An earthquake with a magnitude of 4.3 struck the San Francisco Bay Area in the early hours of Monday according to the United States Geological Survey. This earthquake took place at 2:56 am and the epicentre was located near Berkeley at a distance of less than 2 kilometres east-southeast of the city centre. The shaking woke up the inhabitants throughout the region, including those in Oakland, Richmond, Walnut Creek and San Francisco. According to the USGS reports, the effects of the earthquake were felt as far as Sacramento and San Jose.
Epicentre and area impacted by the earthquake
Seismic Event Overview
USGS registered the earthquake at a depth of approximately five miles. Experts tentatively linked this event to a series of ten smaller quakes which have rattled the Bay Area throughout the month. The Hayward Fault, responsible for Monday’s event, runs beneath Berkeley and stretches through the densely populated East Bay. The fault is known for its destructive potential, having produced a magnitude 6.8 earthquake in 1868. The fault has not experienced a rupture of similar scale since.
Tremors Felt Across San Francisco Bay Area and Beyond
More than 24,000 people logged shaking reports through USGS’s “Did You Feel It?” tool online, with residents feeling a sharp jolt, rattling windows and shifting shelves. The Modified Mercalli Intensity Scale classified the shaking as “light.” Light shaking can disturb dishes, move items inside homes, and cause some windows to break. “People often do not appreciate that, as they feel as though they were on the brink of disaster,” said Angela Lux, researcher at Berkeley Seismology Lab. “This serves as a crucial reminder of what ‘light shaking’ actually feels like. The Hayward fault has the potential to unleash a considerably larger earthquake.”
Officials Confirm No Major Damage
No injuries or serious damage after the occurrence of the earthquake were reported by authorities. The San Francisco Fire Department stated that there was no imminent danger to the safety of people, and the National Tsunami Warning Centre declared that there was no threat of a tsunami. The most influential effect was on smashed windows and overturned goods, and in some shops in Oakland, plastic bottles and other items were scattered all over the floors. Bay Area Rapid Transit announced slow speeds of trains as the tracks were subjected to safety checks, leading to delays throughout the system.
Residents Awakening and Reactions
Residents in Berkeley, Oakland, and San Francisco described the experience as startling. Hannah Halpern of Oakland said her dog leapt from the bed during the shaking. She stayed awake, concerned about possible aftershocks and the safety of items near her bed. “My husband and I reached across the bed and held hands,” Ms. Halpern explained. “For some reason, last night’s event really affected me.”
KTVU-TV anchor Dave Clark recounted, “Things were shaking in our newsroom. … It caught everyone off guard.” The State issued more than 300,000 early warning notifications to residents, many of whom sought cover as advised by emergency protocols.
X: still great at seeing people’s reactions to earthquakes.
Just had a small one in San Francisco that woke everyone up. pic.twitter.com/qJSgNKUM43
— Robert Scoble (@Scobleizer) September 22, 2025
Scientific Assessments and Risks
USGS estimated a 4% chance another earthquake of magnitude 4 or greater could occur in the next week. Less than 1% chance exists for an aftershock of magnitude 5 or greater. These probabilities decreased through Monday. According to seismologists, earthquakes between 2.5 and 5.4 magnitude typically cause little or no structural damage. The Bay Area’s major faults, including the San Andreas and Hayward, have long histories of producing large seismic events and remain a concern as population and urban infrastructure have grown.
Historical Context
San Francisco and its residents have experienced devastating earthquakes, the 1906 earthquake and subsequent fires took the lives of hundreds of people. In 1989, an earthquake of magnitude 6.9 resulted in the death of 67 people. A 6.7 magnitude earthquake took place in California in 1994, leaving at least 60 deaths and causing damage to the tune of 10 billion dollars. Scientists are warning about the occurrence of a Big One that will hit the world within the next few decades.
Emergency Response and Preparedness
The officials were still communicating with the government agencies to determine any effect on morning travels and essential infrastructure. The Department of Emergency Management of San Francisco suggested “Prepared, San Francisco. Drop, cover and hold on when shaking starts.”
Mayor Daniel Lurie promised the residents that more updates would be provided since first responders are going to conduct checks on the infrastructure. The earthquake preparedness portal is a source of safety information about future seismic events, which is an indication of constant awareness enhancement efforts within the region.
Conclusion
The earthquake on Monday occurred in the most populated area in Northern California leaving no victims or massive destruction of property. The residents throughout the Bay Area were alerted in time and they showed preparedness towards seismic hazards. The incident highlights the need to be aware and ready in case of an earthquake in a region characterised by tectonic activity.
