California's San Andreas fault has been quiet for far too long and is overdue for a major earthquake, a leading geoscientist has announced. In a conference this week, the state was warned to prepare for a potential earthquake as strong as magnitude 8.0. 
 
 "The springs on the San Andreas system have been wound very, very tight. And the southern San Andreas fault, in particular, looks like it’s locked, loaded and ready to go," said Thomas Jordan, director of the Southern California Earthquake Centre. 
 
 Jordan gave his warning in the keynote talk of the annual National Earthquake Conference in Long Beach, the Los Angeles Times reports. 
 
 Here's why he's so worried: research has shown that the Pacific plate is moving northwest relative to the North American plate at a rate of around 5 metres (16 feet) every 100 years - and that's building up a whole lot of tension along the San Andreas fault line that needs to be relieved regularly. 
 
 But the last time southern California experienced a major shake-up was in 1857, when a magnitude 7.9 quake rupture almost 300 km (185 miles) between Monterey County and the San Gabriel Mountains. 
 
 Further south, areas of the fault line have been quiet even longer, with San Bernardino county not moving substantially since 1812, and the region near the Salton Sea remaining still since the late 1600s. 
 
 All of this means that there's a lot of tension underneath California right now. Last year, Jordan's team found there's a 7 percent chance the state will experience a magnitude 8.0 quake in the next three decades. 
 
 And that's a big problem. Back in 2008, a US Geological Survey report found that a magnitude 7.8 earthquake on the southern San Andreas fault could cause more than 1,800 deaths, 50,000 injuries, US$200 billion in damage, and long-lasting infrastructure disruptions - such as six months of compromised sewer systems and ongoing wildfires. 
 
 Even though Los Angeles isn't on the San Andreas fault line, simulations by the Southern California Earthquake Centre show that the shaking would quickly spread there: 
 
 According to their modelling, that size earthquake could cause shaking for nearly 2 minutes, said Jordan, with the strongest activity in the Coachella Valley, Inland Empire and Antelope Valley. 
 
 The reason Los Angeles is at so much risk is because it's built over a sedimentary basin, and the seismic waves spread and get trapped there to cause more extreme and longer-lasting shaking. As you can see in the magnitude 8.0 simulation: 
 
 While Jordan praised recent initiatives to earthquake retrofit buildings in LA, he warned that the rest of the state needs to get ready for the next big one, by making residents more aware of ways to stay safe during an earthquake and when and how to evacuate. 
 
 "We are fortunate that seismic activity in California has been relatively low over the past century," Jordan explained last year. "But we know that tectonic forces are continually tightening the springs of the San Andreas fault system, making big quakes inevitable." ||||| The San Andreas is the state's longest fault and perhaps its most famous—well-known enough to be the standalone title of a recent disaster film. And, says the LA Times, citing an earthquake expert speaking at the National Earthquake Conference, it's also the one we need to be keeping our eyes on the most right now. 
 
 The issue is that the fault line has been too quiet for too long. Scientists have found that the "earthquakes should be relieving about 16 feet of accumulated plate movement every 100 years" on the San Andreas, but the fault hasn't let off any steam in way over a century. 
 
 The southern section of the fault hasn't had a big 'quake since 1857, which "ruptured an astonishing 185 miles between Monterey County and the San Gabriel Mountains," near LA, in a 7.9 earthquake. Other nearby sections of the fault are also overdue. A segment by the Cajon Pass (where the 15 Freeway cuts between the San Bernardino and San Gabriel mountains) "have not moved substantially" since an 1812 earthquake, and over by the Salton Sea, it's been seismically silent as far back as 1680. 
 
 That indicates it's long overdue for a rupture. Or, to put it more chillingly, "The springs on the San Andreas system have been wound very, very tight. And the southern San Andreas fault, in particular, looks like it’s locked, loaded and ready to go." 
 
 The expert, Thomas Jordan, director of the Southern California Earthquake Center, went on to say that, with this information, LA should focus on being prepared for a BIG one—a magnitude 8 or so. (For perspective, a 2008 US Geological Survey study warned that a 7.8 earthquake along the southern San Andreas would send shaking far and wide from the Coachella Valley and Inland Empire to East LA and the San Gabriel Valley, and cause about 2,000 deaths. So, stronger than that.) 
 
 Jordan applauded the city's efforts to retrofit buildings vulnerable to collapse in a strong seismic event, saying, "It’s remarkable that this happened...We know politically how difficult it is to make these kinds of changes." LA's also at work making its cell phone network more resilient to serious shaking so that communication post-'quake would still be possible. 
 
 With most Angelenos less than totally prepared for a significant earthquake, there's no time like the present to get started.
– Here's an unfortunate hypothetical: An earthquake strikes along the San Andreas fault, damaging three aqueducts that cross it some 32 times. Those aqueducts supply Los Angeles with all but 12% of its water—meaning a serious quake could ultimately leave 22 million people without water. (There would be about six month's worth of water stored on the LA side of the fault, but fixing busted aqueducts could take more than twice that long.) Officials have been aware of the potential for a single quake to hit all three aqueducts since 2008, but as the Los Angeles Times reports, they're now moving to do something about it for the first time. But any solution is pretty far off, in terms of time and money—in terms of the latter, the LAT uses the word "billions." None of the aqueducts has yet had to deal with the scenario; the last huge quake (magnitude 7.9) along the fault was in 1857. The Los Angeles aqueduct travels across the fault under a mountain, by way of the five-mile-long concrete Elizabeth Tunnel. Building a brand new tunnel is the priciest option; sending water over the mountains via an electric pumping mechanism is another idea. In the case of the Colorado River Aqueduct, a quake could raise a section of the pipe by 13 feet, and there aren't any pumps in place to ferry the water to LA. The mayor last week requested that proposals on the issue be submitted by July. Meanwhile, the San Diego Union-Tribune reports that there may be another fault to fear: It points to new research that shows the San Jacinto fault could generate an earthquake as powerful as what the San Andreas fault is capable of.