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Humboldt quake a hint of what’s in store By Gary Nelson By Mail Tribune Editorial Board Dec 21, 2022 12:00 AM A A Tuesday morning’s 6.4 magnitude earthquake in Humboldt County on the Northern California coast didn’t do any damage here, although it caused widespread damage in the Ferndale area. Some Rogue Valley residents received alerts on their cellphones thanks to early-warning technology. Humboldt County residents experienced their second quake in a year. This one left 72% of county utility customers without power, and damaged roads and bridges along with buildings. Residents of that area are more accustomed to quakes than those of us in the Rogue Valley because the region is seismically very active, averaging about 80 earthquakes a year of magnitude 3 or greater. While the entire coast is subject to subduction zone quakes in which one crustal plate slides beneath another, Tuesday’s quake occurred in what is known as the Mendocino Triple Junction, where three plates interact at once, resulting in a large number of earthquakes. Southern Oregon experiences earthquakes, too, but far less frequently. At the same time, our region is overdue for a truly massive quake in what is known as the Cascadia Subduction Zone. The Humboldt quake was a 6.4. A Cascadia quake that occurred in 1700 was estimated at 8.7 to 9.2. Authorities have estimated a modern-day Cascadia quake could cause $32 billion in damages. In addition to maintaining stockpiles of food and water, local residents can prepare for earthquakes by installing early-warning apps on their smartphones. These apps don’t predict earthquakes, but monitor more than 1,000 seismic sensors that detect energy released in the earth as a quake begins. These initial detections can give as much as 20 or 30 seconds of warning before ground shaking occurs. The farther away the epicenter of the quake, the more time you have to take action. The Medford School District has implemented the ShakeAlert Earthquake Early Warning System operated by the U.S. Geological Survey, and conducts earthquake drills during which students are trained to “drop, cover and hold on” when alerted to do so. As described in Dec. 7 Mail Tribune story, Medford is the only district the state to fully implement it. Two apps — MyShake and QuakeAlertUSA — are available for download. You can also activate emergency alerts through Ashland, Medford or Jackson County emergency services. For more information, visit www.shakealert.org . No one can say for sure when the next major earthquake will occur. But we can be as prepared as possible when it does. Early-warning systems are one way to accomplish that.