Fault Lines Are Creeping in California

It’s all too perfect that there is new, creepy activity happening in the California fault lines just before Halloween. 

California fault lines could be a threat to your house.
Are you prepared, or will the next earthquake spook you?

Recent California Earthquakes

In recent weeks, California has had an uptick in seismic activity, some of which experts have linked to a creeping section of the San Andreas fault system. Most recently, Pleasant Hill and Hollister both experienced magnitude 4.5 and 4.7 earthquakes, respectively. 

To have two 4.5 magnitude quakes in one week in California is a little unusual.

New Movement in the Fault Lines

At the same time, for the first time on record, the Garlock Fault has been moving. This fault houses the potential to produce a magnitude 8 earthquake, and this “creeping” is a by-product of the Ridgecrest earthquakes in July. With the heightened concern about the San Andreas faultline and the “Big One” coming, new or unprecedented activity is enough to catch the attention of seismic experts

The Garlock Fault’s movement is known as “creep”: meaning that it is moving at a slow, continuous pace. Creep is typical among California faults, and creep could also trigger an earthquake nearby. The San Andreas fault has often had spells of creeping in reaction to other nearby earthquakes.  Scientists are especially concerned about the San Andreas’s potential for disaster, but that’s not to say it’s the only cause for concern.

Can creeping fault lines cause earthquakes?

Fault lines are more closely tied together than you would imagine. A seismic event can ripple out and influence the delicate web of fault lines around it. Earthquakes of all sizes are a reality for California life, and what could set off the domino effect is unclear. This rise in seismic activity serves as an important reminder: 

It’s best to assume the Big One could happen at any time, and it’s essential to be ready for it.

The earthquake drought of California will end, but when?

California faces more than a lack of rain. The Los Angeles Times declared that California is in an earthquake drought, and the end of the drought will bring destructive results.

Map of Southern California with active earthquake faults
Low levels of earthquake activity is a high risk for California

When Will the Next Big Earthquake Strike?

In this L.A. Times article, experts paint a clear (and unsettling) picture of a big quake waiting to happen. In fact, California earthquakes are inevitable. We don’t know when or where, but we do know that an earthquake will happen:

“Earthquakes must happen at some point to relieve the immense tectonic forces that are pushing part of the state northwest toward Alaska and the rest southeast toward Mexico.”

L.A. TIMES

While it could be nice to say this drought is good news–who doesn’t like a break from earthquakes, right? –it isn’t. A drought means that there has been more time for tension to build up in the earth’s crust without a way to relieve the tension:

“[There may be periods] where things get kind of all locked up and no earthquakes happen for a while. You store a lot of strain in the Earth’s crust. Once it gets going, it’s like a set of dominoes. You might get multiple events if you have enough strain energy stored in the crust because it’s been a long time since an earthquake.”

Tom Jordan, USC Professor

The New Earthquake Era

Grass growing through a crack in the paved road
Can California handle the earthquake threat below the surface?

This drought also means that Californians aren’t necessarily prepared for a large-scale quake. The last California earthquake that was greater than 7 magnitude was in 1857. The 6.7 magnitude Northridge quake was in 1994 and the 6.9 magnitude Loma Prieta quake was in 1989. There are people alive today who have no personal experience with earthquakes of this size, and there isn’t anyone alive today that would have experienced a California quake as big as the earthquake of 1857.

First-hand experience of a major earthquake tragically brings awareness to the forefront, and few Californians have that experience. Earthquakes almost seem like a myth to some people in California despite the major earthquakes the Loma Prieta and Northridge quakes and other quakes that have struck other countries in recent years. Only 10% of California homeowners have earthquake insurance coverage, and many of those homeowners live within thirty miles of an active fault.

Experts say that it’s important to be prepared. There is, potentially, an entirely new era of earthquakes looming ahead with more frequent (or destructive) events.

What does that new era look like? Are you prepared for the end of the drought? Now is the time to ask yourself these questions and get prepared.