The test went out at 11 a.m. March 27 via cellphone wireless emergency alert (WEA) to more than 40,000 people in a 60-acre area of downtown Oakland. On the federal side, it was supported by agencies including the US Geological Survey with assistance from the Federal Emergency Management Agency’s Integrated Public Alert and Warning System (IPAWS). Locally, the city of Oakland and Alameda County played a part; and at the state level, the California Governor’s Office of Emergency Services (CalOES), UC Berkeley and the California Institute of Technology were involved. Among the findings so far:
• Response was robust. The test generated “double our expectations,” Ryan Arba, branch chief for seismic hazards at CalOES, told Techwire, indicating it generated “between 900 and 1,000 responses” to a survey. The test message containing the survey went out to cell towers in the “alert polygon” and, from there, to people in range of the towers — so boundaries weren’t exact. The survey included questions about when recipients received the alert, what cellphone carrier they used and their data speed.
• The test — made possible by the arrival of faster 4G LTE networks, more modern cellphones capable of delivering a timely alert, and $25 million in state funding — was closely watched by officials, around a dozen of whom timed it at the California Department of Transportation (Caltrans) facility in downtown Oakland. The WEA arrival in about 4 seconds “really encouraged” officials that “in some cases, these alerts can come out within a few seconds, which would really open this up as an alert pathway for sending shake alerts or earthquake early warning,” Arba said.
• Variability — the idea that even in a perfect test, not everyone will get the alert at the same time — was one of the test’s larger lessons.
“We’re hoping that by doing tests like this, we can document what that variability is in a snapshot, and then work with those people who are responsible for that. And in this case, it’s the carriers and their technology and how they’re upgrading their systems,” Arba said.
• It’s not yet entirely clear whether WEA or a downloaded cellphone app may be the quickest way to push out an early earthquake warning to Californians. It’s also far from certain that residents can be counted on to download an app, or receive an alert — so Arba recommended a “multi-pronged approach,” adding: “We encourage everybody to take every step that they can that’s reasonable.”
• CalOES is working with the University of California at Berkeley on potentially expanding its free MyShake app for Android users. The app uses smartphone sensors to sense the vibration of an earthquake, then send anonymized information back to a central warning system. Arba said the agency is also “encouraging anyone else who is interested in developing a cellphone app or another way to distribute those alerts,” and wants to continue “pushing for that.”
