scientists are virtually certain that california will be rocked by a strong earthquake in the next 30 years now they say the risk of a mega quake is more likely than previously thought the chance of a magnitude 8 quake striking the state in the next three decades jumped to 7 per cent from 47 per cent, mainly because scientists took into account the possibility that several faults can shake at once, releasing seismic energy that results in greater destruction while the risk of a mega quake is higher than past estimates, it's more likely   greater than 99 per cent chance   that california will be rattled by a magnitude 67 jolt similar in size to the 1994 northridge disaster brace: a new us geological survey report has increased the likelihood of a magnitude 8 earthquake hitting california over the next 30 years above, a photo of an overpass that collapsed in the 1994 magnitude 67 northridge earthquake  the chance of a northridge size quake was slightly higher in northern california than southern california   95 per cent versus 93 per cent, according to a report released tuesday by the us geological survey '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 seismic calculations largely mirror previous findings issued by the usgs in 2008 back then, scientists also determined that california faced an almost certain risk of experiencing a northridge size quake the new report included newly discovered fault zones and the possibility that a quake can jump from fault to fault because of this knowledge, the odds of a catastrophic quake   magnitude 8 or larger   in the next 30 years increased there is a 93 per cent chance of a magnitude 7 or larger occurring over the same period and a 48 per cent chance of a magnitude 75   similar to previous estimates thousands of quakes every year hit california, sandwiched between two of earth's major tectonic plates, the pacific and north american plates most are too small to be felt of the more than 300 faults that crisscross the state, the southern segment of the san andreas fault   which runs from central california to the salton sea near the us mexico border   remains the greatest threat because it hasn't ruptured in more than three centuries the report found there is a 19 per cent chance in the next 30 years that a northridge size quake will unzip the southern section compared to a 64 per cent chance for the northern section, partly because it last broke in 1906 the southern san andreas is 'ready to have an earthquake because it's really locked and loaded,' field said the report is a forecast, but it is not a prediction experts still cannot predict exactly where or when a quake will hit anywhere in the world in recent years, the usgs and several universities have been testing an early warning system designed to detect the first waves of a jolt and send out an alert before the slower moving damaging waves proponents have said a few seconds of notice can allow trains to slow down, utilities to shut off gas lines and people to duck for cover the public alert system   still in pilot phrase   needs more funding before it can be rolled out statewide
new us geological survey 7 per cent 47 per cent
new us geological survey report increases chances of magnitude 8 earthquake in next three decades to 7 per cent, up from 47 per cent 