Do recent earthquakes make ‘Big One’ more likely? What the scientists say

Over the past few days, the Coachella Valley has experienced more than 20 earthquakes, causing concern among some residents.

After all, the 4.9 magnitude earthquake reported about 12 miles north of Indio on the evening of Monday, January 20 was the first moderate-sized earthquake to hit the region in a while, after all.

After many smaller aftershocks, a larger 4.3 earthquake woke many residents from their sleep at 12:30 am, Wednesday, January 21st.

With Californians consistently worried about “The Big One” – the anticipated massive earthquake that by some measures is deserved for the West Coast of the country – it is understandable that some would be a bit more nervous.

However, experts say the latest moderate earthquakes in Indio are relatively normal for the region. All earthquakes after the initial wave followed the typical aftershock pattern.

“The sequence is kind of working as you would expect, a typical post-4.9 decay,” said Kate Scharer, a research geologist with the US Geological Survey. “If you have a 4.9, you can get 10 or so three magnitudes in the next week.”

It is not for nothing that earthquakes are retroactively called “foreshocks” to the main event. In 1992, the 7.3 Landers earthquake was preceded by a 6.1 earthquake in Joshua Tree more than a month earlier.

Anyway, statistically speaking, such an event is highly unlikely.

Each earthquake carries a 5% chance of being followed by an earthquake of equal or greater intensity within a week, according to the USGS. The magnitude 4.9 earthquake in Indio has a 1% chance of being followed by a magnitude 7 or higher, Scharer said.

“It is what we are expecting from this region,” she added. “We should expect to have these earthquakes.”

Faultlines

The latest group of earthquakes occurred on a little-known fault line below Berdoo Canyon, a backcountry road that leads through Joshua Tree National Park.

About eight miles from the San Andreas Fault, the latest earthquakes may be far enough away to not interact with it, but it is impossible to predict.

One of the reasons why geologists are interested in the interaction between fault lines is because the San Andreas Fault is prone to major earthquakes. Significant rupture has not occurred along the San Andreas Fault for approximately 300 years.

That’s a bit longer than average, but not by much, according to Scharer.

“It’s a really good reminder that some day there’s going to be a big earthquake that’s going to be very challenging for your community or city,” she said. “And so it’s a good reminder to stop and ask what is it that you need to do to be more earthquake prepared?”

What am I supposed to do during an earthquake?

In case of an earthquake, experts urge people to “drop, cover and hold.” This is mainly to prevent them from being crushed by heavy objects.

Dropping to the ground prevents the fall. Covering the head and neck protects sensitive parts of the body. Experts also recommend that people crawl under a table or desk if they are nearby.

Why do earthquakes happen?

The Earth has four layers: the inner core, the outer core, the mantle and the crust. The crust and the surface of the mantle form another area called the “lithosphere,” which acts like a skin around the Earth’s surface, USA TODAY reported.

The lithosphere, however, is not in one piece and exists like a puzzle or a series of fragments, according to the United States Geological Survey. These parts of the lithosphere are not stationary and move slowly. These are called “tectonic plates.”

As the tectonic plates move and shift away from each other, they sometimes collide or collide. This puts stress on the edges of the plates. When the stress becomes too great, it creates cracks called “faults.” The point where these faults run against each other is called the “fault line.”

When there is too much friction between fault lines, energy is suddenly released, causing seismic waves that lead to an earthquake.

What were the largest earthquakes in California’s recorded history?

The largest earthquakes recorded in California since 1800, ranked by magnitude, according to the California Department of Conservation.

• 7.9: 9 January 1857 in Fort Tejon Two killed; created a facial scar of 220 miles

• 7.8: April 18, 1906 in San Francisco Possibly 3,000 killed; 225,000 displaced

• 7.4: 26 Mar 1872 in Owens Valley. 27 killed; three aftershocks of magnitude >6

• 7.4: November 8, 1980 just west of Eureka Injured 6; $2 million in damage

• 7.3: 21 Jul 1952 in Kern County 12 killed; it included three magnitude 6-plus aftershocks in five days

• 7.3: 28 June 1992 in Landers. One killed; 400 wounded; $9.1 million in damage

• 7.2: 22 Jan 1923 in Mendocino. Houses damaged in several cities

• 7.2: April 25, 1992 at Cape Mendocino. 356 injuries; $48.3 million in damage

• 7.1: November 4, 1927 southwest of Lompoc. No major injuries, minor damage in two counties

• 7.1 : 16 October 1999 at Ludlow. Minimal damage due to remote location

When is the next earthquake in California?

It is currently not possible to predict an earthquake, although USGS scientists can calculate “the probability that a significant earthquake will occur in a specific area in a certain number of years”, according to the USGS.

While earthquake predictions and probabilities can be determined, the USGS says those reports are “comparable to climate probabilities and weather forecasts” and not the same as predictions.

A USGS map of America shows that portions of California face a greater than 95% chance of experiencing an earthquake of mild or greater damage in 100 years. In other words, a strong earthquake on the Modified Mercalli Intensity Scale that will be “felt by all” will move some heavy furniture and cause light damage.

No, California will not ‘fall into the ocean’ due to earthquakes

Several hours before Monday’s earthquake, the Seismological Laboratory in Berkeley had published an information leaflet about California and earthquakes, saying that it is a fiction that California could eventually break up and fall into the ocean.

“This is because earthquakes in California cause horizontal movement, not giant sinkholes or land that sinks into the sea,” the lab shared on X. “No part of California is sitting on an ‘edge’ that can break suddenly,” the lab said.

This means that the state will not arise, sink or disappear in the Pacific. Earthquakes will continue the laboratory declared, and the coast will change slowly over millions of years, “but the land is not going anywhere suddenly.”

This article originally appeared on the Palm Springs Desert Sun: Do recent earthquakes make ‘Big One’ more likely? What the scientists say