Mayor Eric Garcetti announced Wednesday that that city’s earthquake-warning app, ShakeAlertLA, is being fine-tuned after residents complained that the smartphone app failed to send out notifications when the Ridgecrest earthquakes rocked the region July 4 and 5, the Los Angeles Times reports.
“Updates to ShakeAlertLA will result in an even more responsive application making our city stronger and our families safer,” Garcetti said.
The system was supposed to give Angelenos about 30 seconds notice before vibrations from the temblors that hit 125 miles northeast of the city arrived here, but no heads-up was sent because that version was programmed to alert users only when “light” shaking—the kind that would rattle dishes—was on its way. The Ridgecrest quakes actually did produce “light” shaking in Los Angeles, but the U.S. Geological Survey had predicted only “weak” shaking.
In the future users will be warned when “weak” vibrations are heading their way, the kind that the Times says can be “felt quite noticeably by people inside, especially on upper floors of buildings, but may not be felt by other people, especially those outside.”
The original settings were intended to warn Angelenos only of quakes that would likely cause damage. Experts, however, say people want more.
“People want lower-threshold alerts,” Berkeley Seismology Lab director Richard Allen told the National Academies of Sciences, Engineering and Medicine last month. “I think that is loud and clear in terms of what we’re hearing from people. They don’t just want warnings for damaging earthquakes…. People expect to get a warning if they’re going to experience the earthquake, i.e. … they’re going to feel significant shaking.”
Researchers believe that people would rather be overinformed than underinformed, even if that means experiencing false alarms.
“That’s part of a sort of generational change that is going on right now,” Allen said. “People would rather have more information than less information and be able to decide what to do with it.”
According to the mayor’s office, ShakeAlertLA, which launched in January, is “the nation’s first test of delivering USGS-generated ShakeAlerts to a large population using a city-developed cellphone app.”
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