Illustration: Sarah Grillo/Axios

When the next "Big One" hits, the U.S. Geological Survey really hopes you'll pay attention to the alert on your phone.

Why it matters: The ShakeAlert system, installed along the West Coast, can provide anywhere from seconds up to a minute of warning to areas outside the epicenter that a big quake is on the way.

  • "Depending on the distance, that could be enough time to automatically slow trains, stop industrial machines, start generators, pull a surgical knife away from a patient or tell students to put the 'drop, cover and hold' drill into action," the AP reports.

Between the lines: The system didn't alert anyone this time, and that was on purpose.

  • The app "will only send out a ShakeAlert — that is, the message — if a particular area experiences a level of shaking that’s potentially damaging," Robert-Michael de Groot of the USGS told The Verge.
  • "This is why we’re saying that it worked exactly as intended because the earthquake was out in Ridgecrest, which is about 150 miles or so from Los Angeles."
  • In LA, "ShakeAlerts only get sent to people when there’s potentially damaging shaking — where things get broken or people can get hurt."
  • "If people are getting ShakeAlerts every single time there’s an earthquake, people are going to begin to ignore them."

The bottom line: A warning only works if people heed it, and hopefully that moment doesn't come for a very long time.

Go deeper ... In photos: California's historic earthquakes, less than two days apart

Go deeper

Updated 2 hours ago - Politics & Policy

Coronavirus dashboard

Illustration: Eniola Odetunde/Axios

  1. Global: Total confirmed cases as of 6:30 a.m. ET: 30,199,007 — Total deaths: 946,490— Total recoveries: 20,544, 967Map
  2. U.S.: Total confirmed cases as of 6:30 a.m. ET: 6,675,593 — Total deaths: 197,644 — Total recoveries: 2,540,334 — Total tests: 90,710,730Map
  3. Politics: Former Pence aide says she plans to vote for Joe Biden, accusing Trump of costing lives in his coronavirus response.
  4. Health: Pew: 49% of Americans wouldn't get COVID-19 vaccine if available today Pandemic may cause cancer uptick The risks of moving too fast on a vaccine — COVID-19 racial disparities extend to health coverage losses.
  5. Business: Retail sales return to pre-coronavirus trend.
Mike Allen, author of AM
2 hours ago - Politics & Policy

Scoop: Mike Bloomberg's anti-chaos theory

CNN's Anderson Cooper questions Joe Biden last night at a drive-in town hall in Moosic, Pa., outside Scranton. Photo: CNN

Mike Bloomberg's $100 million Florida blitz begins today and will continue "wall to wall" in all 10 TV markets through Election Day, advisers tell me.

Why it matters: Bloomberg thinks that Joe Biden putting away Florida is the most feasible way to head off the national chaos we could have if the outcome of Trump v. Biden remained uncertain long after Election Day.

Biden's hardline Russia reset

Photo Illustration: Eniola Odetunde/Axios. Getty Images photos: Mark Reinstein

When he talks about Russia, Joe Biden has sounded like Ronald Reagan all summer, setting up a potential Day 1 confrontation with Russian President Vladimir Putin if Biden were to win.

Why it matters: Biden has promised a forceful response against Russia for both election interference and alleged bounty payments to target American troops in Afghanistan. But being tougher than President Trump could be the easy part. The risk is overdoing it and making diplomacy impossible.