3 October 2024

California was rocked by three earthquakes in less than 24 hours.

The largest was a 3.0 magnitude quake that hit four miles northwest of Walker at 12:33pm local time on Wednesday, followed by a 2.9 magnitude quake struck 10 miles northeast of Barstow at 10:45am local time.

And at 5:40pm, the state suffered another blow as a 2.6 magnitude hit two miles east of Pacheco.

While the seismic events are considered minor, residents of nearby areas, especially near the epicenters, reported feeling the ground shake. So far, no damages or injuries have been reported.

But this anomaly adds to a streak of heightened seismic activity that has reignited fears of The Big One.

There have been no reports of shaking associated with the 2.9 magnitude quake that occurred near Barstow.

But two people – one in Glenbrook, Nevada and another in Martinez, California – reported feeling weak tremors when the 3.0 magnitude earthquake struck near Walker.

This quake occurred along the Walker Lane, a 625-mile-long corridor riddled with hundreds of earthquake faults that runs up and down the border between California and Nevada.

Sixteen people reported feeling weak tremors when the 2.6 magnitude quake struck near Pacheco.

All those who reported shaking were in California, with nine people reporting from Martinez, three from Pleasant Hill, two from Concord, one from Walnut Creek and one from Folsom.

This quake occurred along the San Andreas fault – the volatile boundary between two tectonic plates: the Pacific plate and the North American plate. It runs 800 miles along the coast of California.

Tectonic plates are large, solid pieces of the Earth’s crust that move independently of each other.

Both the southern and northern sections of the San Andreas fault are locked, which means friction has caused the North American and Pacific plates to stick together along these portions of their boundary.

When part of a fault is locked in this way, stress can build up over time and eventually overcome the friction.

When all that stored energy suddenly releases, shockwaves travel up through the Earth’s crust and cause an earthquake.

Both the southern and northern sections of the San Andreas fault have roughly equal likelihood of generating a high magnitude earthquake in the next few decades.

The San Andreas is widely known for its potential to unleash The Big One – a hypothetical, high-magnitude earthquake that will one day occur along this fault.

Researchers have estimated that such a quake would cause roughly 1,800 deaths, 50,000 injuries and $200 billion in damage.

Scientists are not able to predict earthquakes, but they have long warned about the inevitability of The Big One.

In fact, California is overdue for it. Major earthquakes typically occur every 150 to 200 years, but the San Andreas fault hasn’t had one in over three centuries.

California has seen an uptick in seismic activity in recent weeks – reigniting fears of The Big One.

Last month, the state broke its record for the most magnitude 4 and above earthquakes in a single year after a magnitude 4.7 earthquake and five aftershocks rocked Malibu, marking the 14th magnitude 4 or higher earthquake in Southern California this year.

The average number of magnitude 4 and above earthquakes for this region is about eight per year, U.S. Geological Survey (USGS) seismologist Lucy Jones said in a televised Q&A following the earthquake.

But this heightened activity is not a sure sign that The Big One is coming,

Jones said these numbers are ‘not yet statistically significant,’ meaning that experts can’t be sure whether the increase is part of a larger trend, or just a blip.

Therefore, scientists can’t infer any information about ‘the big one’ from these latest quakes. But advancements in earthquake forecasting could eventually help us narrow down a timeline for when it might strike.

The three quakes that occurred in just 24 hours this week add to the sense that California is experiencing an unusual year for seismic activity.

But like the state’s record-breaking number of magnitude 4 quakes this year, this anomaly does not mean that Californians need to brace for The Big One.