance Accelerometer) sensors. Following the progress on instrumentation, the resolution of sensors is mostly upgraded to 24 bits already. Till now, more than 225,000 strong-motion records above 28,000 strong events are collected, and these data were widely applied for the research of strong-motion seismology and earthquake engineering.

For the sake of providing detailed strong-motion parameters immediately after felt earthquake, the data recording of TSMIP stations are gradually upgraded from trigger mode to continuous mode since 2015. At present, at least 1 strong motion station equipped with real-time function at each Taiwan townships. While a felt earthquake occurred, more detailed and observed seismic intensities around strong shaking areas can be provided quickly. Currently, the number of real-time stations has exceeded 350 (Fig.2), and the numbers are still planned to increase in the future.

Fig.1: Distribution map shows the locations of the TSMIP stations.

Fig.2: Distribution map shows the locations of the real-time strong-motion stations.