A High-Density Seismic Network for Earthquake Early Warning in Taiwan Based on Low Cost Sensors

Abstract

Because of persistent collisions between the Philippine Sea plate and the Eurasian plate, Taiwan has been constantly threatened by large and devastating earthquakes that often cause large losses of life and property. To reduce losses caused by future damaging earthquakes, it is crucial for Taiwan to seek solutions through scientific research. The Earthquake Early Warning System (EEWS) is one of the most promising tools for alleviating threats caused by large earthquakes, and has been tested and operated in many countries (Allen et al. , 2009; Lee and Wu, 2009; Satriano et al. , 2011). Taiwan has been developing an EEWS and is one of the leading countries in EEWS practices (Wu et al. , 1998, 1999, 2011; Wu and Teng, 2002; Hsiao et al. , 2009, 2011). The present EEWS in Taiwan has been operated by the Central Weather Bureau (CWB) since 1995 and consists of 109 telemetered seismic stations that span the entire region of Taiwan. The EEWS can provide earthquake information within 20 s following an earthquake occurrence (Hsiao et al. , 2009, 2011; Wu and Teng, 2002). Although a 20 s reporting time is short, if the number of seismic stations operating within the network is increased, this time period can still be reduced. However, the cost of building such a high‐density seismic network by traditional, force‐balance seismometers is extremely high. Since the 1990s, the Micro Electro Mechanical Systems (MEMS) accelerometers introduced in seismic applications (Holland, 2003) have been cost‐saving miniature devices and ideal for recording strong ground motions. The Earthquake Early Warning (EEW) research group at National Taiwan University (NTU) worked with a technology corporation to develop a P ‐wave alert device named P alert (Fig. 1) that uses MEMS accelerometers for onsite …