No, California is not going to fall into the ocean. California is firmly planted in the upper part of the earth's crust in a place where it spans two tectonic plates. The idea that part of California will separate was probably inspired by the San Andreas fault. After all, since the fault runs through California, one part of the state is on the Pacific plate and another on the North American plate.
If those plates are moving in different directions, it makes sense that the two parts of California also move in different directions. California has been a land of hope and dreams, opportunities and infinite possibilities, and a place with allusions to glamour and danger. It is a state in which facts and myths often overlap. According to some geologists, when one of the major earthquakes occurs, California will separate from the mainland and become an island.
Was the state ever an island? He conducted a series of overland expeditions from northern Sonora to areas within or near the Colorado River Delta between 1698 and 1706, partly to provide a practical route between Jesuit missions in Sonora and Baja California, but also to resolve the geographical question. Ascención was a tireless propagandist in favor of the Spanish settlement in California, and his later writings referred to the region as an island. However, despite this evidence, the description of California as an island was revived in the early 17th century. Cortés's limited information about southern Baja California apparently led to the name of the region named after legendary California and to an initial but ephemeral assumption that it was a large island.
The maps published later in Europe during the 16th century, including those of Gerardus Mercator and Abraham Ortelius, correctly depicted Baja California as a peninsula. Major aqueduct networks pumping water into Southern California cross the San Andres fault and could suffer serious damage. The first report of Kino's discovery and his 1701 map showing California as a peninsula were sent to Europe by Marcus Antonius Kappus, a Jesuit missionary from Kamna Gorica (Duchy of Carniola, now Slovenia). The first known reappearance of the island of California on a map dates back to 1622 on a map by Michiel Colijn of Amsterdam.
In fact, the Juan de Fuca Strait is about 48° N, as is the southern end of the large island now called Vancouver Island, while the northern tip of the Gulf of California ends much further south, at about 31° N. The expedition descended the Colorado River in 1604 and 1605, and its participants believed that they saw that the Gulf of California continued northwest (presumably behind the Sierra de Los Cucapah into the Laguna Salada basin and Lake Cahuilla). But while the Great One would definitely cause mass destruction, it would not sink part of California into the ocean, nor would it separate the state from the rest of the country. On the other hand, imagine a film in which a huge earthquake causes parts of California to fall into the ocean, dividing the state and causing a massive tsunami.
The legend was initially steeped in the idea that California was a terrestrial paradise, like the Garden of Eden or Atlantis.