We Asked a Seismologist How Fucked California Would Be in a 'San Andreas'–Style Earthquake
What can a Dwayne Johnson movie teach California about disaster preparedness?
Screencap from the San Andreas Trailer
Maybe you've heard that some of this summer's allotment of CGI skyscraper-snapping is going to come from a disaster movie called San Andreas, starring Dwayne Johnson. This might have left you with questions like "Where can I find a stupidly large screen to watch this stupidly large movie on?" and "Can Dwayne Johnson's year possibly get any better?"
But this fictional movie is about a real geological feature of the West Coast: the San Andreas Fault. Major earthquakes can happen along this underground ridge where two tectonic plates rub together, and they really do threaten California's population centers. That means in addition to the questions above, about the career of the giant, Canadian-American actor formerly named after a geological formation, San Andreas also raises questions about how much Los Angeles and San Francisco need to worry about geology-based catastrophes like the ones in the film.
To find out, we spoke to Dr. Lucy Jones of the United States Geological Survey. Jones, who has been described as LA's "earthquake czar," also serves as the science advisor on seismic safety to Los Angeles Mayor Eric Garcetti. She was kind enough to take a break from studying real catastrophes and advocating for earthquake safety measures to answer some of our questions about a movie.
VICE: So tell me about how the San Andreas fault can kill us.
Lucy Jones: I'm with something called the Science Application for Risk Reduction Project [SAFRR] at the United States Geological Survey, and one of the things that SAFRR does is create scenarios of big geologic disasters so people can prepare for them. We've gone through saying: "What's a big San Andreas earthquake gonna be like?" and we even looked into the possibility that we could be triggering offshore landslides that could create a much smaller—but still damaging—tsunami.
You studied tsunamis like the one in the movie?
Well the tsunami [in the movie] was ridiculous, but they had a nice thing where the hero recognizes that the water being pulled out from the harbor is a sign that a tsunami is coming. And when the heroine knows the tsunami is coming, she does vertical evacuation to get away from it. She has to go all the way to the fifteenth floor though, which is not realistic.
Could a tsunami hit LA?
Actually, here in Southern California the San Andreas is far enough away from the ocean that [in tests] we couldn't get big enough motion underwater to get a decent landslide, or any sort of tsunami. We also did a different scenario: an Alaskan earthquake creating a big tsunami. We were trying to make the worst one we could for Southern California, because basically our client was the Port of Los Angeles, and they wanted to understand what they should be preparing for. We had a hard time getting any tsunami close to this region.
We have a lot of nuclear waste here in California, kind of like in Fukushima. Is that a worry that's not in the film?
Nuclear waste storage is sorta crazy. We aren't willing to build repositories, so we leave it on an active fault. But it depends on how they're being stored. Because of earthquake engineering, our buildings are a lot stronger and it takes very strong shakes to bring them down.
In a worst-case-scenario earthquake, what kind of building collapses would we see?
The reality is that it's a relatively small percentage of the buildings. When we did an analysis, putting together all of our data about how buildings get damaged, and what are the buildings here in Southern California, we ended up estimating that 1,500 buildings would collapse.
But that's a lot!
That's out of about 5 million buildings. Only about one in every 5,000 buildings would actually collapse. It's about one in 16 that would have damage exceeding ten percent of the value of the building. That's not a level of damage you can see really clearly.
Would skyscrapers tip over sideways, like in the movie?
No, no. To fall sideways, you have to have an incredibly strong building to hold together, and only break at the bottom.
Has that ever happened before?
We've seen that once in Chile. There was a building that basically was quite good, except there was a defect on the first floor, and it ended up literally breaking off at the first floor and going sideways.
But modern skyscrapers could fall down too?
There's a difference of opinion. People are building them, and believing they're making them [strong enough]. We actually just got a seismogram—which measures how the ground moves—from Kathmandu that would be very hard on a very tall building.
Wait, you were recording the ground shakes during the Kathmandu earthquake?
We happened to have a seismogram in the basement of the US embassy. So we just got this record, and people are having a debate about it.
What are they saying?
Whether or not we could lose a high-rise is a matter of debate. We did address that issue—this was published in 2008—and we finally got a consensus in the engineering community that said given these ground movements, the collapse of a pre-1994 high-rise is a credible scenario. And this record from Kathmandu would support that.
So, it is possible that we might lose a few high-rises, but not most of them.
Well at least there's that.
And they aren't going to collapse from the bottom. It's gonna be more like 9/11 coming down.
Oh, no. That would be awful.
It would be awful, and there are a lot of unknowns. But it isn't all of [the buildings]. It isn't even widespread.
Another thing that worries me is that we get our water piped in from hundreds of miles away. I worry that those pipes and channels could break.
Yep. You got it. Do you know that I just finished a big program with the mayor of Los Angeles to develop a seismic resilience plan for the city? We took our model of what we think a big earthquake's gonna be like, and looked at what was preventable. And probably the biggest existential threat to the city of Los Angeles is the water system. You know, the water pipes break without earthquakes.
They sure do!
And 15 percent of the pipe in LA is more than 100 years old. I found out all sorts of facts about the water system while I was working with the mayor.
Was he cooperative?
We have a "commitment to a future of seismic resistant pipes." There are pipes that survive earthquakes. We know how to do it.
Can we start soon?
It'll cost billions.
The city council just passed a new budget last week, did it have seismic resistant pipes in there?
The mayor has made a big, daring commitment to getting to that future. He's still working on how he pays for it. It's a long-term process. The main thing with the pipes is, how do you live here afterward? How do you get your economy going again? And then the other aspect is the fires. Trigger fires are going to be a big issue.
Oh, right. The fires.
If we lose a lot of water pipes, it could make it that much worse to control fires. In the movie, they do a good job with the fires up at Coit Tower.
Did they get anything else right?
They had the cell phones going out, and the young heroine knows to go and hunt down an old, copper landline when cell phones don't work. Which is a good point. The fiber ones require electricity.
What about where Paul Giamatti says to get under a desk during an earthquake?
It is accurate. He yells "stop, cover, hold on," and someone runs to a doorway, and he goes, "no, down under the table!" That part's all really good.
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