A prototype earthquake early-warning system worked again Friday night, giving seismologists in Pasadena about a four-second heads-up before shaking was felt from the magnitude 5.1 quake that struck near La Habra.
The system is being tested by a team of scientists on a U.S. Geological Survey project to create a statewide network.
USGS seismologist Lucy Jones has said the system works because while earthquakes travel at the speed of sound, sensors that initially detect the shaking near the epicenter of a quake can send a message faster -- at the speed of light -- to warn residents farther away that the quake is coming.
The system being tested by scientists at the USGS and Caltech previously gave officials at the Pasadena center about a two-second warning ahead of a magnitude 4.4 earthquake that struck near Westwood in March.
Once developed, the system could give downtown Los Angeles 40 to 50 seconds of warning that the "Big One" was headed from the San Andreas fault, giving time for elevators to stop at the next floor and open up, firefighters to open up garage doors, high-speed trains to slow down to avoid derailment and surgeons to take the scalpel out of a patient.
A lack of funds, however, is preventing the system from being ready for prime time.
"It's just a matter of obtaining the funding," said USGS seismologist Robert Graves. It would cost about an estimated $80 million to get the system up and running.
The lack of funding means that some earthquake-sensing stations aren't maintained, so the network isn't yet reliable enough, Jones said.
For example, the nearest seismic warning station near the 6.8 earthquake off the California's northern coast on March 10 was out of order when that temblor hit, she said.
California lawmakers last year passed legislation that prohibits spending state General Fund money on the early-warning system, leaving the state's Office of Emergency Services to look for other sources, both private and public, to cover costs.
Some scientists see that mandate as a setback for the project, which still requires installation of many more ground sensors across the state as well as additional money to operate the network.
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Last year, the earthquake scientists received about $5 million from a federal grant to begin purchasing 100 new sensor stations for Southern California. But without funds to operate it, it's like buying a car but not having enough money for gasoline, officials said.