5.5 Ridgecrest Earthquake Aftershock Rocks Southern California

A quake measuring greater than magnitude-5 struck east of Ridgecrest around 6:30 p.m. tonight.

The U.S. Geological Survey gave a preliminary measurement of 5.1 magnitude and said it stuck a little more than 10 miles south of Searles Valley at a depth of 6.9 kilometers.

Quake expert Lucy Jones said the quake measured in at 5.5 magnitude, though, and she called it a "large late aftershock."

Ridgecrest was hit last year by major back-to-back earthquakes last summer. The first quake, a magnitude 6.4, hit on July 4. That earthquake, the biggest to strike the region in many years, turned out to be a foreshock of a 7.4 magnitude quake that struck the next evening.

As she did when the first big Ridgecrest earthquake happened last year, Jones reminded everyone tonight that there's about a 5% chance that a bigger quake will follow.

Jones told us:

She said that was a common pattern with earthquakes, noting there have been 40,000 quakes in that area since last summer. She called the magnitude 5.5 a "late large aftershock" and she noted the last magnitude 5 aftershock to the 1994 Northridge quake took place in 1997.

LISTEN TO OUR INTERVIEW TONIGHT WITH LUCY JONES

READ THE FULL STORY:

• Yes, The 5.5 Earthquake You Felt Was A Ridgecrest Aftershock

THE BIG ONE IS COMING. GET PREPARED

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 Ridgcrest quakes last year. To help you get prepared, we've compiled a handy reading list

• Your Guide To Surviving The Big One
• For Earthquakes, Forget The 'Go-Bag.' Here's How To Prepare
• How To Not Get Life-Threatening Diarrhea After A Major Earthquake
• 10 Earthquake-Related Questions To Ask Your Landlord Immediately
• Listen to KPCC's Podcast The Big One: Your Survival Guide