Pasadena Scientists Say Earthquake Alert System Successful in Recent Quake

Hundreds of members of the scientific community received ShakeAlert warnings in Tuesday’s quake; local seismologists hopes to grow State system quickly

Published : Friday, August 31, 2018 | 5:44 AM

The ShakeAlert issued Tuesday gave Pasadena scientists two seconds of warning before the temblor's effects were felt here. Image via Twitter.

Could you react to an earthquake with four or five seconds warning? Perhaps you could quickly duck into a doorway? Perhaps your family could duck under the dinner table if an alarm went off at meal time. Perhaps a trained surgeon could halt before he makes his incision.

This week’s Tuesday afternoon 3.5 mile-deep earthquake, which was centered about 15 miles east of Pasadena in La Verne. It took one second for the earthquake to reach the surface and become detected by the California Integrated Seismic Network.

In 3.3 seconds a ShakeAlert was issued throughout the Network’s system.

La Verne itself received zero seconds of warning, but cities 20 miles away received almost five seconds of warning. Los Angeles, 28 miles away, received 8.3 seconds of warning. With a ShakeAlert, those receiving the alerts in more distant locations will have more time to act but will experience less intense shaking.

Tuesday's 4.4 earthquake hit La Verne at 7.33 p.m.

A ShakeAlert is an early warning from a system that detects significant earthquakes so quickly that alerts can reach many people before shaking arrives, an innovative technology that will improve over time.

After the system is fully deployed and the public begins to receive ShakeAlerts, Southern California residents will learn that they should act quickly, and to “Drop, cover, and hold on.”

The United States Geological Survey (USGS) is partnering with ShakeAlert. working to implement earthquake early warnings across the West Coast to complement existing tools that contribute to risk reduction.

Although the ShakeAlert Earthquake Early Warning System is not yet complete, technologies to allow rapid mass public alerting are in development and being tested.

Robert deGroot, staff scientist with the U.S .Geological Survey in Pasadena, said Thursday that while it’s still very early in the construction and implementation phase, the system worked as designed during Tuesday’s tremor.

“Scientists don’t know an earthquake is happening until it reaches the surface,” deGroot said. “Once it’s picked up by the seismometers, then that information gets sent to several processing centers on the west coast, which determine whether or not an alert should be issued. That took the additional three point three seconds to generate the alerts.”

“That 4.3 seconds of warning included the time for the earthquake to get from four miles under the earth to the surface,” said deGroot, “and then once the alert is generated, then it gets distributed through a whole variety of channels through a variety of apps that people are operating in our test groups and other places.”

In other words, the system is pretty complex and pretty fast, as it needs to be, said deGroot. But the system has limitations.

“If you’re sitting right on top of where that quake reaches the surface, then it’s likely you will not get an alert before you feel the shaking because you’re right there.”

But deGroot would definitely call Tuesday’s earthquake event a ShakeAlert success.

“The scenario earthquake that we’ve been talking about for years, which is a magnitude 7.8 earthquake on the San Andreas fault, that’s a big earthquake, right?” said deGroot. “And it takes some time for that earthquake to develop, but the whole idea is, is that we would send out an alert so that before the strong shaking reaches your location. In Los Angeles, you could have several seconds to do something about it. One of the elements of the success [on Tuesday] is the fact that we generated the alert in just a few seconds and got it out there and people got the alert.”

Despite the success, deGroot acknowledges that Southern California is a long way from a region-wide alert system, mostly because of cost.

According to deGroot, the current budget estimate for the program is just under $40 million for the construction phase.

“And there’s been a lot of money invested in the system already,” he said.

The USGS has spent somewhere in the average of about $10 million dollars a year for the last several years, said deGroot, “but that money has been going towards not only the build-out of the system but also the annual operations and maintenance.”

DeGroot added, “There might be a more expense associated with this, because we’re also adding the communications, as well as the telemetry infrastructure that goes with basically sending information back and forth, and that could result in some additional costs.”

And while development is moving along steadily, don’t expect to get an earthquake warning on your iPhone anytime soon.

The system is not yet available to the general public, said USGS earthquake early warning coordinator Doug Given for the U.S. Geological Survey.

Given explained, “We have many Beta users who are receiving the alerts through the Internet, and we also have pilot applications that are developing—anything from valves that would shut off, and alerts that would go off or things that would slow and stop trains as they do with BART, and more recently, LA Metro.”

“Some use is already being made of the system,” said Givens, “and we’re expanding that use as quickly as we can.”

The number of current users of the system is probably in the hundreds, says Givens, including Pasadena’s Dr. Lucy Jones at Caltech’s Seismological Laboratory. Givens himself has an app on his phone, but it is only experimental at this point, he says.

Still, Given is cautiously optimistic about the system’s growth.

“The state of California has allocated about $10 million the project and this current fiscal year, they’ve added another $15 million and that is in addition to the federal funding that’s going to the project. So while we’re still at a funding level that’s lower than what we need to complete and more importantly operate the system for the long term, a lot of funding has now been made available both at the state and federal level.”

The server infrastructure has also made steady progress, says Given.

“We’ve made a lot of progress in building out our server infrastructure. We have alert servers in southern California, northern California, and Seattle, and we believe those can sustain a lot of connections to distributors, but they would not be the kind of thing that everybody individually could connect to. We still need redistribution services. That’s what some of our pilot programs are doing.”

But Given is nothing if not realistic about the system’s use and effectiveness.

“I always like to caution folks that this is not earthquake prediction. Sometimes people think, ‘Well, okay, if you’d give me a few seconds now and maybe a few minutes later, and then maybe a few hours sometime in the future..’, but that’s not how it works. This is very rapid detection of the earthquake after it begins.”

Consider yourself warned.