In a single week, six earthquakes struck Southern California. Does that imply the arrival of “The Big One”?

Southern California has been hit by a series of earthquakes in recent days. A 3.6 on May 31 in Ojai. Two of comparable size beneath El Sereno, an East Los Angeles neighborhood. Three more earthquakes in Costa Mesa and Newport Beach.

Do these earthquakes portend the coming of the so-called Big One in a state perched on several, extremely active faultlines, even if they were far milder than historical tremors like the 6.7 Northridge Earthquake of 1994, which resulted in an estimated $20 billion in damage and killed over 57 people?

The infamous 800-mile San Andreas stretch stretches from the vicinity of the Mexican border eastward past Los Angeles and up the coast north of Sacramento.

Around every 180 years, there are significant earthquakes along the fault; the last significant earthquake to strike the San Andreas was in 1906. According to US Geological Survey projections, there is a 60% possibility that in the next 30 years, the Los Angeles area will see an earthquake of magnitude 6.7 or higher.

The Cascadia Subduction Zone, extending from Northern California to British Columbia, Canada, is a source of even more concern. In comparison to past norms, a far bigger earthquake is long overdue.

So, in a place where there are thought to be 35 earthquakes every day, are the recent ones a sign of anything bigger, or are things going on as usual?

For example, the Puente Hills thrust fault, which underlies Orange County and downtown Los Angeles, is just beneath the epicenter of the El Sereno earthquakes. The 10-mile deep fault approaches the surface in the vicinity of the University of Southern California’s Los Angeles campus, angling like a ramp. An earthquake along this fault might have an up to ten-fold increase in intensity compared to regions on bedrock if it strikes the loose soil of the Los Angeles Basin.

On the other hand, the Compton thrust fault, which may raise the LA River by as much as five feet in a powerful earthquake and cause devastating damage to city sewer systems, was the source of the Newport Beach-Costa Mesa earthquakes. In the previous 12,000 years, geologists estimate that there have been six earthquakes along the fault that are larger than a magnitude 7.

Scientists contend that the important factor to examine should be the potential harm that massive earthquakes could cause to heavily populated places, rather than only concentrating on their magnitude. Despite its well-known notoriety, much of the San Andreas passes through sparsely populated desert.

According to Dr. Pat Abbott, an emeritus professor of geology at San Diego State University, “the ‘big one’ in terms of damages and deaths would be ones running through town rather than one that’s a long distance away,” KSWB reported last year. “There are two factors: the magnitude of the earthquake and your location in relation to the fault’s movement.”

He cited large-scale events such as the Northridge earthquake of 1994 and the San Andreas earthquakes of 1857 and 1906, which all occurred below the 8.0 magnitude predicted in “Big One” scenarios but yet produced “horrendous” devastation.

The website of the California Governor’s Office of Emergency Services states that “unfortunately, earthquake prediction remains an extremely challenging endeavor.” “Scientists cannot reliably predict exact earthquakes, but they can monitor fault lines and detect patterns of seismic activity.”

Rather, scientists work mostly on long-term likelihood, which might help guide preparations in high-risk areas for the uncertain day when a huge earthquake occurs.

For example, the USGS predicts that within the next 30 years, there is a 72% likelihood that the San Francisco Bay Area will experience an earthquake of magnitude 6.7 or higher.

The “holy grail” of earthquake science, according to Harold Tobin, a seismologist at the University of Washington, is achieving a higher degree of accuracy in prediction.

He added, “As of yet, science has not discovered a means to produce useful earthquake predictions.” “Time, location, and magnitude would all need to be specified in a useful prediction, and there would need to be sufficient notice in advance for this to be worthwhile.”

Governments can advocate for preparedness measures like digital alert systems, drills, and building retrofits until that magic predictor code is unlocked. Meanwhile, individuals are advised to have emergency kits ready, drop to their knees, cover their head and neck, and cling to something sturdy in the event of an earthquake.


Leave a Reply

Your email address will not be published. Required fields are marked *