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This is the VOA Special English Environment Report.
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| A LosAngeles freeway after a powerful earthquake in1994. |
Scientists in the United Stateshave developed a computer program that they say could provide anearly warning of major earthquakes. The new system is designed togive a warning seconds before an earthquake strikes.
That may not sound like very long. However, it could give peopletime to get under a table or take shelter someplace else. The flowof electric power or gas could be cut. Air traffic controllers couldwarn away pilots. Even so-called "smart buildings" could be designedto get ready.
Richard Allen of the University of Wisconsin and Hiroo Kanamoriof the California Institute of Technology developed the program.They call it the Earthquake Alarm System. A report published inScience magazine describes it.
The system uses a mathematical program to measure informationcollected by instruments deployed across the Los Angeles area.Southern California already has more than one-hundred-fifty seismicstations that measure movements within the ground. The informationthey collect is sent to a high-speed computer.
The two scientists are still developing their system. ButProfessor Allen says it could be put in place in other areas aftertesting is completed.
An earthquake shakes the ground with two kinds of waves. The newsystem uses information from a low-energy wave that moves quicklybut causes little damage. Experts call this the P-wave. The slowerbut stronger S-wave is the main threat to life and property.
Japan already has a system based on P-waves. There, the warningsare used to slow down high-speed bullet trains. Other countries havewarning systems that measure S-waves.
The new system is designed to estimate the strength of theearthquake once the shaking starts. Areas directly above the centerof the earthquake would have the least warning. Distant places mighthave as long as forty seconds.
The scientists are still testing their proposed system in the LosAngeles area. Professor Allen notes that an early warning system forearthquakes would require a major campaign of public education.Then, too, is the problem of the possibility of false alarms.
This VOA Special English Environment Report was written by GeorgeGrow.