Additional Coverage:
- Venezuela quake sparks San Andreas fears as experts warn California could be hit by a 7.8 (themirror.com)
The recent powerful earthquake in Venezuela has reignited concerns about California’s San Andreas Fault, with experts emphasizing that a major West Coast quake-potentially reaching a magnitude of 7.8-is an unavoidable reality.
Venezuela’s 7.5-magnitude quake originated from the Boconó-San Sebastián-El Pilar fault system, which is roughly half the size of California’s San Andreas fault. Despite the size difference, the South American event has heightened fears among Californians.
However, geologists caution that the Venezuelan earthquake does not signal an imminent “Big One” in California. Both regions lie along active plate-boundary fault systems characterized by right-lateral strike-slip motion, where the land on either side of the fault moves horizontally to the right.
Judith Hubbard, a geology professor at Cornell University, explains that large earthquakes (magnitude 7.5 and above) are possible in both fault systems, a fact well known before the recent Venezuelan event. “We cannot predict when these earthquakes will happen,” she notes. “To residents, it remains a vague possibility until it occurs; to scientists, it is an inevitability.”
Dr. Liliane Burkhard of the University of Hawai’i adds that the San Andreas fault is significantly longer and accumulates stress faster than the Boconó fault, meaning it builds displacement more rapidly.
Both faults, however, are capable of producing destructive magnitude 7 earthquakes. She stresses that while the Venezuelan quake does not forecast an immediate event on the San Andreas fault, a large earthquake in Southern California remains possible.
The last major quake there was in 1857, and a rupture involving multiple fault segments could reach a magnitude of 7.8.
The Venezuelan earthquake is classified as a “doublet”-two large quakes occurring close together in time and location, treated as a paired event rather than a mainshock with aftershocks. While rare, this phenomenon is not beyond the realm of possibility. Though the San Andreas fault is not expected to produce a doublet, recent studies reveal that stress beneath Southern California’s fault systems is at historically high levels, raising concerns about a potential multi-fault large earthquake.
Both professors emphasize that the severity of an earthquake’s disaster impact depends on numerous factors beyond magnitude. Damage and casualties are influenced by rupture length, local geology, building standards, time of day, infrastructure resilience, secondary hazards such as landslides and fires, and emergency response effectiveness.
Hubbard underscores that while seismic hazards are well understood, earthquake prediction remains impossible. “The real question is preparation,” she says, highlighting the role of policymakers in enforcing earthquake-resistant construction.
She also points to the importance of public awareness and advocacy in driving meaningful change. “Some regions have made significant progress, others are working toward it, and some still have a long way to go.”
The Venezuelan quake serves as a sobering reminder of the constant seismic threat in fault zones worldwide and the urgent need for preparedness in earthquake-prone areas like California.