Dozens of small earthquakes struck the Fillmore area this week, but the swarm was dying down, a Caltech spokeswoman said midday Thursday.
The temblors began Wednesday, with the first quake at or over the 2.0-magnitude level striking at 4 p.m. about 4 miles west-northwest of the town of Fillmore, in rural Ventura County.
More than 50 quakes struck the area, U.S. Geological Survey seismologist Lucy Jones said on Twitter Thursday morning.
All earthquakes make another quake more likely, so more temblors would “probably” occur, Jones said. There was no way to know if a bigger quake would strike, Jones said.
But around noon, a spokeswoman for Caltech, where Jones is a researcher, said the Fillmore swarm was dying down. Earthquake experts from the university did not plan to address the swarm unless that it started up again, Caltech spokeswoman Deborah Hedges said.
Thursday evening, several more small quakes were reported in the area.
The Fillmore area was struck hard by the 6.7-magnitude Northridge Earthquake in 1994, with many brick buildings collapsing in the historic downtown.
Known for its citrus groves and agriculture, the town is about 45 miles northwest of downtown Los Angeles. It has a population of about 15,000.
.@michelineLynch Over 50 small EQs near Fillmore. All EQs make another more likely, so probably have more. No way to know if one'll bigger.
— Dr. Lucy Jones (@DrLucyJones) July 9, 2015
KTLA’s Steve Bien contributed to this article.