Janice R. Andrews
Southern California is experiencing an unusual surge in seismic activity in 2024, with more moderate-sized earthquakes occurring this year than at any time in the past 65 years. By mid-2024, the region has recorded 15 independent seismic events of magnitude 4.0 or higher, surpassing the previous record of 13 quakes set in 1988.
Several areas have been particularly affected:
- Ontario: Five earthquakes of magnitude 3.0 or higher in the past month
- Malibu: Two significant quakes (4.6 and 4.7 magnitude) in February and September
- Eastside L.A.: Multiple quakes, including a 4.4 magnitude in El Sereno
- Northwest of the Grapevine: The largest quake of the year at 5.2 magnitude
- Near Barstow: A 4.9 magnitude tremor felt across a wide area
Seismologists are unsure about the reasons behind this increased activity. Susan Hough from the U.S. Geological Survey explains that earthquakes often occur in clusters for unknown reasons, likening the pattern to popcorn popping. Despite extensive research, no clear predictive patterns have emerged to link smaller quakes to larger, more destructive events.
The surge in activity has reignited concerns about “The Big One,” a potentially catastrophic earthquake along the San Andreas Fault. While the recent quakes don’t necessarily indicate an imminent major event, they serve as a reminder of California’s seismic risks.
This year marks significant anniversaries of past major earthquakes:
- 35 years since the 1989 Loma Prieta earthquake (6.9 magnitude)
- 30 years since the 1994 Northridge earthquake (6.7 magnitude)
In light of this activity, Californians are encouraged to prioritize earthquake preparedness. The annual Great California ShakeOut drill on October 17 provides an opportunity for residents to practice emergency procedures and check their supplies. Additionally, technology like the USGS ShakeAlert system and smartphone apps can provide early warnings for impending quakes.
While the future remains uncertain, the current seismic activity underscores the importance of staying informed and prepared in earthquake-prone regions.
