Our Past Earthquake Experiences

Real-Time Earthquake Map of California and Nevada on October 17, 2012

Offset Fence along San Andreas Fault

Cracks in Earth Formed by 1964 Alaska Earthquake

Book on Stories from the 1964 Alaska Earthquake

October 17th is the anniversary of the 1989 Loma Prieta earthquake in the San Francisco Bay Area.  We’ve had several personal encounters with earthquakes.  First listed below are useful earthquake links:

California Real Time Earthquake Map (like first picture above):  http://scedc.caltech.edu/recent/index.html

List of Worldwide Earthquakes:  http://earthquake.usgs.gov/earthquakes/map/

Map Pinpointing Today’s Earthquakes:  http://earthquaketrack.com/recent

USGS California Earthquake General Info and Links:  

http://earthquake.usgs.gov/earthquakes/states/?region=California 

Seismological Laboratory:  Earthquake Education and Info for Kids: http://www.seismolab.caltech.edu/gen_eq_info.html

Tsunami Warning Center Links:  http://www.tsunami.noaa.gov/

In California, strain builds up on the San Andreas fault because the Pacific Plate is moving faster than the North American Plate.  Eventually stress fractures the crust and an earthquake occurs. In general, earthquakes that are Richter Magnitude 3 and smaller are not felt unless the epicenter is beneath you.  Magnitude 4 is a little shake.  Magnitude 5 is a noticeable shake, and is 10 times stronger than  4.  Magnitude 6 is a significant shake, and is 100 times stronger than 4.  Magnitude 7 is widespread damage, and is 1,000 times stronger than  4.  Magnitude 8 is catastrophic, and is at least 10,000 times stronger than 4.0.  Magnitude 9 is extremely destructive, and can have worldwide reverberations.   

Richard was a young child when the great Alaska earthquake occurred on Good Friday, March 27, 1964, at 5:36 pm local time.  The USGS lists the 1964 earthquake as Magnitude 9.2.  Most earthquakes last less than 30 seconds, but this one lasted 3-5 minutes!  Try counting out 3 minutes – it is a very long time for catastrophic shaking.  Loss of life was minimized since it was a holiday and most schools and businesses were closed.  It was the largest earthquake ever recorded in North America, and the 2nd largest in the western hemisphere (after the Magnitude 9.5 earthquake in Chile in 1960). 

One couple said that the 1964 Alaska earthquake shook for so long that they sat on the couch to ride it out.  Sandy soil liquefied and rolled like 3-foot-high ocean waves.  Richard’s Dad saw his neighbor working beneath a car.  As the Earth rolled in waves, the car bounced up on a crest.  His friend rolled away before the car crashed back down.  Many people had just finished eating their evening meal.  Pots fell off the stoves and refrigerators toppled over.  Richard’s brother was yanked away from a falling television set.  Cracks split the ground open and then closed back up again.  Trees whipped back and forth.  Boats hit mud bottom as the ocean drained out, and then were pushed inland when the water came back.  A tsunami roared across the Pacific and hit Hawaii and California.  Ocean levels changed around the world, and led to minor flooding in Texas and Louisiana.  Interesting Alaska earthquake stories and pictures are at:  http://www.vibrationdata.com/earthquakes/alaska.htm   A vintage 4 1/2 minute earthquake video from a television show Richard watched as a child is at: http://www.youtube.com/watch?v=wGhYMM2xeEo

In comparison, the 1989 Loma Prieta earthquake was Magnitude 7.0.  It struck at 5:04 pm on October 17th during the middle of the World Series in San Francisco.  The shaking lasted 10-15 seconds.   Loss of life was greater than Alaska because of the dense population and collapse of the Bay Bridge.  We were just getting ready to leave work at the University of California, San Francisco, when it hit.  We felt the building pitch up and down, and grabbed the railing for support.  Security alarms went off all around the city.  Smoke billowed in the distance and meant the damage was significant.  Everything at home had fallen down in the same direction (east).  Vigorous shaking had spilled all of our toilet’s water onto the floor.  Our balcony was deemed unsafe.   It took many weeks before normalcy returned.  For a long time afterward, people were always thinking about where they would run if the shaking returned.  Now millions of people participate in mock earthquake drills every year:  http://www.shakeout.org/

Update:  An earthquake magnitude 6.1 struck Napa Valley, California (north of San Francisco) at 3:20 am local time on Sunday, August 24, 2014.  Details about the quake are at:  http://earthquake.usgs.gov/earthquakes/eventpage/nc72282711#summary

About Pam
Richard and Pam lived in the San Francisco Bay Area 14 years (1987-1999 and 2008-2011). They lived in Florida 13 years previously, until returning in July 2011 to present. They hope their photography will encourage you to get out and discover nature's beauty in your own backyard, parks, and wild places. Click on any pictures on this blog to see them full size with additional details.

9 Responses to Our Past Earthquake Experiences

  1. elisaruland says:

    The Alaskan earthquake sounds like a bad dream, it must have been terrifying. How do you feel about earthquakes now, are you nervous? Something tells me you would take “the big one” in stride, I’ll bet you’re prepared!

    • Pam says:

      Earthquakes were something we prepared for when we lived in California. You actually had to think about the possibility of earthquakes when you decorated your house (i.e., don’t put anything around the bed that could fall on you while sleeping; strap bookshelves to the wall, use gel to hold down precious breakables, etc.). The smaller earthquakes weren’t so bad – it was interesting being reminded that the Earth was “alive”. The bigger ones are serious business, and you have to respect what Mother Nature can do. Personally I would rather face the possibility of a Florida hurricane than an earthquake, because at least I know when a hurricane is coming! No matter where you live, there are always things you should prepare for. Girl Scouts taught me to be ready!

  2. zannyro says:

    WOW!! Scary stuff!!

    • Pam says:

      Yes, it can be unsettling. Really surprising was the earthquake that damaged the National Monument in Washington DC last year. You just never know.

      • zannyro says:

        That’s so true….we had a little baby quake in Indiana a few years back….felt like I was in a popcorn popper….in INDIANA!! When is there ever an earthquake in Indiana?? And now we know that we’re near a fault,,,

  3. Informative post Pam, and the links are very good. We were at the National Building Museum in DC recently, and they had the video of the world series game in 1989. The museum also had an very informative exhibit called “Designing for Disaster” which covered the latest technology for earthquake resistant buildings. If you haven’t read Simon Winchester’s book, “A Crack in the Edge of the World” you should check it out. It’s primarily about the SF earthquake in 1906, but he also discusses earthquakes, plate tectonics, and volcanoes on the other side of the North American Plate … in Iceland. For lots of reasons, I think you’d find it interesting. ~James

    • Pam says:

      Thanks, James! I have read that book, but I think it is time to read it again in light of current events. I’ll have to check out that exhibit next time I visit DC. Have you read all the stuff about animals foretelling earthquakes? That was popular in the Bay Area – of course it was all anecdotal.

      • One of our blogging buddies Lisa, lives in Ecuador where she experiences earthquakes on a regular basis. She brought up this point, and this how I responded: “Lisa, as I said to someone else, I have no difficulty believing that animals in the wild have a better capability to “feel” pre-earthquake micro-vibrations. The official position of the US Geological Survey is that there’s no scientifically documented evidence that confirms the connection. But remember, for a scientist, a positive proof requires a controlled experiment with repeatable results. And as you know, when it comes to earthquakes, you can forget the word “predictable.” So designing and successfully conducting an animal/earthquake experiment is almost impossible. In the meantime, in your part of the world, I’d pay attention when the animals start to act strangely.” ~James

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