The Southern California Seismic Network said the Los Angeles earthquake near Frazier Park early Sunday was likely tied to the Pleito Fault, not the San Andreas Fault or the Garlock Fault. The magnitude 4.1 quake struck at 3:38 a.m., about 1 mile east-southeast of Frazier Park, at a depth of about 8 miles.
Later Sunday, a magnitude 3.2 aftershock followed. Seismologists said that sequence fits a smaller fault system in a region where multiple faults overlap, rather than a break on one of the larger nearby faults that drew immediate attention online.
Frazier Park and Interstate 5
The Pleito Fault runs through the region west of Interstate 5 near Frazier Park. The San Andreas Fault passes just southwest of Frazier Park, while the Garlock Fault lies farther to the east, which is why the location prompted quick comparisons to both major fault lines.
The Southern California Seismic Network said its preliminary analysis pointed to the Pleito Fault. That left the quake in the category seismologists described as relatively common for Southern California, even though the timing and location made it feel more consequential to nearby residents.
San Andreas and Garlock
Online speculation suggested the earthquake had struck at a critical junction between the San Andreas and Garlock faults. Seismologists said it did not appear to have occurred on either major fault, narrowing the focus to the smaller Pleito Fault instead.
The first aftershock was a magnitude 3.2 quake later Sunday morning, and seismologists said smaller aftershocks after a magnitude 4 earthquake can continue for days or even weeks. For people near Frazier Park and in Kern County and beyond, the immediate issue is watching for more aftershocks while the fault readout settles.
What matters now is the fault assignment, because it steers the next round of monitoring toward the Pleito Fault area rather than the larger systems that first drew attention. The quake’s location, depth and aftershocks already point to a localized event, not a rupture on the San Andreas Fault or the Garlock Fault.
