San Francisco International Airport (SFO), a major hub for international air traffic on the West Coast, handled 47 million passengers in the fiscal year 2022-2023. This marks a 34.9% increase from the previous year. The airport faces challenges, including its runways sinking faster than those at other U.S. airports and its location in an area of high seismic activity.
Researchers from Virginia Tech found that SFO’s runways are subsiding at a rate of 10mm annually. “SFO was found to actually have the highest subsidence of the airports that we considered,” said Oluwaseyi Dasho. The uneven sinking can lead to runway damage, with Dasho noting, “When you have differential subsidence along the runway, there is a higher risk of damage along the runway.”
The airport’s vulnerability to earthquakes is another concern. In 2023, a magnitude-3.7 earthquake occurred beneath SFO. The California Earthquake Authority warns of significant earthquake risks in Northern California, estimating nearly a 75% chance of one or more magnitude 6.7 or greater earthquakes striking the region soon.
To mitigate these risks, SFO has taken steps to fortify its infrastructure against earthquakes. Its international terminal building features friction pendulum seismic isolators designed to withstand seismic activity. Additionally, a $150 million project launched in June 2012 updated the air traffic control tower to meet current seismic standards.
Rafael Sabelli from Walter P Moore explained that “a performance-based seismic design methodology was adopted early in the process.” The new control tower can remain operational during significant earthquakes and includes sustainable features like solar panels.
SFO has also made strides in passenger experience and sustainability with recent renovations and certifications for its terminals.
