What is the San Andreas Fault and where does it run?
Mexico was hit with a 7.1 magnitude earthquake on Tuesday, less than two weeks after another quake struck the country on September 7.
With the regular occurrence of the earthquakes in the Central American country, it has sparked concerns that the famous San Andreas Fault in the US could be affected.
Mexico sits atop three of Earth’s largest tectonic plates: the North American plate, the Cocos Plate, and the Pacific Plate.
When these plates slide or move against each other, earthquakes occur.
The earthquake to hit Mexico occurred because there was a reverberation along the boundary between the Cocos and the North American plate – causing a seismic ripple.
The San Andreas Fault was born about 30 million years ago in California, when the Pacific Plate and the North America plate first met.
The San Andreas Fault was responsible for California’s biggest earthquake where it measure 8.1 on the Richter scale.
What is the San Andreas Fault?
The San Andreas Fault is the sliding boundary between the Pacific Plate and the North American Plate
The narrow break between the two plates is called a fault.
The San Andreas Fault appears to look like a long and narrow valley.
In some places, the fault is visible as a series of scarps and ridges.
However in other places, such as Los Angeles, it is more subtle because the fault hasn’t moved in many years.
Where does the San Andreas Fault run?
The fault splits California in two from Cape Mendocino to the Mexican border.
San Diego, Los Angeles and Big Sur are on the Pacific Plate and San Francisco, Sacramento and the Sierra Nevada are on the North American Plate.
On the west side of the fault sits most of California’s population.
How fast do both plates move?
The Pacific Plate is moving to the northwest at 3 inches each year, and the North American Plate is heading south at about 1 inch per year.