An earthquake like Turkey’s would devastate Southern California

The destruction from the 7.8 magnitude earthquake that struck Turkey on Monday is so widespread and intense that it’s hard to fathom.

But California has experienced tremors of this magnitude and larger — and scientists have spent years developing simulations of how “The Big One” would play out in the Golden State.

Here’s a closer look at the risks from the Times pages:

Projection of a massive earthquake in Southern California

An 8.2 magnitude quake is possible on the southern San Andreas Fault and would simultaneously wreak havoc across Southern California, with the fault erupting near the Mexico border into Monterey County.

Such an earthquake would cause widespread damage from Palm Springs to San Luis Obispo — and everything in between, experts say.

In 2008, the US Geological Survey and a number of other state agencies and scientists released a study called the ShakeOut Scenario, which told the story of what might happen if a 7.8 magnitude earthquake returns to Southern California.

A 7.8 magnitude earthquake would be “so strong as to cause widespread damage and consequently affect the lives and livelihoods of all Southern Californians. A disaster is a disaster that runs amok when a society is unprepared for the magnitude of the disruption that will occur,” the report said.

San Andreas Fault at Pallet Creek Road in Juniper Hills.

(Myung J. Chun/Los Angeles Times)

Among the effects, the report found:

• The death toll could be among the worst from a natural disaster in US history: nearly 1,800.
• Los Angeles County could suffer the highest death toll at more than 1,000, followed by Orange County with more than 350 dead.
• Almost 50,000 could be injured.
• The main highways to Las Vegas and Phoenix crossing the San Andreas Fault would be destroyed.
• Around 500,000 to 1 million people could be displaced from their homes.
• Southern California could be isolated for some time, with the region surrounded by mountains and earthquake faults.
• Major utilities such as gas, electricity and cellphone would likely be severely impacted.

What the story tells us

The last seismic event in California to reach a magnitude of 7.8 was the Great San Francisco earthquake of 1906. A magnitude 7.8 earthquake occurred in Southern California in 1857. was 45 times weaker than the so-called Fort Tejon earthquake.)

The last two major earthquakes in Los Angeles – the 1971 Sylmar quake and the 1994 Northridge quake – caused destruction and loss of life. But the worst of the damage was concentrated in relatively small areas and didn’t halt daily life throughout Southern California.

Experts have long warned that a much larger quake will eventually occur, and that the toll will be far greater.

Risk in Northern California

The San Andreas Fault caused the epic 1906 earthquake that destroyed San Francisco.

But the Hayward Fault in the East Bay also poses a major threat, experts say.

A landmark 2018 US Geological Survey report estimates that a magnitude 7 earthquake on the Hayward Fault below Oakland could kill at least 800 people and injure 18,000 others.

Hundreds more could die from fire after a quake along the 52-mile fault. More than 400 fires could ignite, burning the equivalent of 52,000 single-family homes, and a shortage of water for firefighters caused by old underground pipes could make the situation worse, researchers said.

The Hayward Fault is so dangerous because it runs through some of the most densely populated parts of the Bay Area and stretches the entire length of the East Bay from San Pablo Bay to Berkeley, Oakland, Hayward, Fremont and Milpitas.

For all the devastation of the 1906 San Francisco earthquake, its center was offshore in the Pacific Ocean.

build strength

The quake in Turkey is said to have collapsed thousands of buildings in a wide area stretching from the Syrian cities of Aleppo and Hama to Turkey’s Diyarbakir, more than 200 miles northeast. A hospital has collapsed in the Mediterranean coastal town of Iskanderoun, according to the Associated Press.

Building standards in California are significantly stricter. Images in Turkey and Syria show countless collapsed buildings.

California has been working to improve earthquake safety rules for vulnerable buildings.

The ShakeOut scenario focused on non-retrofitted brick buildings, brittle concrete buildings and so-called soft story apartment buildings. Some cities, including Los Angeles and San Francisco, have pushed retrofits for these types of structures.

Last year, LA announced a major milestone: more than 8,000 earthquake-prone buildings across the city were retrofitted at an estimated cost of $1.3 billion. The improvements represent the biggest advance in seismic upgrades in decades, but still leave thousands of buildings vulnerable to damage or even collapse in a catastrophic earthquake.