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 extends across two tectonic plates. The average annual rate of Pacific Plate films relative to the North American plate is 46 mm per year to the northwest (similar to the nail growth rate). This is an average plate movement, while a large earthquake on the San Andres fault could trigger significantly greater localized movement of the order of tens of feet in seconds.
Los Angeles is not the first U.S. city to be threatened by sea level rise and earthquakes. Miami, for example, may be 6 feet below sea level by the year 2100. Already, many areas flood during high tides. Miami Beach was once just a sand bar. It was developed by an ambitious developer in the early 1900s. The new development was hit by several early hurricanes.
Los Angeles sinks because of earthquakes
A recent study found that the land near Los Angeles could sink below sea level in the event of a major earthquake. California has not experienced a major earthquake since 1857, but the nearby fault lines have lowered the ground by up to three feet in the past. A study published in the journal Scientific Reports analyzed these fault lines and determined that Los Angeles may be in danger of sinking.
Los Angeles is located on a number of fault lines, including the San Andreas fault line. Additionally, parts of Los Angeles are built on top of sediment basins that are susceptible to liquefaction. This process causes the soil particles to lose contact with one another and sink, causing buildings to sway and sink.
One of the main concerns is that a major earthquake could destroy entire neighborhoods and communities. It can also cause hundreds of fires and damage to water supplies. Fires can spread rapidly and merge into one another, destroying entire sections of Los Angeles. The earthquake's force can also disrupt water, power, and internet systems. Though most modern buildings survive, afters continue to devastate Los Angeles.
Los Angeles sinks because of sea level rise
Despite the fact that sea level rise has been a major issue for the past several years, California's coast prospered during one of its calmest periods in history, lulling dreaming settlers into a false sense of endless summer. Those tame seas, or sea level suppression, were created by favorable winds that suppressed the rising seas. As a result, Californians built right up to the edge of the water.
Fortunately, Los Angeles is not among the coastal cities that are likely to sink because of sea level rise. Although the city is located above sea level, it could experience more flooding from increased storms and sinking terrain. During high tides, Los Angeles will be at or slightly below sea level, but most of the city won't be flooded.
Los Angeles' coastal area may be in a vulnerable position to sea level rise, because a major earthquake could cause an abrupt sinking of land. The last major quake on the San Andreas fault happened in 1857. Scientists estimate that a major quake will occur about every 150 years.
Los Angeles sinks because of encroaching seas
For residents of coastal cities, the risk of sinking because of encroaching seas is a major issue. Every extra inch of ocean water adds to the erosion of beaches and increases the risk of flooding during hurricanes. It also threatens the city's sea walls and sewers.
In recent years, coastal communities like Pacifica have been struggling with sea level rise. Residents fear their town will disappear because of the rising waters. Already, entire hillsides are crumbling into the ocean, and homeowners are begging for a larger sea wall. For now, the city is doing its part to protect its residents.
Los Angeles sinks because of rising seas
As sea levels rise, the coastline of Southern California could be suddenly submerged, threatening portions of the city. A new study suggests that the area could sink by as much as three feet if a major earthquake occurs. As sea level rises, the impact of such a large earthquake would be magnified by the fact that an area under water would become flooded.
In the past century, global sea levels have risen about 25cm. This amount is projected to increase even more over the next 100 years. This rise is primarily due to the thermal expansion of warmer water. The ocean absorbs more heat than the atmosphere, and the warming of the earth's surface increases the ocean's volume. Increasing temperatures have also accelerated the melting of glacial ice sheets. Because of this, sea levels are expected to rise at an alarmingly fast rate.
In addition to the California coastline, much of the coast of the United States is facing the threat of flooding from rising seas. Fortunately, California has implemented a series of aggressive water management plans to avoid further sinking and raise the land through groundwater replenishment. According to the Surfrider Foundation, a nonprofit environmental organization, California is a "shining example" when it comes to responding to sea level rise.
The nature of the movement of the San Andres fault system means that Los Angeles will one day be adjacent to San Francisco. However, it doesn't allow a massive fall or westward movement to be required for California to fall into the ocean. If plate tectonics followed the laws of Hollywood physics, Los Angeles would be violently tearing off the continent as we speak. The scenario would likely include a Buxom seismologist and a secret nuclear warhead, as well.
So, while there's nowhere for California to fall, Los Angeles and San Francisco are moving toward each other and will one day be adjacent (see below).