What the heck is this? These are fault slickensides (scraping marks from fault motions) at Hoover Dam. Where the movie says there are no faults. |
I love sitting through geology-based movies, so I can sit and smirk at the screen and criticize the horrible geology presented therein. And thus, I expected to do the same this afternoon, when I finally found time to catch "San Andreas". Mind you, there were plenty of geological issues with the movie, but I have to admit I actually enjoyed myself. It was entertaining. So here are some of the thoughts from another geologist named Hayes (the main geologist character in the movie was Lawrence Hayes. I'd feel complimented, but I noticed the movie's screenwriters, at least at some point, were also named Hayes. Plus, CalTech would never hire me).
WARNING: SPOILERS AHEAD!
Let's get the biggest spoiler out of the way first. Hoover Dam, Los Angeles, and San Francisco get destroyed in this movie. Strangely enough, Bakersfield gets nailed pretty badly too. The Hollywood sign and the Golden Gate Bridge get destroyed. If I was the maintenance guy for the Hollywood Sign, I'd be pretty tired of constantly replacing it by now.
Hoover Dam. It has its faults... |
So, the opening scene as I recall involved a distracted young lady driving a mountain highway in the San Gabriel Mountains. A rock hits her windshield, and over the side she goes, at a rate of speed that defied the laws of gravity, and into a canyon so utterly steep that it defied gravity too. I grew up next to the San Gabriel Mountains, and yes, the mountains are steep, but yeesh. This was to establish our star as a superhero (Dwayne Johnson, aka "The Rock", doing better as a sensitive kind of guy than I would have expected).
Here's a steep canyon in the San Gabriel Mountains, but I don't think "The Rock" could fly a helicopter through it. |
I get that a lot, too. |
Well, almost nobody. These people predict earthquakes all the time (credit: Amanda). |
An approximation of the remainder of the movie "San Andreas", courtesy of Amanda |
So here's the thing. The San Andreas is a transform fault, meaning it shifts sideways during earthquakes. It behaves in a segmented manner, with a history of large, but not gigantic, earthquakes (in the real world, the quakes top out at about 7.8-8.0 magnitude, about 1/30th the size of a magnitude 9 quake. The northern segment broke in 1906, the famous San Francisco quake at magnitude 7.8 (the movie "San Francisco", 1936, still stands as one of the best earthquake movies ever). The central segment, from Cajon Pass to Parkfield, broke less famously in 1857. The southernmost segment, down in the Palm Springs/Coachella Valley region, has not gone off in about 350 years. It is pretty much the most dangerous stretch of the fault in California. No, there aren't going to be any magnitude 9+ quakes in California. You'll have to look north to the Cascadia Subduction Zone in Washington and Oregon (and far north California) for that kind of thing.
Now I know it was there because the plot progression demanded it, but this will not happen. The San Andreas will slip sideways 10 or 20 feet, but the ground isn't going to open up like this. The plot was slowing down after Ray's helicopter crash-landed in Bakersfield, and the drive to San Francisco was going to take a boring four hours. Something was needed to make them steal an airplane and get there faster. Oh, and the San Andreas fault is a right lateral fault, meaning during the quake, the side of the fault opposite the observer would shift to the right. The photo is showing a left lateral fault. Oh, and they said this was the Central Valley. The San Andreas doesn't go through the Central Valley. Oh, and because the fault motion is primarily lateral, it doesn't disturb the seafloor enough to do this:
In fact, even the world's worst earthquakes don't make tsunamis this big. Nor do they curl in like a surfer wave on the North Shore of Oahu. But heck, by now our heroes are on a boat, so there are some cool dramatic scenes of ships being destroyed. The cargo ship was great (you'll just have to see the movie). Because the plot demanded it, the movie's only "bad" guy was on the bridge when the wave hit, and he looked just like the lawyer in "Jurassic Park" before the lawyer got munched by a T-rex. Only he wasn't on a toilet.
So there are screams, and explosions, and falling buildings. Really, someone needs to sue the architects, because their skyscrapers kept falling down everywhere. This is another point that needs to be addressed. Most modern buildings will not collapse during the "big one". You will just be asking for a world of hurt if you are trying to get out of such buildings during the quake. As the geologists in the movie said, over and over, "stop, drop, and cover". You'll be much better off.
But like I said, I rather enjoyed the whole movie, and the special effects were quite good, even if these were things that wouldn't happen in real life. Don't use this movie as your education in the nature of earthquakes. I highly recommend this sort of thing: http://www.earthquakecountry.org/roots/. Or this: http://earthquake.usgs.gov/earthquakes/.
Great review Garry. I figured you would have to watch this movie, just to point out all the mistakes.
ReplyDeleteThough Giamatti's little exposition for the class was mostly correct, I cringed when he referred to the "Richter Scale" when talking about the magnitudes of the '60 and '64 quakes.
ReplyDeleteBut my first thought, as the credits rolled by on the drum seismograph, was how poorly first responders were treated in this movie: Johnson's character is supposed to be the hero, but he abandons his job and steals a helicopter when he hears his daughter might be in trouble _400_miles_away!_
His daughter is smart and resourceful, but she steals an emergency kit from a fire truck for her own use. Are we to assume that the truck's crew had abandoned the truck and had no need for the radio, the first-aid kit, etc.? Then I tried to remember scenes showing police or fire crews or paramedics helping anyone in the movie (other than The Rock). Did you see any? I didn't.
So apparently all the first responders in the movie are either dead, incompetent, or have abandoned their posts (probably to rescue their own family members in other towns). At least the crew of that fire truck didn't steal their vehicle to do so.
I didn't catch the Richter part. For those wondering what that means, Richter is only used for smaller quakes, up to 6.5 or so. Larger quakes are measured using the determination of the seismic moment, and converting to a scale roughly similar to Richter. Moment uses the amount of offset, the frictional resistance of the rocks along the fault, and the length of the fault rupture. These are things that are not easy to calculate while the quake is happening!
ReplyDeleteYour comment reminds me of how a great many New Orleans police abandoned their posts during the Katrina hurricane and flooding. There's only so much you can do in the face of overwhelming destruction. But still, the characters in the movie made me think of an alternate title: San Andreas, a Looter's Tale
Damn! Such a great review, criticism notwithstanding, I'll have to see it now. Thanks Garry - you make my day with your geology-based posts - and the photos are always excellent. Cheers!
ReplyDeleteAs with most of the other DESTROY CALIFORNIA movies, this one requires suspension of disbelief and, in essence, the thinking portions of the brain. Good review!
ReplyDeleteSo a pole-vaulting cargo ship caught in the tsunami stood in for Godzilla wrecking the bridge (how many times has it been taken out now?), but GGB came through the quake itself fine. And how about some other odd bits of geography - like the GGB in some scenes appearing to run approximately through Alcatraz? And after the tsunami, the water doesn't go back down - instant sea level rise or did the land subside 100m?
BTW, I understand that recent re-examination of tide gauge records shows that 1906 *did* produce a tsunami - maybe a few inches high.
Still, as movies go, not bad. I saw the 3-D version; not bad, actually without a lot of in-your-face effects - recommended. Oh bother - just go see it - find a $5 Tuesday or something like that, don't blow a wad, and have fun.
A friend calculated that, even if the entire 400 miles of the SAF slipped at once, the maximum offset would still have to be about 0.6 miles in order to produce a magnitude 9.6 earthquake.
ReplyDeleteI laughed out loud at some of the most obvious errors, but the theater had the volume SET SO LOUD no one could possibly have heard me...I ended up using ear plugs for 90% of the movie. Still, an entertaining destruction movie in a chilly theater on a hot summer's day, grievous mistakes or not.
ReplyDelete