One year ago, Ridgecrest, California experienced two major earthquakes. On July 4, 2019, it measured magnitude 6.4. On July 5, a stronger 7.1 quake shook this region, located about 120 miles north of Los Angeles. Thanks to good building codes and relatively sparse population, no lives were lost.
On the silver screen, lots of lives are lost in movies dealing with this topic. Two come to mind: “2012” and “San Andreas”. Roland Emmerich’s “2012” spares no one. The entire earth’s crust fails, making the continents dip into the molten interior of the planet. Special effects are awesome, but the scientific background of the story is sparse. What the movie did get right, though, was the fact that the solid crust on which our cities are built is incredibly thin. Imagine the Earth to be the size of a basketball, and the hard ground below us will be no thicker than a sheet of paper. Its actual thickness is about 15 to 20 miles on continents. Below the oceans, it thins to as little as 3 miles. But there’s no sharp boundary because it keeps getting hotter and softer with increasing depth until at some level it’s completely molten.
“San Andreas”(2015) has been criticized for the super-hero flavor of the script. But its scientific background is much more realistic than “2012”. The San Andreas fault does indeed run through most of California, physically dividing the state. Southwestern California is part of the Pacific Plate while its counterpart belongs to the North American one. Avoiding an old cliché, Director Brad Peyton doesn’t make Southern California fall into the ocean. Instead, the San Francisco area suffers its worst earthquake ever, which is quite a possibility today. Earthquakes cannot be predicted yet, so the major scientific breakthrough in the movie is optimistic. But writers Andre Fabrizio and Carlton Cruze have done detail homework. It isn’t safe to stand in a doorway, as the old urban legend has it. There’s a good chance of a 200-pound lintel falling on your head, with the wall above to follow. In the movie, people use the “drop - cover - hold” principle. An approaching tsunami has a swarm of motorboats heading out to sea, thereby escaping the horrendous breaking waves in the bay. This, plus marvelous special effects, makes “San Andreas” a somewhat exaggerated show with realistic details.
Rudi Kiefer, Ph.D., is a professor at Brenau University, teaching physical and health sciences on Brenau’s Georgia campuses and in China. His column appears Sundays and at gainesvilletimes.com.