Alicia Montiel Rodriguez was in an office building in southern Mexico City Tuesday when alarms began to sound, piercing the air with beeping tones and recorded messages warning that an earthquake was on its way.
“We followed the instructions of the security people and went to preassigned safety zones within the building,” Montiel Rodriguez said in Spanish. “About 10 seconds after everybody got to their zone, the earthquake started.”
Mexico’s early-alert earthquake warning system was established after 10,000 people were killed by a magnitude 8 temblor in Mexico City in 1985. It may have saved lives during Tuesday’s 7.4 magnitude quake, which apparently killed no one despite the violent swaying and collapse of some buildings, and the aftershocks that have rocked the region since then.
But a similar early-warning system planned for the Bay Area and the West Coast has now languished for more than five years, stuck in a perpetual test phase because of a lack of government funding.
Meager federal financing for the West Coast early-warning system received a boost late last year, when the Gordon and Betty Moore Foundation kicked in an extra $6 million over three years. But officials who have been working on the program say much more is needed.
“The main problem is funding,” said Doug Given, a project manager for the U.S. Geological Survey’s earthquake monitoring program. “In the current government financial situation, it’s unlikely that it will be funded to the adequate level soon. We’re still searching for avenues to make it happen.”
Developing such a system in the Bay Area and elsewhere in California, areas that are crisscrossed by fault lines, is more difficult than in Mexico, where shaking is predominantly caused by offshore earthquakes that can take tens of seconds to reach the coastline and seconds more to stretch into populated inland areas, according to Thomas Heaton, the Los Angeles-based director of the Earthquake Engineering Research Laboratory at the California Institute of Technology. Tuesday's quake struck inland, 12 miles below the earth's surface.
The demonstration project in California already works — to a limited extent — using an existing network of earthquake sensors to warn researchers of approaching shaking as it spreads like ripples on a pond away from an epicenter.
The nascent system relies on rapid computer analysis of data from about 400 of the nearly 1,000 sensors managed under the California Integrated Seismic Network, said Heaton, who is involved with the system's development.
The key is analyzing the data from those sensors and sending the results electronically faster than the speed at which earthquake shock waves travel, roughly two miles per second.
While it used to take 30 minutes for geologists to map and project the path of an earthquake, Heaton said computers could now be programmed to make those calculations in seconds.
“That’s basically what early warning is — you’re making the projections as quickly as possible. In the case that you make it fast enough, the projection comes before the shaking,” Heaton said.
But funding woes mean the early-warning system is plagued by too many errors, and crashes too frequently, to be rolled out for transit operators, utilities, building managers and others in California for whom it could be useful. Heaton said at least 200 additional sensors would be needed to provide sufficient data for an accurate early-warning system.
“You just can’t unleash a buggy system,” Heaton said.
Even advance warning of five to 10 seconds could be enough to slow trains before tracks buckle. Elevators could be routed to the nearest floor and their doors opened to prevent passengers from becoming trapped by a blackout. Motorists warned by their networked cars or smartphones could pull over and flick on hazard lights to warn others of the impending tumult. Such measures are already commonplace under a sophisticated early-warning system in Japan.
Such a system here could be connected to smartphones and office buildings, but making the most of the program could require extensive new training, drills and public awareness campaigns.
In Mexico City, those drills happen regularly. David Rojas, 33, an industrial designer who was trained to lead his colleagues out of a building when the alarms sound, said he credits the drills for the calm and orderly evacuation responses to Tuesday’s large earthquake.
“In the case of the secure areas, we have the help of government security workers who block traffic in the streets so people can gather there, where buildings and trees won’t fall on them,” said Rojas, speaking in Spanish on Thursday morning from a patio moments after the building he was visiting was evacuated because of a magnitude 5.2 aftershock.
“There are drills every four months,” Rojas said. “Sometimes they announce, ‘There’s going to be a drill.’ Other times, they do a drill without announcing it’s a drill, so that when the real thing comes, there isn’t as much panic.”