Residents in the Riverside County community of Glen Avon may be feeling a bit rattled with the recent slew of small earthquakes in the area, but the swarm of temblors is quite common, one local seismologist says.
Data from Southern California Earthquake Data Center at Caltech shows hundreds of small quakes have been detected in the Glen Avon area in the past few days, but only two measured above magnitude 3.0. The residential area is part of the city of Jurupa Valley, northwest of the city of Riverside.
The strongest earthquake, measured at magnitude 3.3, occurred around 4:36 p.m. Sunday, about 2 1/2 miles northwest of Glen Avon, according to the U.S. Geological Survey.
Earlier in the day, about 1:05 p.m., a magnitude 3.4 quake struck outside the Glen Avon swarm area – instead centered about 27 miles to the southeast, in a remote area between Hemet and Moreno Valley.
In a tweet, former USGS seismologist Lucy Jones said the seismic activity near Glen Avon is part of “the Fontana trend” in an area that’s a “perennial hotspot” for small temblors that are often in clusters.
Jones called the events “ordinary, common California quakes.”
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. And when it has quakes, they are usually in clusters like this. In other words, ordinary, common California quakes https://t.co/NcjXSupiTv
— Dr. Lucy Jones (@DrLucyJones) May 30, 2019
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. #earthquakeswarm
— Dr. Lucy Jones (@DrLucyJones) June 1, 2019
The Fontana quakes are very small – only a few are even above M2.5, none above M3. They are 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. #earthquakeswarm
— Dr. Lucy Jones (@DrLucyJones) June 1, 2019
