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Sensors 2008, 8(1), 1-9;

Development of an Earthquake Early Warning System Using Real-Time Strong Motion Signals

Department of Geosciences, National Taiwan University, Taipei, Taiwan
Seismological Laboratory, California Institute of Technology, Pasadena, CA, USA
Author to whom correspondence should be addressed.
Received: 20 December 2007 / Accepted: 5 January 2008 / Published: 9 January 2008
(This article belongs to the Special Issue Sensors for Disaster and Emergency Management Decision Making)
PDF [282 KB, uploaded 21 June 2014]


As urbanization progresses worldwide, earthquakes pose serious threat to livesand properties for urban areas near major active faults on land or subduction zonesoffshore. Earthquake Early Warning (EEW) can be a useful tool for reducing earthquakehazards, if the spatial relation between cities and earthquake sources is favorable for suchwarning and their citizens are properly trained to respond to earthquake warning messages.An EEW system forewarns an urban area of forthcoming strong shaking, normally with afew sec to a few tens of sec of warning time, i.e., before the arrival of the destructive Swavepart of the strong ground motion. Even a few second of advanced warning time willbe useful for pre-programmed emergency measures for various critical facilities, such asrapid-transit vehicles and high-speed trains to avoid potential derailment; it will be alsouseful for orderly shutoff of gas pipelines to minimize fire hazards, controlled shutdown ofhigh-technological manufacturing operations to reduce potential losses, and safe-guardingof computer facilities to avoid loss of vital databases. We explored a practical approach toEEW with the use of a ground-motion period parameter τc and a high-pass filtered verticaldisplacement amplitude parameter Pd from the initial 3 sec of the P waveforms. At a givensite, an earthquake magnitude could be determined from τc and the peak ground-motionvelocity (PGV) could be estimated from Pd. In this method, incoming strong motion acceleration signals are recursively converted to ground velocity and displacement. A Pwavetrigger is constantly monitored. When a trigger occurs, τc and Pd are computed. Theearthquake magnitude and the on-site ground-motion intensity could be estimated and thewarning could be issued. In an ideal situation, such warnings would be available within 10sec of the origin time of a large earthquake whose subsequent ground motion may last fortens of seconds. View Full-Text
Keywords: earthquake; early warning system; seismic hazard mitigation earthquake; early warning system; seismic hazard mitigation
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

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Wu, Y.-M.; Kanamori, H. Development of an Earthquake Early Warning System Using Real-Time Strong Motion Signals. Sensors 2008, 8, 1-9.

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