Lucy Jones

Seismologist Lucy Jones described the hundreds of earthquakes that struck Glen Avon recently as the "Fontana trend" because the area is a "perennial hotspot of small quakes."

Have you felt like the earth below you has been shaking a lot recently?

You're not imagining it. Hundreds of earthquakes have struck in the area of Glen Avon, a Jurupa Valley community located in Riverside County, just south of Fontana, starting on May 25 and continuing into June.

The good news is that all of those quakes were very minor (less than magnitude 3.4), and there were no reports of damage. The strongest temblor was a 3.3 on June 2 at 4:36 p.m.

Renowned seismologist Lucy Jones gave the quakes a name -- the "Fontana trend" -- even though their epicenter was technically not in this city.

"This is the Fontana trend -- a perennial hotspot of small quakes, including a M3.1 in Jan. 2018 and a M3.6 in July 2018," Jones said in a Twitter post on May 29. "And when it has quakes, they are usually in clusters like this. In other words, ordinary, common California quakes."

She followed up with another post on May 31: "All the quakes in Fontana over the last few days have released less energy than one M3.3. This is just a place where the earth sputters along instead of letting go all at once."

Jones added that the quakes were "being felt because they are so shallow. When the quake is only 1 mile down, instead of 5 miles or more, you are that much closer to the event."

Seismologists said that this particular swarm was unlikely to lead directly to a bigger quake. However, experts warn that a major quake could still occur at any time in Southern California. For more information, visit

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