click to call

West Coast Seismic Activity History & Key Faults: How to Protect your Real Estate Assets

Last week the Los Angeles Times reported multiple swarms of earthquakes along the California-Mexico border. Earthquake swarms are common in the Imperial Valley and they can be cause for concern as a major, damaging earthquake have been known to follow. However, swarms also happen often in this part California without being followed by a major earthquake. Yet, the article states, “Nonetheless, scientists typically pay close attention to the area, where there are many faults. And there have been moments of greater concern in recent years.” For further details, see full article,

The West Coast of the United States is highly seismically active due to its location along the Pacific Ring of Fire. This region is characterized by frequent and sometimes significant earthquakes due to the interaction of several tectonic plates, particularly the Pacific Plate and the North American Plate. Below is an overview of seismic activity and notable faults.

Key Fault Zones

San Andreas Fault

  • Extends approximately 800 miles through California from the Salton Sea in the south to Cape Mendocino in the north.
  • Known for major historical earthquakes, including the 1906 San Francisco earthquake and the 1989 Loma Prieta earthquake.

Cascadia Subduction Zone

  • Stretches from northern California to southern British Columbia.
  • Capable of producing massive megathrust earthquakes, such as the estimated 9.0 magnitude quake in 1700.
  • Poses a significant tsunami risk.

Hayward Fault

  • Runs through the densely populated East Bay region of the San Francisco Bay Area.
  • Last major rupture was in 1868, and it is considered overdue for another significant event.

San Jacinto Fault

  • Located in Southern California, parallel to the San Andreas Fault.
  • Frequent seismic activity, contributing to the overall seismic risk in the region.




Garlock Fault

  • Extends across Southern California, from the San Andreas Fault to the Mojave Desert.
  • Capable of producing large earthquakes.

Historical Major Earthquakes

1906 San Francisco Earthquake

  • Magnitude: 7.9
  • Extensive damage and fires, with an estimated 3,000 deaths and significant destruction in San Francisco.

1989 Loma Prieta Earthquake

  • Magnitude: 6.9
  • Occurred during the World Series, causing widespread damage in the Bay Area and 63 deaths.

1994 Northridge Earthquake

  • Magnitude: 6.7
  • Hit the Los Angeles area, causing severe damage, 57 deaths, and significant economic loss.

2001 Nisqually Earthquake

  • Magnitude: 6.8
  • Occurred near Olympia, Washington, causing injuries and damage but relatively low casualties due to its depth.

Due to the history and clearly amount of faults in this area it is essential for seismic preparedness, including performing seismic retrofits on vulnerable structures. Below outlines important factors for seismic preparedness.

  1. Building Codes and Standards
  • California Building Code (CBC) and International Building Code (IBC) incorporate stringent seismic provisions.
  • Retrofitting older buildings to meet current standards is a critical ongoing effort.


  1. Public Awareness and Education
  • Earthquake drills and preparedness programs, such as the Great ShakeOut, help educate the public.
  • Information on emergency kits, evacuation plans, and securing household items is widely disseminated.


  1. Early Warning Systems
  • ShakeAlert, an early warning system, provides seconds to minutes of warning before shaking arrives, allowing people and automated systems to take protective actions.


  1. Government and Community Initiatives
  • Various local, state, and federal initiatives support seismic retrofitting, preparedness, and resilience-building efforts.
  • Financial incentives and grants are available to support retrofitting of vulnerable structures.

Seismic Risks and Proactive Measures: Seismic Retrofits

The West Coast remains at high risk for future earthquakes, with significant potential impacts on densely populated urban areas. Scientists emphasize the importance of continued preparedness, research, and infrastructure improvements to mitigate the effects of future earthquakes. Therefore, performing seismic retrofits on commercial real estate assets is imperative to reduce the risk and impact of future seismic events.

Understanding these key points about earthquakes on the West Coast helps emphasize the importance of seismic preparedness and taking proactive measures to ensure the safety and structural integrity of all  structures.

If you have any questions, we are the Seismic Solution Specialists! We have over four decades of experience performing seismic retrofits and structural repairs on all types of buildings across all commercial real estate sectors, especially in occupied spaces with ongoing tenant/ business operations. Contact us We service five states, California, Washington, Oregon, Nevada, and Utah.

Posted Under: Commercial & Industrial Real Estate