An earthquake could wipe out America’s West Coast very soon

California thinks it’s prepared for an overdue earthquake but has no idea of the tsunami heading its way.

Meryl D'Souza June 29, 2016

In January of 1857, Southern California’s section of the San Andreas Fault experienced a magnitude 7.9 earthquake that ruptured about 225 miles between Parkfield and Wrightwood.

The Fort Tejon earthquake was felt throughout much of California, as far north as the city of Marysville and as far south as the mouth of the Colorado River at the Gulf of California in Mexico, and as far east as Las Vegas, Nevada. 

Fort Tejon, which centred around a sparsely populated area and claimed one life after all its destruction, is widely considered the last big earthquake to strike the southern San Andreas Fault.

A little over 150 years since that day, last month, Thomas Jordan, director of the Southern California Earthquake Center, warned California that the San Andreas Fault is “locked, loaded and ready to go” and a major earthquake in the region is overdue.

Most people in the United States and around the world know of the San Andreas Fault. It’s notorious for running the length of California and is perpetually on the verge of unleashing “the big one”.

That’s not without reason. It pays to be cautions when you consider that the tectonic plates that meet at the fault have been moving at the rate of two inches per year. That translates to a shift of about 26 feet in 150 years. Which essentially means that one and a half centuries of plate movement has accumulated and is set to give way at any moment, resulting in a shaker with a possible magnitude 8. 

Thankfully, Los Angeles is taking measures to minimize the damage with Mayor Eric Garcetti passing a law for as many as 15,000 buildings including landmark buildings in downtown, Hollywood and Westwood, to be retrofitted to help withstand violent shaking.

The science of predicting earthquakes has always been uncertain. Before the devastating earthquake in Japan back in 2011, seismologists believed that Japan could not experience an earthquake stronger than magnitude 8.4. In March 2011, Japan was struck by a magnitude 9.0 tremor that not only levelled its cities but also caused a tsunami with 30-foot waves crashing down. 

To give you some perspective of a timeframe, a fifteen second earthquake would have a magnitude of 6.9. A minute-long quake is in the high sevens, a two-minute quake has entered the eights, and a three-minute quake is in the high eights. By four minutes, an earthquake has hit magnitude 9.0.

Seismologists know that every fault line has an upper limit. San Andreas is one of the most studied fault lines in the world whose upper limit is presumed to be at magnitude 8.2 – a powerful earthquake, but, because the Richter scale is logarithmic, not nearly as strong as the 2011 event in Japan.

That’s no reason to downplay California’s predicament however. Along with the San Andreas Fault, Julian C. Lozos, an assistant professor of Geological Sciences at the California State University, Northridge, has reason to believe that the San Jacinto Fault could rupture simultaneously to create a larger earthquake. 

If all this sounds grim to you, be warned that it’s just the tip of the proverbial cake. While Lisa Grant Ludwig, professor at the University of California, told CNN that the region is not prepared for a scenario where it may have to withstand simultaneous earthquakes from both the San Andreas Fault and San Jacinto Fault, scientists were and still are, trying to figure out how to deal with the relatively unknown Cascadia fault.

Deep in the belly of the planet - which we’re slowly killing - lies the Cascadia subduction zone, a fault line that stretches 700 miles along the Pacific Northwest with the potential to cause the worst natural disaster in the history of North America, if it ruptures entirely. 

“Cascadia can make an earthquake almost 30 times more energetic than the San Andreas to start with,” Chris Goldfinger, a professor of geophysics at Oregon State University told CNN. “Then it generates a tsunami at the same time, which the side-by-side motion of the San Andreas can't do”.

The New Yorker quotes Kenneth Murphy FEMA’s Regional Administrator for Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, saying, “Our operating assumption is that everything west of Interstate 5 will be toast.”

The same story goes on to say: "FEMA projects that nearly thirteen thousand people will die in the Cascadia earthquake and tsunami. Another twenty-seven thousand will be injured, and the agency expects that it will need to provide shelter for a million displaced people, and food and water for another two and a half million.

Perhaps the scariest takeaway from this story is the fact that since the Cascadia lies underwater, there is no way to predict when the fault line will rupture. Which essentially means the people there are not only hopelessly unprepared, they won’t even know what’s happening until the desolation has already begun.

Remember the San Andreas disaster movie last year starring Dwayne 'The Rock' Johnson? That may end up moving into the Documentary genre.