The San Andreas Fault Line runs across much of California, as do other smaller fault lines, and consequently, earthquakes are common in the region.
Scientists have warned for some time that a superquake on the West Coast ("The Big One") is inevitable. All research points that there's enough pressure for it to happen any day it likes now, and there's a 70% chance that it won't wait more than 30 years. Many people have gotten the impression that California is one earthquake/nuclear explosion/meteor impact away from snapping off (neatly at the state line) and falling into the Pacific Ocean. In speculative fiction, don't be surprised if part or all of California has suffered this calamity, whether it's the focus of the work, part of a cavalcade of worldwide natural disasters, or just a throwaway reference. To writers who have Horrible Hollywood in mind, it's good riddance if Los Angeles were to fall off the face of the earth.
In Real Life, this is not going to happen, at least not as portrayed in fiction. The San Andreas is a strike-slip fault, which moves the land sideways; at a very gradual rate, with the west side of California drifting northwest and the east side moving southeast. In fact, there are places where it's getting closer together. Also, tectonic activity won't cause the land to sink—it is still part of the earth's crust, not some giant shelf hanging on, although several land portions that run on top of the fault line are below the sea level, so it's conceivable that very long periods of time could see it break off from the mainland and become an island.
Some writers propose that though the California coast would not crumble into the Pacific Ocean from an earthquake, it might be washed away by a following tsunami. While the Japanese Earthquake-Tsunami has shown this is possible even with Strike-Slip faults, it's not very likely.
A subtrope of Artistic License Geology. If portrayed onscreen, it will usually use Earthquakes Cause Fissures, but may be more justified depending on the circumstances. A regional-scale Apocalypse How.
Warning: May contain spoilers
- The Infinity Gauntlet shows the West Coast Avengers watching on in horror after Thanos's angry outburst of energy hits the Earth and sends not just California, but the entire West Coast collapsing into the Pacific Ocean. Japan suffers a similar fate.
- Bomb Queen pulls this in the Image Comics universe.
- Lex Luthor's Evil Plan in Superman is to hit California with a nuclear missile, which will fracture the fault line and sink California into the ocean. He plans to make a fortune by buying worthless property in the Nevada desert and then sell it as beachfront resorts once California is gone.
Luthor: We all have our little faults. Mine's in California.
- In Escape from L.A., a portion of the California coast has become separated from the mainland by a quake that flooded San Fernando Valley, and turned into a Wretched Hive of a prison.
- In 2012, the San Andreas fault line goes absolutely berserk. In this movie, southern California is apparently suspended over a gigantic cavern of magma, and a sufficiently strong quake will cause pieces of the surface to fall into the cavern.
- Semi-averted in Demolition Man, where Lieutenant Lenina Huxley references "THE earthquake", the proverbial super-quake that California is "due for". Rather than explain how it tore a chunk off the coastline, it's implied that it merely destroyed most of the entire San Diego/Santa Barbara/Los Angeles area, leading to the creation of the new San Angeles metropolis.
- The Evil Plan in A View to a Kill involves the destruction of Silicon Valley by water, caused by flooding the San Andreas fault. The villain was hoping to give himself a monopoly on microchips.
- San Andreas is an earthquake disaster movie about "The Big One". Ultimately, it avoids the idea that California would completely sink in such a catastrophe, although the fissure created fills with water, and a good half of the state is flooded by the tsunami and the shattering Hoover Dam.
- The Last Days of the Late, Great State of California by Curt Gentry is written as a semi-fictional retrospective on California's history after the California coast west of the fault line sank into the ocean due to a 9.0 earthquake.
- Under the City of Angels by Jerry Earl Brown. In the Back Story, a series of earthquakes leaves Los Angeles underwater.
- Dream Park: In the Back Story, a major earthquake in California knocks Los Angeles into the Pacific Ocean. One of the rides at Dream Park is a simulated exploration of the underwater remains of the city.
- In the backstory of Transformers: Shattered Glass, after Earth suffered through a nuclear exchange during World War III this was the fate of not just California, but a good chunk of the surrounding states as well.
- California had set sail in Marooned in Real Time, but it was millions of years later.
- In the opening novel of The Survivalist series by Jerry Ahern, WW 3 causes this to happen. A woman asks the protagonist if her husband might have survived because he lived on the landward side of the San Andreas fault; Rourke has to explain that the subsidiary effects of California sliding into the sea would have killed anyone there as well. In a later novel Rourke discovers that the detonation of all those nuclear weapons has created an artificial fault line in the Florida Panhandle, which is also about to slide into the sea — basically this trope played out on the opposite side of the US as California is no longer available.
- In After Man: A Zoology of the Future, an elongated island of temperate woodlands is visible off the Pacific coast of North America. Justified because it's 50 million years in the future, and was most likely a result of thousands of incremental earthquakes and landslides gradually splitting it away from the mainland.
- In a humorous short story A Slight Miscalculation by Ben Bova a scientist predicted that the upcoming quake will cause most of California to sink. Except that his computer insists that California would stay and the rest of North America will sink. The computer was right.
- In The Space Merchants, atomic bomb tests seem to have kicked the San Andreas Fault into overdrive. Southern California has yet to slide into the ocean, but earthquakes happen there daily. Earthquake insurance policies don't cover the territory, but construction companies are always hard at work in replacing buildings that fell down.
- The Made-for-TV Mini Series 10.5 ends with a superquake (with the titular Richter scale rating) that destroys the entire western seaboard of the United States, leaving a giant island where most of California used to be. The follow-up, 10.5: Apocalypse, takes it Up to Eleven by use of superfaults that split the whole of North America in half. After it aired, the Internet briefly filled with jokes about it being a prequel to Escape from L.A.
- In an episode of Sliders, they slide into a world where California has broken up into islands.
- An episode of Seaquest DSV where the crew traveled to the future featured this.
- An episode of Star Trek: Voyager mentions an earthquake that caused the Los Angeles region to sink under 200 meters of water to become one of Earth's largest coral reefs.
- Fringe: In the second season finale "Over There," a map of the country on Walternate's office wall shows California as mostly underwater. It's implied that this may be another Fringe-event disaster much like the blight and amberization of Boston.
- On Defiance, the massive amount of terraforming that Earth underwent at the end of the Pale Wars, among others things, apparently triggered this. In the present, the area where Los Angeles used to be is now an island chain called Angel Ark.
- In the Tool song "Ænema", the singer is praying for this to happen to Los Angeles, since the only way to fix it is to "flush it all away". It's inspired by the Bill Hicks "Arizona Bay" routine, which is directly referenced in the chorus. The album artwork features "before" and "after" maps that show most of California gone.
- Discussed in the Warren Zevon song "Desperadoes Under the Eaves":
And if California falls into the oceanLike the mystics and statistics say it willI predict this hotel will be standingUntil I pay my bill.
- The Decemberists' "Calamity Song" mentions "California succumbed to the fault line."
- The song "Ocean Front Property" by George Strait, although it's more of a "It will never happen!" than suggesting that it will.
'Cause I don't love you, and now if you'll buy thatI got some ocean front property in Arizona.From my front porch you can see the sea.
- Mentioned in the Steely Dan song "My Old School", with the line "California tumbles into the sea," though it's more in the sense of "A thing that's almost certainly never going to happen."
- The subject of the calypso-flavored 1969 novelty hit "Day After Day (It's Slippin' Away)" by Shango:
Where can we go when there's no San Francisco?Better get ready to tie up your boat in Idaho!
- "Antennas" by punk band Rancid contains the chorus that proclaims "So with no evacuation / Let California fall into the fuckin' ocean", the NOFX cover ends with the lines "Let's all sink with California / As it falls into the sea.", which are also the lyrics to the song "Sink with California" by Youth Brigade.
- "California Jam" by Klaatu is a Beach Boys pastiche that contrasts the sun & surf lifestyle with the future, when "the San Andreas misfortune" will make California "a place in our memory".
- The famed early 20th century psychic Edgar Cayce predicted that California would get destroyed by earthquakes and consumed by the Pacific, and many major cities such as Los Angeles and San Francisco would disappear.
- In Deus Ex, much of Southern California and the Baja California peninsula are missing from in-game maps; in the backstory, they collapsed into the ocean. The city of Pasadena is now on the coast, albeit a ghost of it's former self, since Los Angles and surrounding cities such as Glendale, Burbank, and Hollywood have been lost.
- In Alone in the Dark 3, the Big Bad has a plan pretty much like the one from the Superman example, just replace "Arizona" with "Ghost Town Slaughter Gulch" and "increasing real estate" with "fulfilling an ancient native prophecy to become a god".
- In Future Cop: L.A.P.D. Los Angeles is devastated and run by crime after a civil war, a huge storm and a massive earthquake, which has separated a part of the area into an island (used as a weapons test range. Said island also contains a joke level only accessible after all versus maps against the AI Sky Captain were won up to difficulty 10 each. It replaces all machines and towers with stuff like flowers and butterflies and has goofy music to boot.
- Arcade America has the earthquake triggered by a buttload of dynamite some monsters blew attempting to wake the Heavy Sleeper protagonist.
- In the Web video The End of the World, the narrator suggests at the end that California should split off "to go hang with Hawaii". Alaska can come too. (https://www.youtube.com/watch?v=84Ud3V9NPw8)
- The SCP Foundation plays with it in SCP-1238, a species of rock-eating fish that have created such a vast network of tunnels that much of northern California and the Pacific Northwest are just sinkholes waiting to happen. A big enough earthquake could cause a chain reaction where all of the tunnels collapse, resulting in the undermined area collapsing below sea level and inland areas being flooded, while leaving everything south of San Francisco alone.
- According to the forum RP Scary News out of Tokyo-3, this happened in the wake of Second Impact as a result of violent earthquakes. The remains of Los Angeles and San Francisco are archipelagoes, and several communities in the Mojave Desert are now only a few miles inland; Lancaster is described as a "thriving seaside community" in a news report.
- This was the conclusion of Dexter's California vacation. California had a big earthquake as they were leaving, and it went out to sea (neatly along the state line) as California Island.
- Possibly meant as a humorous variation on this: In the Futurama episode "Game of Tones", an alien ship's sonic blasts cause Florida (not California) and part of its neighboring states to split from North America.
- While not as big as the trope usually calls for (as in, California didn't sink or detach) but still in its spirit, Animaniacs did a musical number about a real-life quake to hit the Los Angeles area.
- Invoked and played straight in an episode of 2 Stupid Dogs, "Day Dream": the possibility is mentioned several times, and then the earthquake hits and sinks the entire state of California, except for the two dogs who sleep throughout the whole disaster.
- In Jackie Chan Adventures, Bai Tza the water demon attempts to magically sink San Francisco using the fault line, as her previous kingdom (Atlantis) is now an empty ruin.
- Inverted in one episode of Eek! The Cat. Eek and the family are visiting California while an earthquake strikes it, with this trope being mentioned. A few instants later, it is revealed the rest of United States sank instead (and precisely around the borders, no less).