Minor Earthquake Under San Francisco’s Airport Rattles Nerves

A 3.7-magnitude earthquake hit San Francisco on Friday evening, with an epicenter under the city’s international airport, the United States Geological Survey said.

The quake struck about eight miles beneath the airport at 6:38 p.m. local time, the U.S.G.S. said. There were no immediate reports of injuries or damage at the airport or elsewhere.

For some people across the San Francisco Bay Area, the quake produced a thud, as if something large were hitting a nearby building.

There were no active travel alerts related to the earthquake on the San Francisco International Airport’s website as of about 10:30 p.m. on Friday. A spokesman for the airport did not immediately respond to a request for comment.

The earthquake was minor by California standards but notable for its location directly beneath a major airport that lies near the San Andreas Fault, a major one that runs from Northern to Southern California.

The airport, which served about 20 million passengers last year, has an air traffic control tower that is designed to withstand a magnitude 8.0 earthquake.