Tom Heaton was sitting in his kitchen in Pasadena on Monday morning when an alert went off on his laptop warning him that an earthquake had struck about 40 miles away in Encino.
Seconds later, he felt the shaking.
"It was fantastic," said Heaton, director of Caltech's Earthquake Engineering Research Laboratory. "It was bam bam, then it shook. It was probably about three seconds" between the alert and the shaking.
Within a few years, all Californians should have access to those kinds of warnings, a crucial few seconds that could give emergency officials and residents time to brace for a major temblor.
But as work on the statewide early warning system kicks into high gear, government scientists and private companies are jockeying over how the system should operate.
Among the questions still to be decided: whether it will be a strictly free system or whether a more advanced, paid system for governments and other institutions will be incorporated.
Some private companies already sell earthquake alerts to city governments, businesses, fire departments, schools and other groups.
By far, the most prominent in California is Seismic Warning Systems Inc. in Scotts Valley. The company has both government and private clients, particularly across southwestern California, where the San Andreas fault and other seismic dangers loom large.
In endorsing the statewide warning system last year, the state Legislature mandated that it be a public-private partnership, creating some unease between entrepreneurs and scientists, who have toiled on a public warning system.
The legislation states that no state general fund money can be used to cover the estimated $80 million it will take to complete the system. That leaves the Office of Emergency Services to look for other sources — both public and private — to cover those costs before January 2016.
Some scientists saw that mandate as a setback for the project, which still requires installation of many more ground sensors around the state and additional money to operate the network.
Without state money, the public and private sectors are going to have to work together to cover those costs. Public scientists say the lack of state money is likely to slow the process.
Heaton, who for years has been part of a team of scientists on a U.S. Geological Survey project to create the statewide network, admits the relationship between the two sides has been chilly at times.
"It's hard enough if we're all pulling together," Heaton said. "I totally agree we need private enterprise, but though they don't explicitly state it, they seem to be saying, 'public sector, just get out of the way.' They seem to be somewhat threatened by the idea there will be a public system."
Both the public and private warning systems work when sensors in the ground detect the first signs of earth movement, known as P waves, that travel at the speed of sound. The more damaging shaking, called the S wave, lags behind at a slower speed. The greater the distance from the epicenter, the more time population centers have to prepare. A quake at the center of the city could provide little to no warning.
Early warning systems already are used in Japan and Mexico.
Seismic Warning Systems officials argued that they could partner with the state to build a better network that is cheaper to operate. They say they use two sensors at a fault location to avoid false alarms.
"Not only for less money, but faster, more reliable," said George E. Dickson III, chairman and chief executive of the company.
A few hours after the Monday quake in Encino, the company shared an email stating that its technology might have been able to give more of a warning than the USGS alert Heaton received. But because the company doesn't have instrumentation in L.A., the claim was only an estimate based on how its technology works elsewhere.
Dickson said his firm is happy to work with the state to create the alert system but stressed his company is going to continue to expand its paid services.
"Government, businesses and consumers already pay for services they deem valuable," he said.
Scientists working on the public alert effort said their idea would be for people to install a quake warning program on their computers and mobile devices. If a large earthquake occurred, the warning would take over the screen with a countdown to shaking — which depends on how far one is from the epicenter.
It's a variation on the approach the USGS and other agencies now use for distributing information about quakes after they happen. That signal could be plugged into automated systems that trigger safety mechanisms such as stopping a train to avoid a derailment.
Seismic Warning Systems' approach has not been to alert individuals, but businesses, government agencies and first responders. Its clients include hospitals, schools and laboratories. The company charges schools $1,200 and fire stations $2,500 a year for alerts.
The firm's alerts can be plugged into automated systems that, among other things, open firehouse doors so that a strong earthquake doesn't jam them, preventing critical equipment from getting out.
Ken Johnson, chief of the Paso Robles Fire Department, said the system worked after the 6.5 San Simeon earthquake in 2003, giving more than 10 seconds warning and opening bay doors.
The two sides also have not completely agreed on how large an earthquake should be to trigger a notification. Seismic Warning's early alert systems are activated for earthquakes of a magnitude 5 or greater, which is a threshold the company said its clients have felt appropriate.
USGS researchers argue that alerting to some smaller earthquakes, including aftershocks, puts them and larger earthquakes in context.
"If the system came on and said it was a three and a half, it's telling you, don't have a cow," Heaton said. "Anything you feel, most people would want an alert."
No decisions have been made about how the system will operate and whether there will be a revenue-generating aspect of the program. Scientists believe some version of the alert will be available to anyone who signs up for it.
Seismic Warning Systems has shown there is a market for quake early warnings in places such as the Coachella Valley. Tom Kirk, executive director of the Coachella Valley Assn. of Governments, said the fact that the San Andreas fault is a visible neighbor in the region was a large incentive.
"We are so close to ground zero and for us, much like our brothers and sisters in the Bay Area, the San Andreas fault is very real," he said.
Last week, Imperial County voted to award a federal-state grant to Seismic Warning Systems to deploy an early warning network. The grant money came as a result of the 7.2-magnitude Easter Sunday earthquake that shook the California-Mexico border in 2010.
Imperial County Fire Chief Tony Rouhotas said $250,000 will be paid to the company to implement early warnings in about 20 buildings, most of them devoted to emergency response.
"That's just the start," he said. "What we do after we get this initial system and how we expand it after that is really up to money and ideas."
One thing everyone seems to agree on is that the system needs to be completed and used more widely. Richard Allen, director of UC Berkeley's Seismological Laboratory, said it's a shame that only a handful of researchers now get early alerts from the USGS.
"About 50 people get early warnings," he said. "The rest of California does not, and that's wrong. And that's why it's very important to get this funded and get these warnings to people."
Times staff writer Rong-Gong Lin II contributed to this report.