A number of earthquakes were reported off the shore of Southern California on June 5.
The U.S. Geological Survey (USGS) measured a 4.3 magnitude quake near San Clemente Island, 67 miles southwest of Huntington Beach at 3:47 a.m. local time.
There were no reports of damage or injuries.
San Clemente is the southernmost of the Channel Islands and owned by the U.S. Navy. Seismic activity is not unusual in the area, according to the Associated Press.
Nearly four hours later, a second 4.3 magnitude quake was measured off the south end of San Clemente Island.
The USGS confirmed the second tremor at 7:32 a.m. and said that it occurred in the same area as the first quake that hit at 3:47 a.m.
The second tremor also did not see any immediate reports of damage or injury.
The USGS Did You Feel It website received at least three citizen reports from the area between Simi Valley in northern Ventura County and Rialto in eastern San Bernardino County.
There were further reports of tremors from the Orange County cities of Aliso Viejo, Laguna Niguel, Laguna Beach, Irvine, Costa Mesa, and Mission Viejo according to CBSLA. LA County’s coastal communities like San Pedro and Rancho Palos Verdes also reported feeling the quake.
The San Clemente Island quakes came less than a week after a hundreds of tremors hit the San Bernardino community of Glen Avon, nearly 100 miles away.
Dr. Lucy Jones, seismologist and chief scientist at the Dr. Lucy Jones Center for Science & Society, believes that anyone who felt the recent Glen Avon earthquake swarm between May 25 and June 3 are unlikely to have felt the latest quakes.
“Two magnitude fours off San Clemente Island ... tens of times more energy released in these two than in the hundreds in Glen Avon,” Jones said on Twitter. “Nobody who felt Glen Avon would feel these and vice versa. Southern California (SoCal) is earthquake country.”
Now we have a quake cluster in a different part of SoCal. Two M4s off San Clemente Island. Nobody who felt Glen Avon would feel these and vice versa. Tens of times more energy released in these 2 than in the hundreds in Glen Avon. SoCal is earthquake country
— Dr. Lucy Jones (@DrLucyJones) June 5, 2019
The Caltech-USGS report on the Glen Avon Earthquake Swarm 5/25-6/3//2019. "Based on past historic recordings this swarm is only expected to generate events of magnitude less than 4.0."
— Dr. Lucy Jones (@DrLucyJones) June 4, 2019
Jones said that more earthquakes are being detected now thanks to the installation of more seismic stations.
“We are seeing more small quakes in SoCal because we put in more seismic stations to do earthquake early warning,” Jones said on Twitter. “All earthquakes follow a distribution where small ones are much more common than bigger ones. Each unit of magnitude smaller means 10 times more quakes.”
All #earthquakes follow a distribution where small ones are much more common than bigger ones. Each unit of magnitude smaller means 10x more quakes. We are seeing more small quakes in SoCal because we put in more seismic stations to do earthquake early warning
— Dr. Lucy Jones (@DrLucyJones) June 4, 2019
The Glen Avon swarm is mostly really tiny quakes. If this was happening 10 years ago, the website would be showing a small fraction of the number. Swarms like this happen somewhere in CA every year. Lots of tiny quakes just means we have lots of tiny quakes.
— Dr. Lucy Jones (@DrLucyJones) June 4, 2019
The Associated Press contributed to this article.
