In another forehead-slapping moment of cow-dumb scripting, Carla Gugino looks directly at a huge ravine and asks, "what is this?" It's a huge ravine, Carla. You're looking directly at a huge ravine. Sure, the line was to set up the response "It's the San Andreas fault" but with just ten extra seconds of thought, they could have provoked line without making their female lead look like an drum-headed idiot who doesn't know what a ravine is. She didn't even have to say anything! The Rock could have just volunteered the information. Then they walked back to their car, pausing only for Carla to look at the vehicle and probably wonder "...what is this?"