The San Andreas Fault is one of the most feared regions for its seismic activity. Although there has not been a significant movement in recent years, seismologists consider that it could happen at any time.
The planet has a very complex configuration, it is not only a land mass covered by sea in some regions, but it has a layered structure, each of which has an important function. As if it were a living being, the Earth has its own ways of releasing energy and thus continues to restructure itself over the eons.
What is a geological fault?
The main layers that make up the Earth are first, its core, which is then covered by the mantle and finally the Earth’s crust. Each of these layers, in turn, is subdivided and one of the regions closest to the crust is the lithosphere, which is where the tectonic plates live.
The lithosphere is where the mantle and the Earth’s crust meet, so it is made up of solid material that comes together in the form of tectonic plates. As we know, these constantly move under our feet, causing earthquakes.
But it may happen that some of these movements are so abrupt or simply that the tension in certain places is such that I end up breaking the lithosphere. This rupture is called a geological fault, which in simpler words is when the Earth’s crust cracks, causing sections of land to rise or sink and generating a boundary between two tectonic plates.
The San Andreas Fault
There are faults of different types and sizes, however, one of the most important is precisely because it is one of the largest of its kind. It runs from north to south through the state of California, United States and extends to Baja California in Mexico. It delimits the North American plate from the Pacific tectonic plate.
In total, it extends for 1,286 kilometers and is divided into three sections: north, center and south, with the northern region being the most famous for the 1906 earthquake that had an estimated magnitude of 7.9 and that devastated San Francisco. The fault begins in the city of Hollister and runs through at least eight major cities in California and Baja California. San Francisco, Daly Ciry, Palo Alto, Palmdale, Desert Hot Spring, Palm Spring and Mexicali, the latter in Mexico, are part of the cities that rise above the San Andreas Fault.
What would happen if the fault collapses?
More than 38 million people live in the vicinity of the fault, so a large earthquake would greatly affect large cities. The fault has already gone through significant activity, 160 years ago the northern part ruptured during the 1857 earthquake that raised the ground up to 9 meters. Later in 1906, another earthquake occurred in the central section, which killed 3,000 people in the city of San Francisco.
However, the one that currently worries seismologists the most is the southern region, which has not seen activity in nearly 300 years and has been accumulating tension for a long time, which is why they believe it could cause an earthquake at any time. Especially because according to research, the frequency of earthquakes in this region is every 150 years.
According to researchers from the United States Geological Survey who developed a computer model to simulate an earthquake on the southern fault zone, the next big event could have a magnitude of 7.8. The movement would initiate a rupture near the Salton Sea in California, which would then shoot north along the entire fault until it touches Los Angeles.
The number of victims would amount to more than 50 thousand people affected by the movement, hence the great importance of construction regulations and action measures in the event of a disaster of this nature. Despite everything, it is not known when this event could occur, but seismologists are sure that the fault will collapse at some point in history.