(.) – Southern California residents are on high alert after a 7.1-magnitude earthquake that struck communities near the Mojave Desert on Friday, just a day after another 6.4-magnitude earthquake in the same area.
The United States Geological Survey (USGS) warned that another earthquake of similar magnitude could occur next week, while aftershocks have occurred, on average, once a minute since Friday night.
READ: More than 4,700 earthquakes have been registered since Thursday in California
Although those earthquakes occurred along a fault near Ridgecrest, California, they reminded geologists of the imminent danger of another major earthquake along the mighty San Andrés fault, further west, which could cause significant damage. higher.
In light of this week’s earthquakes, USGS researchers reiterate that there is a 70% chance that an earthquake of magnitude 6.7 or greater will affect the San Francisco Bay area along the fault zone of San Andrés before 2030.
Here’s what you should know about that towering fault and what it means for future earthquakes in California.
It is not a single failure, but an entire network
Failures occur when rocks on both sides push or slide on top of each other, displacing the Earth’s crust.
Although the movement is generally imperceptible, the rocks continue to push but get stuck at the edges of each other. Pressure builds up until tension overcomes friction, creating a sudden release of energy that sends seismic waves through the ground, called earthquakes.
The San Andrés fault zone is an 800-mile (nearly 1,300-kilometer) boundary between the Pacific tectonic plate to the west and the North American plate to the east. Here, the plates squeeze each other horizontally at a rate of about 2 inches (5.1 centimeters) per year, and the slight movement can cause some milder tremors.
READ: What we know so far about the powerful second earthquake in California
The fault zone is not a single line, but a fault system that winds through California, including densely populated areas such as Los Angeles and San Bernardino counties.
The last major earthquake to occur along the San Andrés fault zone was in 1906, when a 7.9 magnitude earthquake and subsequent fire ripped through parts of San Francisco and killed 3,000 people, the most deadly in the history of the United States.
But going over 100 years without significant seismic activity along the fault zone is an anomaly, geologists say, and could presage a major earthquake along the fault.
Recent earthquakes may not trigger the great earthquake ‘
This week’s earthquakes are unlikely to trigger the major earthquake that geologists predict: At its closest point, the San Andreas fault is more than 150 miles away from the Mojave Desert, USGS seismologist Susan Hough told KTLA, affiliate of ..
Although it is difficult to predict exactly when the earthquakes will occur or what their magnitude will be, the researchers urge residents and local officials to prepare now and adapt the structures to resist the seismic force before the next major quake – or the major earthquake.