San Francisco Seismic Zone • 180 km Monitoring Radius
Real-Time Earthquakes in San Francisco, United States
Live seismic telemetry, active fault rupture tracking, and ground motion hazard monitoring for the San Francisco metropolitan area.
Landmark Historical Earthquakes in San Francisco
Significant seismic benchmarks, cataloged damage, and engineering lessons shaping modern safety standards.
South Napa / West Napa Fault
Largest earthquake in the San Francisco Bay Area since Loma Prieta; caused 1 fatality, over 200 injuries, and $1B in damages, sending strong tremors throughout the Bay Area and validating early warning system capabilities.
Seven Trees / East San Jose (Calaveras Fault)
Shallow strike-slip rupture on the Calaveras Fault that shook the entire Bay Area, triggering statewide ShakeAlert mobile early warnings across millions of smartphones before ground motion arrived.
Offshore San Francisco / Daly City
Ruptured 470 km of the San Andreas Fault, destroying over 80% of San Francisco through shaking and a catastrophic four-day conflagration that killed over 3,000 residents and reshaped California urban history.
Loma Prieta / Santa Cruz Mountains
Struck during the 1989 World Series, causing 63 fatalities, collapsing the upper deck of the Cypress Viaduct in Oakland, collapsing a span of the Bay Bridge, and igniting severe Marina District liquefaction and fire.
Seismic Geology & Soil Amplification in San Francisco
Plate boundaries, tectonic kinematics, and local geotechnical ground response characteristics.
The San Francisco Bay Area is sliced by a network of high-strain strike-slip faults that accommodate the northwestward motion of the Pacific Plate. The San Andreas Fault proper passes within 5 km of the ocean coastline and directly through Daly City, while the Hayward, Calaveras, and San Gregorio faults parallel it to the east and west, boxing the urban core into high seismic risk.
Local Soil Profile & Ground Motion Resonance
San Francisco contains extensive artificial fill built over 19th-century shipwrecks and bay mud along the Marina District, Financial District, Mission Bay, and SoMa. During seismic shaking, saturated sandy fills rapidly undergo liquefaction, losing bearing capacity and amplifying ground shaking 2 to 3 times relative to bedrock on Twin Peaks or Telegraph Hill.
Major Active Fault Systems Near San Francisco
Seismogenic fault lines, maximum credible magnitudes (MCE), and proximity to the metropolitan center.
San Andreas Fault (Peninsula & North Coast Segments)
The primary plate boundary fault running just offshore of Ocean Beach and through the Crystal Springs Reservoirs on the Peninsula; ruptured for 470 km in 1906.
Hayward Fault
Considered America’s most urbanized and dangerous fault, traversing Oakland, Berkeley, Hayward, and Fremont directly beneath critical infrastructure.
San Gregorio Fault Zone
Major coastal strike-slip fault running offshore past Half Moon Bay and Point Reyes, intersecting the San Andreas near Bolinas.
Seismic Safety, Observatory & Building Codes
Official seismological monitoring, building construction standards, early warnings, and emergency response.
Frequently Asked Questions About Earthquakes in San Francisco
Authoritative answers to common questions regarding seismic risks, building safety, and preparedness in San Francisco.
When is the next major earthquake expected in San Francisco?▾
The Working Group on California Earthquake Probabilities (WGCEP) calculates a 72% probability of an M 6.7 or larger earthquake striking the San Francisco Bay Area before 2043, with the Hayward and San Andreas faults having the highest individual likelihoods.
Why did the Marina District suffer such severe damage in 1989?▾
The Marina District was constructed on loose sand and rubble fill placed over soft bay mud for the 1915 Panama-Pacific International Exposition. When seismic waves arrived from Loma Prieta, the water-saturated fill liquefied, causing soft-story apartment buildings to lean and collapse.