Summary: Development of earthquake early warning system in Taiwan
and Ta-Liang Teng4
Received 7 November 2008; revised 3 December 2008; accepted 12 December 2008; published 30 January 2009.
 With the implementation of a real-time strong-motion
network by the Central Weather Bureau (CWB), an earthquake
early warning (EEW) system has been developed in Taiwan.
In order to shorten the earthquake response time, a virtual
sub-network method based on the regional early warning
approach was utilized at first stage. Since 2001, this EEW
system has responded to a total of 225 events with
magnitude greater than 4.5 occurred inland or off the
coast of Taiwan. The system is capable of issuing an
earthquake report within 20 sec of its occurrence with good
magnitude estimations for events up to magnitude 6.5.
Currently, a P-wave method is adopted by the CWB system.
Base on the results from 596 M ! 4.0 earthquakes recorded