The goal of an earthquake early warning system (EEW) is to identify where and when an earthquake has occurred and then warn those in danger. We think of earthquakes as happening instantaneously but from the detection of the initial event there is time until the effects are noticed. An early warning of even 6 to 19 seconds could allow sensitive infrastructure like factories or power plants to enact automated precautions, reducing damage and allowing for quicker recovery. Warnings of 30 seconds could prevent 95 per cent of potential mortalities in some large cities. It is exactly these crucial seconds that Lin is trying to provide. His team's work centres on developing an integrated EEW for Taiwan which, once proven effective, to help bring this system to other countries who live with the threat of seismic activity. The EEW developed by Lin works through detecting the seismic waves that earthquakes produce. When an earthquake strikes the ground shakes, this creates seismic waves that move through the earth. These waves, exactly like a ripple in a pond, move out from the epicentre. The first wave, known as the primary wave is low intensity and will not affect structures significantly. The secondary wave however arrives a bit later and causes the intense shaking, damage and casualties. 'The goal of the system is to deploy onsite Earthquake Early Waring System (EEWS) to detect the seismic waves and provide warning for the neighborhoods,' explains Lin. The regional detectors and EEWS can be deployed to monitor a whole country. For traditional regional EEWS, like Japan, once a wave is detected the information is sent to a central server which determines the epicentre of the quake, the magnitude of the earthquake and the peak ground acceleration, an important measure of earthquake intensity. 'With these measurements the server can then predict where peak ground acceleration will exceed thresholds likely to cause damage and send the alarm,' says Lin. The whole process takes only about 15 seconds, which is extremely valuable time for those further away from the epicentre, but because the wave can move up to 90km within these 15 seconds there is a blind spot of about 90km in the regional Earthquake Early Waring System. Lin points out that a blind spot of this size may be fine for some regions. 'In Japan the epicentre of the typical hazardous earthquake is in the east sea bed about 100km from the shore but for Taiwan the epicentres are typically below a city.' Therefore, Lin has developed an integrated approach combining the regional EEW with onsite EEW. The onsite EEWs are installed in cities and monitor local seismic activity. They can predict peak ground acceleration for local area from the primary wave within 1 to 3 seconds and reduce the blind spot to 20 or 30km. Each system has its advantages and disadvantages but integration provides maximum coverage.