More than 200 tremors have been recorded along the San Andreas Fault line near the Salton Sea since Monday September 26, and the U.S. Geological Survey has issued an earthquake advisory for Southern California.
The earthquake warning affects Ventura, San Diego, San Bernardino, Riverside, Orange, Los Angeles, Kern and Imperial counties, and residents there are advised to stock up on food and water in case of an emergency.
Seismologists and earthquake experts agree the tremors are really bad news, and it could mean a large quake is imminent, Thomas H. Jordan, director of the Southern California Earthquake Center, told the Los Angeles Times.
“Any time there is significant seismic activity in the vicinity of the San Andreas fault, we seismologists get nervous because we recognize that the probability of having a large earthquake goes up.”
The Salton Sea tremors, which measure from magnitude 1.4 to 4.3, are occurring near a series of small faults that are connected to the San Andreas, and they could be adding stress and increasing the chances of a major quake.
As the number of earthquakes decreases over time, the chance of a major tremor drops, seismologist Lucy Jones told the Los Angeles Times.
“This is close enough to be in that worry zone. It’s a part of California that the seismologists all watch.”
The chances of a major tremor decrease with each new day. For the moment, however, the chance of a major earthquake in Southern California stands at 1 out of 100, Mark Ghilarducci, director of California’s Office of Emergency Services, told CBS News.
“The threat of an earthquake on the San Andreas fault hasn’t gone away, so this is another important opportunity for us to revisit our emergency plans and learn what steps you need to take if a significant earthquake hits.”
The earthquake swarm happened in an area experts call the Brawley seismic zone, which has only witnessed three other swarms since sensors were installed in 1932. This particular area of the San Andreas hasn’t ruptured since 1680, so a major quake is long overdue.
The real fear is that a quake near the Salton Sea could cause a domino affect that could run from Los Angeles to Imperial County. Another possibility is that a tremor could set off the San Jacinto Fault, which would in turn rupture the San Andreas.
The so-called double-fault earthquake could devastate Southern California. Experts have modeled the quake and predict it would have a magnitude of around 7.8, cost thousands of lives, and cause billions in damages, Ghilarducci told CBS News.
“California is earthquake country. We must always be prepared and not let our guard down.”
Experts also think the San Andreas is smoother than other fault lines, which gives it the ability to continue shaking and turn into a real danger for those nearby.
Californians have long feared “the big one,” an earthquake so devastating it separates the state from the rest of the country and while that might be a scenario out of a Hollywood movie, a large tremor could seriously damage the state.
[video src="http://earthquake.usgs.gov/regional/nca/simulations/shakeout/movies/ShakeOut_mapview.mp4" /]
In 2008, earthquake experts created the ShakeOut simulation that modeled a 7.8 earthquake beginning under the Salton Sea and spreading out in every direction. The model shows the collapse of Interstate 15, the severing of rail lines, and the collapse of the Inland Empire’s historic brick buildings that have never been retrofitted.
Los Angeles would witness the toppling of steel and metal buildings and the killing of thousands. Shock waves would be felt as far away as Bakersfield, Oxnard, and Santa Barbara.
Experts recommend stocking up on canned food and bottled water and having flashlights as well as batteries on hand in the case of a blackout.
[Feature Image by David McNew/Getty Images]