A harbinger of doom new report indicates that in the event of a massive earthquake along the San Andreas Fault, California could be looking at 3.5 million damaged homes and over $289 billion worth of damage. This gloomy prediction comes via data firm CoreLogic. Before you start crawling under your sturdiest table, however, know that this kind of devastation is unlikely. The earthquake in question is an 800-mile-long, 8.0 quake, running from Eureka all the way down to Imperial County. Such a quake would achieve cinematic, only-Dwayne-The-Rock-Johnson-can-save-us-now proportions. But a quake of this scope occurs about once every 150,000 years, the L.A. Times reports. Which means that you can take comfort in knowing that you and everyone you know will be long dead by the time it arrives.
So, why the doom? The government uses a model called Third Uniform California Earthquake Rupture Forecast (UCERF3), which includes all potential earthquake scenarios, no matter how unlikely.
Some sections of the San Andreas are referred to as "creeping." U.S. Geological Survey scientist David Lockner described the creeping portion this way: "It seems weak enough that it slides slowly and continuously, rather than in a jerky motion." This is in contrast to "locked" portions, which essentially jam up and then produce tumultuous earthquakes.
Scientists previously thought that only small earthquakes 5.0 and under could occur in creeping areas. When it comes to the San Andreas, these particular areas are located in San Benito and Monterey counties, two side-by-side counties just south of Santa Cruz. In the event of a big quake north or south of these counties, the creeping areas were believed to be a kind of buffer, only allowing devastation to one side or the other. However, more current computer simulations indicate that a quake could possibly move through a creeping section.
"These segments are where earthquakes would tend to die," Nadia Lapusta, a geophysics and mechanical engineering at Caltech said. "But during an earthquake, you generate frictional heat, just like when you're rubbing your hands, and the properties of the fault can change."
Lapusta said that this is what could have happened in 2011, when the Tōhoku region of Japan was struck with an unpredicted and devastating 9.0 earthquake and tsunami, resulting in over 15,000 deaths.
Back to CoreLogic's reports:
The major highlight of the new UCERF3 model is the conclusion that a single large earthquake could now simultaneously rupture the full length of the San Andreas fault spanning Northern and Southern California. Once considered impossible, the largest earthquakes (magnitude 8.0 and higher) can now cause damage over a much larger area, affecting a greater population and causing even more property damage than previously understood. Risk managers have traditionally viewed Northern California and Southern California earthquake risk as uncorrelated because of the perceived independence of the faults in the northern and southern regions of the state. Based on UCERF3 hazard data, the new modeled view of earthquake risk in California from CoreLogic illustrates that there is now a higher conditional probability of losses impacting both regions simultaneously.
But again, that's highly unlikely.
A more realistic quake in Southern California would be an 7.8 quake that runs from the Salton Sea to the Inland Empire, with a projected 2,000 deaths, 50,000 injuries and $200 billion in damage. So, still not great, but not quite as apocalyptic.
