PREPARING THE PUBLIC FOR AN ALERT (EEW)

Important questions remain as cities move to deploy earthquake alert systems

While rolling out earthquake early-warning tech is a step in the right direction, it doesn't address how cities should prepare the public for receiving an alert.

By Michael Grass

Published April 25, 2019

SEATTLE — As earthquake early-warning (EEW) technology becomes more widely available on the West Coast in the coming years, there will also be a considerable need for public outreach efforts to effectively educate alert recipients on how they should respond in the seconds before serious shaking arrives.

During a public town hall meeting Tuesday night in Seattle, which is hosting the Seismological Society of America's annual meeting this week, Harold Tobin, director of the Pacific Northwest Seismic Network at the University of Washington, asked an important question: "Do people understand what to do when we send out an early warning alert?"

Beyond addressing this question in reference to public-facing applications for quake alerts, town hall panelists also looked at some of the pilot projects underway to integrate EEW technology into infrastructure in order to protect vital machinery and systems.

Increasing preparedness with ShakeAlert

The ShakeAlert system on the West Coast, which has been under development in recent years by the U.S. Geological Survey in collaboration with state and university partners, relies on networks of seismometers that can quickly detect and pinpoint the location of an earthquake from its initial P-waves and quickly relay alerts before the major shaking arrives from the quake's more destructive S-waves. It can't predict a quake, but once one is detected, recipients of the alerts — whether they're people with smartphone apps or EEW-integrated building systems and infrastructure networks — can take quick action before the serious shaking starts.

In some scenarios, that means there could be enough time for people inside buildings to take shelter under a sturdy table and pedestrians to move away from quake-vulnerable windows, brick facades and overhead hazards. In infrastructure applications, EEW systems could automatically close valves on water tanks, power down vital equipment or slow commuter trains to reduce the risk of a derailment.

As part of quake resiliency initiatives undertaken by Los Angeles Mayor Eric Garcetti's administration, the nation's second-largest city built and deployed a ShakeAlert app for public use in January. It's the first such app in the nation.

The system can send out an alert to the public for earthquakes with magnitudes of 5.0 and higher. Southern California has not yet seen a quake reach that threshold since the app's launch, but the region continues to face major seismic threats from numerous faults. The app currently works only for users in Los Angeles County, but there are efforts underway to expand it to other places on the West Coast, including Seattle, which Tobin said could get a ShakeAlert App in one to two years.

The amount of lead-time before the serious shaking starts — anywhere from a few seconds to upwards of a minute in some cases — depends on the distance an alert recipient is from the quake's epicenter and ShakeAlert network's ability to quickly relay a warning. (Existing emergency notification systems for amber alerts and severe weather warnings are currently too slow for seismic events.) The closer you are to a quake's epicenter, the less time you have to react to an early-warning alert.

Expanding EEW networks

While authorities in Japan and Mexico built their own earthquake early-warning systems decades ago, the U.S. has lagged behind the development of its own EEW network due to a lack of federal and state funding. But there's been more momentum in recent years to secure funding, which has led to more seismometers deployed on the West Coast and the building of a prototype system, which has been successfully tested.

Expanding EEW networks to the entirety of the West Coast will cost $40 million in capital investments and $28 million in annual operating expenses, Tobin said.

For the West Coast's most populous areas, EEW alerts could save many lives in some of their most-feared quake scenarios. In Southern California, for instance, quake alert recipients in downtown Los Angeles could have a one-minute advance warning for a 7.8 magnitude quake that originates on the southern San Andreas Fault Zone near the Salton Sea, about 165 miles away. But there are, of course, other Big One scenarios. Los Angeles would have far less time to react to a quake that originates closer to the city — or directly under it.

In the Pacific Northwest, the Big One scenario that greatly concerns seismologists and emergency managers is the next magnitude 9.0 megaquake along the Cascadia Subduction Zone, which lies off the coasts of Washington and Oregon. When EEW systems are deployed more broadly in the coming years, alerts recipients in Seattle and Portland might have upwards of one minute to respond before the serious shaking reaches them in some scenarios involving the subduction zone. Those directly along the Pacific coast will face far more severe shaking and a quake-generated tsunami that thousands will need to outrun in order to reach safety on higher ground.

Sandi Doughton, a Seattle Times reporter and author of "Full Rip 9.0: The Next Big Earthquake in the Pacific Northwest," noted during the event that on the coast, EEW could give people "a head start" out of the inundation zone. But even when EEW eventually becomes available for coastal residents, the likely quake scenarios there remain particularly dire.

Of the seven projects recently announced by Seattle Mayor Jenny Durkan's Innovation Advisory Council, two are earthquake related. Amazon Web Services and Twitter will be working with Seattle's Office of Emergency Management to develop a local ShakeAlert prototype and a damage assessment tool.

Doughton said that while the ongoing development of EEW applications is promising and potentially life-saving for alert recipients, it's no substitute for substantive state and local policy changes needed to mandate seismic upgrades for vulnerable buildings, an area where the Pacific Northwest has lagged behind California.

For public officials, Doughton said "there are many other things they could be doing that aren't as sexy and not as flashy" when it comes to seismic resiliency. "I think a lot of politicians latch onto [EEW technology] because it's an easy fix."

In the meantime, discussions are underway among U.S. seismologists, emergency management professionals and social scientists about how earthquake alert messages should be crafted to be the most effective for recipients.

Learning from Mexico City

Many on the West Coast have been closely watching Mexico City, which deployed a quake alert system in 1991 that relays warnings via a network of 1,200 sirens — there are also private-sector providers that use push notifications to relay alerts to cellphones — and has years of experience observing how residents respond to quake alerts, including false alarms or quakes that are identified by seismic networks but don't necessarily produce detectable shaking in the capital.

In September 2017, there were five events that triggered alerts in Mexico City, including a false alarm, a smaller quake, and then on Sept. 19, a pre-planned citywide earthquake drill followed by an actual magnitude 7.1 quake a few hours later that damaged many buildings and killed a few hundred people.

"Mexico City ran those experiments for us" in September 2017, said Scott Miles of the University of Washington's Department of Human Centered Design and Engineering, who as a social scientist has been part of a team studying how people respond to EEW alerts.

Among the best practices from Mexico City's experience that Miles cited: Once an alert is sent out, be ready to send out a follow-up message or messages that offer not only additional information on the seismic event, but also consistent information. It's also crucial to be ready to send out a follow-up message after false alarms.

EEW’s impact on infrastructure

While deploying EEW technology to the public presents tough questions on how to design and implement effective public education, efforts to integrate early-warning applications into infrastructure continues.

In Spring 2018, Bothell, WA-based RH2 Engineering worked to deploy the first EEW applications for a Seattle-area water utility, the Northeast Sammamish Sewer and Water District, as part of a ShakeAlert deployment pilot project.

Michele Campbell, a RH2 Engineering earthquake early warning program manager, said that for a water utility, an EEW alert system is valuable beyond protecting infrastructure. It's about protecting frontline workers, too. 

"Earthquake early warning systems could give them precious seconds to jump out of the way of dangerous machinery," Campbell said, noting that protecting workers is of utmost importance when they'll be needed to immediately start recovery efforts. In the case of the next major quake along the Cascadia Subduction Zone, some water systems in the region are expected to be offline for a few weeks in more rosy projections to many months in the worst scenarios.

Deploying EEW-integrated valves to water tanks can help preserve a utility's water supply and protect vulnerable equipment, like pumps, from power surges. Because each water system is different in its design and faces various risks depending on an earthquake's size, severity and origin, Campbell said that EEW-integrated water utilities, with pre-programmed automated actions, might choose to close valves on certain tanks and power down particular pumps while trying to maintain operations elsewhere, depending on the immediate threat.

"It's relatively low-cost compared to other seismic preparedness actions," Campbell said

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