In the minutes before a deadly tornado struck Moore, Okla., earlier this year, sirens wailed, warning of the imminent threat. That advance notice that gave residents extra time to take cover, and may have been the difference between life and death.
But early-warning technology isn’t restricted to tornadoes. California researchers are developing a similar system for earthquakes. While the technology makes sense to deploy in seismically active regions in the West, experts believe the system could be an even more important priority for the eastern states.
Unlike the West Coast -- which has many fault lines that break up the Earth’s crust and stunt how the quake’s energy is transmitted -- the East Coast is made up of harder, less active and colder ground, which enables energy waves released by earthquakes to travel further.
For example, the 5.8-magnitude earthquake that struck Virginia on Aug. 23, 2011, was average in its intensity, but its impact was felt by more than 37 million people from Boston to South Carolina.
With its dense population centers and older structures, the Eastern seaboard could suffer catastrophic destruction from a stronger tremor. An early warning, though, could give residents a critical 30- to 90-second heads-up to prepare.
“In some ways there’s almost more of a need [for an early warning system] on the East Coast because the buildings are so much worse,” said seismologist Lucy Jones, senior science advisor for the Natural Hazards Mission of the U.S. Geological Survey (USGS). “The earthquakes are less likely, but they do happen and when they do, they cause more damage at the same size.”
Brian Blake, program coordinator for the Central U.S. Earthquake Consortium, agreed. He explained that many of the older buildings in the U.S., particularly those in the Central and Eastern areas of the country were built before strict seismic provisions were in place.
While Blake supports early warning technology, he was adamant that public awareness regarding the threat of earthquakes is essential for the system to be successful. He explained a lot of states have an earthquake risk that’s widely known to the scientific community, but not necessarily to the public at large -- and they need to be informed.
“Having the warning system in place without the public knowing there’s a threat would not do a whole lot of good,” Blake said.
How it Works
Early warning systems operate using a series of sensors that relay information to a central location. In an earthquake, these in-ground sensors pick up on seismic activity and trigger alerts that can be sent out before the shaking starts, enabling residents and key decision makers to proactively take steps to ensure personal and public safety.
An early warning system should give people the opportunity to secure themselves properly. In addition, the notification that an earthquake is coming may enable power stations or even trains to shut down, reducing the risk of deadly explosions or derailments, respectively.
The train derailment risk was one of the reason’s Japan’s earthquake early warning system was launched in 2007. The technology provided the public with advance warning of the 9.0 magnitude Tohoku earthquake in March 2011. The alerts were automatically broadcast across TV and radio based on the data from sensors. Residents also received smartphone notifications.
In many areas of the U.S. that experience earthquakes, seismic sensors are already embedded in the ground for research and observational purposes. But according to Blake, the technology is needed in other regions. He said existing sensors can pick up where an earthquake is and how big it was, but in order to give a detailed view of the quake and trigger an early warning, a larger grid of the devices are needed.
“It’s not a question of how few you need, it’s really a question of how many we can put in,” Blake said. “Because the more we put in, the better data and response we’ll be able to generate.”
First Steps in California
A bill that would create an earthquake early warning system in California is under consideration in the state legislature. Sponsored by state Sen. Alex Padilla, S.B. 135 requires the California Office of Emergency Services, in collaboration with the California Institute of Technology, the California Geological Survey, the University of California-Berkeley, the USGS and other partners to develop an earthquake warning system for an estimated $80 million. If the legislation is signed by Gov. Jerry Brown, Jones believes the technology will spread nationwide.
Sen. Padilla was sold on the effectiveness of early warning systems after watching footage of Japan’s technology. The rapid notification it provided to citizens made him an instant believer on how valuable an extra 30 seconds can be to prepare for an earthquake.
“I figured by advancing legislation in the state capital and making it a priority in the state, we can find an alternative or multiple sources of funding so we can put in a system as soon as possible,” Padilla said. “Because whether it is a year from now or five years from now, I don’t want to be here after the next ‘Big One’ asking myself why I didn’t try to do something about it.”
The California Institute of Technology and the Japan Agency for Marine-Earth Science and Technology published a study in January that concluded that an earthquake involving both the Los Angeles and San Francisco metropolitan regions may be possible.
If SB 135 becomes law, Jones sees the project as a regional endeavor, including the states of Washington and Oregon. She said that the Pacific Northwest actually has the potential for an earthquake bigger than anything in California because of the Cascadia Subduction Zone, a fault that runs from Vancouver Island, British Columbia, Canada; to Northern California.
In the meantime, Jones has been setting up agreements with risk communication and design professionals to come up with a messaging system that can get information out to people effectively in the seconds before a quake. In addition, she believes a training program will be necessary so that people will know what to do when they get an earthquake notification.
“We don’t think people are going to be able to make the decision to act correctly without thinking about it beforehand,” Jones said. “People don’t usually make decisions in seconds. So a critical part of [this is] training.”