Alerts Near and Far
Public earthquake warning systems have existed in one form or another for decades. In the 1960s Japanese engineers built seismometers into the tracks of the new Shinkansen bullet trains. Excessive shaking would sound an alarm, giving the conductor a chance to slow the train. Later, scientists designed systems that would use far-flung seismometers to relay warnings in advance of the heaviest shaking. Mexico’s network is designed to detect earthquakes near the coastline and broadcast warnings in Mexico City, an aging metropolis of more than 20 million people built on a silty lakebed that amplifies seismic waves. The distance between the coast and the city can provide more than 60 seconds of warning.
Mexico’s system came online back in 1993. Two years later it would experience its first serious test. On October 9, 1995, a magnitude 8.0 earthquake struck just off the coast of Manzanillo. The warning system picked up the tremor and broadcast alerts on television and radio stations in Mexico City and via a dedicated radio alert system similar to weather radio in the U.S. As a result of the warning, officials were able to stop the metro system 50 seconds before the shaking arrived, and schools were evacuated as planned.
Japan’s system, which went live in 2007, makes heavy use of personal technology. Alerts go out not only on television and radio but through special receivers in homes, offices and schools. Pop-up windows on computers show a real-time map with the epicenter’s location and the radiating seismic waves. A timer counts down to the shaking at your location and highlights predicted intensity. Cell phone providers broadcast a text message–like warning to all phones with a characteristic audible alarm. Critical industries such as nuclear power stations, rail systems, airports and hazardous manufacturing facilities use dedicated communications systems tailored to their needs.
Japan’s experience shows that earthquake warning systems do not just help protect lives, they also help the bottom line. In 2003 two earthquakes near Sendai, Japan, caused more than $15 million in losses to the OKI semiconductor manufacturing plant because of fire, equipment damage and loss of productivity. The plant had to be shut down for periods of 17 and 13 days, respectively, following the quakes. The company then spent $600,000 to retrofit the factory and to install a warning system. In two similar earthquakes since, the factory suffered only $200,000 in losses and 4.5 and 3.5 days of downtime.
The California Curse
California is earthquake country. In 2006 a consortium of universities and state and federal agencies joined forces to develop ShakeAlert, a warning system for the state. Right now a prototype system links together approximately 400 seismic stations and will soon send alerts to a small group of test users. The finished system will provide not only immediate single-station alerts to those near the epicenter but also widespread network-based alerts to those farther away. If all goes well, alerts will be available within five seconds after the first P-wave hits.
Yet California still has a long way to go before it can be blanketed with a comprehensive network such as Japan’s. The 400 existing seismic stations are concentrated around the San Francisco Bay and Los Angeles metropolitan areas, leaving gaps elsewhere. Even though most Californians live near these two areas, the gaps both slow the system and reduce its accuracy, because it takes longer to detect the P-waves at multiple locations. In Japan instruments are spaced every 15 miles across the entire country. That level of spacing in California would deliver the best system performance, with fewer false and missed alarms and more warning time.
Those alerts, like Japan’s, would leverage the networked gadgets that most people carry every day. Individuals would get an alert on their mobile phone indicating predicted shaking intensity, a countdown until the shaking starts, and perhaps a simple instruction such as “get under a table” or “move to your safe zone.” Larger organizations with infrastructure spread over a region will likely want more detailed information such as a real-time map showing the wave progression and the distribution of ground shaking across the affected area.
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9 Comments
Add CommentThis is just another example of big guv'ment poking into our private lives. Probably lead to a tax increase.
Reply | Report Abuse | Link to thisLiving in the heart of San Francisco, I used to wonder why I seemed so sensitive to earthquake tremors, but I found out a couple of weeks ago. I sleep in a waterbed (you will have to pry it from my cold dead fingers)and every time there is a significant temblor, it sloshes, giving me a couple of seconds to at least throw a pillow over my head. Also, a properly filled waterbed can be used as a potable water source in case of a major quake.
Reply | Report Abuse | Link to thisThis article fails to point out that California does have an operational Earthquake Warning System in the Coachella Valley (Palm Springs) area. Is developed by a commercial company and could be expanded to cover the state in a much more cost effective and timely fashion than creating a new and untested system.
Reply | Report Abuse | Link to thisI'm curious as to what Scientific Aemrican is? Apparently this is from a forthcoming article of theirs. Does anyone edit anything anymore?
Reply | Report Abuse | Link to thisAssuming you have not put any chemical preservatives in the water, and that you run the water through some sort of filtration device, it could be used in an emergency. Always a good idea to have a good filtration system anyways.
Reply | Report Abuse | Link to thisAlso if you have a water heater there is 30-50 gallons depending on size.
Earthquakes are the result of strain-energy release from parts of the outer crust of the earth. Can we not measure these stress levels in order to predict how their growth can occur and eventually reach a magnitude where there is a structural failure?
Reply | Report Abuse | Link to thisI thought the old advice to get under a table wasn't used any more and you should get down *next* to the table instead, so that it absorbs the shock, but creates a 'safe triangle' instead of bashing in your skull? Is the advice still to get *under* something?
Reply | Report Abuse | Link to thisYes, stress measuring systems have been developed and proposed for earthquake prediction. For example, US patents 7,513,167 and 5,576,485, both from Dr. Serata, a Japanese-American who also happens to have survived Hiroshima. Why has this system not been deployed? No funding from government, and private industry cannot see an immediate return on investment, so no private funding either.
Reply | Report Abuse | Link to thisCheck out this YouTube I ran across:
Reply | Report Abuse | Link to thishttp://www.youtube.com/citizentube?feature=ticker#p/c/0870831CE43351E1/35/oQVPfQu50yY
I presume the countdown is based on the distance from the epicenter to some logical, standard location like central Tokyo.