“They tell me the faultline runs right through here,” goes a lyric to the old John Hartford tune “California Earthquake.” The infamous fault in question is the San Andreas and it’s so big, widespread, and potentially destructive that the question isn’t whether the “The Big One” will strike the Left Coast one day but when. That inconvenient truth scares the hell out of most residents but somehow gets moviemakers – even L.A.-based ones, maybe especially L.A.-based ones – hot and bothered. Witness such all-star Mother Nature-flexes-her muscles ‘70s disaster cheese fests as Earthquake and its many bastard children spawned by the likes of contemporary moviemakers Roland Emmerich, Michael Bay and other heirs to the tinny throne of producers Ross Hunter (Airport) and Irwin Allen (The Towering Inferno, The Poseidon Adventure).

Now comes $100 million worth of CGI-generated earth splitting and building tumbling in San Andreas in which huge swaths of L.A., Nevada, and San Francisco bite the dust; high-rises topple like dominoes, fires ravage the rubble, and zillions of extras run, scream, and die agonizingly (all in 3D if you choose). Good times. Of course, since we’re now way past the comparatively posh Reagan era ‘70s and real movie stars like Charlton Heston, Paul Newman, and Steve McQueen are long gone, San Andreas is a pretty stripped-down affair.

Somehow, the movie’s gigantic budget could only accommodate the salary of one genuine star: Dwayne Johnson, cast as an ace L.A. Search and Rescue chopper pilot (nickname: “Godzilla”) and who spends most of the flick’s 123-minute running time utterly ignoring the cries of bleeding, mangled survivors of a catastrophic West Coast earthquake to instead pick his way through the ruin of San Francisco in search of daughter (the likeable Alexandra Daddario, who is, by the way, a mere 14 years younger than Johnson). Soldiering along with Johnson on the cliché ridden rescue operation are his estranged wife (Carla Gugino), her oily, filthy rich mogul boyfriend (Ioan Gruffud), and a couple of jittery Brit brothers (Hugo Johnstone-Burt, Art Parkinson). Spoiler Warning: Some of them live.

As directed by Brad Peyton (Journey 2: The Mysterious Island) from a screenplay of strung-together clichés blamed on Carlton Cuse (Lost, Bates Motel), the plot and characters are as sturdy as tissue paper. But, hey, who shells out $10 bucks plus drinks and popcorn for a movie like San Andreas expecting anything but wall-to-wall destruction porn? If you’ve been itching to see three West Coast locales brought to their knees on screen via crazy good special effects — hello, tsunami, adios Hoover Dam; whoops, there goes the Golden Gate Bridge! — this is your jam. The jaw-dropping mega-destruction and incredible stunts ease up every once in a while to accommodate sideline characters like an adrenaline junkie reporter (Emmy winner Archie Panjabi, from The Good Wife) and a genius Caltech seismologist (Paul Giamatti, making bank) who mutters big science talk from a very safe building and warns that a second, even bigger quake is imminent. At least Giamatti, who acts like he was spliced-in from another movie, gets to voice dialogue a bit more complex than the movie’s standard, slack-jawed stuff that runs along the lines of “Oh, shit!”

For connoisseurs of unintentionally terrible movies, San Andreas delivers more than a few hearty belly laughs. It’s so ridiculous, formulaic, and shameless that the wrap-up includes an American flag flapping in the breeze while the surviving cast members make their best can-do, “I will survive” faces. * ½