|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).
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|
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.
|This is the absolute best lesson in the entire movie. Get under cover, preferably with an attractive person. If the building really does collapse, who do you want to spend time with while waiting to be rescued?|
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/.