South Napa Report

Earthquake warning provided by our QuakeGuard products successfully protected fire stations in the City of Vallejo, CA during the 6.0 South Napa Earthquake on August 24, 2014.
The earthquake
South Napa USGS shakemap
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At 3:20AM PT on August 24, 2014, there was a magnitude 6.0 earthquake near American Canyon, California, about midway between the cities of Napa and Vallejo. The earthquake ruptured north towards Napa, which experienced the worst damage. There was also major damage in Vallejo.

City of Vallejo
Vallejo Fire Station FS27
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The City of Vallejo installed QuakeGuardsOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter.TM in all of its fire stations in 2002 and 2003. In an earthquake, the QuakeGuardsOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. quickly evaluate the P-wavesPrimary, or P, waves are the fastest moving waves produced by an earthquake and are first to arrive. They do not carry much energy and cause only slight shaking.: the first waves to arrive. If the P-wavesPrimary, or P, waves are the fastest moving waves produced by an earthquake and are first to arrive. They do not carry much energy and cause only slight shaking. indicate that serious ground motions are coming, the QuakeGuardsOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. start an audio alert to warn the fire fighters and open the equipment bay doors to prevent them from jamming.

Epicenter
South Napa epicenter with Vallejo fire stations
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On the map, the South Napa epicenterThe location on the surface directly above the point deep in the earth, called the Hypocenter, where the earthquake starts. is shown as a red star and the fire stations in Vallejo are shown as black squares. The nearest station is only 6 miles from the epicenterThe location on the surface directly above the point deep in the earth, called the Hypocenter, where the earthquake starts. and the farthest is 9.8 miles away. It took only 2 seconds for the first waves to reach the surface (which was the first opportunity to detect the earthquake) and only 4 seconds before the serious shaking started at the nearest fire station.

QuakeGuards
South Napa epicenter with Vallejo warning times
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The QuakeGuardsOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. were installed 12.5 years earlier but were ready when the earthquake struck. The nearest station got 1.7 seconds of warning and the farthest station received 2.4 seconds. This shows the speed of the QuakeGuardOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter.. An infinitely fast system would only be able to provide 2 seconds of warning. We provided 1.7 seconds.

See what good are just a few seconds?

Warning Times
South Napa map with earthquake warning results
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1.7 and 2.4 seconds don't sound like a lot of warning, but the stations, like the seriously damaged areas, are all near the epicenterThe location on the surface directly above the point deep in the earth, called the Hypocenter, where the earthquake starts.. Buildings that were red-taggedBuildings that are damaged too severely to be re-occupied are "red-tagged". Many of these are ultimately demolished. due to damage are shown as red squares. Other earthquake warning systems would have produced no warning at all for anyone in Vallejo or Napa. Only QuakeGuardOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. is fast enough to provide a warning near the epicenterThe location on the surface directly above the point deep in the earth, called the Hypocenter, where the earthquake starts..

Worst Case Epicenter
An epicenter in Vallejo
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Had the epicenterThe location on the surface directly above the point deep in the earth, called the Hypocenter, where the earthquake starts. been in Vallejo, as shown here, the QuakeGuardsOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. would have still provided over 1 second of warning.

The QuakeGuardOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. has no Blind ZoneA region, centered on the epicenter, where no warning is provided before serious ground motions arrive. A few seconds of delay producing a warning can produce a Blind Zone covering 400 square miles. for any earthquake. For shallow earthquakes, less than 2 miles deep, the QuakeGuardOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. initiates its actions upon the arrival of the S-waveSecondary, or S, waves are the first waves to arrive from an earthquake that are large enough to cause damage. They are slower than P-waves but cause much greater shaking.. For earthquakes deeper than 2 miles, the QuakeGuardOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. initiates actions shortly (0.5 seconds) after the arrival of the P-wavePrimary, or P, waves are the fastest moving waves produced by an earthquake and are first to arrive. They do not carry much energy and cause only slight shaking. and provides a proportional amount of warning time. The average earthquake in California is 5 miles deep.

Blind Zone
Map showing locations of red tagged buildings from South Napa Ea
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Systems with Blind ZonesA region, centered on the epicenter, where no warning is provided before serious ground motions arrive. A few seconds of delay producing a warning can produce a Blind Zone covering 400 square miles. provide no protection for local earthquakes. Unfortunately, most of the California population is threatened by local earthquakes. Examples of these include 1868 HaywardA magnitude 6.8 earthquake, in Hayward. 30 people were killed., 1906 San FranciscoA magnitude 7.8 earthquake, 5 miles from San Francisco. 3000 people were killed., 1933 Long BeachA magnitude 6.4 earthquake, in Long Beach. 115 people were killed., 1971 San FernandoA magnitude 6.6 earthquake, 8 miles from San Fernando. 65 people were killed., 1987 Whittier NarrowsA magnitude 5.9 earthquake, 9 miles from downtown Los Angeles. 8 people were killed., 1994 NorthridgeA magnitude 6.7 earthquake, in Northridge. 60 people were killed., and 2014 South NapaA magnitude 6.0 earthquake, 6 miles from Napa. 1 person was killed..

A system that takes 5 seconds to produce a warning will produce a Blind ZoneA region, centered on the epicenter, where no warning is provided before serious ground motions arrive. A few seconds of delay producing a warning can produce a Blind Zone covering 400 square miles., as shown in the map, that is 15 miles in diameter covering over 700 square miles. Notice that all of the serious damage happened inside that 5-second Blind ZoneA region, centered on the epicenter, where no warning is provided before serious ground motions arrive. A few seconds of delay producing a warning can produce a Blind Zone covering 400 square miles.. Our system has no Blind ZoneA region, centered on the epicenter, where no warning is provided before serious ground motions arrive. A few seconds of delay producing a warning can produce a Blind Zone covering 400 square miles..

QuakeGuard Network
Map showing warning contours for the future QuakeGuard network
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We are working on a network of QuakeGuardsOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. to detect earthquakes and send a warning to everyone who is threatened. The QuakeGuard NetworkA network of seismic stations, based on the latest generation of QuakeGuards, to provide earthquake warning in California. will increase the amount of warning time, as shown by the contours on the map. The warning times for the South Napa earthquake would increase to between 2 and 3.5 seconds.

During the South NapaA magnitude 6.0 earthquake, 6 miles from Napa. 1 person was killed. earthquake our customers experienced the effectiveness and reliability of our QuakeGuardOur earthquake warning product capable of initiating alerts and protective actions for every earthquake, even at the epicenter. earthquake warning capabilities. Soon, all of California will be able to benefit from this protection.