Faults and Earthquakes in Southern California and Why it is Important for People and Businesses to Prepare
We believe that southern California is an amazing place to live and work. However, residing in the region comes with some caveats. No one typically likes traffic, wildfires, prolonged excessive heat waves, flash floods, debris flows, smog, landslides, or earthquakes. Interestingly, the natural southern California landscape and a lot of what we love about it, the mountains, beaches, deserts, etc., exist because of most of the natural processes just mentioned…the predominant one being past earthquakes.
Google Earth image showing the San Andreas Fault (bold red line), which is the transform tectonic plate boundary between the Pacific and North American plates. Colored lines indicate Quaternary faults of southern California. Black arrows indicate direction of relative tectonic plate motion (right lateral).
Earthquakes occur on faults, which are planar breaks in the Earth’s crust. There are hundreds of faults in southern California, some are small, some are big, and some are really big. Earthquakes are amazing natural phenomena that occur when a fault ruptures (when one piece (or block) of Earth’s crust rapidly grinds past an adjacent block). An enormous amount of energy that likely accumulated over hundreds, and in some cases thousands of years, is released in all directions from the rupturing fault surface. Some of the energy released during fault rupture is in the form of seismic waves, which cause the ground surface to move and is what we perceive as shaking and call “earthquakes”. There are a number of different factors that contribute to the intensity and duration of shaking, generally, major earthquakes result in large ground motions, which may be violent and occur for longer periods of time than anyone is happy to endure.
Why Prepare?
In the past in southern California, and in other locations around the world, earthquakes have brought people together in a unique way. There is a good chance following a major earthquake in the densely populated metropolitan and suburban areas of southern California, neighbors will help neighbors and strangers will help strangers. A major earthquake will be a regional event that will likely disrupt, delay, and overwhelm emergency services instantly.
We believe that the first reason to prepare is to help ensure the immediate safety of yourself, your family, your business, and those around you during an earthquake. First and foremost, you should know how to protect yourself once you feel the ground start to move or get a ShakeAlert on your cell phone indicating seismic waves are headed your way.
It is critical to take steps to prepare while being mindful and accurately informed about your hazard and risk, as they can differ based on where your home or work is located. These are important factors that will help you ensure the longer-term safety, security and well being of your loved ones for what could be a significant amount of time following a major earthquake.
Doing #’s 1 and 2 will help to improve personal preparedness and resilience, which in turn helps improve societal resilience. For each prepared person, household, and business, the need for immediate and longer term assistance following a major earthquake is reduced and helps to increase the rate of recovery.
Earthquake Monitoring
California Integrated Seismic Network
Earthquake Preparedness, Insurance, and General Information