The chance of a Northridge-size quake was slightly higher in Northern California than Southern California — 95 percent versus 93 percent, according to a report released Tuesday by the U.S. Geological Survey. Now they say the risk of a mega-quake is more likely than previously thought. The new report included newly discovered fault zones and the possibility that a quake can jump from fault to fault. USGS forecast: Chances of magnitude-8 earthquake up to 7 percent USGS forecast: Chances of magnitude-8 earthquake up to 7 percent SEE MORE VIDEOS 
 
 Have scientists observed earthquakes jumping faults before? Scientists said the Baja California quake directed tectonic stress northward, putting Southern California at a higher risk for a future quake. The southern San Andreas is "ready to have an earthquake because it's really locked and loaded," Field said. The report found there is a 19 percent chance in the next 30 years that a Northridge-size quake will unzip the southern section compared to a 6.4 percent chance for the northern section, partly because it last broke in 1906.  LOS ANGELES (AP) — Scientists are virtually certain that California will be rocked by a strong earthquake in the next 30 years. Experts say they can't predict when exactly the next big earthquake will come, but they're getting better at modeling the possibilities. "California is earthquake country, and residents should live every day like it could be the day of a big one," USGS geophysicist and lead author Ned Field said.
– The latest US Geological Survey forecast for California doesn't contain much that will reassure people worried about earthquakes—unless they find fatalism reassuring. The report says there is not only a 99% chance of a 6.7 magnitude or greater quake like the 1994 Northridge one hitting the state in the next 30 years, the chances of a mega-quake of 8 magnitude or greater are significantly higher than earlier thought, the AP reports. "California is earthquake country, and residents should live every day like it could be the day of a big one," says lead author Ned Field, a USGS geophysicist. He says that out of the state's hundreds of faults, the "locked and loaded" San Andreas Fault is still the biggest threat. Field says the odds of a mega-quake in the next three decades have risen to 7% from 4.7% since the 2008 forecast because scientists now have a better understanding of the fault system and how quakes can jump from fault to fault, the Los Angeles Times reports. In California, "it has become increasingly apparent that we are not dealing with a few [well-separated] faults, but with a vast interconnected fault system," he says. The USGS still can't predict exactly when an earthquake will hit, but it's testing an early warning system that will give authorities vital seconds to do things like shut off gas lines and slow down trains, the AP reports. (Another federal study warns that small, fracking-linked quakes in Oklahoma and Kansas are making a big one more likely.)