Earthquake Vulnerability in San Francisco, CA

The United States ranks #4 in the world as the country with the most earthquakes. According to the  USGS , Alaska has the most earthquakes per year, but California has the most earthquakes that cause damage in the United States. Thousands of earthquakes occur in the state each year, mostly concentrated mostly in the Bay Area and Los Angeles regions, some of the most populated areas.

• Magnitude – earthquakes usually begin causing damage when they get to a magnitude of  4 or 5 . The next major earthquake to hit San Francisco is likely to surpass this at 6.7 or greater.
• Location – areas closer to a fault line experience earthquakes the most intensely as they are closer to the source. San Francisco is within 25 miles of two major fault lines, the Hayward Fault and the San Andreas Fault.
• Population – a higher population density area means that there is a higher chance of more people getting hurt in a disaster. San Francisco has a population of 873,965 occupying just under 50 square miles of land, according to the  2020 and 2010 censuses .
• Infrastructure– earthquakes are most fatal when people are in or surrounded by unsafe buildings. Despite efforts to safeguard the city, San Francisco still has almost 5,000 soft-story buildings that need to be updated.

Which parts of San Francisco are the most vulnerable to a major earthquake?

The greater Bay Area faces high earthquake risk. Fortunately, no single location in San Francisco is not at the highest risk based on all of these variables. Instead, there are multiple combinations of factors to consider that places different neighborhoods at a higher risk. This means that safeguarding these areas that are likely to be severely affected are location-dependent because they are at risk of different things in an earthquake.