An earthquake with a preliminary magnitude of 4.2 — initially reported as a 4.5 — struck near San Bernardino Wednesday night shortly before 7:45 p.m. Shaking has been reported to the U.S. Geological Survey’s Did You Feel It? app from Los Angeles and down into Orange County.
No significant damage was immediately reported.
Lucy Jones, a noted seismologist, took to X (formerly known as Twitter) to explain that the location of the epicenter was "pretty deep 15 km) very close to the San Jacinto fault." Jones went on to saw "that part of the fault is generally locked — it had a M7 in the 19th century."
M7 references the Mercalli scale, which measured the intensity of shaking.
The U.S. Geological Survey’s earthquake early warning system is triggered depending on intensity of the shaking and can offer seconds of warning. Alerts were delivered Wednesday night. Here's what the USGS had to say on social media about how they determine when and where to send it:
"The #ShakeAlert system estimated the quake at/above magnitude 4.5 so alerts were delivered to cell phones by @USGS partners @MyShakeApp, @SanDiegoCounty #ShakeReadySD @Android."
Asked by one person in L.A. why they didn't see an alert, USGS officials responded that the estimated intensity of shaking at his location was below the alert trigger.
What was clear right away is that the shaking activated Southern California earthquake Twitter (apparently now called X) with the memes and commentary kicking right back up.
Small quake. Basic.
— -Kryss Anderson (@KryssAnderson) January 25, 2024
But what does this mean for me? Is another giant quake coming? Do I need more earthquake water and emergency food? cause I ate mine during the power outage 2 weeks ago 😭
— Lesbian Roller Derbyists for Pritzker (@Derbyists4Pritz) January 25, 2024
No quake shaking over here…too busy letting go of today’s work vibes.#whatearthquake pic.twitter.com/YpXRaha6yi
— Eleanor Rigby 🧙♀️ (@OhMeowItsNorms) January 25, 2024
oof i always think of the big one everytime a quake happens… but then forget about it the next day 😅
— ౨ৎ sam⁷⁼¹₁₃ | #1 jimin lover !! 🩵 (@jmzf4ce) January 25, 2024
Here at LAist we really urge you not to forget. A true Big One is inevitable and we all need to get ready. Check out the resources below. And if you need more motivation, listen to our award-winning podcast that got (scared) a lot of folks to finally put together their survival plans.
Jacob Margolis' reporting informed this story. This is a developing story and more information will be added as it becomes available.
We don't want to scare you, but the Big One is coming. We don't know when, but we know it'll be at least 44 times stronger than Northridge and 11 times stronger than the Ridgecrest quakes in 2019. To help you get prepared, we've compiled a handy reading list
