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You get that earthquake notification yesterday morning? Plenty of people did, and plenty of them freaked out. A 6.0? Near here? Uh-oh! They were right to be worried; it was a nothingburger up here in Humboldt, but a chunk of Mendocino got rocked by the quake, which the US Geological Survey (USGS) later downgraded to a 5.6. 

The ShakeAlert system isn’t 100% perfect, Cal Poly Humboldt geology professor Eric Riggs explained to the Outpost yesterday, but it’s definitely better than having nothing. The USGS monitors signals detected by seismograph networks, which, when it thinks an earthquake is happening, takes a few seconds to crunch some data: How powerful are the tremors? How far are they spreading? and spits out a message to people it thinks may be in the danger zone. If Humboldt had been closer to the epicenter, residents’ phones may have made a whole lot more noise, screaming and buzzing instead of passively pushing through a notification telling people they might feel some shaking. 

“Because it is an automatic system, it does make errors,” Riggs said. “It’s doing as best it can, as fast as it can. The whole point is to give people a few extra seconds to get safe, and to shut down critical systems, or to lock things up so they don’t swing around.”

Enduring a couple small false positives is far safer than confronting a real earthquake with no heads-up. There’s a sweet spot, Riggs said; people in Ukiah and Willits got their warnings while they were already being tossed around. 

Riggs is part of a team working on improved alert technology that, for the last few years, has been utilizing the fiber-optic cables internet company Vero has installed. Scientists monitor the data the cables are carrying. When the cables vibrate, the pulses of light that computers turn into data change, and the scientists working on the project have figured out how to interpret those altered pulses, recognizing if the cables have picked up on an earthquake. 

The improvements over using traditional seismographs are immense. The signals move much faster — at the speed of light, far faster than an earthquake can move, although only after a computer takes about five or six seconds to decide if the data it’s receiving means there’s an earthquake and the signal is broadcast. It allows victims of an imminent earthquake to have a few extra seconds to prepare. 

For now, they’re only monitoring the lines Vero’s put down around Arcata, out to Willow Creek and down to Eureka. Someday, it’ll reach up to Trinidad, and once they figure out how to implement it on a wider scale, maybe elsewhere on the West Coast. A few other universities (CalTech, the University of Washington, Stanford, to name a few) are tinkering with their own systems.

It’s not entirely perfect. Because it’s always “on,” and the cables are so long, it generates reams of data, terabytes of the stuff scientists have to sift through. But they’re slowly working through the kinks. But even once it’s out of the experimental phase, some overreactions are probably inevitable. 

“For those few seconds, when it works, it makes a difference,” Riggs said. “Between you, me, and the doorpost, I think I would rather have a couple of false positives than miss one.”