On August 23, 2011, residents all up and down the eastern seaboard were rattled by the 5.8 earthquake. Looking at the tweets from around the country you could see the incredible volume on the east coast, and a good number of mocking comments from the west coast talking about “how you don’t know what real earthquakes are like”.
But there’s one thing that both the Bay Area and the Megalopolis of the Northeast have in common. In the past 25 years, both have been affected by relatively distant earthquakes and people believe they’re prepared for a big event since they’ve “lived through” that previous event. I know I’ll get slack for comparing the East Coast to the West Coast, but the perception that “I’ve been through this before” can be one of the greatest challenges facing personal preparedness (Second is “I’ve never seen it, so it’s never happened here before”)
This phenomenon isn’t isolated to earthquakes – unfortunately it occurs with all hazards. “I’ve been through tornadoes before” – only to experience Tuscaloosa or Joplin. “I made it through Camille” – only to experience Katrina”. Disasters are unique – every event is different, however when we base out current preparedness on our own personal experiences, we all too often find ourselves in the next major disaster wishing we had been more prepared or wondering what we could have done to be more prepared.
History has no surprises… the same phenomenon occurred with San Francisco in 1906. At the time of the 1906 earthquake, over a generation had passed since the October 21, 1868 Hayward Earthquake (nearly 40 years). There were many new residents to California that had not lived there in the 1868 event. Additionally, the rapid growth of the area and relative absence of major earthquakes likely contributed to the “need to develop” in areas of greater risk. In USGS Professional Paper 1515 “The San Andreas Fault System, California” (click to view the report) Dr. William Ellsworth describes this phenomenon when describing the 1868 Hayward Earthquake:
“Known as the “great San Francisco earthquake” until 1906, one of California’s most destructive earthquakes occurred on October 21, 1868, resulting from slip on the Hayward Fault. Heavy damage occurred in communities situated along the fault and in San Fransico and San Jose. Sadly, many of the engineering lessons learned from this earthquake and openly discussed at the time, such as the hazards of building on “made ground” reclaimed from the San Francisco Bay or the admonition to “build no more cornices,” were long forgotten by the time of the 1906 quake.” (requoted from Berkeley Seismological Laboratory – http://seismo.berkeley.edu/faq/1868_0.html)
The 1906 earthquake and subsequent fires killed over 3,000 people – still one of the deadliest natural disasters in American history. Do you think that this type of an event couldn’t occur today with our modern technology and improved structures? Think again… That’s what many of us said back in 1995 when a 6.9 earthquake hit Kobe, Japan – an earthquake where 5,000 were killed in a major urban area of an industrialized nation. The same USGS publication from above also provides this sobering statement:
“As demonstrated by the aftermath of 2005’s Hurricane Katrina, recovery from such catastrophic events can take years. According to another recent study, a repeat of the 1868 earthquake could cause economic losses (including damage to buildings and contents, business interruption, and living expenses) exceeding $120 billion, with more than 90% of both residential and commercial losses being uninsured. Also, damage to infrastructure and other long-term economic effects could substantially increase the total losses.”
For those of us who deal with history and lessons learned from previous disasters, wars, etc we see common lessons learned. When we don’t learn the lessons of history and choose not to apply them to change the course of our current situation and direction, we are likely doomed to repeat the mistakes of the past. Earthquake and all-hazard preparedness starts with an awareness of your historical hazards and preparing for those hazards to occur at any time. Yes, we need to live our lives, but when we are not prepared for what is likely to occur, we do a disservice to those whose job it is to keep us safe.
On October 20th, two separate earthquakes occurred on the near Berkeley, CA along a stretch of the Hayward Fault. These quakes measured 3.8 (816pm) and 4.0 (241pm) on the Richter scale – enough to startle people, but not enough cause damage. The events occurred only hours after the statewide earthquake drill known as the Great California Shakeout and the day before the 143rd anniversary of the October 21, 1868 earthquake. Also, the 22nd anniversary of the 1989 Loma Prieta earthquake occurred earlier in the week on October 17th. The timing is a coincidence, but this should serve as a wakeup call for those in high risk zones for hazards. You can see winter storms, floods and hurricanes coming sometimes days out. However earthquakes happen with little or no notice and you must be prepared.
These catastrophic disasters have occurred before and have occurred in YOUR area. For the rest of us outside the active fault systems of the Pacific Northwest, this needs to be a wakeup call for us as well. What are my hazards? What has happened in my area before? If my community prepared for the next major disaster. If you want more information on preparedness for earthquakes, check out the Great California Shakeout website at http://www.shakeout.org/.
- USGS Resources – October 21, 1868 Hayward Fault Earthquake
- 1868 Earthquake Page – The Virtual Museum of the City of San Francisco
- USGS Report w/ Modified Mercalli Intensity Maps for the 1868 Hayward Earthquake Plotted in ShakeMap Format (Downloads Section has Graphics and Shapefiles)
- A Virtual Tour of the 1868 Hayward Earthquake in Google Earth