On April 18th, 1906, the deadliest quake in U.S. History woke the residents of San Francisco in the pre-dawn hours with extreme shaking. The destruction was massive.
The Great San Francisco Quake - The Numbers
- 7.8 magnitude
- 1 minute of shaking was felt
- 296 miles around the epicenter experienced quaking
- 6 miles – how far the Salinas River was diverted from its original channel
- 30 fires broke out following the massive earthquake due to gas main breaks
- 3 days and nights – how long the city burned
- 500 city blocks were destroyed before the fires were contained
- $350 million worth of damage ($8.97 billion today)
- 400,000 people lived in San Francisco at the time; over half became homeless
- 3,000 people lost their lives
This devastation led to extensive research in the aftermath of the quake.
The United States Geological Survey (USGS) formed a commission of over 25 earth scientists to study the effects and causes of the quake. Their study, released in 1908, is believed to be the most extensive and influential report on a single earthquake.
Many geological breakthroughs, including the formulation of the elastic rebound theory, were formed by that commission.
These breakthroughs, combined with a public united to prevent further devastation, has shaped our understanding of earthquakes.
The epicenter, just off the coast of San Francisco, fell on the Loma Prieta segment of the San Andreas Fault. This section of the fault would awaken years later during the Loma Prieta Earthquake of 1989.
The Loma Prieta Earthquake
In October 1989. Loma Prieta segment of the San Andreas Fault experienced another major earthquake.
The Loma Prieta Earthquake was centered just 10 miles northeast of Santa Cruz, reaching a peak magnitude of 6.9 on the Richter scale.
Though the shaking lasted only 20 seconds, the effects were enormous.
Sixty-seven people were killed, more than 3,000 were injured, and another 12,000 were displaced.
Seventy-three years passed between the Great San Francisco Earthquake and the Loma Prieta Earthquake. One would think that all that time would allow geologists and seismologists to study earthquakes to a point where this sort of destruction would be preventable.
Unfortunately, that will never be the case. In fact, seismologists were aware of the possibility of a major quake. In June and August of 1989, there were minor foreshocks that hinted at a larger earthquake on the horizon.
Even with that information, scientist could not predict the location, magnitude, or timing of what was coming.
Prevention and prediction of earthquakes is not possible. But one simple step can make a difference.
Why Earthquake Preparation Matters
Living on the West Coast comes with the ever-present awareness of earthquakes.
Those of us who make the choice to live near fault lines know that, at any moment, we could lose it all.
And yet, we become complacent. The constant threat gets pushed to the back of our minds until the next quake happens, and then we make a few attempts to prepare. But that is not the best way to stay safe.
The Great San Francisco Earthquake and the Loma Prieta Earthquake occurred decades apart, with unceasing research in between. Yet, that knowledge could not accurately predict or prevent the damage that occurred in 1989.
Nor will it prevent the damage caused by the next big one that the USGS believe will occur within the next decade.
The one thing that will make a difference for your survival is you.
Your preparation could mean the difference between life and death for your loved ones.
So often, earthquake preparation focuses on surviving the earthquake itself. But, as with the Great San Francisco Earthquake, the initial quake is often just a trigger for larger problems like fires, landslides, and flooding.
Preparation for the days following the quake will greatly increase your chances of survival.
Don’t allow complacence to set in.
If the Great San Francisco Earthquake taught us anything over the past 112 years, it’s that earthquakes do not care about research. They do not give us warning.
It’s your responsibility to prepare, for your family’s sake.