If you live in California — or even if you don’t — you probably think about earthquakes every now and then, and most likely have heard of the San Andreas Fault.
From what I understand, this fault is a boundary where two parts of the earth’s crust (the Pacific plate – under the Pacific Ocean and the North American plate) meet.
The San Andreas Fault stretches for 810 miles (1300 km) across California, from the Salton Sea in the south all the way to Humboldt County, 200 miles north of San Francisco. It is the most studied boundary plate on our planet for the following reasons:
- it is on land, and therefore easier to study than tectonic plates that meet in the ocean
- the fault is in close proximity to educational institutions and organizations dedicated to earthquake research
There are cities and communities that sit directly on the San Andreas Fault, and we lived in one of these communities while stationed at a base in the Mojave Desert in Southern California.
Late in the summer of 1981, Jeff and I drove from our military base in the high desert to the San Gabriel mountains. He wanted to show me the little town where he and his friend, Bill, skied during the winter. The town we visited is called Wrightwod, and about 40 miles (64 km) away from the base, at 6,000 feet (1809 m) elevation.
At the time, there were just over 2,000 people living there, though in the winter, there were many more as it was a popular ski resort area about 75 (124 km) miles from Los Angeles, in San Bernardino County.
While in Wrightwood, we went to a pub, where the bartender overheard us talking about how beautiful it was there. He told us about a little cabin for rent just down the street. On a lark, we decided to visit the cabin, and met the owners (who lived in the house next door).
It was partly furnished, had 1 bedroom, a fireplace, a loft space, and knotted pine walls. It faced California’s State Highway 2, and behind the cabin was a hill.
We rented it on the spot, not even thinking about the drive we had to make back and forth from the base (about 45 minutes to 1 hour each way).
Shortly after our move, we met a fellow service member living there, and a civilian who also worked at the base, meaning we were able to join in a carpool.
Later on, I learned that the town sat on the San Andreas Fault from a newspaper article a co-worker showed me. Wow…. a fault…oh, what is a fault? Earthquakes… really?
Philippine Casiguran Earthquake
When I was little and we lived in Manila, a big earthquake hit the Philippines. I remember my mother rushing us outside (that is what you were told to do back then), and the distraught neighbors around us talking about fires and something about the Ruby Tower.
With a bit of research, I found out that the Philippine earthquake happened in 1968 and was called the “Casiguran earthquake”.
Since it happened at night, I most likely was asleep when it hit. More about this earthquake from a Wikipedia article:
The city of Manila was the hardest hit with 268 people killed and 261 more injured.
Many structures that suffered severe damage were built near the mouth of the Pasig River on huge alluvial deposits.
A number of buildings were damaged beyond repair while others only suffered cosmetic damage.
Two hundred and sixty people died during the collapse of the six-story Ruby Tower, located in the district of Binondo. The entire building, save for a portion of the first and second floors at its northern end, was destroyed. Allegations of poor design and construction, as well as use of low-quality building materials, arose. (More here)
Besides the earthquake in Manila, I had not experienced any other major earthquakes, and none while living in California at that point, so I didn’t really think much more about it.
California 1989 Loma Prieta Earthquake
Years later, we moved to the San Francisco Bay area, and lived here when the Loma Prieta earthquake hit Northern California. The Loma Preita is in a segment of the San Andreas Fault.
The Loma Prieta earthquake is memorable because it happened during a World Series baseball championship, and was broadcast live on national television.
Due to the World Series, casualties were amazingly low (63 deaths and 3,757 injured). Instead of being in the rush hour traffic heading home, many people left work early to watch the game, and traffic was lighter than normal.
While casualties were low compared to other earthquakes of the same magnitude, the Loma Prieta earthquake remains one of the most expensive natural disaster in the history of the United States.
My younger sister was working in a San Francisco high-rise office building at the time of the earthquake.
It took us 5 hours to reach her by phone, when she finally made her way home…and we were relieved to find out she was safe and unhurt.
We lived in the East Bay, and I was in the car on the way to pick up my older sister when the earthquake happened. I suddenly lost the radio signal, and felt the car making unusual movements — movements that I could not control with my steering wheel.
A few minutes later, I arrived at my older sister’s workplace. She was already outside of the office building where she worked, and felt the earth quake beneath her feet, and saw the building she was just in, move and slightly sway. She opened the car door and got in…we both couldn’t believe that a strong earthquake had just occurred.
We rushed to pick up my daughter from her after-school care. She was outside at the playground during the earthquake, and she (and her teachers) told us they distinctly remembered that the birds stopped chirping right before and after the shaking.
We tuned into the news as soon as we got home — and were glued to the television set for hours.
It was a mistake, because the constant image of fires in the Marina District of San Francisco, and the collapse of a portion of the Bay Bridge made my daughter anxious about crossing the bridge, for many years after the earthquake!
San Andreas Fault North / South
Another well-known earthquake in California was the 1906 San Francisco earthquake, which destroyed 80% of San Francisco and killed 3,000 people. The 1906 earthquake is also connected to the north part of the San Andreas Fault.
In terms of the death toll, the 1906 earthquake is the worst natural disaster in California’s history.
The part of the fault where Wrightwood is located is in the south part the San Andreas Fault.
If you want to read more about Wrightwood as it relates to the San Andreas Fault, past earthquakes and predictions for future earthquakes, visit this GeoScience World article.
There have been many earthquakes in this part of the fault, and they note “These observations and elapsed times that are significantly longer than mean recurrence intervals at Wrightwood and sites to the southeast suggest that at least the southermost 200 km of the San Andreas fault is near failure.“
San Andreas – The Movie
You may hear even more about the San Andreas Fault this summer.
An earthquake disaster movie with Dwayne Johnson (The Rock) is now playing in movie theaters, and it is called (what else?) San Andreas.
Here is the preview…
Nothing like seeing the place where you live (and that you love) destroyed and in total chaos…with millions of people in peril.
But at least it is just a movie, and perhaps it will make us think about our emergency preparedness, and supporting strict building codes and improvements that incorporate new technology to save lives in the event of “the big one”.
If the “big one” hits, will California fall into the Pacific Ocean?
The San Andreas movie trailer shows the ground splitting, complete destruction of buildings in downtown Los Angeles, and a tsunami in the process of finishing off the city of San Francisco.
The tsunami scenario is certainly real… and of all the natural disasters in the world’s history (i.e., volcanoes erupting, heatwaves, floods, typhoons, cyclones) earthquakes by far have killed more people than any other.
But the myth that you may have heard of — that California could somehow fall into the sea — when the big one hits, well, it is just that, a MYTH.
From the Earthquake Mythology page of the California Department of Conservation:
…The San Andreas Fault System is the dividing line between two tectonic plates. The Pacific Plate is moving in a northwesterly direction relative to the North American plate. The movement is horizontal, so while Los Angeles is moving toward San Francisco, California won’t sink. However, earthquakes can cause landslides, slightly changing the shape of the coastline.
To further allay immediate concerns about a complete change in the California landscape should the big one occur on the San Andreas Fault (SAF), here is a clip from SanAndreasFault.org: on how long it would take for California to look different from how we see it today:
I don’t know about you, but for me…that’s good to know!
Do you live in an earthquake prone area?
It seems to me that the entire state of California is earthquake prone, but it has not stopped people from living here. There are now 38 million people that live in California — that is 1 out of every 8 Americans.
Have you heard about the San Andreas Fault or do you have earthquakes worries where you live? I would also like to hear about your own earthquake experience, so please do leave comment.