Earthquake Hazards Program

The nighttime Oakland city skyline as seen from San Francisco with the Bay Bridge in the foreground

A modern coral reef in Dry Tortugas National Park. There is little living coral and high rates of bioerosion. Photo taken under research permit number DRTO-2018-SCI-0005. Credit: Lauren Toth, USGS

The HayWired earthquake scenario, led by the U.S. Geological Survey (USGS), anticipates the impacts of a hypothetical magnitude-7.0 earthquake on the Hayward Fault. The fault is along the east side of California’s San Francisco Bay and is among the most active and dangerous in the United States, because it runs through a densely urbanized and interconnected region. 

The choice when issuing earthquake warnings is to: 1) issue alerts for weak shaking and potentially provide long warning times, but risk sending alerts for the many events that do not go on to produce damaging ground shaking, or 2) issue alerts only when ground shaking is expected to be damaging, with the tradeoff that the alert will be sent much later, reducing the

Title: ShakeAlert: The Path to West Coast Earthquake Early Warning ... how a few seconds can save lives and property

• The ShakeAlert earthquake early warning system will begin limited operations this year.
• Alerts could save lives and properties but several challenges remain.
• With millions at risk, why isn't full public alerting happening yet?

The Dec. 4, 2017 Thomas fire, Southern California's largest wildfire on record, burned more than 280,000 acres across Ventura and Santa Barbara counties for nearly a month.

Geologists assess boulders displaced during the Montecito debris flow event on Jan. 9, 2018.  

Swimming pool sign spray-painted to warn first responders and others to be careful around the potentially dangerous area. 

USGS geologists deployed to Santa Barbara County to support a geohazard assessment of the Montecito area

Map of historic seismicity, major faults, and paleoseismic summary of San Andreas Fault system.

A team of USGS scientists spent two weeks in the isolated Glacier Bay National Park, exploring one of the fastest-moving faults in North America.