Earthquake early warning from Seismic Warning Systems. Would you trust your life or business to a technology without a perfect record?

"The world leader in earthquake early warning and the only company with a 10 year track record without a false positive..."

Home

Contact Us
Technology
P-wave
Datasheets

QuakeGuard Technology

All earthquakes produce a series of different types of shock waves, which travel at different speeds and carry different amounts of energy. The fastest shock waves, and the first to arrive, are called P waves. These travel about twice as fast as the next fastest shock waves and rarely cause any damage. The next shock waves to arrive are called Shear waves (or S waves), followed by Love waves and Rayleigh waves, which cause most of the damage by earthquakes.

Since the P waves arrive first, they can provide an advance notice of the heavy shaking to follow. The warning time is about 1 second for every 5 miles of distance to the Hypocenter of the earthquake. This amount of warning can give automated systems plenty of time to respond and enough time for people to react.

The use of P waves to produce an early warning system has been hampered in the past by two technical problems: how to eliminate false positives (triggering on man-made vibrations); and how to distinguish between small earthquakes (which should be ignored) from large ones. SWS has solved both of these problems.

Operating Principle
The QuakeGuard seismic warning system relies on the early detection of non-destructive, fast moving waves emanating from the origin of an earthquake.

An earthquake produces four types of waves that emanate from its Hypocenter; P or primary waves, S or shear waves, L or Love waves, and R or Rayleigh waves.  A P-wave, non-destructive and imperceptible to humans, is a vertical motion wave that travels faster and can be sensed much earlier, depending upon distance from epicenter, than destructive S- and R-waves.

The QuakeGuard technology detects the non-destructive P-waves while filtering other sources of vibrations that can lead to false alarms.  The elimination of false warnings is a result of QuakeGuard's patented DSP algorithms that filter detected vibrations to isolate the signature waveforms of a seismic event that has just occurred.  Depending on the geological composition of the terrain and the distance from the epicenter of the seismic event, a warning of 10 to 60 seconds is possible.

Intellectual Property
SWS has received multiple patents for discriminating between conventional earth tremors and those that are precursors to an earthquake, and the use of multiple sensors to discriminate between man-made vibrations and earthquakes. These patents cover technology to eliminate false positives, which is a key differentiator, advanced sensor design and several signal analysis techniques. SWS has corresponding international patent applications pending.
University of British Columbia Tests
"The results of the tests showed, in general, that QuakeGuardTM is sensitive enough to detect small vertical ground motions, thereby providing a warning time before the arrival of more damaging horizontal motions produced by earthquakes. Warning time will allow users enough time to take precautionary action in the event of an upcoming seismic shaking. The warning time will depend, of course, on the earthquake type, the epicentral and focal distances, and the geological conditions of the site where the device is to be installed."

Dr. Carlos E. Ventura,
Earthquake Research Laboratories,
University of British Columbia.


SWS Logo
TEL: 831-440-1122
FAX: 831-440-1131
info@seismicwarning.com
Privacy Policy